SEMICONDUCTOR SEMICONDUCTOR DEVICES WITH VOLTAGE DETECTION AND PHOTONIC TRANSMISSION AND INTEGRATED

专利摘要:
Traction-strained germanium is provided which may be sufficiently constrained to provide an almost direct bandgap material or a direct bandgap material. Stress materials constrained by compression or tensile stress in contact with germanium regions induce a uniaxial or biaxial tensile stress in the germanium regions. Stressor materials may include silicon nitride or silicon-germanium. The resulting constrained germanium structure can be used to emit or detect photons, including, for example, for the generation of photons in a resonant cavity to produce a laser.
公开号:FR3072834A1
申请号:FR1859821
申请日:2018-10-24
公开日:2019-04-26
发明作者:Paul A. Clifton；Andreas Goebel；R. Stockton Gaines
申请人:Acorn Technologies Inc；
IPC主号:

专利说明:

The present invention generally relates to optical systems which include semiconductor light emitting devices or semiconductor light detectors. More specifically, the present invention relates to semiconductor light emission or detection devices which incorporate a constrained group IV semiconductor material in an active region.
There is an uninterrupted interest in the use of group IV semiconductor materials in photonic systems due to the ease of manufacture of these systems and the ease of integration of these group IV photonics with circuit elements. . Silicon, germanium and their alloys are the most frequently considered group IV semiconductors for photonic systems. For example, light emission from or in silicon is of great interest. Silicon and germanium have an indirect band gap, as well as their alloys in their entire range of compositions. Conventionally, these are not effective materials for light emission because the conduction band involved in a direct optical transition is not occupied, so that there is essentially no electron-hole pair which can recombine and generate a photon directly without the additional contribution of another entity such as a mesh vibration or an impurity.
A cost-effective way to integrate photonic functions into silicon-based ULSI chips such as multi-core processors or state-of-the-art memory would pave the way for ambitious architecture changes and improved performance for IT modern. A suggested application of these photonic functions is to replace some of the intra-chip copper interconnects in modern ULSI chips, for example to route data from one processor core to another, where both cores are on the same chip. physical silicon. At the same time, a practical solution using group IV photonics could provide extreme cost reduction benefits when manufacturing more conventional photonics systems.
The main ways to incorporate photonics with existing CMOS process streams include the following topologically distinct options: i) fabricating the optical components before the transistor; ii) fabricating the optical components after integration of the transistors, that is to say either before, or with or directly after the metallic interconnection layers; or iii) fabricate an optically compatible layer using Group IV semiconductors that can be attached to ULSI chips by one of a variety of mechanisms. The attachment mechanisms may include a semiconductor wafer connection, joint packaging of several chips one after the other, where they are linked by wires or connected by characteristics in the housing, and a stack of chips and a connection of these, for example using interconnection vias through silicon (TSVs). The use of a separate optical layer makes it possible to decouple the manufacturing challenges and the critical integration steps encountered in the manufacture of electrical interconnections of transistors and ULSI from those required for the optical layer.
On the other hand, it is advantageous to emit light from the chip to avoid coupling and alignment problems which would otherwise have to be solved. Light emission from the chip is a big challenge when using Group IV semiconductors as the optically active light emitting material in the optical layer. The literature reports light emission in silicon using the Raman effect to convert light delivered from outside of a certain wavelength to a different wavelength. Light emission using the Raman effect is a low efficiency process.
An optical system or an optical layer generally comprises several functional components. An optical layer usually includes a light source, perhaps with a built-in bandwidth filter to select the wavelength, that is, the "color" of light used over a broad spectrum. The light source can be a laser which emits coherent light or a light emitting diode. The light source can be either directly modulated, for example, by modulating the current through the light source, similar to switching an incandescent lamp on and off (up and down), or by modulating information on the "light beam" through a separate component outside the light source, that is, using a modulator. External modulators are known in the art, including ring modulators and Mach-Zehnder modulators.
An optical layer usually comprises at least one waveguide which can convey light in the form of a continuous wave or in a modulated form, that is to say, as a signal, from a point to a other. Considerations of waveguide performance include attenuation, the degree to which light is lost per unit length, for example due to light scattering or due to light absorption in the waveguide or an adjacent material. Another important performance measure is the ability of the waveguide to return light guided in another direction with a small return radius without significant loss of light. Tight deflection radii can be obtained, for example, by using high confinement waveguides in which the refractive index of the guide is considerably higher than in the surrounding volume so that the intensity of the wave light is mainly transported inside the volume of the waveguide. The interaction between a return radius and a loss of the evanescent part of the light intensity outside the waveguide is an important parameter for the design of ring modulators or routing switches. Tight deflection angles can also be easily obtained by means of mirrors for which the angle between the direction of incoming light and the normal to the surface of the mirror is substantially identical to that between the direction of outgoing light and normal direction to the mirror. Another aspect is the degree to which the waveguide maintains a given polarization of light.
An optical layer usually includes a routing or switching element which receives light from an incoming waveguide and which selects from one of a number of outgoing waveguides one or more waveguides which will carry the outgoing light. A mirror can be imagined as a routing element with incoming and outgoing waveguides. Other examples for these elements include networked waveguide couplers, multimode interference couplers and ring couplers.
An optical layer usually includes a detector that measures the intensity of incoming light accurately and at high speeds. Often the detectors are reverse polarized photodiodes. The sensitivity and the external and internal quantum efficiency of the photodiodes should preferably be high for the wavelength of light to be detected. Often their speeds are limited by the RC value, the product between the capacitance of the detector (junction capacitance and parasitic capacitance) and the resistance value and the capacitance of the conductors leading to the reverse polarized junction. The RC value measures the time for the charge carriers generated at the detector junction to be able to deliver a detectable current at the terminal of the electric detector, i.e., the external speed of the detector.
An optical layer usually includes control electronics, either on the same optical layer or in a separate layer, for example, in the CMOS chip for which the photonic layer performs part of the interconnection.
Bandwidth specifications for future data transmission, for example between electronic racks in server farms, from one card to another card, from a processor to an electrical circuit board or to a memory, will continue to be develop in a data bandwidth range of several Tbit / s. Common optical components for light sources, modulators or even detectors cannot operate at these frequencies. More specifically, the capacity to place information on a carrier beam, either by direct modulation of light sources, or by means of a modulator, does not currently exceed frequencies of several tens of Gbit / s.
Therefore, an approach in which multiple light beams (equivalent to a number of bus lines) are used to transmit data in parallel is necessary to obtain system bandwidths in the order of Tbit / s. If the light beams carrying the information have different wavelengths, multiple carrier signals can be transmitted through a single waveguide and couplers. Such a method called wavelength division multiplexing (WDM) is well known in telecommunications. A multitude of point-to-point connections using the same wavelength or similar wavelengths can be imagined and waveguides can even cross, since the light beams do not interact with each other with the others.
It is desirable to build such a WDM system or a point-to-point network of connections in a single optical layer to reduce costs.
Several methods for generating light in an optical layer are known. One method is the hybrid laser, which performs light amplification by letting a certain light energy guided in a silicon waveguide reach or extend in a multiquic well material based on optically active InP, in which l Light amplification is obtained by electrically pumping the optically active transitions in the direct band gap InP-based material.
Another method of the prior art uses a reduction of the direct band gap of germanium which is achieved by the biaxial stress of germanium. The constraint occurs due to an absence of correspondence between the coefficients of thermal expansion of the germanium and of the substrate on which the germanium is deposited in a process step at high temperature. When the temperature drops, the germanium becomes biaxially tensed to a low degree, generally less than 0.3%. In this case, the stress is not strong enough to completely transform the germanium into a direct band gap material and the weakest energetically transition from the conduction band to the valence band of germanium continues to be a transition which is not optically possible (i.e. it is indirect and involves another quasi-particle such as a phonon or a mesh vibration). The predominance of the indirect band transition is countered by doping an active region of the very strongly n-type light emitting device, so that the states in the lowest conduction band valley are populated. Under a high level of electrical injection of carriers in the n + region, the carriers (electrons) spread from the conduction band valley for which an optical transition is prohibited (indirect forbidden band) into the conduction band valley energetically slightly higher for which optical transition is possible (direct band gap). The forbidden transition becomes saturated, and carriers spread into more efficient direct forbidden band transition states.
When light is generated from the chip, that is to say inside its optical layer, the optical layers can use homogeneous materials or a system of heterogeneous materials. In a homogeneous material system, light is emitted and detected in a material which is chemically substantially the same for all components of the system, such as the light source, the waveguide, the modulator, the switch or the detector . In a heterogeneous material system, light is emitted in a material that is chemically different from the material of the waveguide or the detector.
One aspect of the present invention provides an optical device having a germanium region in contact with a plurality of stressor regions. The plurality of stressor regions induce a tensile stress in the germanium region. The tensile stress in at least part of the germanium region is sufficient to cause part of the germanium region to have a direct band gap. A junction is positioned in or adjacent to the part of the germanium region, the junction having a first side with a first type of majority carriers and a second side with a second type of majority carriers. First and second contacts are respectively coupled to the first side of the junction and the second side of the junction.
According to another aspect of the present invention, an optical device comprises first and second germanium regions. The first germanium region is in contact with a first tensile stressor so that the first germanium region has a biaxial tensile stress in at least a first part of the first germanium region. The second germanium region is in contact with a second tensile stressor so that the second germanium region has a biaxial tensile stress in at least a second part of the second germanium region. Optical elements define an optical path through the first and second germanium regions. A junction is positioned in or adjacent to the first and second parts of the first and second germanium regions, the junction having a first side with a first type of majority carriers and a second side with a second type of majority carriers. First and second contacts are respectively coupled to the first side of the junction and the second side of the junction.
In an advantageous embodiment, the first germanium region has a biaxial tensile stress in at least part of the first germanium region sufficient to cause the first part of the first germanium region to have a direct band gap.
The first and second tensile stressors are for example silicon germanium.
In an optical device according to the invention, the optical elements can comprise a first mirror and a second mirror which define a laser cavity. The first mirror and the second mirror can be formed on the end faces of the laser cavity and the laser cavity can be optically coupled to the first and second germanium regions by an evanescent coupling. The laser cavity can also be disposed at least partially in a waveguide, which is for example a waveguide made of silicon or silicon oxide.
In another embodiment according to the invention, the stressor regions can comprise a material stressed by compression, for example silicon nitride.
In an optical device according to the invention, the first and second stressors can be positioned on the opposite sides of the first germanium region. Another embodiment provides that first and second stressors are positioned on one side of a germanium fin and that third and fourth stressors are positioned on an opposite side of the germanium fin and that the fin in germanium includes the first part of the first region in germanium. In this embodiment, the germanium fin may have a thickness of between approximately 40 nanometers and 80 nanometers, the germanium fin may have a width less than one micron, and the stressors being made of silicon nitride.
According to another aspect of the present invention, an optical device comprises a germanium plate comprising first and second faces and first and second ends and first and second layers of stressors on the first and second faces. The first and second layers of stressors induce a biaxial tensile stress in the germanium plate. Optical elements are positioned relative to the germanium plate to define an optical path passing through the germanium plate.
According to another aspect of the present invention, an optical device comprises two or more germanium plates each having first and second faces and first and second ends and first and second layers of stressors on each of the first and second faces. The first and second layers of stressors induce a biaxial tensile stress in the respective plates of the two or more germanium plates. Optical elements are positioned relative to the germanium plates to define an optical path passing through the two or more germanium plates.
