JP2011022233A - Method of manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a liquid crystal display device, capable of easily forming a recess and a contact hole having depths different from each other without using a mask having a complicated structure while suppressing difficulty of adjustment of transmittance. <P>SOLUTION: The method of manufacturing the liquid crystal display device 100 includes an exposure step of forming a contact hole 12a and a recess 12b corresponding to a sub columnar spacer 26b in a flattening film 12 by exposing a region in which the contact hole is to be formed and a region corresponding to the sub columnar spacer 26b of the flattening film 12 using a mask 29 in which a contact hole forming pattern for forming the contact hole 12a to be provided by removing the flattening film 12 and a recess forming pattern having slits 31b each having a width narrower than exposure limit resolution for forming the recess 12b to be provided by removing a part on the surface side of the flattening film 12 are formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to a method for manufacturing a liquid crystal display device including an exposure step of forming a recess in an insulating film.

  Conventionally, a manufacturing method of a liquid crystal display device including an exposure step of forming a depression in an insulating film is known (see, for example, Patent Documents 1 and 2).

  Patent Document 1 includes a step of forming a first spacer and a second spacer on the upper substrate side of an upper substrate (first substrate) and a lower substrate (second substrate) arranged to face each other; A step of forming a planarizing film (insulating film) made of a photosensitive resin on the lower substrate side, and a step of forming a concave portion (a depressed portion) at a position facing the second spacer of the planarizing film on the lower substrate side. A method for manufacturing a liquid crystal display device is disclosed. In the manufacturing method of the liquid crystal display device described in Patent Document 1, the recess formed in the planarizing film is formed by photolithography (exposure process) using a halftone mask. This halftone mask has a transmission part through which almost all of the irradiated light is transmitted, a semi-transmission part in which a film having a low transmittance through which a part of the irradiated light is transmitted, and the irradiated light. And a light shielding portion that does not transmit light. Further, when the light irradiated to the halftone mask is irradiated to the planarizing film through the transmissive part and the semi-transmissive part of the halftone mask, the planarizing film is formed according to the exposure intensity of the irradiated light. The depth of the recess to be formed is determined. The first spacer has a function of maintaining a constant gap between the substrates when the upper substrate and the lower substrate are bonded together. Further, the second spacers are arranged at a predetermined interval without coming into contact with the concave portion on the lower substrate side. When an excessive load is applied to the upper substrate and the lower substrate, or when the upper substrate and the lower substrate are bent toward the liquid crystal layer due to the shrinkage of the liquid crystal layer in a low temperature environment, the second spacer is lowered. The contact between the recesses on the substrate side suppresses the gap between the substrates from becoming too small. At this time, the upper substrate and the lower substrate can bend toward the liquid crystal layer until the second spacer comes into contact with the concave portion, so that the liquid crystal layer sealed between the upper substrate and the lower substrate is It becomes easy to shrink, and it is possible to reduce the negative pressure in the liquid crystal layer. Thereby, it is comprised so that generation | occurrence | production of a bubble may be suppressed in a liquid-crystal layer.

  Further, in Patent Document 2, a step of forming a plurality of columnar structures on the first substrate side of the first substrate and the second substrate disposed so as to face each other, and a photosensitive property on the second substrate side are disclosed. Forming an insulating layer made of the above resin, and simultaneously forming a recess (depression) and a contact hole at a position facing at least one of the columnar structures of the insulating layer. A method for manufacturing a liquid crystal display device is disclosed. In the manufacturing method of the liquid crystal display device described in Patent Document 2, the recess and the contact hole formed in the insulating layer are formed by photolithography (exposure process). It should be noted that a specific method for simultaneously forming both the concave portion and the contact hole is not described, and simultaneous formation using a halftone mask is conceivable as in the case of Patent Document 1. Further, the two types of columnar structures have the same effect as the spacer described in Patent Document 1.

JP 2007-171715 A JP 2008-242035 A

  However, in the method of manufacturing the liquid crystal display device described in Patent Document 1 and Patent Document 2, a film having low transmittance is formed in the semi-transmissive portion of the half-tone mask. There is a problem that the structure of the system becomes complicated. When both the concave portion and the contact hole are simultaneously formed in the planarizing film using a halftone mask, the transmittance is adjusted with a low transmittance film constituting the semi-transmissive portion of the halftone mask. However, it is difficult to form contact holes and recesses having different depths at desired depths.

