• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a method for operating a lithographic apparatus, comprising the following steps: a) providing a substrate with multiple target portions arranged in two or more columns parallel to an axis; b) irradiating a target portion by moving said target portion in a direction parallel to the axis through a radiation beam; c) consecutively irradiating one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the axis, but opposite to the moving direction of the previously irradiated target portion, wherein steps b) and c) are consecutively repeated for another column.
    公开号:NL2018007A
    申请号:NL2018007
    申请日:2016-12-15
    公开日:2017-07-12
    发明作者:Corné Henri De Wit Paul
    申请人:Asml Netherlands Bv；
    IPC主号:
    专利说明:

    LITHOGRAPHIC APPARATUS OPERATING METHOD AND LITHOGRAPHIC
    APPARATUS
    BACKGROUND
    Field of the Invention
    The present invention relates to a method of operating a lithographic apparatus and a lithographic apparatus.
    Description of the Related Art A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. including part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
    In a conventional scanner, the substrate comprises multiple target portions arranged in one or more rows perpendicular to an axis, wherein a target portion is moved through a radiation beam in a direction parallel to the axis. Subsequently, an adjacent target portion in the same row is irradiated until all target portions in said row have been irradiated. The process then proceeds to the next row to irradiate all target portions in said next row. This is repeated until all target portions on the substrate have been irradiated. The process is characterized by movements in the scanning direction during exposure and movements in a step direction perpendicular to the scanning direction in between exposures to move to an adjacent target portion. A drawback encountered during the process of irradiating the target portions in a scanner is that the substrate is heated resulting in a local expansion of the substrate also effecting adjacent target portions, which thermal expansion may still be present during a subsequent exposure, so that complex compensations may be necessary to minimize the undesired negative effects of the thermal expansion of the substrate on the accuracy of the transfer of the pattern to the target portion. A further drawback encountered during the process of irradiating the target portions in a scanner is that the actuators may generate a lot of heat, especially when the desired accelerations are increased to improve throughput. As a consequence, more cooling capacity may be required, but this may result in adding more disturbances or complexity to the lithographic apparatus thereby limiting the performance of the lithographic apparatus.
    SUMMARY
    It is desirable to provide a lithographic apparatus in which the substrate heating and/or the actuator heating is reduced or at least the effects they have on the accuracy of the pattern transfer is reduced.
    According to an embodiment of the invention, there is provided a method for operating a lithographic apparatus, comprising the following steps: a) providing a substrate with multiple target portions arranged in two or more columns parallel to an axis; b) irradiating a target portion by moving said target portion in a direction parallel to the axis through a radiation beam; c) consecutively irradiating one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the axis, but opposite to the moving direction of the previously irradiated target portion; d) consecutively irradiating a target portion in another column by moving said target portion in a direction parallel to the axis through a radiation beam; and e) consecutively irradiating one or more other target portions in the same other column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the axis, but opposite to the moving direction of the previously irradiated target portion. According to another embodiment of the invention, there is provided a lithographic apparatus comprising: - an illumination system configured to condition a radiation beam; - a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; - a substrate table constructed to hold a substrate with a multiple target portions arranged in one or more columns parallel to an axis; - a projection system configured to project the patterned radiation beam onto a target portion of the substrate; - a first positioner to move and position the support in a scanning direction; - a second positioner to move and position the substrate table in the scanning direction and a step direction perpendicular to the scanning direction; - a control unit to control the first positioner and the second positioner, wherein the control unit is configured to control the first positioner and the second positioner in order to: a) orient a substrate on the substrate table such that the axis is parallel to the scanning direction; b) irradiate a target portion by moving said target portion in a direction parallel to the scanning direction through the radiation beam; c) consecutively irradiate one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion; d) consecutively irradiate a target portion in another column by moving said target portion in a direction parallel to the scanning direction through a radiation beam; and e) consecutively irradiate one or more other target portions in the same other column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion.
    BRIEF DESCRIPTION OF THE DRAWINGS
    Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:
    Figure 1 depicts a lithographic apparatus according to an embodiment of the invention; Figure 2 depicts schematically a substrate with multiple target portions;
    Figure 3 depicts schematically an exposure pattern to irradiate the target portions on the substrate of Fig. 2 in accordance with a method according to an embodiment of the invention; and Figure 4 depicts schematically an exposure pattern to irradiate the target portions on the substrate of Fig. 2 in accordance with a method according to another embodiment of the invention.