According to yet another aspect of the present invention, a method of making a semiconductor device includes providing a substrate having a germanium region and etching openings in the germanium region. The process continues with the formation of silicon-germanium in the openings to form an integrated silicon-germanium pattern surrounding a first part of the germanium region, the silicon-germanium regions and the first part of the germanium region having a biaxial tensile stress in the plane.
Yet another aspect of the present invention provides a method of data communication comprising coupling an electrical signal into an optical device comprising a first constrained semiconductor region to generate a sensitive optical signal. The process continues by transmitting the sensitive optical signal through a waveguide comprising a second unconstrained semiconductor region and coupling the sensitive optical signal in a detector comprising a third constrained semiconductor region. The first, second and third semiconductor regions include germanium. In a more specific implementation of this aspect, these regions are essentially self-aligned with each other.
The invention also relates to a method for producing a semiconductor device comprising providing a substrate comprising a germanium region and etching openings in the germanium region. The process continues with the formation of stressor regions in the openings to form a pattern of integrated stressor regions surrounding a first part of the germanium region, where the first part of the germanium region has biaxial tensile stress in the plan.
According to this process, the germanium region can be a germanium layer separated from another part of the substrate by an insulating layer.
A method according to the invention can also form at least four additional parts of the germanium region having a biaxial tensile stress.
In this embodiment, the biaxial tensile stress in the first germanium part and the additional parts may be sufficient in at least parts of the germanium parts to obtain a direct band gap.
A method according to the invention can also include a step of forming a laser cavity so that an amplified light in the laser cavity passes through the first part of the germanium region.
The stressor regions formed by a method according to the invention can be made of silicon-germanium.
The invention will now be described in more detail by way of example with reference to the accompanying drawings, in which:
FIG. 1 schematically illustrates part of a light emission or detection device which may include an active region stressed by traction.
Figure 2 illustrates the results of a simulation based on the structure of Figure 1 which shows a high level of induced stress in a germanium band between integrated silicon-germanium stressors.
FIG. 3 schematically illustrates a germanium region surrounded by a pattern of integrated stressors such as silicon-germanium or silicon nitride, where the integrated stressors have a generally rectangular section.
FIG. 4 (a) illustrates in perspective a germanium layer with a set of separate integrated stressor regions composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride, where the regions of integrated stressors have a generally rectangular section and the stressor regions induce a tensile stress in the adjacent germanium regions.
FIG. 4 (b) illustrates in perspective a germanium layer with a set of separate integrated stressor regions composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride, where the regions of integrated stressors have a generally rounded or circular section and the stressor regions induce a tensile stress in the adjacent germanium regions.
Figure 4 (c) illustrates in perspective a germanium layer with a set of connected integrated stressor regions composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride, where the material of integrated stressor surrounds the periphery of the germanium pillar-shaped regions, the germanium pillar regions having a generally rectangular cross-section and the stressor material inducing a biaxial tensile stress in the plane in the adjacent surrounded germanium regions.
FIG. 4 (d) illustrates in perspective a germanium layer with a set of connected integrated stressor regions composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride, where the material of integrated stressor surrounds the periphery of germanium pillar-shaped regions, the superimposed integrated stressor regions having a generally rounded or, ultimately, circular section, and the stress material inducing biaxial tensile stress in the plane in the regions in germanium surrounded adjacent.
FIG. 4 (e) illustrates in perspective a germanium region in the form of a pillar in regions of integrated stressors composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride. The pillar illustrated can be a pillar in a set of regions in the form of similar germanium pillars, the stressor material inducing a biaxial tensile stress in the plane in the surrounded germanium regions.
FIG. 5 illustrates another implementation of aspects of the invention in which a tensile stress is created in a germanium fin by a force imposed by layers of stressors by compression on the side walls of the germanium fin .
FIG. 6 illustrates a modification of the strategy of FIG. 5 in which a biaxial tensile stress is created in the germanium fin by drawing layers of stressors by compression on the side wall of the germanium fin.
FIGS. 7 (a-b) illustrate, using a three-dimensional simulation, another modification of the strategy of FIGS. 5 and 6 in which a plurality of germanium fins biaxially constrained by traction are provided along an optical path.
Figures 8 (a-b) schematically illustrate a strained germanium strip in which a tensile stress is induced by a material constrained by overlying compression and by an edge relaxation.
FIG. 9 schematically illustrates a band of constrained germanium in which a tensile stress is induced by upper and lower layers of material constrained by compression and by an edge relaxation.
FIG. 10 schematically illustrates a band of constrained germanium in which a biaxial tensile stress is induced in the band by upper and lower layers of material constrained by compression and by an edge relaxation with cuts through the three layers along two axes.
Figure 11 illustrates another preferred modification of the strategy of Figure 10 which limits internal reflections.
FIG. 12 schematically illustrates in section a set of germanium regions of type n tensile stresses deposited epitaxially on a layer of germanium of type p so that the structure can emit or detect photons.
FIG. 13 schematically illustrates in section a set of n-type germanium regions constrained by shallow traction doped by diffusion from an overlying layer of doped polycrystalline silicon.
FIG. 14 schematically illustrates in section a set of n-type germanium regions constrained by epitaxial traction formed on a set of epitaxial p-type germanium regions so that the structure can emit or detect photons.
FIG. 15 schematically illustrates in section a set of p-type germanium regions stressed by traction in contact with an electron-emitting layer so that the structure can emit or detect photons.
FIG. 16 schematically illustrates in section a set of p-type germanium regions stressed by traction in contact with an electron-emitting layer so that the structure can emit or detect photons.
FIG. 17 illustrates in schematic cross section a set of p-type germanium regions constrained by traction in lateral contact with n-type silicon-germanium regions and an electron emitting layer so that the structure can emit or detect photons.
Figure 18 illustrates another strategy, consistent with the structures and processes illustrated in Figures 12 to 17, in which one or more discrete germanium pillars are formed and integrated into a continuous silicon-germanium stressor.
FIG. 19 schematically illustrates a germanium waveguide coupled to a structure having germanium pillars or fins biaxially constrained or constrained in the plane which emit or detect light.
Figure 20 schematically illustrates a configuration in which a layer containing tensile-stressed germanium is coupled to a resonator to provide a laser structure.
Preferred embodiments of the present invention include a light emitting or light detecting device or method that uses a constrained group IV semiconductor as an active region that emits or detects light. The term light is used here in its broad sense to incorporate ultraviolet and infrared ranges. As an example, an implementation of the present invention could provide a semiconductor laser which uses tensile-constrained germanium as the gain medium. More preferably, this specific example may use a region of germanium constrained biaxially by traction to a degree sufficient for at least part of the region of germanium constrained to be a direct bandgap semiconductor.
Certain embodiments of the present invention may use a separate optical layer made of generally homogeneous materials to form various components of an optical layer comprising at least one light source, one or more waveguides, at least one element of routing or switching, or at least one detector. Control electronics are included either in the optical layer or in another layer, for example in an associated ULSI chip. In the case of homogeneous materials, the material constituting the components is of course somewhat different physically, because the use of a system of homogeneous materials requires the local change of some of the optical properties of the material in question, to pass it in various ways from a semiconductor material emitting light (direct forbidden band) to an optically transparent waveguide material (indirect forbidden band) or to a semiconductor material detecting light (direct forbidden band).
More preferably, the modifications necessary to obtain the desired local optical properties are created, for example, by the application of an external stress, in particular a biaxial or uniaxial tensile stress. In addition, preferred implementations locally modify the electrical properties of the semiconductor material in question in usual ways, for example by implantation or diffusion of dopant ions to build electrical devices in the usual way.
Certain preferred embodiments define an optical layer of a generally homogeneous material system for which a part of the semiconductor material in the selected components is caused to have either a totally direct band gap, or a totally indirect band gap. In particularly preferred embodiments, the band gap in the emitter or detector is less than the band gap of the waveguide, so that the waveguide is essentially transparent to the photons emitted by the transmitter or detected by the detector. In the case of a waveguide made of a semiconductor material with an indirect band gap, leaving the waveguide material unconstrained allows the material to maintain a band gap wider than a material d 'transmitter or detector forced. The wider band gap in the waveguide with the indirect nature of the band gap results in lower optical transmission loss in the waveguide material.
For particularly preferred implementations which use constrained germanium for emission or absorption of active light, the source and the detector will be transformed from an indirect semiconductor (and consequently from an optical absorption / emission material relatively ineffective) into a more direct semiconductor (and therefore into an efficient optical absorption / emission material). By declaring that the tensile stress in germanium causes it to become a more direct forbidden band semiconductor, we mean that the tensile stress makes the optical transitions corresponding to the direct transition between the minimum of conduction band at the point gamma and valence band more likely due to the reduced energy band between the minimum conduction band and the valence band at gamma point. That is to say that the germanium strongly constrained by traction has a significant improvement in luminescence corresponding to the direct transition at the gamma point. This significant improvement in luminescence can be exploited to fabricate efficient light emitting devices including light emitting diodes and germanium semiconductor lasers.
In the case of a semiconductor material with a direct band gap such as gallium arsenide, the waveguide can be transformed into a non-absorbent semiconductor by the application of a compressive stress along at least one axis which increases the band gap in the waveguide and makes it more transparent for the wavelengths which are emitted by unmodified solid gallium arsenide. Consequently, transmission losses by absorption are reduced.
The following describes several illustrative implementations of methods and devices which can form components of photonic systems with constrained semiconductor light emission or detection elements.
Group IV semiconductors generally have a diamond structure and, as such, have the main directions <100>, <110> and <111>, which are representative of the symmetry of the crystal structure. These axes are normal to the mesh planes, (100), (110) and (111), respectively. A deformation of the mesh at natural equilibrium (distances between atoms and angles between atoms) leads to changes in the band structure. For example, in the first order, hydrostatic pressure results in a homogeneous volume compression of a cubic mesh and more generally in an increase in the direct band gap. For germanium, the effect of a uniaxial, biaxial and hydrostatic stress on the band structure has long been of scientific interest.
Applying biaxial tensile stress in the plane (100) of germanium makes the material more direct, i.e. an increase in biaxial stress (100) shrinks the direct bandgap faster than the indirect prohibited band. Calculations of the band structure of a germanium biaxially stressed by traction predict that the material becomes completely direct at around 1.9% stress in the plane (100). In addition, uniaxial deformation is reported to lead to a direct band gap when applying uniaxial tension along the <111> direction of germanium.
Of course, a large number of orientations and configurations of constraints with respect to the main directions of a crystal can provide various advantages for transforming a material with an indirect band gap into a material with a more direct band gap.
FIG. 1 shows an example in which integrated silicon germanium (SiGe) stressors are used to constrain by traction a germanium region (such as a fin or a strip) which can be used either for a light emission or for a light detection. In a preferred embodiment, multiple tensile stressors are integrated into a germanium layer, causing a tensile stress in the volume of germanium between any two neighboring tensile stressor regions. The SiGe alloy is a suitable tensile stress material when it is developed epitaxially inside a recess formed in a germanium surface. The SiGe alloy has a crystal lattice spacing which is less than the crystal lattice spacing in germanium. Consequently, when a thin layer of SiGe is developed epitaxially on a germanium surface, the SiGe is under a tensile stress of in-plane mesh adaptation defect. An integrated SiGe stressor constrained by traction induces a tensile stress in laterally adjacent germanium. As a more concrete example, Figure 1 illustrates part of a germanium layer 10. Two long trenches are cut in the surface of the germanium layer 10 and are filled with an epitaxial deposit of SiGe to form integrated stressors 12, 14 on each side of a germanium region 16. The integrated SiGe stressors 12, 14 on both sides of the narrow germanium band 16 induce a uniaxial tensile stress in the germanium volume between the regions of SiGe stressors , as shown in Figure 1. The narrow band of tensile-constrained germanium 16 can be used as the active light-emitting region of a laser or a diode or as the light-sensing region, for example, of a photodiode. The height or thickness, width and length of these structures are preferably selected to obtain desired levels of stress to achieve the appropriate optical functionality for the component. Preferably, the dimensions are selected according to the specific implementation and the other elements of the component.
