JP2010243939A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the aperture ratio of a pixel while suppressing deterioration of image quality of a transmissive liquid crystal display device.
A liquid crystal layer is provided between a first substrate and a second substrate, and the first substrate includes a plurality of scanning signal lines, a plurality of video signal lines, a plurality of TFT elements, A liquid crystal display device having a plurality of pixel electrodes, wherein the TFT element includes a semiconductor layer disposed on the scanning signal line via a first insulating layer, and the video signal line and the semiconductor layer. A drain electrode connected to the pixel electrode and a source electrode connected to the semiconductor layer, wherein the pixel electrode is connected to the source electrode via a contact hole formed in a second insulating layer; The scanning signal line has an opening outside a region intersecting with the video signal line and a region overlapping with the semiconductor layer, and the land of the source electrode The contact hole A liquid crystal display device above the opening of the inspection signal line.
[Selection] Figure 7 (a)

Description

  The present invention relates to a liquid crystal display device and a method for manufacturing the same, and more particularly to a technique effective when applied to a transmissive TFT liquid crystal display device and a method for manufacturing the same.

  Conventionally, liquid crystal display devices include active matrix TFT liquid crystal display devices in which TFT elements, pixel electrodes, common electrodes, and pixels having a liquid crystal layer are arranged in a matrix. Active matrix TFT liquid crystal display devices are widely used in, for example, liquid crystal televisions, liquid crystal displays for personal computers, and liquid crystal displays for mobile phone terminals.

  An active matrix TFT liquid crystal display device has a liquid crystal display panel in which a liquid crystal material is sealed between a pair of substrates. At this time, for example, one of the pair of substrates has a matrix of TFT elements and pixel electrodes connected to the source electrodes of the TFT elements on the surface of a first insulating substrate such as a glass substrate. Has been placed. The substrate on which the TFT elements and the pixel electrodes are arranged in a matrix is generally called a TFT substrate or an active matrix substrate.

  The TFT substrate is provided with a plurality of scanning signal lines and a plurality of video signal lines on the surface of the insulating substrate. At this time, each of the TFT elements arranged in a matrix has a gate connected to one scanning signal line of the plurality of scanning signal lines and a drain connected to one of the plurality of video signal lines. Connected to the video signal line. At this time, in the TFT element, the combination of the scanning signal line to which the gate is connected and the video signal line to which the drain is connected differs for each pixel.

  The other of the pair of substrates is provided with a black matrix, a color filter, a spacer, and the like on the surface of a second insulating substrate such as a glass substrate. The substrate on which the color filter and the like are arranged is generally called a counter substrate.

  In addition, the common electrode may be disposed on the counter substrate side or may be disposed on the TFT substrate side.

  The TFT substrate of the liquid crystal display panel is formed by laminating a plurality of insulating films including an insulating film having a plurality of conductor patterns, a plurality of semiconductor patterns, and an opening pattern on the surface of the first insulating substrate, The video signal line, the TFT element, the pixel electrode, and the like are provided. At this time, the conductor pattern, the semiconductor pattern, and the opening pattern are usually formed by etching using a resist obtained by exposing and developing the photosensitive material film as a mask.

  Conventionally, exposure of a photosensitive material film in a manufacturing method of a TFT substrate is generally performed by an exposure apparatus having a photomask (reticle).

  When the photosensitive material film is exposed by an exposure apparatus having a photomask, for example, light that has passed through the photomask is imaged on the surface of the photosensitive material film by a plurality of lenses. At this time, the pattern of light that forms an image on the surface of the photosensitive material film, for example, is a distortion or distortion caused by the twist or deflection of the photomask or the aberration of the lens. Therefore, the resist obtained by developing the exposed photosensitive material film and the pattern obtained by etching using the resist as a mask have a shape reflecting distortion. Therefore, in the conductor pattern or semiconductor pattern or opening pattern obtained after etching, for example, a shift may occur between the position of the pattern on the first insulating substrate and the position of the pattern in the layout data. .

  In the conventional TFT substrate manufacturing method, for example, the first insulating substrate is distorted by heating or stress in each manufacturing process, and the position of the pattern formed on the first insulating substrate is affected by the distortion. And a pattern position in layout data may occur.

  As described above, when the position of the pattern formed on the first insulating substrate is shifted, for example, the characteristics of the TFT elements in the respective pixels vary, and the image quality of the liquid crystal display device is deteriorated. is there.

  As a method for solving such a problem, for example, the configuration of the exposure apparatus can be improved so that the degree of distortion of the light pattern formed on the surface of the photosensitive material film is reduced, or the exposure can be adjusted according to the distortion. Have been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

JP 2002-222752 A Japanese Patent Laid-Open No. 07-211627 JP 09-082607 A

  By the way, in the conventional manufacturing method of a TFT substrate, usually, after forming a source electrode of a TFT element, a pixel electrode to be connected to the source electrode is formed. At this time, between the step of forming the source electrode and the step of forming the pixel electrode, usually, a step of forming an insulating layer covering the source electrode, and connecting the source electrode and the pixel electrode to the insulating layer Forming a contact hole for the purpose. At this time, for example, the area of the source electrode overlapping with the scanning signal line is made as small as possible in order to reduce the parasitic capacitance formed between the source electrode and the scanning signal line. Therefore, a contact hole for connecting the source electrode and the pixel electrode is usually formed at a position that does not overlap the scanning signal line.

  However, the source electrode is usually formed by etching a highly light-shielding metal film such as an aluminum (Al) film. Therefore, in the case of a transmissive liquid crystal display device having a backlight unit, if a contact hole for connecting the source electrode and the pixel electrode is formed at a position that does not overlap with the scanning signal line, the amount from the backlight unit is increased accordingly. The area (opening area) through which light is transmitted decreases.

  Further, when the photosensitive material film is exposed with an exposure apparatus having a photomask, the degree of distortion differs depending on the exposure apparatus used. For this reason, the position of the contact hole for connecting the source electrode and the pixel electrode differs in the direction and amount of shift depending on the exposure apparatus used when forming the contact hole.

  In addition, the degree of distortion of the latent image pattern in one exposure apparatus is not always constant, and may change due to, for example, aging deterioration or variations in adjustment after maintenance.

  Therefore, in the conventional TFT substrate manufacturing method, for example, even if the contact hole formation position is shifted, the connection with the pixel electrode of the source electrode is ensured so that a sufficient connection area between the source electrode and the pixel electrode can be secured. The size of the region (land) for this purpose is sufficiently larger than the size of the contact hole. Therefore, in a liquid crystal display device having a TFT substrate manufactured by a conventional manufacturing method, there is a problem that it is difficult to increase the aperture ratio of each pixel, that is, the ratio of the opening region to the region occupied by one pixel.

  The methods described in Patent Document 1, Patent Document 2, and Patent Document 3 can be expected to reduce the size of the source electrode land and increase the pixel aperture ratio.

  However, even with the methods described in Patent Document 1, Patent Document 2, and Patent Document 3, contact holes are caused by problems such as differences in the degree of distortion for each exposure apparatus, deterioration with time of the exposure apparatus, and adjustment limits. Therefore, it has become difficult to further increase the accuracy of alignment of the formation position of the source electrode and the land of the source electrode.

  An object of the present invention is to provide a technique capable of improving the aperture ratio of a pixel while suppressing deterioration in image quality of a transmissive liquid crystal display device, for example.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The outline of typical inventions among the inventions disclosed in the present application will be described as follows.

  (1) A first substrate, a second substrate, and a liquid crystal layer disposed between the first substrate and the second substrate, wherein the first substrate has a plurality of scans. A liquid crystal display device having a signal line, a plurality of video signal lines, a plurality of TFT elements, and a plurality of pixel electrodes, wherein the plurality of TFT elements are arranged in a matrix on the first substrate. The TFT element includes a semiconductor layer disposed on the scanning signal line via a first insulating layer, a drain electrode connected to the video signal line and the semiconductor layer, and the pixel electrode. And a source electrode connected to the semiconductor layer, and the pixel electrode is connected to a land provided at one end of the source electrode through a contact hole formed in a second insulating layer. The scanning signal line has a region intersecting with the video signal line and Wherein an opening to the outside in the region which overlaps with the semiconductor layer, wherein the land and the contact hole of the source electrode, the liquid crystal display device located on the opening of the scanning signal lines.