    DETAILED DESCRIPTION
    Figure 1 schematically depicts a lithographic apparatus according to one embodiment of the invention. The apparatus comprises: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation or EUV radiation). a support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device in accordance with certain parameters; a substrate table (e.g. a wafer table) WTa or WTb constructed to hold a substrate (e.g. a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; and a projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W.
    The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, and/or controlling radiation.
    The support structure supports MT, i.e. bears the weight of, the patterning device MA. It holds the patterning device MA in a manner that depends on the orientation of the patterning device MA, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device MA is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA.
    The support structure MT may be a frame or a table, for example, which may be fixed or movable as required. The support structure MT may ensure that the patterning device MA is at a desired position, for example with respect to the projection system PS. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.” The term “patterning device” used herein should be broadly interpreted as referring to any device that can be used to impart a radiation beam with a pattern in its cross-section such as to create a pattern in a target portion of the substrate W. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate W, for example if the pattern includes phase-shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.
    The patterning device MA may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable TCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam which is reflected by the mirror matrix.
    The term “projection system” used herein should be broadly interpreted as encompassing any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors such as the use of an immersion liquid or the use of a vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.
    As here depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array of a type as referred to above, or employing a reflective mask).
    The lithographic apparatus may be of a type having two (dual stage) or more substrate tables (and/or two or more mask tables). In such “multiple stage” machines the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposure. The two substrate tables WTa and WTb in the example of
    Figure 1 are an illustration of this. The invention disclosed herein can be used in a stand-alone fashion, but in particular it can provide additional functions in the pre-exposure measurement stage of either single- or multi-stage apparatuses.
    The lithographic apparatus may also be of a type wherein at least a portion of the substrate W may be covered by a liquid having a relatively high refractive index, e.g. water, so as to fill a space between the projection system PS and the substrate W. An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the patterning device MA and the projection system PS. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term “immersion” as used herein does not mean that a structure, such as a substrate W, must be submerged in liquid, but rather only means that liquid is located between the projection system PS and the substrate W during exposure.
    Referring to Figure 1, the illuminator IT receives a radiation beam from a radiation source SO. The radiation source SO and the lithographic apparatus may be separate entities, for example when the radiation source SO is an excimer laser. In such cases, the radiation source SO is not considered to form part of the lithographic apparatus and the radiation beam is passed from the radiation source SO to the illuminator IT with the aid of a beam delivery system BD comprising, for example, suitable directing mirrors and/or a beam expander. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The radiation source SO and the illuminator IT, together with the beam delivery system BD if required, may be referred to as a radiation system.
    The illuminator IL may comprise an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IT may comprise various other components, such as an integrator IN and a condenser CO. The illuminator may be used to condition the radiation beam, to have a desired uniformity and intensity distribution in its cross-section.
    The radiation beam B is incident on the patterning device MA (e.g., mask), which is held on the support structure MT (e.g., mask table), and is patterned by the patterning device MA. Having traversed the patterning device MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder or capacitive sensor), the substrate table WTa/WTb can be moved accurately, e.g. so as to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (which is not explicitly depicted in Figure 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the support structure MT may be realized with the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WTa/WTb may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the support structure MT may be connected to a short-stroke actuator only, or may be fixed. Patterning device MA and substrate W may be aligned using mask alignment marks Ml, M2 and substrate alignment marks PI, P2. Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the patterning device MA, the mask alignment marks Ml, M2 may be located between the dies. The depicted apparatus can at least be used in scan mode, in which the support structure MT and the substrate table WTa/WTb are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WTa/WTb relative to the support structure MT may be determined by the (de)-magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion.
    In addition to the scan mode, the depicted apparatus could be used in at least one of the following modes: 1. In step mode, the mask table MT and the substrate table WTa/WTb are kept essentially stationary, while an entire pattern imparted to the radiation beam is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WTa/WTb is then shifted in the X and/or Y direction so that a different target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. 2. In another mode, the support structure MT is kept essentially stationary holding a programmable patterning device, and the substrate table WTa/WTb is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is employed and the programmable patterning device is updated as required after each movement of the substrate table WTa/WTb or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as referred to above.