  In addition, when both the recess and the contact hole are to be formed without using the halftone masks as in Patent Document 1 and Patent Document 2, the contact hole forming step and the recess forming step are performed. Since this is necessary, there is a problem that the manufacturing process increases.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to use a mask having a complicated structure and suppress the difficulty of adjusting the transmittance. It is to provide a method of manufacturing a liquid crystal display device capable of easily forming contact holes and recesses (recessed portions) having different depths, and without increasing the number of steps. An object of the present invention is to provide a method of manufacturing a liquid crystal display device capable of easily forming different contact holes and recesses (recesses).

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a method of manufacturing a liquid crystal display device according to one aspect of the present invention includes a first substrate and a second substrate disposed so as to face each other on a first substrate side. A step of forming a spacer and a second spacer, a step of forming an insulating film made of a photosensitive material on the second substrate side, and a contact hole forming for forming a contact hole provided by removing the insulating film Using a mask formed with a pattern and a pattern for forming a recess having an opening having a width smaller than the exposure limit resolution in order to form a recess provided by removing a part of the surface side of the insulating film Then, by exposing the contact hole forming region of the insulating film and the region corresponding to the second spacer, the contact hole and the second space are formed on the insulating film. And a exposure step of forming a recess portion corresponding to the over.

  In the method of manufacturing a liquid crystal display device according to this aspect, as described above, a contact hole forming pattern for forming a contact hole provided by removing the insulating film, and a part on the surface side of the insulating film In order to form a recess portion provided by removing the mask, a mask for forming a recess portion having an opening having a width smaller than the exposure limit resolution is used to form a contact hole formation region of the insulating film and the first layer. The exposure process of forming a contact hole and the hollow part corresponding to a 2nd spacer in an insulating film by exposing each area | region corresponding to 2 spacers is provided. Thus, unlike the case of using a halftone mask, by adjusting the width and size of the mask opening without using a film with low transmittance, the mask opening (semi-transmissive portion) can be easily adjusted. The transmittance can be adjusted. As a result, when the exposure process is performed, a contact hole having a depth corresponding to the contact hole forming pattern and a recess having a depth corresponding to the recess forming pattern are formed. This makes it possible to easily form contact holes and depressions having different depths without using a mask having a complicated structure and suppressing the difficulty of adjusting the transmittance. In addition, since the contact hole forming step and the recessed portion forming step can be performed simultaneously compared to the case where both the contact hole and the recessed portion (recessed portion) are formed without using a halftone mask, Without increasing the number of steps, contact holes and recesses (recesses) having different depths can be easily formed simultaneously.

  In the method for manufacturing a liquid crystal display device according to the above aspect, the first substrate and the second substrate are preferably provided with a plurality of subpixels, and the step of forming the first spacer and the second spacer includes Forming at least one of the first spacer and the second spacer on the pixel. If comprised in this way, while being able to regulate the cell gap between a 1st board | substrate and a 2nd board | substrate with a 1st spacer, the improvement of surface pressing tolerance can be aimed at. In addition, when a load is applied to the first substrate and the second substrate, or the liquid crystal layer provided between the first substrate and the second substrate contracts at a low temperature, the first substrate and the second substrate become liquid crystals. The cell gap between the first substrate and the second substrate when the second substrate side surface of the second spacer abuts against the surface of the recess of the recess portion on the second substrate side when bent to the layer side. , And the generation of low temperature bubbles can be suppressed.

  In the method for manufacturing a liquid crystal display device according to the above aspect, preferably, the pattern for forming the recesses having the opening having a width smaller than the exposure limit resolution is substantially parallel to each other with a space in plan view. It includes a plurality of linear slits arranged side by side. If comprised in this way, when an exposure process is performed, the uneven | corrugated shaped recessed part can be easily formed in the part corresponding to the some linear slit of an insulating film.

  In the method for manufacturing a liquid crystal display device according to the above aspect, preferably, the pattern for forming the recess having the opening having a width smaller than the exposure limit resolution is formed in a polygonal shape or a circular shape when seen in a plan view. Including slits or holes. If comprised in this way, when an exposure process is performed, the uneven | corrugated shaped recessed part can be easily formed in the part corresponding to the slit or hole formed in the polygonal shape or circular shape of the insulating film.

