• 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:
    In the thin film transistor according to the exemplary embodiment of the present invention, a semiconductor layer made of polycrystalline silicon is formed on the insulating substrate with source and drain regions formed on both sides of the channel region and the channel region, respectively, and covers the semiconductor layer. A gate electrode that is part of the gate wiring is formed on the gate insulating film. At this time, the gate electrode is disposed at an arbitrary angle with respect to the growth direction of the grain of the semiconductor layer, more preferably at an angle in the range of 40-50 ° or 130-140 °. Thus, when the gate electrode is disposed at an arbitrary angle with respect to the growth direction of the grain, and when electrons move in the channel region under the gate electrode, a passage is formed so that the electrons can bypass the grain boundary without directly passing through the grain boundary to form a current in the thin film transistor. The characteristics of the thin film transistor for controlling the data signal applied to the pixel and the gate or data driver for outputting the scan signal or the data signal to the gate wiring or the data wiring can be uniformly improved.
    公开号:KR20030046101A
    申请号:KR1020010076503
    申请日:2001-12-05
    公开日:2003-06-12
    发明作者:강명구；김현재；신경주；강숙영；채종철
    申请人:삼성전자주식회사；
    IPC主号:
    专利说明:

    Thin film transistor
    [6] The present invention relates to a thin film transistor, and more particularly, to a thin film transistor having a semiconductor layer of polycrystalline silicon formed through a sequential solid phase crystal process.
    [7] In general, a liquid crystal display device includes two substrates on which electrodes are formed and a liquid crystal material injected therebetween, and the two substrates are printed around the edge and bonded with a sealing material to trap the liquid crystal material. It is supported by the space | interval distributed between.
    [8] The liquid crystal display device displays an image by applying an electric field to a liquid crystal material having an anisotropic dielectric constant injected between two substrates by using an electrode, and controlling the amount of light transmitted through the substrate by adjusting the intensity of the electric field. to be. In this case, a thin film transistor is used to control a signal transmitted to the electrode.
    [9] The most common thin film transistor used in a liquid crystal display device uses amorphous silicon as a semiconductor layer.
    [10] Such amorphous silicon thin film transistors are approximately 0.5 占 . Since it has a mobility of about 1 cm 2 / Vsec, it can be used as a switching element of a liquid crystal display device, but it has a disadvantage that it is not suitable to form a direct drive circuit on the upper part of the liquid crystal panel due to its low mobility.
    [11] Therefore, to overcome this problem, the current mobility is approximately 20 . A polycrystalline silicon thin film transistor liquid crystal display device using a polycrystalline silicon of about 150 cm 2 / Vsec as a semiconductor layer has been developed. Since a polysilicon thin film transistor has a relatively high current mobility, a chip that incorporates a driving circuit into a liquid crystal panel Glass (Chip In Glass) can be implemented.
    [12] As a technique for forming a thin film of polycrystalline silicon, a method of depositing polycrystalline silicon directly at a high temperature directly on top of a substrate, a solid phase crystallization method of laminating amorphous silicon and crystallizing it at a high temperature of about 600 ° C, laminating amorphous silicon, and laser The method of heat treatment using the said, etc. were developed. However, these methods are difficult to apply to the glass substrate for the liquid crystal panel because a high temperature process is required, and has a disadvantage of lowering the uniformity of the electrical characteristics between the thin film transistors due to uneven grain boundaries.
    [13] To solve this problem, a sequential lateral solidification process has been developed that can artificially control the distribution of grain boundaries. This technique takes advantage of the fact that the grains of polycrystalline silicon grow in a direction perpendicular to the interface at the boundary between the liquid region to which the laser is irradiated and the solid region to which the laser is not irradiated. At this time, the laser beam passes through the transmission region of the slit-shaped mask to completely dissolve the amorphous silicon to form a slit-shaped liquid region in the amorphous silicon layer. Subsequently, the liquid crystal silicon is cooled and crystallized. The crystal grows in a direction perpendicular to the interface from the boundary of the solid region where the laser is not irradiated, and the growth of grains stops when they meet at the center of the liquid region. Such a sequential solid phase crystal may be progressed through the entire region by repeatedly moving the slit pattern in the direction of grain growth with a mask.
    [14] However, if the sequential solid-state crystal process is performed while moving the slits of the mask only in the direction of grain growth, crystal grains of several micrometers can be obtained in the direction of grain growth, but in a direction perpendicular to the direction of grain growth. Small crystal grains of thousands of microns are formed. When the crystal grains have anisotropy in this way, the characteristics of the thin film transistors are anisotropic in accordance with the channel direction of the thin film transistors formed on the substrate. That is, a large difference occurs in the current mobility of the thin film transistor with respect to the growth direction of the grain and a direction perpendicular thereto, which is a design that requires the thin film transistors to be arranged in one direction when the thin film transistor is formed on the liquid crystal panel. Difficulties arise.