    Combinations and/or variations on the above described modes of use or entirely different modes of use may also be employed.
    Lithographic apparatus LA is of a so-called dual stage type which has two substrate tables WTa and WTb and two stations - an exposure station and a measurement station- between which the substrate tables can be exchanged. While one substrate on one substrate table is being exposed at the exposure station, another substrate can be loaded onto the other substrate table at the measurement station so that various preparatory steps may be carried out. The preparatory steps may include mapping the surface of the substrate using a level sensor LS and measuring the position of alignment markers on the substrate using an alignment sensor AS. This enables a substantial increase in the throughput of the apparatus. If the position sensor IF is not capable of measuring the position of the substrate table while it is at the measurement station as well as at the exposure station, a second position sensor may be provided to enable the positions of the substrate table to be tracked at both stations.
    The apparatus further includes a lithographic apparatus control unit LACU which controls all the movements and measurements of the various actuators and sensors described. Control unit LACU also includes signal processing and data processing capacity to implement desired calculations relevant to the operation of the apparatus. In practice, control unit LACU will be realized as a system of many sub-units, each handling the real-time data acquisition, processing and control of a subsystem or component within the apparatus. For example, one processing subsystem may be dedicated to servo control of the substrate positioner PW. Separate units may even handle coarse and fine actuators, or different axes. Another unit might be dedicated to the readout of the position sensor IF. Overall control of the apparatus may be controlled by a central processing unit, communicating with these sub-systems processing units, with operators and with other apparatuses involved in the lithographic manufacturing process.
    Fig. 2 schematically depicts a substrate W including multiple target portions arranged in two or more columns parallel to a Y axis. In this schematic example, each target portion is referred to by the letter C followed by an index 1-22 thereby giving each target portion a unique reference symbol used in the below description.
    Target portions C1-C4 are arranged in a first column indicated by reference numeral 1. Target portions C5-C11 are arranged in a second column indicated by reference numeral 2. Target portions C12-C18 are arranged in a third column indicated by reference numeral 3, and target portions C19-C22 are arranged in a fourth column indicated by reference numeral 4. It will be apparent to the skilled person that the invention can be applied to any number of columns and to any number of target portions per column.
    In this embodiment, the target portions C1-C22 have a dimension wi in a direction parallel to the axis Y that is smaller than a dimension 1 in a direction perpendicular to the axis Y, namely the axis X. The dimensions wi and 1 are only shown with respect to target portion Cl9, but apply to all target portions C1-C22. It will be apparent to the skilled person that the target portions can have any size and the particular dimensions and/or the ratio between dimension wi and 1 are not essential to the invention.
    In order to transfer a pattern to each target portion, the target portions may be successively exposed to the pattern in the lithographic apparatus of Fig. 1. A method of operating the lithographic apparatus of Fig. 1 in order to transfer a pattern to target portions will be described by reference to Fig. 3. Fig. 3 depicts the substrate W of Fig. 2 in the same orientation. Many of the reference symbols are omitted from Fig. 3 for simplicity reasons, but target portion Cl is indicated to indicate that the orientation of the images in Figs. 2 and 3 are identical and to allow the reference symbols in Fig. 2 to be matched to the image of Fig. 3.
    In order to transfer a pattern to the target portions, the lithographic apparatus of Fig. 1 is used in scan mode and the substrate W is positioned on the substrate table WTa/WTb. Either by properly positioning the substrate W on the substrate table WTa/WTb or by properly positioning the substrate table WTa/WTb using the second positioner PW, the substrate W is oriented such that the Y axis is parallel to the scanning direction of the lithographic apparatus. The scanning direction of the lithographic apparatus may also be referred to as Y axis, so that in that case the Y axis of the substrate is aligned with the Y axis of the lithographic apparatus.
    In the following description, the process of transferring a pattern to target portions will be described from the perspective of the substrate W in which a radiation beam will travel over a top surface of the substrate. Although this implies that the substrate W is held stationary and the radiation beam is moveable, this is not necessarily the case. It is preferred that the radiation beam is held stationary and the substrate W is moved through the radiation beam. However, both alternatives fall within the scope of the invention.
