JP4689161B2 - THIN FILM TRANSISTOR, DISPLAY DEVICE SUBSTRATE HAVING THE SAME, LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME, AND DEFECT CORRECTION METHOD - Google Patents

Description

  The present invention relates to a thin film transistor, a display device substrate including the same, a liquid crystal display device using the same, and a defect correcting method.

  The active matrix liquid crystal display device includes a plurality of gate bus lines and a plurality of drain bus lines intersecting the plurality of gate bus lines with an insulating film interposed therebetween. For example, a thin film transistor (hereinafter abbreviated as TFT) is formed as a switching element at each intersection of the gate bus line and the drain bus line. The drain electrode of the TFT is connected to the drain bus line, and the source electrode of the TFT is connected to the pixel electrode formed in the pixel. The drain electrode and the source electrode are opposed to each other with a predetermined gap.

  The TFT is turned on only when a predetermined voltage is applied to the gate bus line, and applies a predetermined gradation voltage to the pixel electrode via the drain bus line. When the TFT is turned off, the gradation voltage is held in the pixel electrode. Thereby, the liquid crystal molecules formed by the pixel electrode and the counter electrode and the liquid crystal layer sealed therebetween hold the liquid crystal molecules in a predetermined tilt state, and maintain a desired light transmittance based on the tilt state. An image is displayed.

  In general, since the gap between the source electrode and the drain electrode is as narrow as about 3 to 10 μm, a conductive foreign substance may adhere between the source / drain electrodes in the manufacturing process of the liquid crystal display device, thereby causing a short circuit. A pixel in which a short circuit between the source electrode and the drain electrode occurs becomes a point defect pixel with a bright spot or a dark spot.

  In order to prevent a point defect caused by a short circuit between the source electrode and the drain electrode, a pixel having a redundant structure in which two TFTs are formed in one pixel is known (see Patent Documents 1 to 3). ). FIG. 8 is a partially enlarged view of a pixel having two TFTs 100 and 100 ′. As shown in FIG. 8, on a transparent insulating substrate 103 such as a glass substrate, a plurality of gate bus lines 102 (only one is shown in FIG. 8) extending in the left-right direction in the drawing are formed. In addition, an insulating film (not shown) is formed on the transparent insulating substrate 103 and the gate bus line 102, and a plurality of drain bus lines 104 extending in the vertical direction in the figure intersecting the gate bus line 102 through the insulating film. (Only one is shown in FIG. 8). TFTs 100 and 100 ′ are formed at the intersection between the gate bus line 102 and the drain bus line 104. The TFT 100 and the TFT 100 ′ are electrically connected in parallel between the drain bus line 104 and the pixel electrode 106.

  The gate bus line 102 in the formation region of the TFTs 100 and 100 'functions as the gate electrode of each TFT 100 and 100'. The insulating film on the gate electrode functions as a gate insulating film. On the gate insulating film, an operating semiconductor layer (not shown) and a channel protective film 116 are formed in this order. On both sides of the channel protective film 116 on the operating semiconductor layer, a drain electrode 108 having opposing sides that run over the channel protective film 116 and face each other with a predetermined gap, and an impurity semiconductor layer (not shown) formed in the lower layer, and A source electrode 110 is formed. The drain electrode 108 is connected to the drain bus line 104. A protective film (not shown) is formed on the drain / source electrodes 108 and 110 and the channel protective film 116 exposed in the gap between the drain / source electrodes 108 and 110. A contact hole 112 is formed in the protective film on the source electrode 110, and the pixel electrode 106 formed on the protective film is connected to the source electrode 110 through the contact hole 112. Further, by cutting either the drain electrode 108 or the source electrode 110 along the virtual cutting line 114, the current path of the current flowing between the drain electrode 108 and the source electrode 110 can be cut off.

  The TFT 100 ′ has the same configuration as the TFT 100. The drain electrode 108 ′ is connected to the drain bus line 104, and the source electrode 110 ′ is connected to the pixel electrode 106 through the contact hole 112 ′. Further, by cutting either the drain electrode 108 ′ or the source electrode 110 ′ along the virtual cutting line 114 ′, the current path of the current flowing between the drain electrode 108 ′ and the source electrode 110 ′ can be cut off. It has become.