Advanced CMOS technologies frequently include SiGe source or drain (S / D) regions integrated in the fabrication of high performance P channel field effect transistors. In the case of SiGe source / drain regions integrated in a silicon transistor, a compression stress is obtained in the silicon region between the SiGe stressors. It is the opposite of the stress condition which appears when SiGe stressors are integrated into a germanium device as described here, but the manufacturing processes and technologies, the design considerations and the implementations are very similar.
Figure 2 illustrates a simulation of a structure generally similar to that shown in Figure 1, Figure 2 showing a cross section perpendicular to the longer axis of the strip. The simulation of Figure 2 uses a slightly more complicated and practical structure comprising a buried insulating layer 28 between a semiconductor wafer or a silicon or other substrate 20 and a germanium layer 26 in which trenches are formed and thereafter at least partially filled with silicon-germanium to form regions of tensile stressors 22 and 24. As shown in the simulation of FIG. 2, high levels of stress can be induced, in particular near an upper surface of the germanium band 26.
Alternatively, SiGe stressors can be incorporated into a laser or light emitting diode or germanium photodetector in the form of a matrix of multiple integrated regions having depths and widths of about 100 nm by 100 nm. These dimensions are illustrative and a range of dimensions can actually be used. The particular formulated dimensions are useful for the illustrated configuration. In this strategy, the active light-emitting region of a laser (typical size: width from 0.35 to 1.5 microns, or even more, length from 2 to tens or even hundreds of microns, or even plus) or the light detection region of a photodetector can include numerous germanium regions with a biaxial tensile stress induced along two axes in the plane by adjacent volumes of integrated SiGe. FIG. 3 represents an element of such a matrix in which a biaxial tensile stress is induced in a central germanium region 30 by elements of stressors 32, 34, 36, 38 in adjacent SiGe formed on four sides. The stressors have a generally rectangular section which can, for example, be roughly square. Stressors are illustrated as silicon-germanium, which provides tensile stress to adjacent germanium regions. Other stressor materials could also be used, such as silicon nitride deposited to achieve a tensile stress. The stress distribution is generally not homogeneous and depends on the geometry and other relevant characteristics such as the composition of a silicongermanium stressor. The stress could, for example, be highest around the upper side portions of the germanium region. A biaxial stress can be maximum in a central part of the germanium 30 region.
Figures 4 (a-e) illustrate how a multitude of germanium elements can be arranged in a matrix so that each element has a biaxial tensile stress in at least part of the element. The germanium elements under biaxial tensile stress can be connected to neighboring germanium elements also under biaxial stress, as shown in Figure 4 (a) and Figure 4 (b). Alternatively, the germanium elements can be separated from neighboring germanium elements by the stressor material, as shown in Figure 4 (c) and Figure 4 (d), in which case the separated germanium regions appear as pillars . Although the germanium pillar elements are separated by a stressor material in the plane of the semiconductor wafer, they can of course remain connected by their bases to a remaining layer or a shared or common germanium substrate. In addition, the germanium pillars can have a substantially square section profile or can be rounded, having, at the limit, a circular section profile or a pillar profile with concave side, as illustrated in FIG. 4 (d). FIG. 4 (e) shows one of a set of germanium regions in regions of integrated stressors composed of a material under tensile stress in the plane such as silicon germanium or silicon nitride. The pillar illustrated can be a region in a set of pillar-shaped germanium regions, the stressor material inducing a biaxial tensile stress in the plane in the surrounded germanium regions.
In particularly preferred implementations of this embodiment, a set of constrained germanium elements similar to those illustrated in any view of FIG. 4 can be used as the active light-emitting region of a device. laser or light detection region of a photodetector device. The active light-emitting region of FIG. 4 consists of multiple elements made of germanium which are at least partially biaxially tensile. In order to obtain a laser emission action, the entire volume of an active laser region need not consist of a germanium biaxially constrained by traction, but it is desirable to increase the proportion of the laser volume which is in germanium biaxially constrained by traction. In addition, it is desirable to induce a sufficient tensile stress in the germanium regions so that the regions have a direct band gap on at least part of the regions. In the part of a germanium region with the greatest biaxial tensile stress, the minimum of the direct conduction band (gamma point) is at its lowest energy. In particular, for any part of germanium with a biaxial stress greater than about 1.8% to 2.0%, the direct band gap (at gamma point) should be smaller than the indirect band gap, and this part of germanium can be considered to be a direct bandgap semiconductor. Under these conditions, free electrons will drift towards the part with the greatest biaxial tensile stress (lowest conduction band energy), and this will coincide with the part in which the direct optical transitions are more favorable. As such, even if only a fraction of the volume of germanium in a laser can have a biaxial tension sufficient to induce a direct band gap behavior, it may be adequate for practical purposes of stimulated emission of photons because the part of direct forbidden band is at the same time the germanium part towards which the free electrons are attracted by the developed field because of the level of energy of conduction band in this part. Conversely, the less stressed germanium parts which do not become direct, will remain indirect and will not amplify the light. However, the light emitted by the highly constrained parts having the smallest and direct band gap will not be absorbed in the less constrained parts having a larger and indirect band gap. Although the less stressed germanium parts are not expected to contribute significantly to light emission in the light emitting diode or the semiconductor laser, these parts should not also contribute significantly to the losses. It is nevertheless desirable to increase to a maximum the fraction of germanium in the optically active region which is at a high level of biaxial tensile stress.
Preferably for this configuration, the silicon-germanium stressors are not doped or are not n-type doped to avoid blocking the germanium conduction band and to facilitate the described effect of passage of the carriers in the gain region. by laterally modifying the conduction band. The integrated stressors could alternatively be made of silicon nitride with a developed tensile stress. Methods and tools are well known in the silicon integrated circuit manufacturing industry for depositing silicon nitride films with integrated tensile stress.
In the embodiment illustrated in FIG. 5, a germanium substrate 22 is drawn and etched to form a fin structure 52 in germanium extending above the remaining part of the substrate 50. The fin structure 52 may have, for example, a width of 0.05 µm and a height of 0.15 µm. Compression stressors 54, 56 are formed on the side walls of the germanium fin 52 to impart a uniaxial tensile stress in the germanium fin, as shown schematically by the arrows in Figure 5. Generally, the structure The illustrated one is formed by depositing a conformal covering layer of compression-stressed silicon nitride. The constrained silicon nitride is then preferably removed by etching the top of the fins to allow electrical contact with the top of the fins by etching the layer of silicon nitride so as to leave the silicon nitride only along the side walls. Because the initial stress in the lateral stressors is a compression stress, the lateral stressors 54, 56 extend vertically when they relax and induce a tensile stress in the fin structure 52 in germanium.
Methods and tools are well known in the silicon integrated circuit manufacturing industry for obtaining deposited films of silicon nitride with integrated compressive stress and methods are known for forming the side walls of a material such as silicon nitride by deposition and subsequent anisotropic etching. Only the lateral stressors will impose a uniaxial tensile stress in the vertically directed germanium fin, orthogonal to the plane of the semiconductor chip or the semiconductor wafer. Here again, the active region of fin 52 in tensile germanium of FIG. 5 can act as a light-emitting region or a light-sensing region, depending on the geometry and the subsequent processing. Preferably, the original stress in the lateral stressor structures 54, 56 and the dimensions of the fin 52 are suitable for creating a vertical (uniaxial) tensile stress sufficient to bring part of the active region of the fin 52 to have a direct prohibited band. Previous or subsequent processing can be used to form a generally horizontal p-n junction in the fin structure shown. For example, the illustrated fin structure could be formed as p-type material. A highly n-doped polycrystalline germanium layer is formed on an upper surface of the p-type fin 52. Subsequent annealing causes the n-type dopants to diffuse into the fin structure 52 to preferably form a generally horizontal p-n junction. Preferably, the junction p-n is positioned sufficiently adjacent to the portion constrained by traction of the fin structure 52 to allow the junction to be an effective emitter or detector of photons. For photon emission, electron-hole pairs are generated by a current flowing through the junction and photons are emitted by electron-hole recombination with radiation associated with the preferred direct band gap. For photon detection, the p-n junction is reverse biased so that the photons generate electron-hole pairs which separate and which are detected as electric current through the junction. In photon emission implementations, it is sometimes preferred that the end faces of the germanium fin be coated with one or more reflection layers to produce a resonant cavity.
When positioning the junction, it is preferred that the junction is located so that photon absorption (by creating an electron-hole pair) or photon emission (by radiation recombination of a pair electro-hole) occurs to a sufficient degree in a part of the germanium which is sufficiently tensile to present a direct band and to carry out an effective detection or emission of photons. Alternatively, the tensile stress portion of the germanium preferably includes the weakest band gap for direct optical transition when current injection or other strategy is used with the band gap reduced to achieve efficient emission. Such suitable positioning of a tensile stress region and a junction or part of a junction is identified here as adjacent and includes those positions in which the junction part coincides with a region of tensile stress locally maximum and those in which there is a shift between these positions. The possible acceptable size of a shift depends on the stress level obtained, the application and the geometry of the device. This examination is carried out specifically for the relatively simple geometry of FIG. 5, but also applies to other and more complicated implementations examined in relation to the other figures. In addition, positioning and other considerations are also applicable to implementations in which a tensile stress is insufficient to obtain direct band gap transitions. In these situations, the principles discussed here apply, but are preferably combined with the desired doping, polarization and / or current to achieve sufficient photon emission or detection to be useful. For any laser application, properly reflecting ends of a cavity are preferably provided, losses are maintained at an appropriate low level and sufficient current is supplied so that the cavity provides gain in the manner known to the user. prior art. This examination refers to a junction or junctions. In many cases, the junction will not be a sharp p-n junction, but could actually be a p-i-n junction, p-type and n-type regions being positioned on each side of an active layer which is preferably undoped. A similar pn or p-i-n junction can be used both in light emitting laser diode (or LED) devices and in photodetector devices.
In another improvement of the lateral stressor process, narrow cuts can be etched in the layer of stressors by compression in silicon nitride along the length of the fin, making the lateral silicon nitride discontinuous along the length of the fin. This is partially illustrated in Figure 6, in which a narrow cutout 68 has been etched through one of the lateral structures made of compression-constrained silicon nitride to form multiple lateral compression regions 64, 66 which may extend to the both vertically and laterally to induce both vertical and horizontal stress components in the fin 62 in germanium. At the level of ruptures or cuts in the side wall made of silicon nitride, an edge relaxation (that is to say a relaxation facilitated by an expansion or a contraction at the level of the comparatively unstressed edges of the stressors) induces a additional stress component in the adjacent germanium fin, directed along the longitudinal axis of the fin, as shown in FIG. 6. This configuration induces biaxial tensile stress components in segments of the active region 62 in germanium, which is desirable to modify the band structure of germanium to reduce the band gap for direct optical transitions, preferably to the extent that the direct optical transition is the lower energy transition. As illustrated in FIG. 6, the additional vertical cutouts in the lateral silicon nitride compression layers can be vertical, although the cut lines can also be oriented at a different angle.
Another method for obtaining a biaxial tensile stress in the active germanium element of the laser or of the photodetector introduces breaks or cuts in both the lateral stressor elements and the germanium waveguide longitudinally along the fin to better induce biaxial tensile stress components in the germanium fin. If cutouts are etched in the germanium fin waveguide, the spaces in the germanium along the longitudinal axis of the laser or photodetector may be undesirable since they will act as partial mirrors causing reflections unwanted internals or scattered light generated in the active region of the laser or light in the photodetector. This undesirable behavior can be limited by the deposition of amorphous germanium in the spaces. The edge relaxation that occurs when the spaces are etched in germanium is sufficient to induce a tensile stress along the longitudinal axis of the germanium fin waveguide or the active region. Subsequent filling of the spaces, for example with amorphous germanium, does not remove the tensile stress, but largely removes the dielectric discontinuity in the waveguide or in the active region of the laser or photodetector along the axis of length. That is, filling the spaces with an appropriate material such as amorphous or polycrystalline germanium restores a continuous optical medium along the longitudinal optical axis of the active region of the laser or photodetector, but with a constraint discontinuous traction along the longitudinal optical axis of the active region of the laser or detector.