  (2) In the liquid crystal display device of (1), the distance from the contact hole near the center of the first substrate to the video signal line, and the contact hole near the outer periphery of the first substrate A liquid crystal display device with a different distance to the video signal line.

  (3) In the liquid crystal display device according to (1), a distance from the contact hole near the center of the first substrate to a longitudinal side of the scanning signal line, and the contact near the outer periphery of the first substrate. A liquid crystal display device having a different distance from a hole to a side in a longitudinal direction of the scanning signal line.

  (4) In the liquid crystal display device of (1), one scanning signal line has a plurality of openings, and the contact hole on each opening extends to the video signal line. And a combination of the distance to the side in the longitudinal direction of the scanning signal line is different.

  (5) In the liquid crystal display device according to (1), the standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the contact hole and the land in the first substrate is the first deviation. A liquid crystal display device having a standard deviation smaller than the standard deviation of the distance distribution from the contact hole to the video signal line in the substrate.

  (6) In the liquid crystal display device according to (1), the standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the opening and the land in the first substrate is the first deviation. A liquid crystal display device having a smaller standard deviation of the distribution of the distance between the contact hole and the video signal line in the first substrate.

  (7) In the liquid crystal display device according to (1), the standard deviation of the distribution of the positional deviation in the extending direction of the video signal line between the contact hole and the land in the first substrate is the first deviation. A liquid crystal display device having a standard deviation smaller than the standard deviation of the distance distribution from the contact hole to the longitudinal side of the scanning signal line in the substrate.

  (8) In the liquid crystal display device according to (1), the standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the opening and the land in the first substrate is the first deviation. A liquid crystal display device having a standard deviation smaller than the standard deviation of the distance distribution from the contact hole in the first substrate to the side in the longitudinal direction of the scanning signal line.

  (9) Forming a plurality of scanning signal lines on an insulating substrate, forming a gate insulating film and a plurality of semiconductor layers on the scanning signal lines, and forming a source electrode connected to the semiconductor layer A step of forming an insulating layer on the source electrode, a step of forming a contact hole in a portion of the insulating layer above the land of the source electrode, and on the insulating layer Forming a pixel electrode connected to the land of the source electrode through the contact hole, and the step of forming the plurality of scanning signal lines includes a step of forming a scanning signal line having a plurality of openings. The step of forming and forming the source electrode is a method for manufacturing a liquid crystal display device in which the land of the source electrode is formed on the opening of the scanning signal line, and a layout prepared in advance After forming the contact hole based on the data, the displacement between the position of the contact hole formed in the insulating layer and the position of formation of the contact hole in the layout data is measured, and the position of the contact hole is measured. A method of manufacturing a liquid crystal display device, comprising: correcting the formation position of the opening of the scanning signal line and the formation position of the land of the source electrode in the layout data based on the direction and amount of deviation. .

  (10) In the method of manufacturing a liquid crystal display device according to (9), the correcting step may include correcting the periphery of the contact hole in the pixel electrode based on the direction and amount of displacement of the position of the contact hole. A method for manufacturing a liquid crystal display device, which corrects the formation position of a portion, or the formation position and dimensions.

  (11) In the method for manufacturing a liquid crystal display device according to (9), the step of forming the plurality of scanning signal lines, the step of forming the plurality of source electrodes, and the step of forming the contact hole are respectively photosensitive. A step of exposing the photosensitive material film, and the step of exposing the photosensitive material film in the step of forming the contact hole is performed on the photosensitive material film using a photomask created based on the layout data. Exposing the photosensitive material film with an exposure device that generates a pattern of light to be irradiated, exposing the photosensitive material film in the step of forming the plurality of scanning signal lines, and forming the plurality of source electrodes In the step of exposing the photosensitive material film in the process, the photosensitive material film is irradiated by numerical control based on the layout data, respectively. After exposing the photosensitive material film with an exposure device that generates a light pattern and correcting the layout data in the correcting step, the photosensitive material film is exposed based on the corrected layout data. A method for manufacturing a liquid crystal display device.

  (12) In the method of manufacturing a liquid crystal display device according to (9), in the step of forming the source electrode, a plurality of video signal lines and a drain electrode connected to the semiconductor layer are formed together with the source electrode, and the correction is performed. The method of manufacturing a liquid crystal display device in which the formation position of the video signal line is not changed when the formation position of the land of the source electrode is corrected in the step of performing.

  (13) In the method of manufacturing a liquid crystal display device according to (9), when measuring a deviation between the position of the contact hole formed in the insulating layer and the position of formation of the contact hole in the layout data, the insulation is performed. A method for manufacturing a liquid crystal display device, in which a substrate is divided into a plurality of regions, a shift in a contact hole representing each region is measured, and a shift in a contact hole that is not measured is estimated by statistical processing based on the measurement result.

  According to the liquid crystal display device and the manufacturing method thereof of the present invention, for example, it is possible to improve the aperture ratio of the pixel while suppressing deterioration of the image quality of the transmissive liquid crystal display device.

It is a schematic block diagram which shows an example of schematic structure of the liquid crystal display device concerning this invention. It is a schematic circuit diagram which shows an example of the circuit structure of one pixel in a liquid crystal display panel. It is a schematic plan view which shows an example of the plane structure of a liquid crystal display panel. It is a schematic cross section which shows an example of the cross-sectional structure in the A-A 'line of FIG.1 (c). It is a schematic top view which shows an example of the plane structure of one pixel in the 1st board | substrate of the conventional liquid crystal display panel. FIG. 3 is a schematic cross-sectional view illustrating an example of a cross-sectional configuration of a first substrate taken along line B-B ′ in FIG. It is a schematic plan view for demonstrating the distortion produced in the process of exposing the photosensitive material film | membrane among the manufacturing methods of the conventional TFT substrate. FIG. 4 is a schematic plan view illustrating an example of a displacement of a contact hole in the pixel PT1 illustrated in FIG. FIG. 4 is a schematic plan view illustrating an example of a position shift of a contact hole in the pixel PT2 illustrated in FIG. It is a schematic top view which shows an example of the method of changing the position of the land of a source electrode and making the aperture ratio of a pixel high. FIG. 6 is a schematic cross-sectional view showing an example of a cross-sectional configuration of the first substrate taken along line C-C ′ in FIG. It is a schematic diagram which shows the principle of the manufacturing method of the liquid crystal display device of one Example by this invention. It is a schematic diagram for demonstrating one of the effects in the manufacturing method of the liquid crystal display device of a present Example. It is a schematic top view which shows an example of the planar structure of the periphery of the TFT element in the TFT substrate of the liquid crystal display device to which the principle of a present Example is applied. FIG. 8 is a schematic cross-sectional view illustrating an example of a cross-sectional configuration of a TFT substrate taken along line D-D ′ in FIG. It is a schematic diagram which shows an example of a structure of the layout data of a source electrode. It is a schematic plan view which shows an example of the shift | offset | difference of the formation position of a contact hole. It is a schematic plan view which shows an example of the correction method of the layout data regarding a source electrode. FIG. 6 is a schematic plan view illustrating an example of a method for correcting layout data related to openings of scanning signal lines. It is a schematic plan view which shows an example of the correction method of the layout data regarding a pixel electrode. FIG. 10B is a schematic plan view illustrating an example of a planar configuration of the source electrode at the position where the correction illustrated in FIGS. 9B to 9D is performed and the periphery thereof. It is a schematic cross section which shows an example of the cross-sectional structure of the TFT substrate in the E-E 'line of Fig.10 (a). It is a schematic top view which shows an example of the position shift which arises in the TFT substrate manufactured with the manufacturing method of the liquid crystal display device of a present Example. It is a schematic plan view which shows an example of the definition of the formation position of a contact hole. It is a schematic graph which shows an example of the relationship between the deviation | shift degree of the formation position of the contact hole by distortion, and the deviation | shift degree of the opening part of a scanning signal line.