  Next, a pixel defect correcting method will be described with reference to FIG. FIG. 9 is an enlarged view of the vicinity of the TFTs 100 and 100 ′ and shows a defect correcting method when a foreign substance 118 adheres to the TFT 100 ′. As shown in FIG. 9, when a foreign substance 118 adheres between the drain electrode 108 ′ and the source electrode 110 ′ of the TFT 100 ′ and the electrodes 108 ′ and 110 ′ are short-circuited, the source electrode 110 ′ is virtually disconnected. A laser beam is irradiated along the line 114 ′ to cut the source electrode 110 ′ to form the cut portion 120. Since the current path of the source electrode 110 ′ is cut off by the cutting part 120, no current flows to the source electrode 110 ′. As a result, the TFT 100 ′ is electrically disconnected from the pixel electrode 106. Since the gradation voltage applied to the drain bus line 104 is applied to the pixel electrode 106 via the normally operating TFT 100, the liquid crystal display device can display a desired image. In order to separate the TFT 100 ′ from the pixel electrode 106, the drain electrode 108 ′ may be cut along a virtual cutting line 114 ′ of the drain electrode 108 ′. In addition, when a foreign substance adheres to the TFT 100, the drain electrode 108 or the source electrode 110 is cut by the virtual cutting line 114 of the TFT 100, and the TFT 100 is electrically separated from the pixel electrode 106. Thereby, the normally operating TFT 100 ′ applies a gradation voltage to the pixel electrode 106.

  The size of the TFT 100 needs to be the same as that of a TFT having no redundant structure so that the pixel electrode 106 can be driven by the TFT 100 alone even if the TFT 100 ′ is electrically disconnected from the pixel electrode 106. . For the same reason, the TFT 100 ′ needs to be formed in the same size as the TFT 100. Further, it is necessary to provide a process margin so that the contact holes 112 and 112 'are not connected to each other. For this reason, the contact holes 112 and 112 ′ need to be separated from each other by a predetermined distance, and the TFTs 100 and 100 ′ are limited by the distance and are difficult to form in close proximity. For this reason, the ratio of the area occupied by the TFTs 100 and 100 ′ in the pixel increases, resulting in a decrease in the aperture ratio of the pixel. In addition, since the two contact holes 112 and 112 'must be formed on the pixel electrode 106, the aperture ratio is further reduced.

  If the aperture ratio of the pixels is small, the brightness of the backlight must be increased in order to brighten the screen of the liquid crystal display device. For this reason, the power consumption of a liquid crystal display device increases and it becomes a cause of the performance fall of a liquid crystal display device.

JP-A-5-341316 JP-A-1-169430 Japanese Patent Laid-Open No. 7-104311

  An object of the present invention is to provide a thin film transistor capable of suppressing a decrease in driving capability and increasing an aperture ratio of a pixel, a display device substrate including the thin film transistor, a liquid crystal display device using the thin film transistor, and a defect correcting method.

  The object is to provide a gate electrode formed on a substrate, a drain electrode and a source electrode formed on the gate electrode via an insulating film and having opposing sides facing each other with a predetermined gap along the gate electrode, A thin film transistor formed on the drain electrode or the source electrode and extending from at least one of the opposing sides to a region that does not overlap the gate electrode when viewed in the normal direction of the substrate surface. Achieved.

  According to the present invention, it is possible to realize a thin film transistor capable of suppressing a reduction in driving capability and increasing a pixel aperture ratio, a display device substrate including the thin film transistor, a liquid crystal display device using the thin film transistor, and a defect correcting method.

  A thin film transistor, a display device substrate including the thin film transistor according to an embodiment of the present invention, a liquid crystal display device using the thin film transistor, and a defect correcting method will be described with reference to FIGS. First, a schematic configuration of a thin film transistor (TFT) 1 according to the present embodiment, an array substrate (display device substrate) 3 including the same, and a liquid crystal display device using the same will be described with reference to FIGS. FIG. 1 shows an enlarged view of the vicinity of the TFT 1 of the array substrate 3 as seen from the image display surface. 2 shows an end face shape of the liquid crystal display device in which the liquid crystal display device using the array substrate 3 is cut in the vicinity of the TFT 1, and FIG. 2 (a) shows an end face cut along the line AA in FIG. (B) has shown the end surface cut | disconnected by the BB line of FIG.

  As shown in FIG. 2, the liquid crystal display device has an array substrate 3 on which a TFT 1, a pixel electrode 6 and the like which will be described later are formed. Further, the liquid crystal display device has a counter substrate 5 disposed to face the array substrate 3. Liquid crystal is sealed between the array substrate 3 and the counter substrate 5 to form a liquid crystal layer 7.