    In this example, a pattern is transferred first to the target portion Cl by irradiating the target portion Cl by moving said target portion Cl in a first direction parallel to the scanning direction through the radiation beam, so that effectively the radiation beam travels over the target portion Cl as indicated by arrow A1. In an embodiment, the pattern is scanned through the radiation beam synchronously with the movement of the target portion Cl through the radiation beam, e.g. by moving the patterning device MA parallel or anti parallel through the radiation beam.
    In accordance with this embodiment of the invention, the next target portion to be irradiated is target portion C2, where target portion C2 is adjacent to the previously irradiated target portion Cl and in the same column, namely column 1, as target portion Cl.
    Hence, target portion C2 is consecutively irradiated by moving said target portion C2 through the radiation beam in a second direction parallel to the scanning direction, but opposite to the first direction of the previously irradiated target portion Cl, effectively resulting in the radiation beam traveling over target portion C2 as indicated by arrow A2. Due to the second direction being opposite to the first direction, the direction of arrow A2 is opposite to the direction of arrow Al. In other words, arrow A2 is anti parallel to arrow Al.
    At the end of irradiating the target portion Cl, the radiation beam is at the lower side of target portion Cl as depicted in Figs. 2 and 3. At the start of irradiating the target portion C2, the radiation beam needs to be positioned at the lower side of the target portion C2, so that in between the exposures, the substrate W is moved relative to the projection system for this purpose. This movement is schematically indicated by arrow Bl.
    The process is in this embodiment continued by irradiating target portion C3 as the next target portion, where target portion C3 is adjacent to the previously irradiated target portion C2 and in the same column, namely column 1, as target portions Cl and C2.
    Target portion C3 is irradiated by moving the target portion C3 through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion, i.e. target portion C2. Hence, for target portion C3, the substrate is moved in the first direction similar as for target portion Cl, but opposite to the second direction as for target portion C2, so that the radiation beam effectively moves over target portion C3 as indicated by arrow A3, which is parallel to arrow A1 and anti parallel to arrow A2.
    At the end of irradiating the target portion C2, the radiation beam is at the upper side of target portion C2 as depicted in Figs. 2 and 3. At the start of irradiating the target portion C3, the radiation beam needs to be positioned at the upper side of the target portion C3, so that in between the exposures, the substrate W is moved relative to the projection system for this purpose. This movement is schematically indicated by arrow B2.
    This pattern is repeated until all target portions C1-C4 in column 1 have been irradiated resulting in arrow A4 representative for the movement of the radiation beam over target portion C4 and in arrow B3 representative for the movement in between the exposure of target portion C3 and target portion C4.
    An advantage of this pattern is that from the start of irradiating target portion Cl until the end of irradiating target portion C4, the substrate is mainly moved in the scanning direction only as indicated by arrows A1-A4 and arrows B1 to B3. As a result thereof, the actuators used to position the substrate in the non-scanning direction are used less with respect to prior art patterns, which leads to less heating of the actuators and thus reduces the required cooling capacity. The merits of the invention can also be used to use the same cooling capacity, but for the combination of smaller actuators for the non-scanning direction and larger actuators for the scanning direction compared to prior art lithographic apparatuses, resulting in a higher throughput for the same cooling capacity.
    Further, consecutively irradiating adjacent target portions in the same column has the advantage that the thermal expansion of a target portion due to irradiating the previous target portion is less complex in the non-scanning direction, so that less complex compensations are required to reduce the negative effects of the thermal expansion or that a higher accuracy can be obtained.
    Once all target portions C1-C4 in column 1 have been irradiated, the same process may be repeated for column 2, and subsequently for columns 3 and 4 until all target portions have been irradiated. The corresponding arrows A5-A22 and the arrows B4-B21 are the result thereof and indicate the movements of the substrate W during scanning (the “A”-arrows) and in between exposures (the “B”-arrows). Please note that arrows B4, BI 1 and B18 indicate a shift in the non-scanning direction to move to the next column. These shifts are the only relatively large movements in the non-scanning direction. All other movements are substantially in the scanning direction only.