  In the liquid crystal display device manufacturing method according to the above aspect, the height of the first spacer in the direction perpendicular to the surface of the first substrate is preferably the height of the second spacer in the direction perpendicular to the surface of the first substrate. Almost equal. If comprised in this way, since both a 1st spacer and a 2nd spacer can be formed simultaneously by one exposure process, it can suppress that the number of manufacturing processes increases.

  In the method for manufacturing a liquid crystal display device according to the above aspect, the step of forming an insulating film made of a photosensitive material on the second substrate side preferably forms a planarizing film made of the photosensitive material on the second substrate side. The exposure process includes a step for forming a contact hole in the planarizing film using a mask in which a pattern for forming a contact hole and a pattern for forming a recess having an opening having a width smaller than the exposure limit resolution are formed. And a step of forming a recess corresponding to the second spacer. If comprised in this way, since both a contact hole and a hollow part can be simultaneously formed in the planarization film | membrane by one exposure process, it can suppress that the number of manufacturing processes increases.

  In this case, preferably, the exposure step includes a step of forming the surface of the depression corresponding to the second spacer of the planarization film in a concavo-convex shape, and the top of the convex portion of the concavo-convex shape of the depression is planarized. It is formed so as to be lower than the upper surface of the film other than the contact hole and the depression. If comprised in this way, a predetermined space | interval can be easily provided between the surface by the side of the 2nd board | substrate of a 2nd spacer, and the top part of the convex part of the uneven | corrugated shaped surface of a hollow part.

  In the method of manufacturing a liquid crystal display device including the step of forming the planarization film, preferably, the method further includes the step of forming a thin film transistor on the second substrate side, and the exposure step is performed on the planarization located above the formation region of the thin film transistor. Forming a depression on the surface of the membrane. With this configuration, since the second spacer is arranged above the depression, for example, when the region corresponding to the thin film transistor formation region is shielded by the light shielding film, the thin film transistor and the second spacer are shielded simultaneously. can do.

  In this case, the exposure step preferably includes a step of forming a recess in the vicinity of the contact hole for establishing electrical connection with the source / drain electrodes of the thin film transistor. If comprised in this way, a contact hole and a hollow part can be simultaneously formed in the vicinity of a thin-film transistor.

  In the method for manufacturing a liquid crystal display device according to the above aspect, the exposure step preferably includes a step of forming a recess in the insulating film formed in the transmission region. If comprised in this way, a hollow part can be easily formed in the insulating film formed in the permeation | transmission area | region by using the insulating film which consists of photosensitive materials. Thereby, in the transmissive liquid crystal display device, it is possible to form the second spacer for suppressing the generation of bubbles in the liquid crystal layer.

1 is a plan view of a liquid crystal display device according to a first embodiment of the present invention. It is sectional drawing along the 200-200 line | wire of FIG. It is a flowchart for demonstrating the manufacturing process of the liquid crystal display device by 1st Embodiment of this invention. It is a top view of the mask used for the contact hole and hollow part formation process (exposure process) by 1st Embodiment of this invention. It is a top view of the mask used for the exposure process by 1st Embodiment of this invention. FIG. 6 is a cross-sectional view taken along line 300-300 in FIG. 5. It is sectional drawing for demonstrating the exposure process by 1st Embodiment of this invention. 6 is a cross-sectional view for explaining a pixel electrode forming process according to the first embodiment of the present invention; FIG. It is sectional drawing for demonstrating the alignment film formation process by 1st Embodiment of this invention. It is sectional drawing for demonstrating the exposure process by 1st Embodiment of this invention. It is sectional drawing for demonstrating the exposure process by 1st Embodiment of this invention. It is a top view of the liquid crystal display device by 2nd Embodiment of this invention. It is a top view of the mask used for the exposure process by 2nd Embodiment of this invention. It is a top view of the mask used for the exposure process by 2nd Embodiment of this invention. It is a top view of the mask used for the exposure process by 3rd Embodiment of this invention. It is a top view of the mask used for the exposure process by 3rd Embodiment of this invention. It is a top view of the mask used for the exposure process by 4th Embodiment of this invention. It is a top view of the mask used for the exposure process by 4th Embodiment of this invention. It is a top view of the mask used for the exposure process by 5th Embodiment of this invention. It is a top view of the mask used for the exposure process by 5th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
With reference to FIG. 1 and FIG. 2, the structure of the liquid crystal display device 100 by 1st Embodiment of this invention is demonstrated. In the first embodiment, a case where the present invention is applied to the liquid crystal display device 100 in the vertical electric field mode will be described.