  As shown in FIGS. 1 and 2, the array substrate 3 is formed on a transparent insulating substrate 20 such as a glass substrate and extends in the left-right direction in FIG. 1 (only one is shown in FIG. 1). Have). Further, an insulating film 22 made of, for example, SiNx (silicon nitride) is formed on the transparent insulating substrate 20 and the gate bus line 2 and intersects the gate bus line 2 through the insulating film 22 in the vertical direction in FIG. A plurality of drain bus lines 4 (only one is shown in FIG. 1) are formed. A TFT 1 is formed at the intersection of the gate bus line 2 and the drain bus line 4.

  The gate bus line 2 in the formation region of the TFT 1 functions as the gate electrode 2 ′ of the TFT 1. Further, the insulating film 22 on the gate electrode 2 'functions as the gate insulating film 22'. On the gate electrode 2 ′, for example, an operating semiconductor layer 24 made of amorphous silicon and a channel protective film 16 made of SiNx are formed in this order. On both sides of the channel protective film 16 on the operating semiconductor layer 24, the drain electrode 8 has opposing sides that run over the channel protective film 16 and face each other with a predetermined gap, and an impurity semiconductor layer (not shown) is formed in the lower layer. And the source electrode 10 is formed. The drain electrode 8 is connected to the drain bus line 4. A protective film 26 is formed on the drain / source electrodes 8 and 10 and on the channel protective film 16 exposed in the gap between the drain / source electrodes 8 and 10. A contact hole 12 is formed in the protective film 26 on the source electrode 10, and the pixel electrode 6 formed on the protective film 26 is connected to the source electrode 10 through the contact hole 12.

  The source electrode 10 has a slit 18 that extends from an opposite side facing the drain electrode 8 to a region not overlapping the gate electrode 2 ′ when viewed in the normal direction of the surface of the transparent insulating substrate 20. The slit 18 is used to cut a part of the source electrode 10 when a conductive foreign material adheres between the drain / source electrodes 8 and 10 and is short-circuited. Since the slit 18 is formed by removing the source electrode 10 and the operating semiconductor layer 24 (see FIG. 2B), the channel protective film 16 and the insulating film 22 are exposed at the bottom of the slit 18. The source electrode 10 is divided into three electrode regions 10 a, 10 b, and 10 c by the slit 18.

  By the way, unlike the conventional TFTs 100, 100 ′ (see FIG. 8) in which two contact holes 112, 112 ′ are provided, the TFT 1 has only one contact hole 12, so the length of the slit 18 in the direction along the gate electrode 2 ′. The thickness (width) is not restricted when the contact hole 12 is formed. For this reason, the width of the slit 18 is limited only by the process margin of the manufacturing apparatus, and can be made as narrow as possible. For example, the width of the slit 18 can be formed to about 1 to 3 μm.

  The length (cut amount) of the slit 18 perpendicular to the gate electrode 2 ′ affects the amount of current that can flow through the source electrode region 10 c. The longer the slit 18 is cut, the shorter the width of the current flow path in the source electrode region 10c, and the smaller the amount of current flowing therethrough. Therefore, the amount of current that can be passed through the source electrode region 10c can be increased as much as possible, and the cut amount of the slit 18 is extended to a region that does not overlap the gate electrode 2 ′ so that the source electrode 10 can be cut without damaging the gate electrode 2 ′. Formed. By forming the slit 18 with the width and the cut amount as small as possible, the amount of current flowing between the drain electrode 8 and the source electrode 10 of the TFT 1 having the slit 18 (drain-source current) It can be made almost the same as the drain-source current amount of the TFT not having it.

  The end side (side wall 18c) of the slit 18 facing the end side of the gate electrode 2 ′ and the both end sides (side walls 18a, 18b) of the slit 18 from the end side of the gate electrode 2 ′ to the side wall 18c cut the source electrode 10. Used as a starting point. As shown in FIG. 1, the drain-source current is cut by cutting the source electrode 10 along one of the virtual cutting lines 14 a, 14 b, 14 c extending from the side walls 18 a, 18 b, 18 c to the side wall on the outer periphery of the source electrode 10. A part of the current path can be cut off. Cutting the source electrode 10 with the virtual cutting line 14a can cut off the current path of the current flowing through the source electrode region 10a, and cutting the source electrode 10 with the virtual cutting line 14b can cut off the current path of the current flowing through the source electrode region 10b, When the source electrode 10 is cut by the virtual cutting line 14c, the current path of the current flowing through the source electrode region 10c can be cut off. Further, the virtual cutting lines 14a, 14b, and 14c shown in the drawing are merely examples, and the outer periphery of the source electrode 10 is separated from the side walls 18a, 18b, and 18c so as to cut off the current path of the source electrode regions 10a, 10b, and 10c. It only needs to extend to the side wall.