FIG. 7 illustrates a three-dimensional simulation of another modification of the strategy of FIGS. 5 and 6. FIG. 7 shows a certain number of fins, each fin made of germanium 72 having a dielectric (or insulating) stressor 74, 76 formed each side of the germanium fin. Each of these fins can be formed as described above in relation to FIGS. 5 and 6, including the etching, doping, contact formation and junction strategies mentioned here. Preferably, the dielectric stressors are formed initially so that they exhibit a compressive stress which is relaxed by etching to induce a tensile stress in the germanium fins 72 between the stressors 74, 76. A suitable stressor is nitride of silicon, which can be deposited so that it has a compressive stress which can be relaxed by appropriate etching strategies. As shown in Figure 7 (a), the dielectric stress layers 74, 76 can fill the space between adjacent fins 72 and actually induce a desirable level of biaxial tensile stress in the germanium fins. A simulated biaxial stress in the fins 72 is illustrated in Figure 7 (b), in which the stressor regions have been made invisible to reveal the biaxial stress contours in germanium as evaluated in the main planes of the fins, the clearer contours indicating a greater amplitude of biaxial stress.
The set of biaxially tensed germanium fins can be positioned so that an optical path, for example of a diode, a laser diode or a photodetector, passes through the structure of FIG. 7 so that the optical path passes through a plurality of the fins in a direction parallel to the side fin faces on which the stressors are formed to induce stress. Alternatively, the optical path of the example diode, laser diode or photodetector passes through a plurality of the fins in a direction perpendicular to the side fin faces on which the layers of stressors are formed to induce stress.
For the germanium fin structures discussed above in the examples of Figures 5 to 7, the fins may have a width (separation between the layers of dielectric stressors) between about 20 nanometers and 100 nanometers and, more preferably, between about 40 nanometers and 80 nanometers. The fins preferably have a height (as measured above the remaining germanium layer adjacent to the base of the fin) of less than one micron and, more preferably, less than 400 nanometers. The fins preferably have a length (as measured laterally along the face of the germanium layer adjacent to one of the stressor layers) of less than one micron and, more preferably, less than 400 nanometers. For the implementations of FIGS. 5 to 7 and other implementations of the structures described here, it is preferred that the stress material made of compression-stressed silicon nitride is formed to initially have a stress greater than two gigapascals and, more preferably, greater than three gigapascals.
FIGS. 8 to 11 diagrammatically illustrate an elastic edge relaxation of the stressor layers by compression on the upper and lower surfaces of a germanium strip or plate. The compression stressor layers on the upper surface (or the upper and lower surfaces) of an active region of a germanium laser or band photodetector are drawn and etched in alignment with the active region. Edge relaxation occurs when a stripe pattern is etched through the upper stressor layer, the active layer and, optionally, the lower stressor layer. The compressive stress in the stressor layers induces a tensile stress in the adjacent germanium active layer.
In a first implementation of this strategy, illustrated in FIG. 8 (a), a layer of compression-stressed silicon nitride is deposited on the surface of a semiconductor wafer or of a germanium 80 substrate. process forms a mask on the silicon nitride layer and then etches through the silicon nitride layer and into the surface of the germanium semiconductor wafer to form a germanium 82 strip (or plate) extending over it of the remaining part of the semiconductor wafer 80. The etching through the layer of compression-stressed silicon nitride forms the strip 84 and the etching continues in the substrate, which allows the compression-constrained silicon nitride 84 to relax and induce a tensile stress at least in the upper part of the band 82 in germanium. The resulting constrained surface region of strip 82 can be used to generate or detect photons.
In a currently preferred implementation, a host semiconductor wafer has a germanium layer bonded by semiconductor wafer to the surface of the host semiconductor wafer. For example, the host semiconductor wafer 86 could be a silicon wafer 83 with a layer of surface silicon oxide 85, or a part of an integrated silicon circuit covered with a layer of silicon oxide, and the layer in germanium is bound to the oxide surface in a well known manner. A layer of compressive stressor is then deposited on the germanium layer. For example, commercially available processes are available for depositing suitable compression-stressed silicon nitride layers with integrated stress, such as deposited, greater than two gigapascals or, more preferably, three gigapascals. The structure of FIG. 8 (b) is again formed by drawing and engraving a band of compressive stressor 84, and then engraving a long band of active region in continuous germanium 82, stopping at the surface of the wafer semiconductor 86, as shown in Figure 8 (b). The relaxed edge surface stressor strip 84 induces a uniaxial stress in the germanium strip 82, as indicated by the arrow in FIG. 8 (b). In other embodiments, the etching does not stop at the surface of the semiconductor wafer 86, but rather continues at a small depth in the surface of the semiconductor wafer 86 so as to induce a tensile stress more large in the germanium strip 82. In other embodiments, the etching stops before the surface of the semiconductor wafer 86 is reached so that the germanium strip 82 is in the form of a base in germanium resting on an uncut germanium layer.
FIG. 9 illustrates another configuration which can, compared to the configurations of FIGS. 8 (a) and 8 (b), provide a higher level of stress to a germanium strip in order to better emit or detect photons. The structure of FIG. 9 is formed by sequentially depositing a first layer of material stressed by compression on a host semiconductor wafer 90, by providing a layer of crystalline germanium, and then depositing a second layer of material stressed by compression on the germanium layer. The first and second layers of compression-stressed material may, for example, be compression-stressed silicon nitride and the deposited materials are selected to act as stressors for the germanium layer. The processes for depositing this layer of silicon nitride stressor are known. The process of FIG. 9 continues by drawing and engraving through the stack of layers to form a strip of upper stressor 94, a strip of germanium 92 which is stressed by traction uniaxially in the direction illustrated by the arrow in FIG. 9 The etching can optionally continue through the second compression-stressed layer below the germanium layer to form the lower stress band 96. The etching through or at least in the second compression-stressed layer is preferred , since it allows for more complete edge relaxation and results in a higher level of uniaxial tensile stress. The germanium 92 strip preferably has a width of between 0.04 and 1.0 micron and is preferably tensile stress sufficient to at least parts of the germanium 92 strip having a direct band gap.
A number of factors influence the level of tensile stress in the germanium layer, including the thickness of the germanium layer, the respective thicknesses of the upper and lower stress layers and the level of compressive stress in the stress layers upper and lower. A tensile stress also varies due to the separation between the edge and the part of the germanium layer which is taken into account. A non-uniform distribution of stress is true for all the structures examined or illustrated here. It is preferred that the tensile stress in this region or other germanium regions discussed here (and elsewhere, including above in connection with Figures 5 to 7) is adjusted to obtain efficient photon emission or detection . It should nevertheless be appreciated that the structures and strategies described here can be advantageously used when lower levels of tensile stress are obtained, even when the material has an indirect band gap and a photon emission is based on high levels of injection of carriers.
In other embodiments, the drawing and the engraving are carried out in order to make additional cuts and ruptures in the germanium strip and the layers of stressors stressed by compression (as deposited) adjacent along the longitudinal axis of the strip, breaking the active region strip into shorter segments of length generally in the range 0.04 to 1.0 microns. Such an embodiment is illustrated in FIG. 10. The implementation of FIG. 10 is similar to the embodiments illustrated in FIG. 9, except that, when the strip is drawn and engraved, other drawings and engraving are made to open the edges and a space 108 between the parts of the germanium strip 102, 104.
The space 108 allows the first and second parts of the stressor strip (upper and lower) to relax in an elastic manner by an edge relaxation to induce a tensile stress more effectively in the parts of the germanium strip 102, 104. The relaxation edge which occurs when the spaces are etched in germanium is sufficient to induce a tensile stress in the germanium along the longitudinal axis of the ribbed waveguide or the active region in germanium. The longitudinal tensile stress is induced, in addition to the transverse tensile stress, along the width axis of the germanium strip. This configuration induces biaxial tensile stress components in the germanium active region segments which is desirable to modify the band structure of germanium to reduce the band gap for direct transitions. As illustrated in FIG. 10, the additional vertical cuts in the lateral layers made of compression-constrained silicon nitride can be vertical or the cutting lines can be oriented at an angle different from the vertical.
Immediately after the spaces have been created, the parts of the stress band relax laterally and induce a tensile stress in the remaining parts of the germanium band. Subsequent filling of the spaces, for example with amorphous or polycrystalline germanium, does not remove the tensile stress in the remaining parts of the germanium strip, but largely removes the dielectric discontinuity in the waveguide or the active region of the laser or of the photodetector between the different parts of the germanium strip along the longitudinal (or optical) axis of the device. This is illustrated schematically in Figure 11, in which amorphous or polycrystalline germanium 116, 118 is deposited in spaces such as space 108 between the parts of the germanium strip 102, 104. Refilling the spaces again with a suitable material restores a continuous optical medium in the segmented germanium band of the active region of the laser or of the photodetector which has a discontinuous tensile stress.
In certain embodiments of the laser diode or of the tensile-stressing germanium photodetector diode, the material 116, 118 which fills the spaces between the segments of the germanium active region can be doped and used as an electrical conductor in the diode. In a preferred embodiment, the filling material is n + doped polycrystalline SiGe and acts as an electron emitter in the laser diode, emitting electrons laterally in regions 102, 104 in p-type doped constrained germanium. The n-type doping of polycrystalline germanium or silicon-germanium during a deposition is well known and easily accomplished.
Figures 12 to 17 show various variants for forming an electrical junction for a system which desirably comprises tensile-stressed germanium. The standard operating mode of a semiconductor laser requires that an stimulated emission of photons occur in an active region formed at the junction of two regions of material, one region providing a source of holes and the other region providing a source of electrons so that radiation recombination of holes and electrons occurs in the vicinity of the junction of the two regions. The two material regions are generally p-type and n-type semiconductor regions, respectively, and form a pn junction where they meet. If a region which is neither strongly p-type nor strongly n-type is present between the n-type and p-type regions, the junction is called a pin junction in which the nominally undoped region is considered "intrinsic" . In some implementations, an undoped layer or layers are provided between the p-type and n-type layers to form the desired junction.
In the constrained germanium laser, the region of efficient radiation recombination of carriers (electrons and holes) preferably coincides with the region of maximum biaxial tensile stress in germanium. In preferred embodiments of the device, the region of maximum current density across the pn junction coincides, to the greatest degree possible, with the region of maximum biaxial or uniaxial tensile stress in germanium. The plane of the pn or pin junction can be mainly parallel to the wafer surface or can be mainly perpendicular to the wafer surface. Given the difficulties of n-type doping of germanium by activation of implanted donor species, it may be preferred that the n-type germanium region is formed in an n-type doped state, or in the semiconductor wafer of departure (which may be solid germanium or germanium on insulator), either in the epitaxial germanium layer as appropriate. The p-type germanium region can be formed by implantation and activation of acceptor species such as boron or by epitaxial growth of a p-type germanium region above n-type germanium. Alternatively, the junction can be formed by epitaxial growth methods starting with a massive semiconductor wafer in germanium type p or a semiconductor wafer in germanium on insulator and developing a layer in germanium type n to form an epitaxial junction.
The electron emitter can be made of a material different from crystalline germanium. N + doped regions are difficult to manufacture in germanium due to poor activation of donors implanted in germanium. A deposited electron-emitting material may be preferred, in which the emitting material may be any: amorphous or polycrystalline germanium doped in situ n +; amorphous or polycrystalline silicon or amorphous or polycrystalline silicon doped n + in situ; a metal with a low extraction work with an extraction work of less than 4.3 eV; or a metal with low extraction work with an interfacial dielectric layer between the metal and the germanium, the dielectric layer being thin enough to allow a current of electrons to flow through it. In embodiments in which the germanium layer is on an insulator such as a buried oxide (BOX), the contact with germanium (generally of type p) is preferably a separate contact.
In the embodiment of the laser, the diode or the photodetector in constrained germanium with integrated SiGe stressors, illustrated in FIG. 4 and in FIGS. 12 to 17, a pn junction or epitaxial pin can be formed in the germanium before that the stress regions in SiGe are formed. In this case, the regions of stressors in SiGe can be undoped, p-type doped or n-type doped. Separate electrical contacts are made for the n-type and p-type regions in germanium.