Hereinafter, the present invention will be described in detail together with embodiments (examples) with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same function are given the same reference numerals and their repeated explanation is omitted.

FIG. 1A to FIG. 1D are schematic views for explaining an example of a schematic configuration of a liquid crystal display device according to the present invention.
FIG. 1A is a schematic block diagram showing an example of a schematic configuration of a liquid crystal display device according to the present invention. FIG. 1B is a schematic circuit diagram illustrating an example of a circuit configuration of one pixel in the liquid crystal display panel. FIG. 1C is a schematic plan view illustrating an example of a planar configuration of the liquid crystal display panel. FIG.1 (d) is a schematic cross section which shows an example of the cross-sectional structure in the AA 'line of FIG.1 (c).

  The present invention is desired to be applied to a high-definition active matrix TFT liquid crystal display device such as a liquid crystal television or a medical liquid crystal display. A liquid crystal display device to which the present invention is desired is, for example, as shown in FIG. 1A, a liquid crystal display panel 1, a first drive circuit 2, a second drive circuit 3, a light source 4 of a backlight unit, And a control circuit 5. In addition, such a liquid crystal display device includes, for example, a prism sheet and a light diffusion sheet (not shown).

The liquid crystal display panel 1 is an active matrix type, and has a plurality of scanning signal lines 6 and a plurality of video signal lines 7. At this time, the display area DA of the liquid crystal display panel 1 is composed of a plurality of pixels arranged in a matrix. At this time, one pixel has a TFT element 8 (active element), a pixel electrode 9, a liquid crystal capacitor C _LC , and a holding capacitor C _STG as shown in FIG. 1B, for example.

  The TFT element 8 is a transistor having a gate electrode, a gate insulating film, a semiconductor layer, a source electrode, and a drain electrode. The gate electrode of the TFT element 8 is connected to one scanning signal line 6 and is usually formed integrally with the scanning signal line 6. The drain electrode of the TFT element 8 is connected to one video signal line 7 and is usually formed integrally with the video signal line 7. The source electrode of the TFT element 8 is connected to the pixel electrode 9 and is usually connected through a contact hole formed in the insulating layer. Note that the drain electrode and the source electrode of the TFT element 8 vary depending on the level relationship between the potential of the video signal line 7 and the potential of the pixel electrode 10 when the TFT element 8 is turned on. The TFT elements 8 arranged in a matrix in the display area DA have a combination of the scanning signal line 6 to which the gate electrode is connected and the video signal line 7 to which the drain electrode is connected for each pixel. Different.

The liquid crystal capacitor C _LC is a capacitor formed by the pixel electrode 9, a common electrode (not shown), and a liquid crystal layer (not shown), and may be called a pixel capacitor. The storage capacitor _CSTG is, for example, a capacitor formed by the pixel electrode 9, the storage capacitor line 10, and an insulating layer (not shown), and may be referred to as an auxiliary capacitor, a storage capacitor, or the like. Some recent liquid crystal display devices (liquid crystal display panel 1) do not have a storage capacitor _CSTG .

Each pixel has, for example, a parasitic capacitance C _GS formed between the source electrode of the TFT element 8 and the scanning signal line 6 in addition to the liquid crystal capacitance C _LC and the holding capacitance C _STG .

  The liquid crystal display panel 1 includes a first substrate 11 and a second substrate 12 as shown in FIGS. 1C and 1D, for example. A liquid crystal layer LC is disposed between the substrate 12 and the substrate 12. At this time, the first substrate 11 and the second substrate 12 are bonded to each other with an annular sealing material 13 surrounding the display area DA, and the liquid crystal layer LC includes the first substrate 11, the second substrate 12, And is sealed in a space surrounded by the sealing material 13. In addition, the liquid crystal display panel 1 includes a first polarizing plate 14 and a second polarizing plate 15 that are disposed with the first substrate 11, the liquid crystal layer LC, and the second substrate 12 interposed therebetween. At this time, one or more retardation plates are arranged between the first substrate 11 and the first polarizing plate 14 and between the second substrate 12 and the second polarizing plate 15, respectively. It is sometimes done.

  The first substrate 11 has a scanning signal line 6, a video signal line 7, a TFT element 8, a pixel electrode 9, a first alignment film, and the like, and is generally called a TFT substrate, an active matrix substrate, or the like. . In the following description, the first substrate 11 is referred to as the TFT substrate 11.

  The second substrate 12 includes a lattice-shaped light shielding film called a black matrix, a color filter, a second alignment film, and the like, and is generally called a counter substrate, a color filter substrate, and the like. In the following description, the second substrate 12 is referred to as the counter substrate 12.

  Further, the common electrode may be provided on the TFT substrate 11 or may be provided on the counter substrate 12. Specific examples of the configuration of the TFT substrate 11 and the counter substrate 12 will be described later.

  In the liquid crystal layer LC, the alignment (alignment) of liquid crystal molecules when the potential difference between the pixel electrode 9 and the common electrode is 0 is determined by, for example, the alignment directions (rubbing directions) of the first alignment film and the second alignment film. It has been. The orientation of the liquid crystal molecules changes depending on the potential difference between the pixel electrode 9 and the common electrode.

  The 1st polarizing plate 14 and the 2nd polarizing plate 15 are arrange | positioned so that the polarization transmission axis in each polarizing plate may orthogonally cross, for example.

  The first drive circuit 2 is a circuit that generates a video signal (gradation voltage) to be applied to the pixel electrode 9 of each pixel via the video signal line 7 and the TFT element 8, and generally includes a data driver, a source driver, and the like. is called.

  The second driving circuit 3 is a circuit that generates a scanning signal for selecting a pixel for writing a video signal applied to the video signal line 7 to the pixel electrode 9, and is generally called a scanning driver, a gate driver, or the like. ing.

  The light source 4 is a light emitting element that emits light to irradiate the liquid crystal display panel 1, and for example, a cold cathode fluorescent tube (CCFL) or a light emitting diode (LED) is used. The light emitted from the light source 4 is converted into a planar light beam using an optical sheet such as a prism sheet or a light diffusion sheet. Moreover, when converting the light emitted from the light source 4 into a planar light beam, a light guide plate may be used in addition to the optical sheet. At this time, the planar light beam is normally incident on the liquid crystal display panel 1 from the first polarizing plate 14 side.

  The control circuit 5 is a circuit that controls the operation of the first drive circuit 2 and the second drive circuit 3, the brightness of light emitted from the light source 4, and the like, and generally includes a T-CON, a TFT controller, and the like. being called.

  The liquid crystal display device having the structure as shown in FIG. 1A controls the amount of light transmitted (brightness) in each pixel when the liquid crystal display panel 1 is irradiated with a planar light beam. And visualize the image. The amount of light transmitted through each pixel varies depending on the relationship between the polarization state of light that has passed through the first polarizing plate 14 and the liquid crystal layer LC and the polarization transmission axis of the second polarizing plate 15. The polarization state of the light transmitted through the liquid crystal layer LC is determined by the alignment of the liquid crystal molecules and the thickness of the liquid crystal layer LC. As described above, the orientation of liquid crystal molecules is determined by the magnitude of the potential difference between the pixel electrode 9 and the common electrode. The common electrode is fixed at a predetermined potential. Accordingly, the brightness of the pixel is controlled by the potential of the gradation voltage applied (written) to the pixel electrode 9.

  In addition, a liquid crystal display device (liquid crystal display panel 1) such as a liquid crystal television is compatible with RGB color display, for example. At this time, the color of one dot of the video or image is, for example, the brightness of three pixels: a first pixel having a red filter, a second pixel having a green filter, and a third pixel having a blue filter. Expressed in combination.

  In addition, a liquid crystal display device in which the polarization transmission axis of the first polarizing plate 14 and the polarization transmission axis of the second polarizing plate 15 are orthogonal to each other is usually when the potential difference between the pixel electrode 9 and the common electrode is zero. The alignment of the liquid crystal molecules is controlled so that the so-called normally black display (sometimes referred to as normally closed display) becomes the darkest.