    [15] An object of the present invention is to provide a thin film transistor using polycrystalline silicon having a uniform current mobility.
    [1] 1 is a schematic diagram schematically illustrating a sequential lateral solid phase crystallization process of crystallizing amorphous silicon into polycrystalline silicon by irradiation with a laser;
    [2] 2 is a diagram showing the microstructure of polycrystalline silicon in the process of crystallizing amorphous silicon into polycrystalline silicon through a sequential lateral solid phase crystallization process,
    [3] 3 is a cross-sectional view showing the structure of a polysilicon thin film transistor according to an embodiment of the present invention;
    [4] 4A to 4E are cross-sectional views illustrating a method of manufacturing a polysilicon thin film transistor according to an embodiment of the present invention according to a process sequence thereof.
    [5] 5A and 5B are layout views illustrating a grain growth direction of a polycrystalline silicon and an arrangement structure of a gate electrode in a polysilicon thin film transistor according to an exemplary embodiment of the present invention.
    [16] In order to solve the above problems, in the present invention, the gate electrode is disposed to have an arbitrary angle with respect to the grain growth direction.
    [17] In this case, the gate electrode preferably has an angle in the range of 40-50 ° or 130-140 ° with respect to the grain growth direction.
    [18] More specifically, in the thin film transistor according to the present invention, a semiconductor layer including a source region and a drain region formed of polycrystalline silicon and formed on both sides of the channel region is formed on the substrate. On the gate insulating film covering the layer, a gate electrode is formed which is arranged at an arbitrary angle other than vertical and horizontal with respect to the grain growth direction of the polycrystalline silicon. In addition, source and drain electrodes are electrically connected to the source and drain regions, respectively.
    [19] The thin film transistor according to the present invention may further include a pixel electrode connected to the drain electrode, and the pixel electrode is preferably made of a transparent conductive material or a conductive material having a reflectance.
    [20] Next, a thin film transistor using polycrystalline silicon according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings so that a person skilled in the art may easily implement the present invention.
    [21] 1 is a schematic diagram illustrating a sequential side solid state crystallization process of crystallizing amorphous silicon into polycrystalline silicon by irradiation with a laser, and FIG. It is a figure which shows a microstructure.
    [22] As shown in FIG. 1, in the sequential side solid-state crystal process, an amorphous silicon layer formed on an insulating substrate by irradiating a laser beam using a mask 300 having a transmission region 310 formed in a slit pattern ( Locally completely melt 200 to form a liquid region 210 in the amorphous silicon layer 200 corresponding to the transmission region 310. At this time, grains of the polycrystalline silicon grow in a direction perpendicular to the interface at the boundary between the liquid region 210 irradiated with the laser and the solid state region 220 not irradiated with the laser. The growth of grains stops when they meet at the center of the liquid region, and when the slit pattern of the mask is moved in the direction of grain growth and irradiated with a laser beam, the lateral growth of grains can continue to determine various particle sizes as desired. Figure 2 shows the grain structure of polycrystalline silicon when the slit pattern is formed in a horizontal direction by using a mask having a slit pattern formed in the horizontal direction, and the grain is grown perpendicular to the slit pattern and grows in the vertical direction. Able to know. However, if the slit pattern of the mask is moved only in the direction of grain growth, the sequential solid-phase crystallization process yields several micrometers of grains in the direction of grain growth, but is perpendicular to the direction of grain growth. Small crystal grains of about thousands of microns are formed. At this time, if the gate wiring passing through the semiconductor layer of the thin film transistor is perpendicular to the grain growth direction, the channel direction formed in the semiconductor layer of the thin film transistor is parallel to the grain growth direction, so that the current mobility of the thin film transistor is 100 cm 2 /. When the gate wiring is parallel with the grain growth direction, the channel direction of the thin film transistor is perpendicular to the grain growth direction, and the current mobility of the thin film transistor is lower than 50 cm 2 / Vsec. As described above, the current mobility of the thin film transistor is greatly varied according to the direction of the gate wiring overlapping the semiconductor layer. As a result, the thin film transistor formed on the upper portion of the liquid crystal panel is very nonuniform depending on its position. In order to solve this problem, in the present invention, the gate lines are arranged to have any angle other than horizontal or vertical with respect to the grain growth direction.
    [23] Next, a structure of a thin film transistor according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.
    [24] 3 is a cross-sectional view illustrating a structure of a polycrystalline silicon thin film transistor according to an embodiment of the present invention, and FIGS. 4A to 5B illustrate a method of manufacturing a polysilicon thin film transistor according to an embodiment of the present invention according to a process sequence thereof. It is a cross section.