Insulating silicon oxide regions can be formed by being self-aligned with the silicon-germanium (SiGe) stressor regions by a method described later. The desired pattern of a matrix of integrated regions is defined by lithography and dry (plasma) etching in a layer of silicon nitride which is deposited on the germanium. Germanium is etched where it is not covered by silicon nitride to create recesses in the germanium surface. The recesses are filled with an epitaxial SiGe alloy by a process such as chemical vapor deposition (CVD). If the CVD epitaxial process is selective, the SiGe grows epitaxially only in the recesses and not on the silicon nitride. If the CVD process is non-selective, SiGe is deposited on all exposed surfaces, in which case a subsequent leveling process such as chemical mechanical polishing (CMP) is used to remove SiGe from the surfaces of silicon nitride leaving SiGe only in mask openings and in recesses in the germanium structure. At this stage in the process with the silicon nitride mask still covering the germanium surfaces, an oxidation process is applied so that the exposed surfaces of embedded (integrated) SiGe are oxidized. This develops a thin insulating layer of silicon oxide or silicon-germanium oxide on the regions in SiGe and in self-alignment with these. The silicon nitride is then removed using selective wet etching and the upper surfaces of the biaxially stressed germanium elements are exposed. At the same time, the removal of the silicon nitride allows a more complete transfer of stress from the SiGe regions which are biaxially stressed by traction in the plane of the semiconductor wafer towards the laterally adjacent germanium regions which also become biaxially stressed by traction in the plane of the semiconductor wafer.
FIG. 12 shows an implementation for forming a tensile-constrained germanium structure for a photon emitter or a photon detector. For ease of description, this structure will be described with reference to a germanium laser diode using a biaxial tensile stress in the plane and, more preferably, a direct band gap optical transition.
Those skilled in the art will understand that the present structure could be implemented as a simple light emitting diode, rather than as a laser and that, with correct polarization and amplification, the illustrated structure could be used as a detector. such as a photodiode. As indicated above, suitable junctions include pn junctions and pin junctions. Figure 12 begins as illustrated with a p-type germanium substrate 120, which could alternatively be a p-type layer on an insulating layer such as a buried oxide (BOX) layer. In addition, the p-type germanium layer illustrated could be positioned on or above a silicon comprising silicon circuit elements or optical elements such as waveguides based on silicon or oxide structures. of silicon. These various possibilities for the germanium substrate are similar for the other implementations illustrated in FIGS. 12 to 18 and are not thus repeated in the description of these illustrations.
The implementation of FIG. 12 preferably forms a structure similar to that illustrated in FIG. 4 with the stress and the optical properties described above in relation to FIG. 4. In the implementation of FIG. 12, a layer 124 of intrinsic or lightly doped n-type germanium is deposited epitaxially on the p-type germanium substrate 120, n-type doping being preferably performed in situ during deposition. A mask, such as a silicon nitride mask, is formed on an intrinsic or lightly doped n-type epitaxial germanium layer, openings in the mask defining a matrix pattern such as a checkerboard pattern above the layer 124 of epitaxial germanium intrinsic or lightly doped n-type. The dimensions of the regions can vary while achieving the desired tensile stress and the regions could, for example, generally have a square top section and could be about 0.04 to 1.0 micron side. The etching through the germanium layer 124 and preferably in the p-type substrate 120 progresses to form a corresponding set of openings or recesses in the germanium structure. Regions 126 of silicon-germanium are preferably formed epitaxially by a selective chemical vapor deposition in the openings in the layer 120 of p-type germanium and the layer 124 of intrinsic or lightly doped n-type germanium as defined through the openings in the silicon nitride mask. In this illustration, the silicon-germanium regions can be undoped or intrinsic. If the silicon-germanium regions 126 are not selectively deposited or if this is preferred otherwise, chemical mechanical polishing can be performed to remove excess silicon-germanium. Thereafter, the exposed silicon-germanium is preferably oxidized by exposing the surfaces to an oxidizing environment to form the insulating silicon-germanium oxide structures 128. Preferably, the mask layer of silicon nitride is then removed.
As described above, the formation of the adjacent silicon-germanium regions and around the germanium regions creates biaxially tensile silicon-germanium regions, which in turn induce biaxial tensile stress in the plane in the germanium regions. 124. Preferably, the biaxial tensile stress is sufficient to cause these parts of the germanium regions to have a direct band gap so that they can be pumped and effectively produce an optical output. These regions 124 in biaxially tensile germanium can then be used as components of a laser gain region. The silicon germanium regions 126 are therefore also in the laser gain region and do not contribute to the generation of an optical output. Contacts are formed on the intrinsic or lightly doped n-type germanium regions. For example, a layer 122 of n-type doped amorphous or polycrystalline silicon-germanium or n-type doped germanium could be provided to form a contact on the regions 124 of n-type germanium. Similarly, a region 129 of p-type doped amorphous or polycrystalline silicon-germanium may be provided to form a contact on the substrate or the region 120 of basic p-type germanium, or other methods such as metal plugs can be used. An additional treatment is preferably applied to produce mirrors which define a resonator or a laser cavity encompassing at least part of the germanium constrained so that the regions of germanium biaxially constrained by traction can perform a laser action.
Figure 13 illustrates a different process for providing a structure generally similar to that illustrated in Figures 4 and 12. Similar structures are indicated in Figure 13 by numbers identical to those used in Figure 12. Here the process begins with a p-type germanium substrate or layer 120, which is drawn and etched by forming a mask of silicon nitride with a matrix of openings and then by dry etching (with plasma) to form recesses. Silicon-germanium regions 126 are developed, preferably by selective chemical vapor deposition, to form regions tensile in the plane with the remaining parts of the germanium substrate 120 extending between the silicon-germanium regions 126. The parts of the germanium substrate 120 underlying the silicon-germanium regions are stressed by compression in the plane. The exposed surfaces of the silicon-germanium regions 126 are oxidized and then the mask of silicon nitride is removed. The silicon or silicon germanium or amorphous, polycrystalline or crystalline germanium highly doped n-type is deposited and appropriately drawn to form the layered structure 139 illustrated in FIG. 13. The doped layer 139 is in contact with the surface of the germanium layer 120 in the matrix pattern defined between the silicon-germanium regions 126. The oxidized silicon-germanium layers 128 separate the silicon-germanium regions 126 from the doped layer 139 so that the dopants of the doped layer 139 do not not diffuse in the silicon-germanium 126. regions. The structure is heated, for example by rapid thermal annealing, to diffuse the n-type dopants of the heavily doped n-type layer 139 in the surface of the germanium 120 to form regions. shallow n-type 134 in a matrix pattern, also forming junctions in the same matrix pattern. The resulting structure can be incorporated into a diode, laser or detector, as described above. In addition, the resulting structure will have a stress distribution and therefore be able to generate broadband transmission. For laser applications, mirrors can be used to select the desired wavelength from this broadband emission, advantageously providing a range of gains and possible output wavelengths. For detectors or diodes, filters can be formed adjacent to the emission or detection regions to select emission or detection wavelengths.
FIG. 14 illustrates another variant of the tensile-constrained germanium structure which can be used to emit or detect photons. The structure and processes of Figure 14 are similar to those illustrated and described in connection with Figure 12, and thus the detailed description is not repeated. The structures which are substantially similar between Figures 12 and 14 are identified by the same reference numbers. The structure of FIG. 14 is formed on a substrate 140 made of highly p-type germanium doped. A layer 142 of p-type doped epitaxial germanium is deposited on the substrate of more heavily doped p-type germanium. Subsequent processing follows, for example, as described above in connection with Figure 12. The resulting structure of Figure 14 has properties similar to that of the structure of Figure 12, but with a more conductive p-type substrate so that there is less series resistance and that a photon emission and detection device is generally more efficient.
FIG. 15 shows another implementation of the germanium structure constrained by biaxially pulling in the plane of FIG. 4. The substrate 150 is a p-type germanium which is drawn with a silicon nitride or another mask to define a matrix of stressor positions. The etching in the p-type germanium substrate 150 forms a matrix of recesses in which silicon germanium is deposited epitaxially, preferably using a selective chemical vapor deposition, forming silicon germanium 156 constrained by biaxially pulling. The silicon-germanium regions 156 are oxidized to form silicon-germanium oxide regions 158. Surface portions 155 of the p-type germanium substrate are therefore biaxially stressed by tensile force applied from the regions in surrounding silicon-germanium 156, as discussed above. Removing the silicon nitride mask allows for more complete stress transfer. In the process of Figure 15, an electron emitting material 159 is deposited and drawn as shown. A deposited electron emitting material may be preferred to provide more conductivity or more design flexibility. A suitable emitter material can be any one: amorphous or polycrystalline germanium doped in situ n +; amorphous or polycrystalline silicon or amorphous or polycrystalline silicon-germanium doped in situ n +; a metal with low extraction work; or a low extraction metal with an interface dielectric layer which is thin enough to be electrically conductive between the metal and the germanium.
In the configuration of FIG. 15, the preferred radiation recombination for an emitter such as a laser mainly occurs in the parts
155 biaxially higher tensile stresses of the P-type germanium substrate
FIG. 16 shows a modification of the configuration of FIG. 15, in which oxide regions are not formed in the silicon germanium regions 156 and the electron-emitting layer 169 is formed in direct contact with the silicon regions. germanium 156. The other aspects of the configuration of FIG. 16 are identical to those examined above in relation to FIG. 15 and its process.
FIG. 17 provides another modification of the structure of FIG. 16 in which the regions of silicon-germanium 176 are doped during the deposition so that the regions of silicon-germanium 176 are of type n. In this configuration, electrons can be injected from the electron-emitting layer 169 above the regions 155 in germanium constrained by traction and laterally from the regions in silicon-germanium 176 around the regions 155. The regions in silicon -germanium 176 of type n increase the emission of electrons in the regions of radiation recombination, in particular in the regions with higher stress of the regions 155 in constrained germanium, and thereby increase the efficiency of the emission process of photons. For detector implementations, the structure illustrated in Figure 17 provides an additional junction area for collecting electron-hole pairs generated by photons, providing a more efficient detector structure. The structures illustrated in FIGS. 12 to 17 allow emission and detection of photons using similar structures, generally simplifying the construction of emitters such as diodes or lasers as well as detectors such as photodiodes on the same substrate. (semiconductor wafer) using at least some common process steps.
Preferred embodiments of the illustrations of FIGS. 4 and 12 to 17 position four regions of stressors integrated in silicon-germanium around a region in germanium constrained biaxially in the plane. In an assembly comprising a number of biaxially constrained germanium regions according to these embodiments, integrated silicon-germanium regions can be adjacent to multiple germanium regions. The silicon-germanium regions constrained by traction on at least two sides, and preferably four sides, of the germanium region preferably induce a biaxial stress in the germanium region. In certain implementations, the silicon-germanium regions are not substantially connected to the adjacent silicon-germanium regions (nearest neighbor). The silicon-germanium stressor regions can have a square, rectangular, rounded or circular lateral section. In particularly preferred implementations of these embodiments (non-continuous stressor), the width (or equivalently, the length) of each lateral dimension of the germanium region between opposite integrated silicon-germanium stressor regions is less than 400 nanometers and preferably less than 100 nanometers. Preferably, the tensile-stressed silicon-germanium regions have a silicon composition between 20% and 100% of silicon and preferably between 40% of silicon and 60% of silicon. The preferred embodiments of the present invention are implemented with a region of substantially 100% germanium (which, given the deposition environments, can include silicon in a measurable amount), but it should be understood that the regions in germanium could be implemented in a future implementation with a certain amount of silicon or carbon and be included in the teaching of the present invention.
FIG. 18 illustrates a preferred embodiment of the structures and processes illustrated in FIGS. 12 to 17, in which one or more discrete germanium pillars are formed and integrated in a layer of silicon-germanium stressors subsequently deposited. Generally, the structure of Figure 18 is formed on a germanium substrate by making a mask by a lithography process or any other drawing process to define the locations and extent of isolated germanium pillars. The drawing and engraving define the lateral extent of the germanium pillars. The engraving depth defines the height of the pillars. Pillars are sideways isolated, but are preferably not isolated from the underlying germanium substrate so that adjacent pillars share a common germanium region or substrate. The pillars could, for example, have a height above the region or the germanium substrate remaining between about 20 nanometers and 400 nanometers or, more preferably, between about 40 nanometers and 100 nanometers. The germanium pillars can have a square, rectangular, rounded or circular lateral section and preferably have a lateral dimension greater than 20 nanometers and less than 200 nanometers and, more preferably, have a lateral dimension between 30 nanometers and 100 nanometers. Preferably, the germanium pillars are formed into a regular assembly such as a "checkerboard" pattern in which the pillars are spaced by uniform X and Y partitions.