  The driving method (display method) of the liquid crystal display device according to the present invention may be any of the conventionally known driving methods of liquid crystal display devices. Therefore, in this specification, detailed description regarding the driving method of the liquid crystal display device is omitted.

2A and 2B are schematic diagrams for explaining an example of a schematic configuration of one pixel in a conventional liquid crystal display panel.
FIG. 2A is a schematic plan view illustrating an example of a planar configuration of one pixel on a first substrate of a conventional liquid crystal display panel. FIG. 2B is a schematic cross-sectional view illustrating an example of a cross-sectional configuration of the first substrate taken along line BB ′ in FIG.

  In the liquid crystal display device according to the present invention, the common electrode may be disposed on the TFT substrate 11 or may be disposed on the counter substrate 12. When the liquid crystal display device is a vertical electric field drive method such as a VA method or a TN method, the common electrode is disposed on the counter substrate 12. At this time, the common electrode is usually one large-area electrode shared by all pixels.

  A TFT substrate 11 in a conventional vertical electric field drive type liquid crystal display device (liquid crystal display panel 1) has, for example, a structure as shown in FIGS. A scanning signal line 6, a storage capacitor line 10, a first insulating layer 17, a semiconductor layer 18 of a TFT element 8, and a video signal line 7 (TFT element) are formed on one insulating substrate 16 (surface facing the liquid crystal layer LC). 8), the source electrode 19 of the TFT element 8, the second insulating layer 20, the pixel electrode 9, and the first alignment film 21 are formed.

  At this time, the pixel electrode 9 is connected to the land 19 </ b> L of the source electrode 19 through the contact hole 20 </ b> H formed in the second insulating layer 20. At this time, a part of the pixel electrode 9 overlaps the storage capacitor line 10 via the first insulating layer 17 and the second insulating layer 20.

  Note that the conventional liquid crystal display panel 1 does not include the storage capacitor line 10, and a scanning signal line in which a part of the pixel electrode 9 is not connected to the gate electrode of the TFT element 8 connected to the pixel electrode 9. 6 may be superimposed.

Further, in the conventional liquid crystal display panel 1, in order to reduce the parasitic capacitance C _GS formed between the source electrode 19 and the scanning signal line 6, for connecting to the pixel electrode 9 of the source electrode 19. The portion (land 19L) is drawn out to a position that does not overlap the scanning signal line 6. Therefore, the contact hole 20H of the second insulating layer 20 is formed at a position that does not overlap the scanning signal line 6.

  Although the description using the drawings is omitted, the counter substrate 12 is formed on a second insulating substrate such as a glass substrate (a surface facing the liquid crystal layer LC), for example, a black matrix, a color filter, an overcoat layer. A columnar spacer, a common electrode, and a second alignment film are formed.

  The black matrix is, for example, a grid-like light shielding film that extends to a position overlapping the scanning signal line 6 and the video signal line 7 of the TFT substrate 11.

  The color filter includes, for example, three types of filters, a red filter, a green filter, and a blue filter, and any one of the three types of filters is arranged in one pixel. At this time, the arrangement of the color filters with respect to the pixels arranged in the x direction is, for example, the first pixel having the red filter, the second pixel having the green filter, and the third pixel having the blue filter in this order. Try to line up. At this time, the arrangement of the color filters for the pixels arranged in the y direction is such that, for example, pixels having filters of the same color are arranged.

3, 4 (a), and 4 (b) are schematic diagrams for explaining one of the problems in the conventional method for manufacturing the TFT substrate 11.
FIG. 3 is a schematic plan view for explaining distortion generated in a process of exposing a photosensitive material film in a conventional TFT substrate manufacturing method.
FIG. 4A is a schematic plan view illustrating an example of the positional deviation of the contact hole in the pixel PT1 illustrated in FIG. FIG. 4B is a schematic plan view showing an example of the positional deviation of the contact hole in the pixel PT2 shown in FIG.

  When the liquid crystal display panel 1 is manufactured, the liquid crystal display panel 1 is generally manufactured by a so-called multi-planar method in which a plurality of liquid crystal display panels 1 are manufactured at once using a set of large area insulating substrates (mother glass). When manufacturing the liquid crystal display panel 1 used for a large-screen liquid crystal display device such as a liquid crystal television, for example, four liquid crystal display panels 1 are manufactured at once using a set of large-area mother glass. At this time, for example, as shown in FIG. 3, the TFT substrate 11 is formed in each of the four regions 2201, 2202, 2203, and 2204 of one large-area mother glass 22. Although not shown, the counter substrate 12 is formed in each of the four regions of the other mother glass. Then, after these two mother glasses are bonded together to enclose the liquid crystal layer LC, four regions are cut out to obtain four liquid crystal display panels 1.

  In the case of so-called four-chamfering, in which four liquid crystal display panels 1 are manufactured collectively using one set of mother glass, when one entire photosensitive material film is exposed, conventionally, for example, one region and its region This is performed in four steps using an exposure apparatus having a photomask in which an exposure pattern for the periphery is formed.

  At this time, the light passing through the photomask is imaged on the surface of the photosensitive material film by, for example, a plurality of lenses. However, the pattern of light imaged on the surface of the photosensitive material film may be, for example, distortion or distortion of the photomask or distortion due to lens aberration. Therefore, when the photosensitive material film is exposed using a photomask, for example, as shown in FIG. 3, the exposure target areas specified by the layout data (that is, areas 2201, 2202, 2203, 2204) Deviations occur between the exposed areas EA1, EA2, EA3, and EA4.

  In exposure using a photomask, when the exposure target area and the actual exposure area match, a latent image (pattern of the exposed portion) reflecting the layout data is formed in the exposure target area. . Therefore, when distortion occurs in the light pattern imaged on the surface of the photosensitive material film, the latent image of the photosensitive material film is distorted.

When distortion as shown in FIG. 3 occurs in the exposure of the photosensitive material film performed in the step of forming the contact hole 20H in the second insulating layer 20, in the pixel PT1 in the region 2201, for example, FIG. as shown in), the formation position of the contact hole 20H ₁ (center position) Δx1 the -x direction, shifted by Δy1 in the -y direction. At this time, in the pixel region 2201 PT2, for example, as shown in FIG. 4 (b), the formation position of the contact hole 20H ₂ (center position) Δx2 in the x-direction, displaced by Δy2 in the -y direction. Incidentally, in FIG. 4 (a) and 4 (b), dotted circle 20H ₀ indicates the formation position of the contact hole 20H that is specified by the layout data.

  As described above, when distortion occurs in the exposure of the photosensitive material film performed in the step of forming the contact hole 20H in the second insulating layer 20, the direction and shift amount of the formation position of the contact hole 20H formed in the region 2201 are shifted. The size of is different for each pixel.

  In addition, when distortion occurs in the exposure of the photosensitive material film performed in the step of forming the contact hole 20H in the second insulating layer 20, the degree of distortion with respect to the region 2201, that is, the direction in which the contact hole 20H is formed or the amount of displacement is shifted. The size of is usually different for each exposure apparatus used.

  Therefore, in the conventional method of manufacturing the TFT substrate 11, for example, as shown in FIGS. 4A and 4B, the dimension R1 of the land 19L of the source electrode 19 is set in the direction of the position of the contact hole 20H. Even if it is shifted to, a large value is set so that a sufficient connection area between the source electrode 19 and the pixel electrode 9 can be secured. Therefore, as in the conventional TFT substrate 11, when the land 19L of the source electrode 19 is drawn out to a position where it does not overlap the scanning signal line 6, the area from which the light from the backlight unit is transmitted (opening area). Decreases, and the aperture ratio of the pixel decreases.

FIG. 5A and FIG. 5B are schematic diagrams for explaining an example of a method for increasing the aperture ratio of a pixel.
FIG. 5A is a schematic plan view showing an example of a method for increasing the aperture ratio of the pixel by changing the land position of the source electrode. FIG. 5B is a schematic cross-sectional view illustrating an example of a cross-sectional configuration of the first substrate taken along the line CC ′ of FIG.