  As shown in FIG. 1, the liquid crystal display device 100 according to the first embodiment is provided with a scanning line 1 and a signal line 2 arranged so as to intersect the scanning line 1. A plurality of sub-pixels 3 (sub-pixels 3a, 3b, and 3c) are provided corresponding to the positions where the scanning lines 1 and the signal lines 2 intersect. Each of the plurality of sub-pixels 3 (sub-pixels 3a, 3b, and 3c) is provided with a bottom gate type thin film transistor (TFT) 4.

As a cross-sectional structure of the sub-pixel 3 (sub-pixels 3a to 3c), a gate electrode 6 is formed on the surface of the TFT substrate 5 as shown in FIG. The TFT substrate 5 is an example of the “second substrate” in the present invention. An insulating film 7 including a gate insulating film 7 a made of SiN is formed on the surfaces of the gate electrode 6 and the TFT substrate 5. A semiconductor layer 8 is formed so as to face the gate electrode 6 and the insulating film 7. The semiconductor layer 8 is made of a-Si and n ⁺ Si. A source electrode 9 and a drain electrode 10 are formed on the semiconductor layer 8. The gate electrode 6, the insulating film 7, the semiconductor layer 8, the source electrode 9 and the drain electrode 10 constitute the thin film transistor 4.

  Further, a passivation layer 11 made of SiN is formed so as to cover the source electrode 9 and the drain electrode 10. A planarizing film 12 made of a photosensitive acrylic resin is formed on the surface of the passivation layer 11. The planarizing film 12 is an example of the “insulating film” in the present invention. Here, in the first embodiment, the contact hole 12 a is formed in the planarizing film 12 by completely removing the planarizing film 12. In the region corresponding to the sub-pixel 3 c of the planarization film 12, a recess 12 b is formed by removing a part from the surface side of the planarization film 12 in the thickness direction of the planarization film 12. The surface of the recess 12b has an uneven shape (wave shape). The distance L1 between the flat surface (upper surface) 12c of the planarizing film 12 and the top 12d of the convex portion on the surface of the recess 12b is about 0.5 μm. The distance L2 between the top 12d of the convex portion on the surface of the recess 12b and the bottom 12e of the recess of the recess 12b is about 0.4 μm.

  In addition, a pixel electrode 13 made of a transparent electrode such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is formed so as to cover the planarizing film 12. Further, the pixel electrode 13 and the drain electrode 10 are connected through the contact hole 11 a of the passivation layer 11 and the contact hole 12 a of the planarizing film 12. An alignment film 14 made of an organic film such as polyimide is formed on the surface of the pixel electrode 13.

  A counter substrate 21 is provided so as to face the TFT substrate 5. The counter substrate 21 is an example of the “first substrate” in the present invention. A black matrix 22 made of resin or the like is formed on the surface of the counter substrate 21.

  A color filter (CF) 23 is formed on the surface of the black matrix 22. As shown in FIG. 1, the color filter 23 is made up of three color filters 23 of red (R), green (G), and blue (B), and is provided for each of the sub-pixels 3a to 3c. . As shown in FIG. 2, an overcoat layer (OC) 24 as a protective film is formed on the surface of the color filter 23. A counter electrode 25 made of a transparent electrode such as ITO or IZO is formed on the surface of the overcoat layer 24.

  In the first embodiment, a main columnar spacer (PS) 26a made of a photosensitive resin made of a photosensitive acrylic resin or the like is provided on the surface of the counter electrode 25 corresponding to the sub-pixel 3b. The main columnar spacer 26a is an example of the “first spacer” in the present invention. Further, the main columnar spacer 26a has a function of adjusting the cell gap (distance between the TFT substrate 5 and the counter substrate 21).