    In some situations, especially when the dimension wi of the target portions is smaller than the dimension 1 of the target portions, the new pattern may result in a higher throughput. An advantage is at least that improving the actuation power in the scanning direction has a more positive effect on throughput for the new pattern according to a method according to the invention than the same improvement of actuation power in the non-scanning direction for prior art patterns.
    Although the pattern has been described starting at target portion Cl, it may very well have another starting point. Target portions C4, C19 and C22 may also form suitable starting points. Another method of operating the lithographic apparatus of Fig. 1 in order to transfer a pattern to target portions of substrate W of Fig. 2 will be described by reference to Fig. 4. Fig. 4 depicts the substrate W of Fig. 2 in the same orientation. Many of the reference symbols are omitted from Fig. 4 for simplicity reasons, but target portion Cl is indicated to indicate that the orientation of the images in Figs. 2 and 4 are identical and to allow the reference symbols in Fig. 2 to be matched to the image of Fig. 4.
    For simplicity reasons, only the movements of the substrate W during irradiation of the target portions are shown using the arrows A1-A22, where the index of the arrow is indicative for the order in which the target portions are irradiated. The movements in between the exposures, i.e. the arrows starting with the reference symbol “B”, have been omitted, but can be derived from the “A” arrows and from the characteristics of the “B” arrows shown in Fig. 2.
    As indicated by the “A” arrows, the order of irradiating the target portions is: C1-C3-C18-C16-C14-C12-C10-C8-C6-C19-C21-C2-C4-C17-C15-C13-C11-C9-C7-C5-C20-C2 2.
    The main difference between this pattern and the pattern of Fig. 3 is that consecutively irradiated target portions in the same column are non-adjacent. Another difference is that, with the exception of the transition from C12 to CIO and the transition from Cl3 to Cll, consecutively irradiated target portions are either in the same column or in non-adjacent columns. An advantage of this pattern is that the influence of substrate heating due to exposure of a target portion on the accuracy of the transfer of the pattern for the next target portion is less due to the larger distance between consecutively irradiated target portions due to the skipping of target portions and columns compared to the pattern depicted in Fig. 3.
    Due to the different pattern, the target portions in Fig. 4 are passed twice below the projection system, during the first pass, about half of the target portions is irradiated and during the second pass the other half of the target portions is irradiated, while in Fig. 3 all target portions are irradiated in a single pass. In other words, in Fig. 4, during the first pass target portions are irradiated such that consecutively irradiated target portions are non-adjacent to each other until target portions in all of the columns are irradiated, and during the next pass, target portions are irradiated such that consecutively irradiated target portions are non-adjacent to each other until all target portions are irradiated. It can also be envisaged that more than two passes are required to irradiate all target portions on the substrate.
    To carry out the method according to the invention as described above, the control unit LACU is configured to control the first positioner and the second positioner in order to: a) orient a substrate on the substrate table such that the axis is parallel to the scanning direction; b) irradiate a target portion by moving said target portion in a direction parallel to the scanning direction through the radiation beam; c) consecutively irradiate one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion; d) consecutively irradiate a target portion in another column by moving said target portion in a direction parallel to the scanning direction through a radiation beam; and e) consecutively irradiate one or more other target portions in the same other column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion.
    The second positioner may further be optimized for the method, e.g. by comprising a long-stroke module and a short-stroke module as described above, wherein the substrate table is supported by the short-stroke module, wherein the short-stroke module in turn is supported by the long-stroke module, wherein the long-stroke module allows to move and position the substrate table in the scanning direction and the step direction, wherein the short-stroke module allows to move and position the substrate table in the scanning direction and the step direction, and wherein a moving range of the short-stroke module relative to the long-stroke module in the scanning direction is significantly larger than in the step direction. Hence, all efforts are put in accurately and quickly positioning the substrate table in the scanning direction and the positioning abilities in the non-scanning direction, i.e. the step direction, are limited to accurate positioning. Hence, the actuators for the non-scanning direction do not have to apply relatively large accelerations for the step movement and can thus be designed smaller.