In order to increase the aperture ratio of the pixel, for example, the land 19L of the source electrode 19 may be moved onto the scanning signal line 6. However, simply changing the position of the land 19L of the source electrode 19 increases the area of the source electrode 19 in the region overlapping the scanning signal line 6 and increases the parasitic capacitance _CGS . Increases the feedthrough voltage. Therefore, in order to increase the aperture ratio of the pixel, for example, as shown in FIG. 5A and FIG. 5B, an area of the scanning signal line 6 that does not overlap with the semiconductor layer 18 or the video signal line 7. It is desirable that the opening 6H is formed in the opening 6 and the land 19L of the source electrode 19 is disposed on the opening 6H. In this way, it is possible to suppress an increase in the area of the source electrode 19 that overlaps the scanning signal line 6, and it is possible to suppress an increase in the parasitic capacitance _CGS .

  However, when the exposure performed in the step of forming the contact hole 20H in the second insulating layer 20 is performed by an exposure apparatus having a photomask, the dimension R1 of the land 19L of the source electrode 19 is set to the contact hole as described above. It is necessary to make the value sufficiently larger than the opening dimension R2 on the bottom surface of 20H. At this time, if the opening dimension R2 of the bottom surface of the contact hole is about 5 μm, the dimension R1 of the land 19L of the source electrode 19 needs to be about 12 μm, for example.

Further, when the exposure performed in the step of forming the scanning signal line 6 and the step of forming the source electrode 19 is also performed by an exposure apparatus having a photomask, for example, the positional deviation of the land 19L of the source electrode 19 due to distortion is taken into consideration. There is a need. Therefore, in order to suppress deterioration in image quality due to variations in parasitic capacitance C _GS in each pixel, the dimension R3 of the opening 6H of the scanning signal line 6 formed below the land 19L of the source electrode 19 and the land of the source electrode 19 The difference M (margin) from the 19L dimension R1 needs to be about 4 μm, for example. At this time, if the dimension R1 of the land 19L of the source electrode 19 is 12 μm, the dimension R3 of the opening 6H of the scanning signal line 6 needs to be about 16 μm, for example.

  On the other hand, the width W1 of the scanning signal line 6 in a large and high-definition liquid crystal display device such as a recent liquid crystal television is about 40 μm, for example. At this time, if the opening 6H having the dimension R3 of about 16 μm is formed in the scanning signal line 6, the width W2 of the scanning signal line 6 in that portion is reduced to about 4 μm. Furthermore, the opening 6H of the scanning signal line 6 needs to be formed for each pixel. For this reason, one scanning signal line 6 has hundreds to thousands of places where the width (cross-sectional area) is remarkably reduced.

  At this time, a portion of the scanning signal line where the width is remarkably reduced has a wiring resistance larger than that of the other wide portion (the portion without the opening 6H). For this reason, if there are many portions where the width of the scanning signal line is remarkably reduced, the delay amount of the signal applied to the scanning signal line increases, leading to deterioration of the image quality of the liquid crystal display device. In particular, in a recent large-screen liquid crystal television or the like, the length (the dimension in the extending direction) of one scanning signal line 6 is very long, for example, from several tens of centimeters to over 1 m. As a result, the amount of signal delay increases significantly, and the image quality of the liquid crystal display device may be significantly degraded.

  In order to suppress an increase in signal delay due to the formation of the opening 6H, for example, it is considered that the width W1 of the scanning signal line 6 may be partially increased and the width W2 may be increased. However, if the width W1 of the scanning signal line 6 is increased, the opening area of the pixel is naturally reduced by the increased width.

  As described above, the conventional method for manufacturing the liquid crystal display panel 1 (TFT substrate 11) in which the photosensitive material film is exposed by the exposure apparatus having the photomask improves the aperture ratio of the pixel and suppresses the deterioration of the image quality. There is a problem that it is difficult to achieve both.

  Then, the inventors of the present application have studied a method for solving the above-described problem, that is, a method for simultaneously improving the aperture ratio of the pixel of the liquid crystal display device and suppressing the deterioration of the image quality. It has been found that the TFT substrate 11 may be manufactured by such a method.

6 (a), 6 (b), 7 (a), and 7 (b) are schematic diagrams for explaining the principle of the manufacturing method of the liquid crystal display device of one embodiment according to the present invention. .
FIG. 6A is a schematic diagram showing the principle of a method for manufacturing a liquid crystal display device according to an embodiment of the present invention. FIG. 6B is a schematic diagram for explaining one of the effects in the manufacturing method of the liquid crystal display device of the present embodiment.
FIG. 7A is a schematic plan view showing an example of a planar configuration around a TFT element in a TFT substrate of a liquid crystal display device to which the principle of this embodiment is applied. FIG. 7B is a schematic cross-sectional view showing an example of a cross-sectional configuration of the TFT substrate taken along the line DD ′ in FIG.

In the method of manufacturing a liquid crystal display device of this embodiment (TFT substrate 11), for example, if a shift in position of the contact hole 20H ₀ at the position and layout data of the contact hole 20H formed in the second insulating layer 20 occurs, The position of the land 19L of the source electrode 19 is shifted based on the direction and amount of the shift. That is, when the TFT substrate 11 is prototyped based on layout data prepared in advance, for example, as shown in FIG. 6A, the formation position of the contact hole 20H in a certain pixel is Δx1, − If it is shifted by Δy1 in the y direction, the position of the land 19L of the source electrode 19 of the pixel in the layout data is shifted by Δx1 in the −x direction and Δy1 in the −y direction in accordance with the shift of the contact hole 20H. In FIG. 6A, the dotted circle 20H ₀ and the two-dot chain circle 19L ₀ are respectively the contact hole 20H formation position and the land 19L of the source electrode 19 specified by the layout data prepared in advance. The formation position of is shown.

  As described above, when the position of the land 19L of the source electrode 19 in the layout data is shifted in accordance with the shift of the formation position of the contact hole 20H, for example, as shown in FIG. 19L can be reduced to a dimension R1 ′ smaller than the conventional dimension R1, and can approach the dimension R2 of the contact hole 20H.

  Therefore, when the principle (manufacturing method) of the present embodiment is applied and the land 19L of the source electrode 19 is moved over the opening 6H of the scanning signal line 6, the TFT elements 8 formed according to the layout data and The peripheral configuration is, for example, as shown in FIGS. 7 (a) and 7 (b).

  At this time, if the opening dimension R2 of the bottom surface of the contact hole 20H is about 5 μm, the dimension R1 ′ of the land 19L of the source electrode 19 is the conventional dimension R1 shown in FIGS. 5B and 6B. For example, about 8 μm.

  Further, when the opening 6H of the scanning signal line 6 is formed, the same principle is applied, and the position of the opening 6H in the layout data is changed in accordance with the change of the position of the land 19L of the source electrode 19. The difference M ′ (margin) between the dimension R3 ′ of the opening 6H formed under the land 19L and the dimension R1 ′ of the land 19L can be reduced to about 2 μm, for example. At this time, if the dimension R1 of the land 19L is 8 μm, the dimension R3 ′ of the opening 6H can be set to about 10 μm, for example.

  Therefore, when the width W1 of the scanning signal line 6 is about 40 μm, which is the same as the conventional case, the width W2 ′ in the portion where the opening 6H is formed is increased to about 10 μm. Therefore, an increase in the delay amount of the signal applied to the scanning signal line 6 can be suppressed, and deterioration of the image quality of the liquid crystal display device can be suppressed.

  However, the conventional manufacturing method of the TFT substrate 11, that is, the manufacturing method in which the exposure performed in the process of forming the scanning signal lines 6 and the exposure performed in the process of forming the source electrode 19 are performed by the exposure apparatus having a photomask When the principle (manufacturing method) of this embodiment is applied, for example, there are the following problems.

  When the formation position of the land 19L or the opening 6H in the layout data is changed (corrected) based on the displacement of the formation position of the contact hole 20H, it is necessary to newly create a photomask reflecting the change.