  In the first embodiment, on the surface of the counter electrode 25 corresponding to the sub-pixel 3c, a sub-columnar spacer 26b made of a photosensitive resin made of the same photosensitive acrylic resin as the main columnar spacer 26a is provided. Yes. The sub columnar spacer 26b is an example of the “second spacer” in the present invention. Further, the sub-columnar spacer 26b is disposed in a region facing the hollow portion 12b when seen in a plan view. In addition, the surface in the arrow Z1 direction of the sub columnar spacer 26b formed in the subpixel 3c and the surface in the arrow Z2 direction of the recess 12b are arranged at a predetermined interval.

  In the first embodiment, as shown in FIG. 1, the main columnar spacer 26a and the sub columnar spacer 26b are provided so as to overlap the thin film transistor 4 in a plan view and are formed in a substantially circular shape. ing. Further, the height h1 in the Z direction of the main columnar spacer 26a is substantially equal to the height h2 in the Z direction of the sub columnar spacer 26b. An alignment film 27 made of an organic film such as polyimide is formed on the surfaces of the main columnar spacer 26a and the sub columnar spacer 26b. The alignment film 27 formed on the surface of the main columnar spacer 26a is disposed so as to contact the alignment film 14 on the TFT substrate 5 side.

  A liquid crystal layer 28 is provided between the alignment film 14 and the alignment film 27. A backlight 40 is provided on the TFT substrate 5 on the arrow Z1 direction side. The backlight 40 is configured such that light is emitted from the TFT substrate 5 side toward the counter substrate 21 side (arrow Z2 direction side).

  Next, a manufacturing process of the liquid crystal display device 100 according to the first embodiment of the present invention will be described with reference to FIGS.

First, in the TFT formation step S1 on the TFT substrate 5 side shown in FIG. 3, as shown in FIG. 6, a gate made of an Al / Mo layer is formed on the surface of the TFT substrate 5 from the lower layer to the upper layer by photolithography and etching. The electrode 6 is formed. An insulating film 7 including a gate insulating film 7a made of a SiN film is formed on the gate electrode 6 and the TFT substrate 5 by a CVD (Chemical Vapor Deposition) method. Then, a two-layer structure of an a-Si layer and an n ⁺ Si layer having n-type conductivity is formed by photolithography and etching so as to overlap with the gate electrode 6 in plan view through the gate insulating film 7a. A semiconductor layer 8 is formed.

  Next, the source composed of the Mo / Al / Mo layer on the semiconductor layer 8 in order from the lower layer to the upper layer, which overlaps the gate electrode 6 and the semiconductor layer 8 in plan view and is electrically connected to the semiconductor layer 8. Electrode 9 and drain electrode 10 are formed. Thereby, the thin film transistor 4 is formed.

  Next, in the passivation film forming step S2 of FIG. 3, a passivation film 11 as a protective film made of a SiN film is formed by CVD so as to cover the source electrode 9, the drain electrode 10 and the insulating film 7.

  Next, in the planarization film forming step S3 in FIG. 3, the planarization film 12 made of an acrylic photosensitive resin is formed on the surface of the passivation film 11 by a coating method. Here, in the first embodiment, in the contact hole / dent forming step (exposure step) S4 of FIG. 3, a mask 29 is disposed so as to face the planarizing film 12, as shown in FIG. In this mask 29, a light shielding film 31 made of a metal such as chromium is formed on the surface of the glass substrate 30 (arrow Z1 direction side). In addition, as shown in FIG. 4, the light shielding film 31 of the mask 29 includes a rectangular (square) opening 31a (contact hole forming pattern) for forming the contact hole 12a and a recess 12b. A plurality of slits (patterns for forming recesses) 31b having a width smaller than the exposure limit resolution for forming are formed.

  In the first embodiment, the slits 31b are linearly formed so as to extend along the arrow Y direction, and are arranged substantially parallel to each other with the same interval L4 in the X direction. The width L3 of the slit 31b in the X direction is about 1 μm. Further, an interval (distance) L4 between the slit 31b and the slit 31b is about 3 μm. Further, as shown in FIG. 5, in the sub-pixel 3c, the slit 31b of the mask 29 is arranged in a region overlapping the region where the sub-columnar spacer 26b on the counter substrate 21 side is formed in plan view. . Further, in the sub-pixel 3b, since no depression is formed, the mask 29 is not provided with the slit 31b.