  Next, a defect correcting method for the TFT 1 will be described with reference to FIGS. FIG. 3 shows a defect correction method for the TFT 1. As shown in FIG. 3, when the foreign substance 28 adheres to the source electrode region 10b side and the drain electrode 8 and the source electrode 10 are short-circuited, the drain electrode 8 and the source electrode 10 are not affected by the gate voltage of the gate electrode 2 ′. A current flows during the period. As a result, a predetermined gradation voltage is not applied to and held in the pixel electrode 6, and the pixel becomes a point defect pixel of a bright spot or a dark spot.

Therefore, the cut portion 30 is formed by cutting the source electrode region 10b by irradiating laser light along the virtual cutting line 14b of the source electrode region 10b to which the foreign substance 28 is adhered. Since the slit 18 is formed to extend to a region that does not overlap with the gate electrode 2 ′, the gate electrode 2 ′ is not damaged by the laser beam when the source electrode region 10b is cut. Since the current path of the source electrode region 10b is cut off by the cutting part 30, no current flows through the source electrode region 10b. Thereby, the short-circuit portion between the drain electrode 8 and the source electrode 10 is electrically disconnected from the TFT 1. Further, even if the source electrode region 10c is cut by the virtual cutting line 14c, the current flowing through the source electrode region 10b can be blocked by the source electrode region 10c, so that the short-circuit portion between the drain electrode 8 and the source electrode 10 can be electrically Can be separated.
When a foreign substance adheres to the source electrode region 10a side and the drain electrode 8 and the source electrode 10 are short-circuited, the source electrode region 10a is cut by the virtual cutting line 14a, and the drain electrode 8 and the source electrode 10 are short-circuited. The part is electrically disconnected from TFT1.

  FIG. 4 shows a conceptual diagram of the current path of the drain-source current before and after cutting the source electrode region 10b. FIG. 4A shows a current path before cutting, and FIG. 4B shows a current path after cutting. As shown in FIG. 4A, before the source electrode region 10b is cut, the current supplied from the drain electrode 8 flows into the source electrode regions 10a and 10b facing the drain electrode 8, so that the operating semiconductor layer 24 ( The current path in FIG. 2) is almost rectangular.

  However, as shown in FIG. 4B, no current flows through the source electrode region 10b after the source electrode region 10b is cut. For this reason, since the current supplied from the drain electrode 8 facing the source electrode region 10b flows toward the source electrode region 10a, the current path in the operating semiconductor layer 24 has a trapezoidal shape. Since the width of the slit 18 is narrow, a part of the current supplied from the drain electrode 8 facing the source electrode region 10b can flow into the source electrode region 10a while the TFT 1 is in the on state. Therefore, a decrease in the driving capability of the TFT 1 after the source electrode region 10b is cut is suppressed.

  As described above, according to the present embodiment, even if the foreign matter 28 adheres to a part of the TFT 1 and a short-circuit defect occurs between the drain electrode 8 and the source electrode 10, a part of the source electrode 10 is cut. Thus, the short-circuit defect portion can be electrically separated from the TFT 1.

  In addition, since it is possible to suppress a decrease in the driving capability of the TFT 1 after correcting the short-circuit defect, the size of the TFT 1 can be made smaller than the TFTs 100 and 100 ′ having the conventional redundant structure. Thereby, the occupation ratio of the area of TFT1 with respect to one pixel can be reduced. Further, since the TFT 1 is connected to the pixel electrode 6 by only one contact hole 12, the ratio of the area occupied by the contact hole 12 in the pixel electrode 6 is smaller than that of the conventional pixel. Accordingly, the aperture ratio of the pixel is increased. Thereby, even if the brightness of the backlight is lowered, the display screen can be made sufficiently bright, so that the power consumption is reduced and the performance of the liquid crystal display device is improved.