  In addition, when the exposure performed in the process of forming the source electrode 19 is performed by an exposure apparatus having a photomask, the above distortion is usually generated. For this reason, a deviation corresponding to the degree of distortion occurs between the formation position of the land 19L of the source electrode 19 actually formed and the formation position in the layout data. Therefore, when changing (correcting) the formation position of the land 19L in the layout data based on the deviation of the formation position of the contact hole 20H, the deviation of the formation position of the land 19L must be taken into consideration.

  Similarly, when the exposure performed in the step of forming the scanning signal line 6 is performed by an exposure apparatus having a photomask, distortion similarly occurs. For this reason, a deviation corresponding to the degree of distortion occurs between the formation position of the opening 6H of the actually formed scanning signal line 6 and the formation position in the layout data. Therefore, when the formation position of the opening 6H in the layout data is changed (corrected) based on the deviation of the formation position of the contact hole 20H, the deviation of the formation position of the opening 6H must also be considered.

  Therefore, when the principle (manufacturing method) of the present embodiment is applied to the conventional manufacturing method of the TFT substrate 11, the manufacturing efficiency of the TFT substrate 11 decreases and the manufacturing cost increases.

  Furthermore, the degree of distortion varies depending on the exposure apparatus used, as described above. Therefore, when the principle (manufacturing method) of the present embodiment is applied to the conventional manufacturing method of the TFT substrate 11, for example, the TFT substrate 11 is manufactured based on the same layout data and manufactured on different manufacturing lines (manufacturing systems). There is a problem that it is difficult to ensure the uniformity of image quality in the liquid crystal display device.

  Then, as a result of studying a method for avoiding the occurrence of the above problems, the inventors of the present application have performed exposure performed in the process of forming the scanning signal line 6 and exposure performed in the process of forming the source electrode 19. The present inventors have found that an exposure apparatus called a direct drawing method or a direct method may be used.

  In the direct drawing type exposure apparatus, an area that can be exposed at one time is set as a set of a plurality of minute areas, and light irradiation or irradiation is performed for each minute area by numerical control based on layout data created by CAD or the like. It is an exposure apparatus having MEMS (Micro Electro Mechanical Systems) that independently control non-irradiation. At this time, the MEMS has, for example, an optical component composed of a plurality of micromirrors, and controls the direction of each micromirror by numerical control to generate a pattern of light to be applied to the photosensitive material film. Can be done. That is, the direct drawing type exposure apparatus forms a predetermined photosensitive pattern (latent image) on the photosensitive material film by numerically controlling the MEMS instead of using a photomask. At this time, the area that can be exposed at one time is usually narrower than one exposure target area of the photosensitive material film. Therefore, when exposing with a direct drawing type exposure apparatus, the area that can be exposed at one time is scanned. The entire exposure target area is exposed.

  FIG. 8 is a schematic diagram showing an example of the configuration of the layout data of the source electrode.

  For example, as shown in FIG. 8, the layout data of the source electrode 19 includes a first graphic 19S in contact with the semiconductor layer 18, a second graphic (land 19L) connected to the pixel electrode 9, and the first graphic 19S and the land. It consists of three figures of the third figure 19J connecting 19L. FIG. 8 is a diagram in which layout data is visualized, and information regarding the first graphic 19S in the actual layout data includes, for example, parameters indicating that the graphic is a rectangle, coordinates of the start point P1 (X1, Y1) ), A dimension HX1 in the x direction, and a dimension HY1 in the y direction. The information related to the second graphic (land 19L) in the actual layout data includes, for example, a parameter indicating that the graphic is circular, the coordinates (X2, Y2) of the center P2, and the radius R1 '. The information about the third graphic 19J in the actual layout data includes, for example, a parameter indicating that the graphic is a rectangle, the coordinates (X3, Y3) of the start point P3, the dimension HX3 in the x direction, and the dimension in the y direction. It consists of HY3.

  When exposing a photosensitive material film with a direct drawing type exposure apparatus, the position and size of a region to be exposed are specified based on the layout data having the above configuration, and light is irradiated only to the specified region. The MEMS is controlled as follows. Therefore, when a direct drawing type exposure apparatus is used for the exposure performed in the process of forming the source electrode 19, the land 19L is formed only by changing the numerical values of the coordinates (X2, Y2) of the center P2 of the second figure, for example. The position can be changed.

  Further, as described above, the direct drawing type exposure apparatus does not use a photomask. Therefore, when exposing a photosensitive material film using a direct drawing type exposure apparatus, the pattern of light irradiated on the surface of the photosensitive material film corresponds to, for example, distortion caused by twisting or bending of a conventional photomask. There is no distortion. Furthermore, when the photosensitive material film is exposed with a direct drawing type exposure apparatus, the alignment accuracy between the region that can be exposed at once and the mother glass 22 is equivalent to the alignment accuracy in the exposure apparatus having a photomask. It is. Therefore, when a direct drawing type exposure apparatus is used for the exposure performed in the process of forming the source electrode 19, the deviation between the formation position and dimension of each source electrode 19 to be formed and the formation position and dimension in the layout data is This is much smaller than when exposed using a photomask.

  Therefore, if a direct drawing type exposure apparatus is used for the exposure performed in the process of forming the scanning signal line 6 having the opening 6H and the exposure performed in the process of forming the source electrode 19, the land of the opening 6H and the source electrode 19 is used. For the change (correction) of the position of 19L, only the displacement of the formation position of the contact hole 20H needs to be considered.

  Further, as described above, the direct drawing type exposure apparatus can change the position and size of the exposed portion only by changing the numerical value of the layout data (numerical data) to be used. Therefore, when a direct drawing type exposure apparatus is used for the exposure performed in the process of forming the scanning signal line 6 having the opening 6H or the exposure performed in the process of forming the source electrode 19, an exposure apparatus that uses a photomask. Compared to the above, it becomes easier to change (correct) the formation positions of the opening 6H, the land 19L, and the like.

  From the above, in the process of forming the scanning signal line 6 having the opening 6H and the process of forming the source electrode 19 when manufacturing the TFT substrate 11 based on the principle of the present embodiment. When a direct drawing type exposure apparatus is used for the exposure to be performed, it is possible to suppress a decrease in manufacturing efficiency of the TFT substrate 11 and an increase in manufacturing cost.

  Further, if the exposure performed in the process of forming the scanning signal line 6 having the opening 6H and the exposure performed in the process of forming the source electrode 19 are performed by a direct drawing type exposure apparatus, for example, the same layout It is easy to ensure uniformity in image quality in liquid crystal display devices manufactured based on data and manufactured in different manufacturing lines (manufacturing systems).

FIG. 9A to FIG. 9D are schematic views for explaining one specific example of the manufacturing method of the liquid crystal display device of this embodiment.
FIG. 9A is a schematic plan view showing an example of the displacement of the contact hole formation position. FIG. 9B is a schematic plan view illustrating an example of a method for correcting layout data relating to the source electrode. FIG. 9C is a schematic plan view showing an example of a method for correcting layout data regarding the opening of the scanning signal line. FIG. 9D is a schematic plan view illustrating an example of a method for correcting layout data relating to pixel electrodes.

  When manufacturing the TFT substrate 11 by applying the principle (manufacturing method) as described above, first, one or several TFT substrates 11 are prototyped based on layout data prepared in advance. Then, the displacement of the formation position of the contact hole 20H in each pixel of the prototype TFT substrate 11 is measured. Note that since the TFT substrate 11 used in a liquid crystal television or the like has millions of pixels, it is inefficient to measure the displacement of the formation position of the contact hole 20H for all the pixels. Therefore, when measuring the displacement of the formation position of the contact hole 20H, for example, the display area DA is divided into several hundreds of small areas, and the displacement of the formation position of the contact hole 20H is changed from one to several places for each small area. It is desirable to measure and statistically estimate the deviation of the formation position of the remaining contact hole 20H from the result.