After having formed the set of germanium pillars, the fabrication of the structure of FIG. 18 continues by depositing a layer of silicon-germanium around the pillars. The silicon-germanium is deposited on the surface of the germanium substrate so that the silicon-germanium will be in a tensile state. Preferably, the tensile-stressed silicon-germanium layer has a silicon composition of between 20% and 100% of silicon, preferably between approximately 40% of silicon and 60% of silicon. As discussed above in connection with Figures 12 to 17, the silicon-germanium deposition process can be carried out selectively, or can be carried out and then the excess silicon-germanium can be removed, for example, by polishing chemical mechanical. As also described above, the tensile stress-induced silicon-germanium layer induces a lateral biaxial tensile stress in the germanium pillars, preferably to an extent to cause the direct optical transition to be the lowest band gap biaxially constrained germanium pillars. The manufacturing and the more specific structural strategies illustrated in and described in relation to FIGS. 12 to 17 can be implemented in the geometry and the arrangement of germanium pillars illustrated in FIG. 18. In FIG. 18, which represents a part of the active region of a constrained germanium laser according to an embodiment of the invention, multiple regions of pillars 182 are formed into an assembly drawn by an etching in the germanium layer 180 and a filling of the etched trenches with a material constrained by traction such as silicon-germanium epitaxial, as represented by the region 184. In the particular example represented here, the trenches surrounding each pillar in germanium are deliberately fused so that the filling material of the trenches constrained by traction forms a continuous region 184.
It is, of course, also possible to combine the overlaying layer of stressors (for example silicon nitride constrained biaxially by compression in the plane) with integrated stressors (for example germanium silicon constrained biaxially by compression in the plane) with germanium biaxially constrained by traction. Preferably, the overlying stress layer has openings in which the integrated stressors are formed so that they cover the germanium regions to be stressed. Furthermore, preferably, the overlying stressor is removed after the constrained germanium has been formed.
The invention proposes the possibility, in another improvement, of intentionally positioning pillars or fins of constrained germanium with high optically active emission (for example regions 182 in FIG. 18) at specifically determined locations along the axis main optic of the resonant cavity of the laser corresponding to a spacing equal to half a wavelength of the resonant optical mode of the cavity. That is, one or more rows of optically active germanium elements can preferably be spaced at half-wavelength intervals from the desired optical mode of the laser cavity. This allows optimization of the amplification of light in the cavity and minimization of reabsorption (optical loss) by eliminating (avoiding) regions of germanium constrained at locations which do not contribute to amplification of light and which n 'would add other than electrical and optical energy losses.
The fabrication of light emitting diodes or lasers or photodetectors in a tensile-stressed semiconductor body (e.g. germanium) allows an entire photonic system comprising light emitters, optical couplers, waveguides and photodetectors to be combined and integrated into the same semiconductor layer (for example germanium). When an emission or a detection of light is necessary, the semiconductor is differentiated by constraining by traction locally the semiconductor (for example germanium), the constraint bringing the forbidden band of the optical semiconductor (for example germanium) to be narrowed and the band gap of the semiconductor to become more direct. When an emission or a detection of light is not necessary, the semiconductor is not intentionally constrained by traction and the forbidden band remains wide and indirect. Examples of optical components in which emission or detection of light is not necessary include waveguides and optical couplers, and preferably the semiconductor regions (for example, made of germanium) corresponding to these components. circuits are not intentionally constrained. In a preferred embodiment, the semiconductor is germanium and germanium is locally biaxially stressed by traction at locations where an active optoelectronic device such as a laser, a light emitting diode or a photodetector is manufactured. In a preferred embodiment, the biaxial tensile stress is greater than or equal to about 2% in a sufficient proportion of the germanium region in an active optoelectronic device to achieve the desired active optoelectronic device functionality, whether it be of a photon emission, or whether it is a photon detection. The regions of active optoelectronic device are preferably differentiated from the regions of passive optoelectronic device essentially by the degree of tensile stress and thus less by a difference in the elementary composition of the active material. Conventional photonic integrated circuits use only or essentially changes in elementary composition to differentiate active optoelectronic devices from passive optoelectronic devices.
In an example of a photonic integrated circuit based on conventional indium phosphide, the passive waveguide is a layer of indium phosphide and the active components include an active layer comprising multiquic wells of indium gallium arsenide or indium gallium arsenide indium phosphide. Light is emitted from indium gallium arsenide which is an optically active direct bandgap semiconductor material as a result of its chemical composition, and not as a result of stress in the material. Here, the light is emitted by a material which is not the same material as the waveguide material. Generally, the light emitting material is added to the waveguide material by epitaxial growth or by a bonding process wherever a laser is manufactured. Preferred aspects of the present invention facilitate the use of the same material as an emitter or detector and as a waveguide by modifying the optical properties of the material at least in part by imposing a stress.
Generally, the assembly of optical networks consisting of light emitters, modulators, waveguides and detectors, together, requires alignment of components in three dimensions and at angles with a very high degree of control and precision. A typical quality factor when aligning the optical axis of a waveguide with that of a detector is to obtain at least 50 to 80% transmission, which requires, for beam profiles gaussian, alignment better than about 10% of the cross-sectional dimension of the waveguide, which is of the order of 0.1 µm. This is usually done with a lot of effort, using active or passive alignment strategies. Consequently, production and cost problems make optical network components much more expensive than semiconductor integrated circuits. Great efforts are being made to find cost effective and integrated assembly solutions. Aspects of the present invention can be used to limit assembly and alignment problems. A typical process flow diagram for developing optical aspects of a system implementing aspects of the present invention uses the steps already used in the manufacture of integrated circuits. The use of existing technologies offers the possibility of applying well-established procedures for improving productivity and reducing costs to optical, communication or other interconnection systems.
The fabrication of an optical (photonic) system integrated into a single semiconductor layer uses established initial manufacturing processes currently used in advanced microelectronic manufacturing: wet cleaning, epitaxy of group IV elements (silicon, germanium or their alloy), deposition of dielectric films, drawing by lithography and removal of material by appropriate wet and dry etchings, followed by CMP, and various steps for doping and making electrical contact on the electrical components of the optical system. A bond, a hetero-epitaxy of III / V or II / VI composite semiconductors or the deposition of non-group IV materials, whether crystalline or non-crystalline, can complement aspects of the optical systems described here, but do not are not essential for the realization of integrated photonic systems. A preferred method for fabricating an integrated photonics system on a semiconductor wafer may require little alignment of optical components other than self-alignment.
In a preferred embodiment, the invention provides an optical system in which, at least in certain implementations and in particular in preferred implementations, all the components including a transmitter, a waveguide and a detector are made substantially from the same element (for example germanium), where the material is locally and selectively constrained so that it becomes optically active with a band structure which corresponds to the band structure of a semi - direct bandgap conductor, only when required by the system designer, that is, in the gain medium of lasers, in light emitting diodes or in photodetectors. Preferably, a waveguide defined in part laterally by materials with low dielectric constant, an emitter such as a laser having a gain region comprising one or more regions of biaxially constrained germanium and a detector such as a photodiode comprising one or more regions of germanium biaxially constrained, with the waveguide, of the active regions of the transmitter and of the detector self-aligned with one another.
In the embodiments shown in FIGS. 12 to 17, as described above, the emitter layer above the regions of constrained germanium may be made of germanium or silicon or of an amorphous or polycrystalline doped silicon-germanium alloy. In these embodiments, it is advantageous to select a thickness and a cross-section geometry for the emitter layer so that the light intensity profile (mode field pattern) is partially contained in the germanium layer and partially in the emitter layer with the aim of maximizing the superimposition of the light intensity profile and the volume of the pillar or fin regions in optically active biaxially constrained germanium. The regions biaxially constrained in germanium can be in the upper part of the germanium waveguide structure. Those skilled in the art can design the overall structure to position the optical mode with the maximum optical intensity coinciding with the most highly stressed germanium regions. By these means, the amplification of light by a stimulated emission in the regions of constrained germanium is optimized. This preferred embodiment is shown in FIG. 19 in which the laser is formed in a ribbed waveguide 192 which is etched in a germanium layer 190. The rib is covered on the adjacent sides by regions of dielectric material to low index, such as silicon oxide, 194 and 196. Regions of tensile stressors in silicon-germanium are indicated by the reference 197 and the germanium columns between the silicon-germanium stressors are biaxially and optically active, which allows radiation recombination and stimulated light emission. The emitter region 198 is formed on the laser emission region of the germanium rib in a pattern which optionally covers the low index regions 194 and 196. In the body of the laser, the optical intensity profile is preferably centered in the highly biaxially stressed regions of the germanium pillars in the rib, as indicated by the dotted line 199 which represents the mode field pattern in the germanium laser. In another improvement, the emitter region 198 is chamfered or has a narrowed thickness along the axis of the germanium rib in the direction away from the laser emitting region so that the intensity profile optical (fashion field pattern) is repositioned in the body of the ribbed germanium waveguide. In this case, the polycrystalline emitting material does not cover the germanium waveguide, except where an optically active device such as a laser or a photodetector is present.
It will be appreciated that the structure illustrated in Figure 19 can accommodate the other transmitter structures illustrated in Figures 4 and 12-17 in the general region indicated by 199 in Figure 19 and with similar operation and advantage. Furthermore, the structure generally illustrated in FIG. 19 can also be used to make a detector. Optical signals are generated in the emitter or laser region 199 and propagate through the corner structure and in the ribbed waveguide 192. These optical signals can be generated by a control circuit in a processor circuit. or silicon memory as part of an electrical bus to optical transaction so that the optical signals carry data from a processor or memory circuit. Optical signals propagate through the ribbed waveguide 192 to a nearby or remote detector location, where optical signals can be converted to electrical signals for further processing in a processor, memory storage, or other process wish. A detector can be coupled to a waveguide ribbed by a corner such as the corner 198 illustrated in FIG. 19 and in a region with fins or pillars in biaxially tensile germanium configured as a detector, as illustrated in Figures 4 and 12 to 17 and as described above. Preferably, the active regions of both the transmitter and the detector are self-aligned with the ribbed waveguide and with each other.
Circuit elements in a processor can be coupled to circuit elements in a spaced or distant part of the processor by providing an optical plane such as a germanium layer. Control circuit elements in the processor deliver a set of data in parallel to a suitable set of transmitters such as lasers. Lasers could each have the configuration as illustrated in Figure 19 and produce optical outputs modulated by the output of the control circuit elements which is coupled into a corresponding set of ribbed waveguides. Signals transmitted in parallel through the corresponding set of ribbed waveguides are supplied to a corresponding set of detectors comprising fins or pillars made of biaxially tensile germanium, as described above. The outputs of the detector assembly are supplied to control circuits which supply the recovered signal to an electric bus which distributes the signals in the processor.
Figure 20 shows another configuration for a laser incorporating one of the constrained germanium gain structures discussed above. As illustrated, a constrained germanium structure 202 such as any of those discussed above which preferably has sufficient tensile constrained germanium present through at least part of the structure 202 is provided in contact with an optical structure 200. For example, the optical structure 200 may be a waveguide or an optical cavity for a laser with mirrors 204, 206 formed on opposite surfaces of the optical structure 200. The optical structure could, for example, be a silicon waveguide, a silicon oxide waveguide or other suitable structure for a laser cavity. The mirrors 204, 206 on each end of the optical structure, for example, could be distributed Bragg reflectors, the structure and manufacture of which are well known. In the illustrated configuration, one of several laser modes can be coupled in the constrained germanium parts of the structure 202 to be amplified by the gain of the region. The coupling between structures 200 and 202 can be, for example, an evanescent coupling. Preferably, sufficient gain is obtained to provide gain to the laser cavity by modes coupling to the adjacent gain medium. Other configurations for the laser structure can be used, including those that have mirrors formed directly on the constrained germanium structure. Various mirrors, including reflecting or partially reflecting surfaces, can be used, as is known in the prior art. A similar strategy can be used to achieve evanescent coupling between a waveguide and a photodiode structure as illustrated and described above to achieve an effective detector for guided optical signals.
The present invention has been described in terms of certain preferred embodiments. Those skilled in the art will appreciate that various changes and modifications could be made to the specific preferred embodiments described herein without departing from the teaching of the present invention. Accordingly, the present invention is not intended to be limited to the specific preferred embodiments described herein, but instead the present invention should be defined by the appended claims.