    In an embodiment, the short-stroke module is moved relative to the long-stroke-module by applying forces between the short-stroke module and the long-stroke module. This may have the advantage that the long-stroke module can act as reaction mass for the short-stroke module and no separate reaction mass is required.
    In case exposure is done via a liquid between the projection system and the substrate, the lithographic apparatus comprises a liquid immersion member to cover at least a portion of the substrate by a liquid so as to fill a space between the projection system and the substrate during exposure, wherein the liquid immersion member comprises a member that is moveable relative to the projection system in the scanning direction in order to move along with the irradiated target portion during exposure. This allows to move the meniscus of the liquid in the same direction as the target portion, thereby minimizing the velocity difference between meniscus and substrate and allowing higher moving velocities of the substrate without breaking the meniscus.
    It is noted that the term “consecutive” or “consecutively” in this context means that no other exposures or irradiation of target portions takes place in between the respective steps. However, it does not exclude other operations to be performed in between the respective steps, such as measurement steps, calibration steps, positioning steps, etc.
    Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, liquid-crystal displays (LCDs), thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion", respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology tool and/or an inspection tool. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.
    Although specific reference may have been made above to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.
    The terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g. having a wavelength of or about 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm), as well as particle beams, such as ion beams or electron beams.
    The term “lens”, where the context allows, may refer to any one or combination of various types of optical components, including refractive, reflective, magnetic, electromagnetic and electrostatic optical components.
    While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, the invention may take the form of a computer program containing one or more sequences of machine-readable instructions describing a method as disclosed above, or a data storage medium (e.g. semiconductor memory, magnetic or optical disk) having such a computer program stored therein.
    The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the clauses set out below. Other aspects of the invention are set out as in the following numbered clauses:
    CLAUSES 1. A method for operating a lithographic apparatus, comprising the following steps: a) providing a substrate with multiple target portions arranged in two or more columns parallel to an axis; b) irradiating a target portion by moving said target portion in a direction parallel to the axis through a radiation beam; c) consecutively irradiating one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the axis, but opposite to the moving direction of the previously irradiated target portion; d) consecutively irradiating a target portion in another column by moving said target portion in a direction parallel to the axis through a radiation beam; and e) consecutively irradiating one or more other target portions in the same other column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the axis, but opposite to the moving direction of the previously irradiated target portion. 2. The method according to clause 1, wherein consecutively irradiated target portions in the same column are adjacent to each other. 3. The method according to clause 1, wherein steps d) and e) are repeated until target portions in all of the two or more columns are irradiated. 4. The method according to clause 1, wherein steps d) and e) are repeated until all of the multiple target portions on the substrate are irradiated. 5. The method according to clause 1, wherein consecutively irradiated target portions in the same column are non-adjacent to each other. 6. The method according to clause 1, wherein consecutively irradiated target portions are either located in the same column or in non-adjacent columns. 7. The method according to clause 6, wherein irradiating takes place via a liquid disposed between an optical member and the substrate, and a meniscus of the liquid is moved in the same direction as the target portion. 8. A lithographic apparatus comprising: - an illumination system configured to condition a radiation beam; - a support constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; - a substrate table constructed to hold a substrate with a multiple target portions arranged in one or more columns parallel to an axis; - a projection system configured to project the patterned radiation beam onto a target portion of the substrate; - a first positioner to move and position the support in a scanning direction; - a second positioner to move and position the substrate table in the scanning direction and a step direction perpendicular to the scanning direction; - a control unit to control the first positioner and the second positioner, wherein the control unit is configured to control the first positioner and the second positioner in order to: a) orient a substrate on the substrate table such that the axis is parallel to the scanning direction; b) irradiate a target portion by moving said target portion in a direction parallel to the scanning direction through the radiation beam; c) consecutively irradiate one or more other target portions in the same column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion; d) consecutively irradiate a target portion in another column by moving said target portion in a direction parallel to the scanning direction through a radiation beam; and e) consecutively irradiate one or more other target portions in the same other column by moving each of the one or more other target portions through the radiation beam in a direction parallel to the scanning direction, but opposite to the moving direction of the previously irradiated target portion. 