  At this time, it is assumed that the formation position of the contact hole 20H of a certain pixel is shifted by Δx1 in the −x direction and Δy1 in the −y direction, for example, as shown in FIG. In this case, the layout data of the source electrode 19 in this pixel is, for example, as shown in FIG. 9B, the formation position of the land 19L (second graphic) of the source electrode 19 is Δx1, −x in the −x direction. Correction for shifting by Δy1 in the y direction is performed. At this time, the third figure 19J of the source electrode 19 may be left as it is, or as shown in FIG. 9B, the formation position may be shifted in accordance with the correction of the land 19L.

  The source electrode 19 is formed simultaneously with the video signal line 7. At this time, the channel width and the channel length of the TFT element 8 change when the formation position and dimensions of the first figure 19S of the source electrode 19 and the first figure 7D of the drain electrode integrally formed with the video signal line 7 are changed. End up. Further, when the formation position of the graphic 7L of the video signal line 7 is changed, the positions of the video signal line 7 and the light shielding film formed on the counter substrate 12 are shifted, and the aperture ratio is lowered. Therefore, the formation positions and dimensions of these figures 19s, 7D, and 7S in the layout data are left as they are.

  Next, since the formation positions of the land 19L (second graphic) and the third graphic 19J of the source electrode 19 are changed, for example, as shown in FIG. In the layout data, correction is performed by shifting the formation position of the opening 6H by Δx1 in the −x direction and Δy1 in the −y direction.

  If the formation position of the contact hole 20H is deviated, the formation position of the first figure 9B in the layout data related to the pixel electrode 9 and the layout data relating to the pixel electrode 9 are shown in FIG. Correct the dimensions.

  Thus, when the layout data regarding the scanning signal line 6, the layout data regarding the source electrode 19, and the layout data regarding the pixel electrode 9 are corrected in accordance with the displacement of the formation position of the contact hole 20H, the exposure data is obtained based on the corrected layout data. create.

  After the exposure data is created based on the corrected layout data in the above procedure, the TFT substrate 11 is formed using the exposure data thereafter. At this time, the exposure performed in the step of forming the scanning signal line 6, the exposure performed in the step of forming the video signal line 7 and the source electrode 19, and the exposure performed in the step of forming the pixel electrode 9 are respectively direct drawing type exposures. Do it with equipment. Then, the location on the TFT substrate 11 has a configuration as shown in FIGS. 10A and 10B, for example.

FIG. 10A and FIG. 10B are schematic views showing an example of the configuration of the source electrode and its periphery in the TFT substrate manufactured by the manufacturing method of the liquid crystal display device of this example.
FIG. 10A is a schematic plan view showing an example of the planar configuration of the source electrode at the location where the correction shown in FIGS. 9B to 9D is performed and the periphery thereof. FIG. 10B is a schematic cross-sectional view illustrating an example of a cross-sectional configuration of the TFT substrate taken along line EE ′ of FIG.

  The TFT substrate 11 manufactured after correcting the layout data as shown in FIGS. 9B to 9D has the source electrode at the location and the periphery thereof, for example, as shown in FIG. The configuration is as shown in FIG. At this time, the formation positions of the opening 6H of the scanning signal line 6, the land 19L of the source electrode 19, and the contact hole 20H are respectively set to Δx1 in the −x direction and −y direction from the position of the layout data prepared in advance. It shifts by Δy1. However, the width W3 + W4 of the scanning signal line 6 around the opening 6H is substantially the same value as the width W2 '× 2 in FIG. Therefore, the liquid crystal display device (TFT substrate 11) manufactured by the manufacturing method of this embodiment can suppress an increase in signal delay due to an increase in wiring resistance.

11, FIG. 12A and FIG. 12B are schematic diagrams for supplementary explanation regarding the configuration of the TFT substrate manufactured by the manufacturing method of the liquid crystal display device of the present embodiment.
FIG. 11 is a schematic plan view showing an example of a positional shift that occurs in the TFT substrate manufactured by the manufacturing method of the liquid crystal display device of the present embodiment.
FIG. 12A is a schematic plan view showing an example of the definition of the contact hole formation position. FIG. 12B is a schematic graph showing an example of the relationship between the degree of displacement of the contact hole formation position due to distortion and the degree of displacement of the opening of the scanning signal line.

  In the manufacturing method of the liquid crystal display device (TFT substrate 11) of the present embodiment, the exposure performed in the process of forming the scanning signal line 6 and the exposure performed in the process of forming the source electrode 19 are performed by a direct drawing type exposure apparatus. ing. Therefore, there is almost no displacement between the opening 6H of the scanning signal line 6 and the land 19L of the source electrode 19. However, when exposing the photosensitive material film with the direct drawing type exposure apparatus, for example, the relative positional relationship between the optical system having the MEMS and the stage holding the mother glass 22 is mechanically shifted. . Therefore, in the TFT substrate 11 manufactured by the manufacturing method of the present embodiment, for example, as shown in FIG. 11, the formation position of the opening 6H of the scanning signal line 6 is specified by the corrected layout data. There may be a deviation of Δx3 from the position in the x direction. That is, the position of the opening 6H of the scanning signal line 6 and the land 19L of the source electrode 19 may be shifted by Δx3.

As described above, when the positions of the opening 6H of the scanning signal line 6 and the source electrode 19 (the land 19L thereof) are shifted, for example, the area of the overlapping region of the source electrode 19 and the scanning signal line 6 in each pixel varies. May occur, and the size of the parasitic capacitance C _GS formed between the source electrode 19 and the scanning signal line 6 may vary.

  Accordingly, the inventors of the present application have determined the degree of deviation of the formation position of the opening 6H of the scanning signal line 6 and the formation position of the contact hole 20H due to distortion in the manufacturing method of the liquid crystal display device (TFT substrate 11) of this embodiment. The relationship between the degree of deviation and the following was found.

  First, the degree of displacement of the formation position of the contact hole 20H due to the distortion is, for example, as shown in FIG. 12A, from the distance x + Δx from the center of the contact hole 20H to the video signal line 7 and from the center of the contact hole 20H. The distance y + Δy to the side in the longitudinal direction of the scanning signal line 6 was measured and examined. The distance x + Δx is a distance when x is formed at the position specified by the layout data, and Δx is the amount of deviation in the x direction from the position specified by the layout data. The distance y + Δy is a distance when y is formed at a position specified by the layout data, and Δy is a shift amount in the y direction from the position specified by the layout data.

  At this time, when the shift amount Δx of the distance x + Δx from the center of the contact hole 20H to the video signal line 7 in the plurality of TFT substrates 11 formed using different exposure apparatuses is measured and statistically processed, the distance x + Δx For example, the distribution is as indicated by a solid curve Q1 shown in FIG. In FIG. 12B, the vertical axis K is the ratio of pixels whose deviation in the x direction is Δx (μm). Moreover, in FIG.12 (b), (alpha) is a positive real number, for example, is 2-3. In FIG. 12B, β is a positive real number with 0 <β <1.

  Further, when the same measurement and statistical processing are performed on the amount of deviation in the x direction of the position where the opening 6H of the scanning signal line 6 is formed on the TFT substrate 11, the amount of deviation is shown in FIG. The distribution was as shown by the dashed curve Q2.

  As described above, the standard deviation σ2 of the displacement amount in the x direction of the position where the opening 6H of the scanning signal line 6 is formed is smaller than the standard deviation σ1 of the displacement amount of the contact hole 20H in the x direction due to distortion.

  Although not shown in the drawing, the same result is obtained with respect to the amount of deviation in the y direction, and the standard deviation of the amount of deviation in the y direction of the position where the opening 6H of the scanning signal line 6 is formed is equal to that of the contact hole 20H due to distortion. It became smaller than the standard deviation of the deviation amount in the y direction.

Therefore, the liquid crystal display device having the TFT substrate 11 manufactured by the manufacturing method of this embodiment is based on, for example, the difference in the parasitic capacitance C _GS formed between the source electrode 19 and the scanning signal line 6 in each pixel. Degradation of image quality can also be suppressed.

  As described above, according to the liquid crystal display device of this embodiment and the manufacturing method thereof, it is possible to improve both the aperture ratio of the pixel and prevent the deterioration of the image quality.