  Next, a first modification of the present embodiment will be described with reference to FIG. FIG. 5 shows an enlarged view of the vicinity of the TFT 1 of the array substrate 3 of this modification as seen from the image display surface. In the following modified example, the same reference numerals are given to components having the same functions and functions as the components of the TFT 1 of the above-described embodiment shown in FIG. 1, and the description thereof is omitted. In the above embodiment, the slit 18 is formed in the source electrode 10. On the other hand, the present modification is characterized in that a slit 18 is formed in the drain electrode 8.

  As shown in FIG. 5, since the TFT 1 is connected to the pixel electrode 6 by one contact hole 12, the width of the slit 18 is restricted when the contact hole 12 is formed as in the above embodiment. There is no. As a result, the size of the TFT 1 can be made smaller than those of the conventional TFTs 100 and 100 ′ having the redundant structure, and the area occupation ratio of the TFT 1 with respect to one pixel can be reduced. Further, the ratio of the area that the contact hole 12 occupies the pixel electrode 6 is smaller than that of the conventional pixel. Thereby, the aperture ratio of the pixel can be increased.

  The TFT 1 can cut off the drain electrode 8 along any one of the virtual cutting lines 32a, 32b, and 32c, thereby cutting off a part of the current path of the drain-source current. Even if a foreign substance (not shown) adheres and a short-circuit defect occurs between the drain electrode 8 and the source electrode 10, the drain electrode regions 8 a, 8 b, 8 c of any one of the virtual cutting lines 32 a, 32 b, 32 c If any one of them is cut, the short-circuit defect portion can be electrically separated from the TFT 1. In this case, a part of the drain electrode 8 corresponding to the current supply side is cut, and the drain-source current amount after cutting is lower than that before cutting, but it does not reach a bright spot or dark spot, and is practical. It doesn't matter.

  As described above, in this modified example, although the driving capability of the TFT 1 is slightly reduced, the aperture ratio can be increased, so that the performance of the liquid crystal display device can be improved.

  Next, a second modification of the present embodiment will be described with reference to FIG. FIG. 6 shows an enlarged view of the vicinity of the TFT 1 of the array substrate 3 of this modification as seen from the image display surface. In the above embodiment, one slit 18 is formed in the source electrode 10. In contrast, the present modification is characterized in that two slits 18 and 18 ′ are formed in the source electrode 10.

  In order to make the amount of current that can be supplied to the pixel electrode 6 by each of the source electrode regions 10a, 10b, and 10d substantially the same as the amount of current that can be supplied by each of the source electrode regions 10a and 10b of the above-described embodiment, The size of the TFT 1 in the above needs to be about 1.5 times the size of the TFT 1 in the above embodiment. However, since the TFT 1 is connected to the pixel electrode 6 through one contact hole 12, the width of the slits 18, 18 ′ is not restricted when the contact hole 12 is formed. For this reason, the slits 18, 18 'can be made as small as possible. As a result, the ratio of the area occupied by the TFT1 to one pixel can be made smaller than the ratio of the conventional TFTs 100 and 100 'to one pixel. Further, the ratio of the area that the contact hole 12 occupies the pixel electrode 6 is smaller than that of the conventional pixel. Thereby, the aperture ratio of the pixel can be increased.

  When a foreign substance (not shown) adheres to the source electrode region 10d and the drain electrode 8 opposite to the source electrode region 10d and a short-circuit defect occurs between the source electrode 10 and the drain electrode 8, the source electrode region is indicated by the virtual cutting line 14c. If 10d is cut, the short-circuit defect portion can be electrically separated from the TFT1. In this case, since the current can be supplied to the pixel electrode 6 by the source electrode regions 10a and 10b, the driving capability of the TFT 1 is higher than that in the above embodiment. In addition, when a foreign substance adheres to the source electrode region 10c, the source electrode region 10d, and the drain electrode 8 facing these, even if the source electrode regions 10b and 10c are cut by the virtual cutting lines 14b and 14c, the source electrode region 10a Thus, a current can be supplied to the pixel electrode 6.

  As described above, in this modification, although the aperture ratio is slightly reduced, it is possible to suppress the decrease in the driving capability of the TFT 1 after the defect correction, so that the performance of the liquid crystal display device can be improved.