    [25] As shown in FIG. 3, the upper portion of the insulating substrate 10 includes source and drain regions 22 and 23 formed on both sides of the channel region 21 and the channel region 21, respectively, and is made of polycrystalline silicon. The semiconductor layer 20 is formed. At this time, as shown in FIG. 5A, the grain boundary, that is, the growth direction of the grains of the polysilicon layer 20 is formed in the vertical direction. Here, the source and drain regions 22 and 23 may be doped with n-type or p-type impurities and include a silicide layer. A gate insulating layer 30 made of silicon oxide (SiO 2 ) or silicon nitride (SiNx) covering the semiconductor layer 20 is formed on the substrate 10, and the gate insulating layer 30 on the channel region 21 is formed. The gate electrode 40 which is a part of the gate wiring is formed in the upper part. In this case, as shown in FIG. 5B, the gate electrode 40 is disposed at an arbitrary angle with respect to the grain growth direction, more preferably at an angle in the range of 40-50 ° or 130-140 °. In this way, when the gate electrode 40 is disposed at an arbitrary angle with respect to the growth direction of the grain and electrons move in the channel region 21 under the gate electrode 40, a passage through which electrons can bypass without directly passing through the grain boundary is provided. Is formed to increase the current mobility of the thin film transistor. In the experimental example, the current mobility of the thin film transistor was as high as 80 cm 2 / Vsec similarly to the case where the gate electrode 40 was formed perpendicular to the grain growth direction. Therefore, the thin film transistor is disposed by adjusting the angle of the gate electrode 40 with respect to the growth direction of the grain, thereby improving the characteristics of the thin film transistor and simultaneously controlling the data signal applied to the pixel, the gate wiring or the data wiring. The characteristics of the thin film transistor of the gate or the data driver for outputting the scan signal or the data signal can be made uniform. Here, the gate line may include a gate line transferring the scan signal to the gate electrode 40 or a gate pad receiving the scan signal from the outside and transmitting the scan signal to the gate line. An interlayer insulating film 50 covering the gate electrode 40 is formed on the gate insulating film 30, and the gate insulating film 30 and the interlayer insulating film 50 are the source and drain regions 22 and 23 of the semiconductor layer 20. Has contact holes 52, 53. An upper portion of the interlayer insulating layer 50 faces the source electrode 62 with the source electrode 62 and the gate electrode 40 connected to the source region 22 through the contact hole 52, and faces the contact hole 53. A drain electrode 63 connected to the drain region 23 is formed through. Here, the source and drain electrodes 62 and 63 are part of the data wire, and the data wire is connected to the source electrode 62 and receives the data signal from the outside and transmits the data signal to the data line. It may include a data pad. A protective insulating film 70 is formed on the interlayer insulating film 50, and a contact hole 73 exposing the drain electrode 63 is formed on the protective insulating film 70, and ITO (ITO) is formed on the protective insulating film 70. A pixel electrode 80 made of indium tin oxide (IZO), indiumzinc oxide (IZO), or a conductive material having a reflectance is formed and connected to the drain electrode 63 through the contact hole 73.
    [26] In the method of manufacturing a thin film transistor according to the exemplary embodiment of the present invention, first, as shown in FIG. 4A, amorphous silicon is deposited and patterned on the upper portion of the substrate 10 by low pressure chemical vapor deposition or plasma chemical vapor deposition or sputtering. The silicon thin film 25 is formed.
    [27] Subsequently, as shown in FIG. 4B, a sequential lateral solid phase crystal process of forming a liquid region by irradiating a laser beam to the amorphous silicon thin film 25 using a polysilicon mask having a slit pattern in the horizontal direction to form a liquid region. Proceeding to form the semiconductor layer 20 of polycrystalline silicon. At this time, as shown in FIG. 5A, the grain grows in the vertical direction.
    [28] Subsequently, as shown in FIG. 4C, silicon oxide (SiN 2 ) or silicon nitride is deposited to form a gate insulating film 30. Subsequently, the gate material 40 is formed to have an arbitrary angle with respect to the growth direction of the grains as shown in FIG. 5B by depositing and patterning a conductive material for gate wiring.
    [29] Next, as shown in FIG. 4C, the source and drain regions 22 and 23 are formed by ion implanting and activating n-type or p-type impurities into the semiconductor layer 20 using the gate electrode 40 as a mask. At this time, between the source and drain regions 22 and 23 is defined as a channel region 21.
    [30] 4D, an interlayer insulating film 50 covering the gate electrode 40 is formed on the gate insulating film 30, and then patterned together with the gate insulating film 30 to form a source of the semiconductor layer 20. And contact holes 52 and 53 exposing the drain regions 22 and 23.