9. The lithographic apparatus according to clause 8, wherein the control unit is further configured to control the first positioner and the second positioner in order to repeat steps d) and e) until all of the multiple target portions on the substrate are irradiated. 10. The lithographic apparatus according to clause 8, wherein the control unit is further configured to control the first positioner and the second positioner such that consecutively irradiated target portions in the same column are adjacent to each other. 11. The lithographic apparatus according to clause 8, wherein the control unit is further configured to control the first positioner and the second positioner such that consecutively irradiated target portions in the same column are non-adjacent to each other, and such that consecutively irradiated target portions are either located in the same column or in non-adjacent columns. 12. The lithographic apparatus according to clause 8, wherein the second positioner comprises a long-stroke module and a short-stroke module, wherein the substrate table is supported by the short-stroke module, wherein the short-stroke module in turn is supported by the long-stroke module, wherein the long-stroke module allows to move and position the substrate table in the scanning direction and the step direction, wherein the short-stroke module allows to move and position the substrate table in the scanning direction and the step direction, and wherein a moving range of the short-stroke module relative to the long-stroke module in the scanning direction is significantly larger than in the step direction. 13. The lithographic apparatus according to clause 12, wherein the short-stroke module is moved relative to the long-stroke-module by applying forces between the short-stroke module and the long-stroke module. 14. The lithographic apparatus according to clause 8, comprising a liquid immersion member to cover at least a portion of the substrate by a liquid so as to fill a space between the projection system and the substrate during exposure, wherein the liquid immersion member comprises a member that is moveable relative to the projection system in the scanning direction in order to move along with the irradiated target portion during exposure.
    权利要求:
    Claims (1)
    [1]
    A lithography device comprising: an illumination device adapted to provide a radiation beam; a carrier constructed to support a patterning device, the patterning device being capable of applying a pattern in a section of the radiation beam to form a patterned radiation beam; a substrate table constructed to support a substrate; and a projection device adapted to project the patterned radiation beam onto a target area of the substrate, characterized in that the substrate table is adapted to position the target area of the substrate in a focal plane of the projection device.
    类似技术:
    公开号 | 公开日 | 专利标题
    US9857694B2|2018-01-02|Estimating deformation of a patterning device and/or a change in its position
    US9726988B2|2017-08-08|Multi-stage system, a control method therefor, and a lithographic apparatus
    NL2019140A|2018-02-09|A positioning system, method to position, lithographic apparatus and device manufacturing method
    NL1035995A1|2009-03-31|Lithographic apparatus, stage apparatus and device manufacturing method.
    US8947640B2|2015-02-03|Positioning device, lithographic apparatus, positioning method and device manufacturing method
    US9885964B2|2018-02-06|Lithographic apparatus and device manufacturing method
    KR101421540B1|2014-07-22|Reticle assembly, a lithographic apparatus, and a method to project two or more image fields in a single scanning movement of a lithographic process
    NL2008695A|2012-11-27|Lithographic apparatus comprising substrate table.
    US7136147B2|2006-11-14|Lithographic apparatus and device manufacturing method
    NL2003854A|2010-06-23|Lithographic apparatus and device manufacturing method.
    US8411247B2|2013-04-02|Lithographic apparatus and positioning apparatus
    NL2018007A|2017-07-12|Lithographic apparatus operating method and lithographic apparatus
    US9910367B2|2018-03-06|Lithographic apparatus, method for positioning an object in a lithographic apparatus and device manufacturing method
    US10429750B2|2019-10-01|Alignment mark recovery method and lithographic apparatus
    US20210079971A1|2021-03-18|Method for Manufacturing Damper Device, Lithographic Apparatus, Projection System, and Device Manufacturing Method
    NL1035920A1|2009-03-30|Lithographic System, Lithographic Apparatus and Device Manufacturing Method.
    JP4494304B2|2010-06-30|Method for generating a marker on a substrate, lithographic apparatus and device manufacturing method
    US7961291B2|2011-06-14|Lithographic apparatus and device manufacturing method
    NL2021057A|2019-01-25|Method to obtain a height map of a substrate having alignment marks, Substrate alignment measuring apparatus and Lithographic apparatus
    NL2019331A|2018-02-09|Positioning system, control system, method to position, lithographic apparatus and device manufacturing method
    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    EP16150586|2016-01-08|
    [返回顶部]