  Next, a third modification of the present embodiment will be described with reference to FIG. FIG. 7 shows an enlarged view of the vicinity of the TFT 1 of the array substrate 3 of this modification as seen from the image display surface. In the above embodiment, the gate bus line 2 in the formation region of the TFT 1 functions as the gate electrode 2 ′ of the TFT 1. On the other hand, the present modification is characterized in that the TFT 1 includes a gate electrode 34 that protrudes from the gate bus line 2.

  As shown in FIG. 7, in this modification, the gate electrode 34 is formed between the drain bus line 4 and the pixel electrode 6, so that the width of the pixel electrode 6 in the horizontal direction in the drawing is shortened. However, the height of the pixel electrode 6 in the vertical direction in the drawing can be increased by the amount that the TFT 1 is not formed on the gate bus line 2. For this reason, the pixel electrode 6 in this modification can be formed in substantially the same area as the above-described embodiment. Since the TFT 1 and the pixel electrode 6 are connected by one contact hole 12, the ratio of the area that the contact hole 12 occupies the pixel electrode 6 can be the same as in the above embodiment. Therefore, the aperture ratio of this modification can be made almost the same as the aperture ratio of the above embodiment.

Further, by forming the slit 18 in the source electrode 10, even if a foreign matter (not shown) adheres to a part of the TFT 1 and a short-circuit defect occurs between the drain electrode 8 and the source electrode 10, A short-circuit defect portion can be electrically disconnected from the TFT 1 by cutting a part. If the TFT1 and the slit 18 are formed to have the same size as the TFT1 and the slit 18 in the above embodiment, even if a part of the source electrode 10 is cut, a decrease in the driving capability of the TFT1 can be suppressed.
Thus, according to this modification, the same effect as the above-described embodiment can be obtained.

The present invention is not limited to the above embodiment, and various modifications can be made.
In the above embodiment, the TFT 1 for driving the pixel electrode 6 has been described as an example, but the present invention is not limited to this. For example, a thin film transistor that is integrally formed on the array substrate 3 and used for a peripheral drive circuit that drives the gate bus line 2 and the drain bus line 4 may have the same configuration as the TFT 1. Also in this case, it is possible to suppress a decrease in driving capability of the thin film transistor after the defect correction.

  In the second modification of the above embodiment, the slits 18 and 18 ′ are formed in the source electrode 10, and in the third modification, the slit 18 is formed in the source electrode 10. Not limited. For example, the slits 18 and 18 ′ may be formed in the drain electrode 8. Also in this case, the aperture ratio can be improved.

  Moreover, in the said embodiment, although the slit 18 is formed in either the source electrode 10 or the drain electrode 8, this invention is not limited to this. For example, the slit 18 may be formed in both the source electrode 10 and the drain electrode 8. Also in this case, the aperture ratio can be improved.

  In the above embodiment, the liquid crystal display device has been described as an example, but the present invention is not limited to this. For example, the present invention can be applied to a thin film transistor used in an organic EL (electroluminescence) display device, a display device substrate including the thin film transistor, and a defect correction method.

The thin film transistor according to the embodiment described above, the display device substrate including the thin film transistor, the liquid crystal display device using the thin film transistor, and the defect correcting method are summarized as follows.
(Appendix 1)
A gate electrode formed on the substrate;
A drain electrode and a source electrode, which are formed on the gate electrode through an insulating film and have opposing sides facing each other with a predetermined gap along the gate electrode;
A thin film transistor, comprising: a slit formed on the drain electrode or the source electrode and extending from at least one of the opposing sides to a region not overlapping with the gate electrode when viewed in a normal direction of the substrate surface.
(Appendix 2)
In the thin film transistor according to appendix 1,
A thin film transistor, wherein the insulating film is exposed at a bottom portion of the slit when viewed in a normal direction of the substrate surface.
(Appendix 3)
In the thin film transistor according to appendix 1 or 2,
A thin film transistor, wherein a plurality of the slits are formed.
(Appendix 4)
A gate bus line,
A drain bus line formed to intersect the gate bus line through an insulating film;
A display device substrate comprising: the thin film transistor according to any one of appendices 1 to 3 formed at an intersection of the gate bus line and the drain bus line.
(Appendix 5)
In the display device substrate according to attachment 4,
The display device substrate, wherein the gate electrode of the thin film transistor is connected to the gate bus line, the drain electrode is connected to the drain bus line, and the source electrode is connected to a pixel electrode.
(Appendix 6)
In a liquid crystal display device having a pair of substrates disposed opposite to each other and a liquid crystal layer sealed between the substrates,
One of said pair of board | substrates is a display apparatus substrate as described in appendix 4 or 5, The liquid crystal display device characterized by the above-mentioned.
(Appendix 7)
In a defect correction method for a thin film transistor having a gate electrode, a drain electrode and a source electrode,
When a foreign substance adheres between the drain electrode and the source electrode and a short-circuit defect occurs, the outer periphery of the source electrode or the drain electrode is formed from a side wall of a slit provided in at least one of the drain electrode or the source electrode. Cutting a part of the source electrode or the drain electrode to the side wall;
The defect correcting method, wherein the short-circuit defect portion is electrically separated from the thin film transistor.