  Therefore, when the driving voltage of the pixel is set to the same as the conventional setting, the luminance of each pixel is increased, and the liquid crystal display device can be increased in luminance.

  Further, in the case where the luminance of the pixel is set to be the same as that in the past, the driving voltage of the pixel can be lowered, and the liquid crystal display device can have low power consumption.

  Further, according to the method of manufacturing the liquid crystal display device of the present embodiment, the scanning signal in the step of exposing the photosensitive material film that is performed a plurality of times (in this embodiment, five times) in the step of manufacturing the TFT substrate 11. It is performed in the step of exposing the photosensitive material film performed in the step of forming the line 6, the step of exposing the photosensitive material film performed in the step of forming the video signal line 7 and the source electrode 19, and the step of forming the pixel electrode 9. Only the step of exposing the photosensitive material film is performed by a direct drawing type exposure apparatus. Therefore, it is possible to suppress a decrease in manufacturing efficiency due to exposure of the photosensitive material film with a direct drawing type exposure apparatus.

  Further, when exposure is performed with a direct drawing type exposure apparatus, the pattern of light applied to the photosensitive material film can be changed simply by correcting the layout data. Therefore, the manufacturing method of the liquid crystal display device of this embodiment is also effective in reducing the manufacturing cost.

  The present invention has been specifically described above based on the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. is there.

For example, in this specification, the case where the present invention is applied to the TFT substrate 11 having the configuration as shown in FIGS. 2A and 2B is taken as an example. However, the present invention is not limited to such a TFT substrate 11, for example, to a manufacturing method of a TFT substrate 11 in which the planar layout of the TFT element 8, the planar shape of the pixel electrode 9, the formation method of the storage capacitor _CSTG , etc. Of course, it can be applied.

  The present invention is not limited to the manufacturing method of the TFT substrate 11 of the vertical electric field drive type liquid crystal display panel 1 in which the common electrode is disposed on the counter substrate 12, but is similar to the TFT substrate 11 of the IPS type liquid crystal display panel 1. Of course, the present invention can also be applied to the manufacturing method of the TFT substrate 11 in which the common electrode is disposed on the first insulating substrate 16.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display panel 2 ... 1st drive circuit 3 ... 2nd drive circuit 4 ... Light source 5 ... Control circuit 6 ... Scanning signal line 6H ... Opening part 7 ... Video signal line 8 ... TFT element 9 ... Pixel electrode 10 ... Retention capacitance line 11... First substrate (TFT substrate)
12 ... Second substrate (counter substrate)
DESCRIPTION OF SYMBOLS 13 ... Sealing material 14 ... 1st polarizing plate 15 ... 2nd polarizing plate 16 ... 1st insulating substrate 17 ... 1st insulating layer 18 ... Semiconductor layer 19 ... Source electrode 19L ... Land 20 ... 2nd insulating layer 20H, 20H ₁ , 20H ₂ ... contact hole 21 ... first alignment film 22 ... mother glass

Claims (13)

A first substrate; a second substrate; a liquid crystal layer disposed between the first substrate and the second substrate;
The first substrate has a plurality of scanning signal lines, a plurality of video signal lines, a plurality of TFT elements, and a plurality of pixel electrodes.
The plurality of TFT elements are liquid crystal display devices arranged in a matrix on the first substrate,
The TFT element includes a semiconductor layer disposed on the scanning signal line via a first insulating layer, a drain electrode connected to the video signal line and the semiconductor layer, the pixel electrode, and the semiconductor A source electrode connected to the layer,
The pixel electrode is connected to a land provided at one end of the source electrode through a contact hole formed in a second insulating layer,
The scanning signal line has an opening outside a region intersecting with the video signal line and a region overlapping with the semiconductor layer,
The liquid crystal display device, wherein the land of the source electrode and the contact hole are on the opening of the scanning signal line.   The distance from the contact hole near the center of the first substrate to the video signal line is different from the distance from the contact hole near the outer periphery of the first substrate to the video signal line. The liquid crystal display device according to claim 1.   The distance from the contact hole near the center of the first substrate to the longitudinal side of the scanning signal line, and the distance from the contact hole near the outer periphery of the first substrate to the longitudinal side of the scanning signal line The liquid crystal display device according to claim 1, wherein One scanning signal line has a plurality of openings.
2. The contact hole on each of the openings has a combination of a distance to the video signal line and a distance to a side in a longitudinal direction of the scanning signal line differing from each other. Liquid crystal display device.   The standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the contact hole and the land in the first substrate is from the contact hole to the video signal line in the first substrate. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is smaller than a standard deviation of the distance distribution.   The standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the opening and the land in the first substrate is the contact hole in the first substrate in the first substrate. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is smaller than a standard deviation of a distribution of distances from the video signal line.   The standard deviation of the distribution of the positional deviation in the extending direction of the video signal line between the contact hole and the land in the first substrate is the length of the scanning signal line from the contact hole in the first substrate. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is smaller than a standard deviation of a distribution of distances to a side in the direction.   The standard deviation of the distribution of the positional deviation in the extending direction of the scanning signal line between the opening and the land in the first substrate is from the contact hole in the first substrate in the first substrate. 2. The liquid crystal display device according to claim 1, wherein a standard deviation of a distribution of distances to a side in a longitudinal direction of the scanning signal line is smaller. Forming a plurality of scanning signal lines on an insulating substrate; forming a gate insulating film and a plurality of semiconductor layers on the scanning signal lines; forming a source electrode connected to the semiconductor layer; A step of forming an insulating layer on the source electrode; a step of forming a contact hole in a portion of the insulating layer on a land of the source electrode; and the contact on the insulating layer. Forming a pixel electrode connected to the land of the source electrode through a hole,
The step of forming the plurality of scanning signal lines forms a scanning signal line having a plurality of openings,
The step of forming the source electrode is a method of manufacturing a liquid crystal display device in which the land of the source electrode is formed on the opening of the scanning signal line,
After forming the contact hole based on layout data prepared in advance,
Measure the deviation between the position of the contact hole formed in the insulating layer and the position of formation of the contact hole in the layout data,
And correcting the formation position of the opening of the scanning signal line and the formation position of the land of the source electrode in the layout data based on the displacement direction and displacement amount of the contact hole. A method for manufacturing a liquid crystal display device.   The correcting step also corrects the formation position, the formation position, and the size of the peripheral portion of the contact hole in the pixel electrode based on the direction and amount of displacement of the contact hole position. A method for manufacturing a liquid crystal display device according to claim 9. The step of forming the plurality of scanning signal lines, the step of forming the plurality of source electrodes, and the step of forming the contact hole each include a step of exposing a photosensitive material film,
The step of exposing the photosensitive material film in the step of forming the contact hole is an exposure apparatus that generates a pattern of light to be irradiated to the photosensitive material film using a photomask created based on the layout data. Exposing the photosensitive material film;
The step of exposing the photosensitive material film in the step of forming the plurality of scanning signal lines and the step of exposing the photosensitive material film in the step of forming the plurality of source electrodes are each based on the layout data. After the photosensitive material film is exposed by an exposure device that generates a light pattern to be irradiated to the photosensitive material film by numerical control, and the layout data is corrected in the correcting step, the correction is performed. The method for manufacturing a liquid crystal display device according to claim 9, wherein the photosensitive material film is exposed based on layout data. The step of forming the source electrode forms a plurality of video signal lines and a drain electrode connected to the semiconductor layer together with the source electrode,
10. The method for manufacturing a liquid crystal display device according to claim 9, wherein when the land formation position of the source electrode is corrected in the correcting step, the formation position of the video signal line is not changed.   When measuring the displacement between the position of the contact hole formed in the insulating layer and the position of formation of the contact hole in the layout data, the insulating substrate is divided into a plurality of regions, and contacts representing the respective regions 10. The method of manufacturing a liquid crystal display device according to claim 9, wherein the deviation in the hole is measured, and the deviation in the contact hole that is not measured is estimated by statistical processing based on the measurement result.

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