    [31] Subsequently, as shown in FIG. 4E, a metal for data wiring is deposited and patterned on the insulating substrate 10 to be connected to the source and drain regions 22 and 23 through the contact holes 52 and 53, respectively. Drain electrodes 62 and 63 are formed.
    [32] Next, as shown in FIG. 3, after applying the protective insulating film 70 thereon, the contact hole 73 exposing the drain electrode 63 is formed by patterning. Subsequently, the pixel electrode 80 is formed by stacking and patterning a transparent conductive material such as ITO or IZO or a conductive material having excellent reflectivity.
    [33] As described above, in the present invention, by arranging the gate electrode to have an arbitrary angle with respect to the grain growth direction, the current mobility of the polysilicon thin film transistor can be ensured to be high, and the current mobility of the thin film transistor can be made uniform throughout the substrate.
    权利要求:
    Claims (4)
    [1" claim-type="Currently amended] A semiconductor layer made of polycrystalline silicon and including a channel region and source and drain regions formed on both sides of the channel region,
    A gate insulating film covering the semiconductor layer,
    A gate electrode formed over the gate insulating film in the channel region, the gate electrode being disposed at an arbitrary angle other than vertical and horizontal with respect to the grain growth direction of the polycrystalline silicon;
    Source and drain electrodes electrically connected to the source and drain regions, respectively
    Thin film transistor for a display device comprising a.
    [2" claim-type="Currently amended] In claim 1,
    And the gate electrode is disposed at an angle in the range of 40-50 ° or 130-140 ° with respect to the growth direction of the grain.
    [3" claim-type="Currently amended] In claim 1,
    And a pixel electrode connected to the drain electrode.
    [4" claim-type="Currently amended] In claim 3,
    The pixel electrode is a thin film transistor made of a transparent conductive material or a conductive material having a reflectance.
    类似技术:
    公开号 | 公开日 | 专利标题
    JP2017199007A|2017-11-02|Display device
    US9136288B2|2015-09-15|Display device
    US6346718B1|2002-02-12|Electro-optic device, drive substrate for electro-optic device and method of manufacturing the same
    CN101118913B|2011-01-19|Display device and method of manufacturing the display device
    JP4211967B2|2009-01-21|Method for crystallizing silicon using mask
    US5619044A|1997-04-08|Semiconductor device formed with seed crystals on a layer thereof
    EP0886319B1|2002-10-23|Method for making a thin film transistor
    JP4640690B2|2011-03-02|Manufacturing method of active matrix organic EL display device
    CN100356506C|2007-12-19|Crystal mask, amorphous silicon crystallization method and method of manufacturing array base plate using same
    JP4634147B2|2011-02-23|Method for manufacturing electronic device with thin film transistor
    US7208873B2|2007-04-24|Organic electroluminescence display device and method for fabricating the same
    KR101230299B1|2013-02-07|Thin film transistor array panel
    US6262438B1|2001-07-17|Active matrix type display circuit and method of manufacturing the same
    US7507645B2|2009-03-24|Method of forming polycrystalline semiconductor layer and thin film transistor using the same
    US6013544A|2000-01-11|Method for fabricating a semiconductor device
    US7279383B2|2007-10-09|Liquid crystal display device and method of fabricating the same
    US6627471B2|2003-09-30|Method of manufacturing an array substrate having drive integrated circuits
    US7611932B2|2009-11-03|Method of manufacturing a thin film transistor
    US7691545B2|2010-04-06|Crystallization mask, crystallization method, and method of manufacturing thin film transistor including crystallized semiconductor
    KR20040038729A|2004-05-08|Active matrix substrate and display device
    KR100616708B1|2006-08-28|array board of liquid crystal display and fabrication method thereof
    US6825070B2|2004-11-30|Electro-optical apparatus, driving substrate for an electro-optical apparatus and method of manufacturing them
    CN100517733C|2009-07-22|Poly-silicon thin film transistor array substrate and method for fabricating the same
    KR100487426B1|2005-05-04|Method For crystallizing Polysilicon, Method For Fabricating Polysilicon Thin Film Transistor And Liquid Crystal Display Device By Said Method
    US6861300B2|2005-03-01|Fabricating method of polysilicon thin film transistor having a space and a plurality of channels
    同族专利:
    公开号 | 公开日
    KR100767380B1|2007-10-17|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2001-12-05|Application filed by 삼성전자주식회사
    2001-12-05|Priority to KR1020010076503A
    2003-06-12|Publication of KR20030046101A
    2007-10-17|Application granted
    2007-10-17|Publication of KR100767380B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR1020010076503A|KR100767380B1|2001-12-05|2001-12-05|A thin film transistor|
    [返回顶部]