It is the enlarged view which looked at TFT1 vicinity of the array board | substrate 3 of the liquid crystal display device by one embodiment of this invention from the image display surface. It is a figure which shows the end surface shape which cut | disconnected TFT1 vicinity of the liquid crystal display device by one embodiment of this invention. It is a figure which shows the defect correction method of TFT1 of the liquid crystal display device by one embodiment of this invention. It is a conceptual diagram of the current path of the drain-source current before and after cutting of the source electrode region 10b of the liquid crystal display device according to the embodiment of the present invention. It is the enlarged view which looked at TFT1 vicinity of the array substrate 3 of the 1st modification of the liquid crystal display device by one embodiment of this invention from the image display surface. It is the enlarged view which looked at TFT1 vicinity of the array substrate 3 of the 2nd modification of the liquid crystal display device by one embodiment of this invention from the image display surface. It is the enlarged view which looked at TFT1 vicinity of the array substrate 3 of the 3rd modification of the liquid crystal display device by one embodiment of this invention from the image display surface. It is a pixel having a conventional redundant structure, and is an enlarged view in the vicinity of TFTs 100 and 100 ′ formed in the pixel. It is a figure which shows the defect correction method of conventional TFT100,100 '.

Explanation of symbols

1, 100, 100 'TFT
2, 102 Gate bus line 2 ', 34 Gate electrode 3 Array substrate 4, 104 Drain bus line 5 Counter substrate 6, 106 Pixel electrode 7 Liquid crystal layer 8, 108, 108' Drain electrode 8a, 8b, 8c Drain electrode region 10, 110, 110 'Source electrodes 10a, 10b, 10c, 10d, 10e Source electrode regions 12, 112, 112' Contact holes 14a, 14b, 14c, 32a, 32b, 32c, 114, 114 'Virtual cutting lines 16, 116 Channel protection Film 18 Slit 18a, 18b, 18c Side wall 20, 103 Transparent insulating substrate 22 Insulating film 22 'Gate insulating film 24 Operating semiconductor layer 26 Protective film 28, 118 Foreign matter 30, 120 Cutting part

Claims (5)

A gate electrode formed on the substrate;
An operating semiconductor layer formed on the gate electrode through an insulating film;
A drain electrode and a source electrode formed on the operating semiconductor layer and having opposing sides facing each other with a predetermined gap along the gate electrode;
Formed on the drain electrode or the source electrode, and used to cut a part of the drain electrode or a part of the source electrode when the drain electrode and the source electrode are short-circuited; And a slit extending from at least one of the opposing sides to a region not overlapping with the gate electrode when viewed in a line direction. The thin film transistor according to claim 1, wherein
A thin film transistor, wherein the insulating film is exposed at a bottom portion of the slit when viewed in a normal direction of the substrate surface. A gate bus line,
A drain bus line formed to intersect the gate bus line through an insulating film;
A display device substrate comprising: the thin film transistor according to claim 1, wherein the thin film transistor is formed at an intersection of the gate bus line and the drain bus line. In a liquid crystal display device having a pair of substrates disposed opposite to each other and a liquid crystal layer sealed between the substrates,
4. A liquid crystal display device, wherein one of the pair of substrates is a display device substrate according to claim 3. In the thin film transistor defect correction method according to claim 1 or 2 ,
When a foreign substance adheres between the drain electrode and the source electrode and a short-circuit defect occurs, the outer periphery of the source electrode or the drain electrode is formed from a side wall of a slit provided in at least one of the drain electrode or the source electrode. Cutting part of the source electrode or part of the drain electrode to the side wall;
The defect correcting method, wherein the short-circuit defect portion is electrically separated from the thin film transistor.

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