权利要求:
Claims (17)
[1" id="c-fr-0001]
1. Integrated photonic system comprising:
an optical layer of a semiconductor device, said optical layer comprising a plurality of components comprising at least one light source, one or more waveguides, at least one routing or switching element, or at least a detector, said optical layer being made of a generally homogeneous material;
in which the optical properties of the generally homogeneous material comprising the optical layer change locally in the vicinity of the respective components to pass from light emitting semiconductor material, direct band gap, to an optically transparent waveguide material, band gap indirect, or to a light-sensing semiconductor material, direct band gap.
[2" id="c-fr-0002]
2. An integrated photonic system according to claim 1, wherein local changes in optical properties are created by applications of a stress in the optical layer.
[3" id="c-fr-0003]
3. Integrated photonic system according to claim 2, in which the stress is a biaxial tensile stress.
[4" id="c-fr-0004]
4. Integrated photonic system according to claim 2, in which the stress is a uniaxial tensile stress.
[5" id="c-fr-0005]
5. Integrated photonic system according to one of claims 1 to 4, in which a forbidden band of a semiconductor comprises the optical layer in an area which comprises a light emitter or a light detector is less than the forbidden band of the semiconductor comprising the optical layer in an area which comprises a waveguide.
[6" id="c-fr-0006]
6. Integrated photonic system according to one of claims 1 to 5, in which the waveguides are formed of an unconstrained semiconductor material with an indirect forbidden band larger than the forbidden band of the constrained semiconductor material light emitter or light detector.
[7" id="c-fr-0007]
7. Integrated photonic system according to one of claims 3 to 6, in which the generally homogeneous material comprises germanium.
[8" id="c-fr-0008]
8. Integrated photonic system comprising a plurality of optical devices including light emitters, optical couplers, waveguides and light detectors combined and integrated into a single optical semiconductor layer, in which the optical layer of semiconductor is differentiated in those of optical devices in which an emission or detection of light is required by locally constraining in traction the semiconductor in areas of optical devices, the constraint causing a forbidden strip to be narrowed and to become more direct only in areas where the semiconductor is not intentionally stressed in tension.
[9" id="c-fr-0009]
9. Integrated photonics system according to claim 8 wherein said same semiconductor layer comprises germanium.
[10" id="c-fr-0010]
10. The integrated photonic system as claimed in claim 8, in which in those optical devices in which emission or detection of light is not required, the semiconductor is not intentionally constrained in traction and the band gap of the semi- conductor remains broad and indirect.
[11" id="c-fr-0011]
11. The integrated photonic system according to claim 10, wherein those of the optical components in which emission or detection of light is not required are waveguides.
[12" id="c-fr-0012]
12. The integrated photonic system as claimed in claim 10, in which those of the optical components in which emission or detection of light is not required are optical couplers.
[13" id="c-fr-0013]
13. The integrated photonic system according to claim 9, in which the germanium is biaxially tensile locally in locations where an active optoelectronic device is manufactured.
[14" id="c-fr-0014]
14. The integrated photonic system according to claim 9, wherein the local tensile stress is equal to or greater than about 2%.
[15" id="c-fr-0015]
15. Integrated photonic system according to one of claims 1 to 14, in which control electronics are included in an optical layer.
[16" id="c-fr-0016]
16. Integrated photonic system according to one of claims 1 to 14, in which control electronics is included in a layer other than the optical layer.
[17" id="c-fr-0017]
17. Integrated photonic system according to one of claims 1 to 14, in which the control electronics are included in an associated ULSI chip.

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---

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---

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---

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---

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---

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---

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---

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---

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---

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---

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---

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---

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---

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---

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引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

---

US6724088B1|1999-04-20|2004-04-20|International Business Machines Corporation|Quantum conductive barrier for contact to shallow diffusion region|

---

CN100399586C|2002-06-19|2008-07-02|麻省理工学院|GE photodetectors|

---

US6909151B2|2003-06-27|2005-06-21|Intel Corporation|Nonplanar device with stress incorporation layer and method of fabrication|

---

US7211458B2|2005-08-08|2007-05-01|North Carolina State University|Methods of fabricating strained semiconductor-on-insulator field-effect transistors and related devices|

---

US7596158B2|2005-10-28|2009-09-29|Massachusetts Institute Of Technology|Method and structure of germanium laser on silicon|

---

US7569869B2|2007-03-29|2009-08-04|Intel Corporation|Transistor having tensile strained channel and system including same|

---

US7875522B2|2007-03-30|2011-01-25|The Board Of Trustees Of The Leland Stanford Junior University|Silicon compatible integrated light communicator|

---

KR101361129B1|2007-07-03|2014-02-13|삼성전자주식회사|luminous device and method of manufacturing the same|

---

US7674669B2|2007-09-07|2010-03-09|Micron Technology, Inc.|FIN field effect transistor|

---

US7851325B1|2008-09-12|2010-12-14|Acorn Technologies, Inc.|Strained semiconductor using elastic edge relaxation, a buried stressor layer and a sacrificial stressor layer|

---

US7972916B1|2008-10-22|2011-07-05|Acorn Technologies, Inc.|Method of forming a field effect transistors with a sacrificial stressor layer and strained source and drain regions formed in recesses|

---

DE102008061152B4|2008-12-09|2017-03-02|Osram Opto Semiconductors Gmbh|Optoelectronic semiconductor chip|

---

US8633573B2|2009-02-16|2014-01-21|The Board Of Trustees Of The Leland Stanford Junior University|Strained semiconductor materials, devices and methods therefore|

---

US9065253B2|2009-05-13|2015-06-23|University Of Washington Through Its Center For Commercialization|Strain modulated nanostructures for optoelectronic devices and associated systems and methods|

---

US9245805B2|2009-09-24|2016-01-26|Taiwan Semiconductor Manufacturing Company, Ltd.|Germanium FinFETs with metal gates and stressors|

---

WO2011044226A2|2009-10-07|2011-04-14|University Of Florida Research Foundation Inc.|Strain tunable silicon and germanium nanowire optoelectronic devices|

---

JP5627871B2|2009-10-30|2014-11-19|フューチャー ライト リミテッド ライアビリティ カンパニー|Semiconductor device and manufacturing method thereof|

---

US8731017B2|2011-08-12|2014-05-20|Acorn Technologies, Inc.|Tensile strained semiconductor photon emission and detection devices and integrated photonics system|

---

US9666702B2|2013-03-15|2017-05-30|Matthew H. Kim|Advanced heterojunction devices and methods of manufacturing advanced heterojunction devices|

---

JP2019009196A|2017-06-21|2019-01-17|ルネサスエレクトロニクス株式会社|Semiconductor laser|US8450133B2|2009-03-16|2013-05-28|Acorn Technologies, Inc.|Strained-enhanced silicon photon-to-electron conversion devices|

---

US9059201B2|2010-04-28|2015-06-16|Acorn Technologies, Inc.|Transistor with longitudinal strain in channel induced by buried stressor relaxed by implantation|

---

US10833194B2|2010-08-27|2020-11-10|Acorn Semi, Llc|SOI wafers and devices with buried stressor|

---

US8415221B2|2011-01-27|2013-04-09|GlobalFoundries, Inc.|Semiconductor devices having encapsulated stressor regions and related fabrication methods|

---

US8731017B2|2011-08-12|2014-05-20|Acorn Technologies, Inc.|Tensile strained semiconductor photon emission and detection devices and integrated photonics system|

---

EP2626917B1|2012-02-10|2017-09-27|IHP GmbH-Innovations for High Performance Microelectronics / Leibniz-Institut für innovative Mikroelektronik|A CMOS-compatible germanium tunable Laser|

---

US9490318B2|2012-06-15|2016-11-08|Lawrence Livermore National Security, Llc|Three dimensional strained semiconductors|

---

KR101923730B1|2012-10-15|2018-11-30|한국전자통신연구원|A semiconductor laser and method of forming the same|

---

US9136672B2|2012-11-29|2015-09-15|Agency For Science, Technology And Research|Optical light source|

---

US8867874B2|2012-12-06|2014-10-21|Finisar Sweden Ab|Method for modifying the combining or splitting ratio of a multimode interference coupler|

---

KR102031953B1|2013-05-23|2019-10-15|한국전자통신연구원|Optical input/output device and optical electronic system having the same|

---

US9690042B2|2013-05-23|2017-06-27|Electronics And Telecommunications Research Institute|Optical input/output device, optical electronic system including the same, and method of manufacturing the same|

---

US9299810B2|2013-07-05|2016-03-29|Taiwan Semiconductor Manufacturing Company Limited|Fin-type field effect transistor and method of fabricating the same|

---

US9698296B2|2013-07-08|2017-07-04|Sifotonics Technologies Co., Ltd.|Compensated photonic device structure and fabrication method thereof|

---

US9412911B2|2013-07-09|2016-08-09|The Silanna Group Pty Ltd|Optical tuning of light emitting semiconductor junctions|

---

US9472535B2|2013-11-08|2016-10-18|Wisconsin Alumni Research Foundation|Strain tunable light emitting diodes with germanium P-I-N heterojunctions|

---

TW201530757A|2013-12-30|2015-08-01|Veeco Instr Inc|Engineered substrates for use in crystalline-nitride based devices|

---

JP6228874B2|2014-03-19|2017-11-08|株式会社日立製作所|Semiconductor optical device|

---

JP6379696B2|2014-06-05|2018-08-29|住友電気工業株式会社|Quantum cascade laser diode|

---

US9595812B2|2014-06-23|2017-03-14|The Board Of Trustees Of The Leland Stanford Junior University|Crossed nanobeam structure for a low-threshold germanium laser|

---

CA2958754C|2014-08-15|2021-04-20|Aeponyx Inc.|Methods and systems for microelectromechanical packaging|

---

US9865520B2|2015-08-07|2018-01-09|International Business Machines Corporation|Tunable semiconductor band gap reduction by strained sidewall passivation|

---

DE102016114514B4|2015-10-20|2021-10-14|Taiwan Semiconductor Manufacturing Co., Ltd.|Semiconductor structure and process for their manufacture|

---

US9824943B2|2015-10-20|2017-11-21|Taiwan Semiconductor Manufacturing Company, Ltd.|Semiconductor structure and method for forming the same|

---

CN108369958A|2015-12-24|2018-08-03|英特尔公司|The transistor of germanium raceway groove including elongation strain|

---

US10732349B2|2016-02-08|2020-08-04|Skorpios Technologies, Inc.|Broadband back mirror for a III-V chip in silicon photonics|

---

US10509163B2|2016-02-08|2019-12-17|Skorpios Technologies, Inc.|High-speed optical transmitter with a silicon substrate|

---

FR3051984B1|2016-05-24|2018-05-25|Thales|QUANTUM CASCADE LASER NETWORK WITH BLEED ANTIGUIDAGE IN TYPE IV MATERIAL AND MONOLOBE TRANSMISSION|

---

CN107546116B|2016-06-28|2019-10-18|西安电子科技大学|SiGe selective epitaxy causes Ge collimation tape splicing gap semiconductor material and preparation method thereof|

---

CN107546103B|2016-06-28|2019-09-20|西安电子科技大学|A kind of direct band gap Ge material and preparation method thereof with Si process compatible|

---

US9864136B1|2016-08-09|2018-01-09|Globalfoundries Inc.|Non-planar monolithic hybrid optoelectronic structures and methods|

---

CN107785238B|2016-08-25|2020-07-24|西安电子科技大学|InGaAs material, MOS device based on InGaAs material as channel and preparation method thereof|

---

CN107785234A|2016-08-25|2018-03-09|西安电子科技大学|Strain Ge based on Si substrates1‑xSnxThin-film material and preparation method thereof|

---

CN107785232A|2016-08-25|2018-03-09|西安电子科技大学|Direct band gap Ge materials and preparation method thereof are caused based on LRC technique SiGeC selective epitaxies|

---

WO2018096037A1|2016-11-23|2018-05-31|Rockley Photonics Limited|Electro-optically active device|

---

EP3714321A1|2017-11-23|2020-09-30|Rockley Photonics Limited|Electro-optically active device|

---

WO2018100157A1|2016-12-02|2018-06-07|Rockley Photonics Limited|Waveguide optoelectronic device|

---

KR20180090107A|2017-02-02|2018-08-10|삼성전자주식회사|Spectrometer and apparatus for measuring substance in body|

---

CN107221583B|2017-05-17|2019-01-29|福建海佳彩亮光电科技有限公司|A kind of vertical structure LED and its preparation process|

---

IL254295D0|2017-09-03|2017-10-31|Yeda Res & Dev|Optical bus for a multi-core processor|

---

US10928588B2|2017-10-13|2021-02-23|Skorpios Technologies, Inc.|Transceiver module for optical communication|

---

CN108878550B|2018-06-29|2020-04-03|江苏宜兴德融科技有限公司|Multi-junction solar cell and preparation method thereof|

---

US10962810B2|2018-09-27|2021-03-30|Massachusetts Institute Of Technology|Strained germanium silicon optical modulator array including stress materials|

---

US10665512B2|2018-10-17|2020-05-26|International Business Machines Corporation|Stress modulation of nFET and pFET fin structures|

---

CN109390845B|2018-10-31|2020-02-21|华中科技大学|Strain germanium laser and manufacturing method thereof|

---

US11133649B2|2019-06-21|2021-09-28|Palo Alto Research Center Incorporated|Index and gain coupled distributed feedback laser|

---

FR3101727B1|2019-10-08|2021-09-17|Commissariat Energie Atomique|method of manufacturing at least one voltage-strained planar photodiode|

---

CN112467514A|2020-11-10|2021-03-09|华中科技大学|Semiconductor device with wide working temperature range|

法律状态:
2019-07-26| PLFP| Fee payment|Year of fee payment: 8 |

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2020-07-28| PLFP| Fee payment|Year of fee payment: 9 |

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2021-07-26| PLFP| Fee payment|Year of fee payment: 10 |

优先权:

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申请号 | 申请日 | 专利标题

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US13/209,186|US8731017B2|2011-08-12|2011-08-12|Tensile strained semiconductor photon emission and detection devices and integrated photonics system|

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US13209186|2011-08-12|

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