  Further, by making the opening widths of the opening 31a and the slit 31b of the mask 29 different, the amount of light transmitted through the opening 31a and the slit 31b is made different when UV irradiation is performed by an exposure process (photolithography). It is possible. In the first embodiment, since the light amount is adjusted by controlling the opening width of the slit 31b, the light amount is compared with the case where the light amount is adjusted using a film having a low transmittance such as a halftone mask. Is easy to adjust. Then, by using the mask 29 to expose the region for forming the contact hole 12a of the planarizing film 12 and the region corresponding to the sub-columnar spacer 26b, the contact hole 12a and the recess 12b are simultaneously formed in the same process. The Accordingly, as shown in FIG. 7, the contact hole 12a and the recess 12b formed in the planarizing film 12 can be formed with different depths (thicknesses). Further, the recess 12b is formed in the vicinity of the contact hole 12a.

  Further, UV irradiation is performed through the plurality of slits 31 b of the mask 29, whereby a plurality of irregularities are formed on the surface of the recess 12 b of the planarizing film 12. The planarizing film 12 is a positive type film. Thereby, the UV irradiated portion of the planarizing film 12 is removed, and the portion of the planarizing film 12 that is not irradiated with UV remains without being removed.

  Next, in the pixel electrode formation step S5 of FIG. 3, as shown in FIG. 8, the pixel electrode 13 made of ITO, IZO or the like is formed on the surface of the planarizing film 12 by sputtering. At this time, in the first embodiment, a part of the pixel electrode 13 is electrically connected to the drain electrode 10 in the contact portion 10a via the contact holes 11a and 12a. Further, the surface of the pixel electrode 13 is formed in a shape reflecting the surface shape (uneven shape) of the recess 12b.

  Next, in the alignment film formation step S6 of FIG. 3, as shown in FIG. 9, an alignment film 14 made of polyimide is formed on the surface of the pixel electrode 13 by a coating method. The surface of the alignment film 14 is formed in a shape reflecting the surface shape (uneven shape) of the recess 12b.

  Next, in the black matrix forming step S7 on the counter substrate 21 side shown in FIG. 3, as shown in FIG. 10, a film made of, for example, a black resin material is formed on the surface of the counter substrate 21, and etched. Then, a black matrix (BM) 22 is formed.

  Next, in the color filter forming step S8 of FIG. 3, as shown in FIG. 10, the red (R), green (G), and blue (B) color filters (CF) 23 are sub-pixels 3a to 3c (FIG. 3). 1)) and is formed using photolithography.

  Next, in the overcoat layer forming step S9 of FIG. 3, as shown in FIG. 10, an overcoat layer (OC) 24 is formed so as to cover the surface of the color filter 23 (and the black matrix 22 between the color filters 23). Form. The overcoat layer 24 is formed so as to cover substantially the entire surface of the black matrix 22 and the color filter 23.

  Next, in the counter electrode formation step S10 of FIG. 3, as shown in FIG. 10, a counter electrode 25 made of ITO, IZO or the like is formed on the surface of the overcoat layer 24 by sputtering. The counter electrode 25 is formed across the plurality of subpixels 3.

  Next, in the columnar spacer forming step S11 of FIG. 3, an acrylic photosensitive resin film 26 is formed on the entire surface of the counter electrode 25 as shown in FIG. The photosensitive resin film 26 is a negative type film. A mask 33 is disposed so as to face the photosensitive resin film 26. The mask 33 has a transmission part 34 for transmitting UV light irradiated during the exposure process. Further, a light shielding film 35 is formed on the mask 33. Then, the photosensitive resin film 26 is irradiated with light (UV light) through the mask 33. Then, as shown in FIG. 11, the photosensitive resin film 26 corresponding to the region where the light shielding film 35 is not formed is left without being removed, and the main columnar spacer 26a and the sub columnar spacer 26b are formed. Further, the photosensitive resin film 26 corresponding to the region where the light shielding film 35 is formed is removed.

  Next, in the alignment film forming step S12 of FIG. 3, as shown in FIG. 11, an alignment film 27 made of polyimide or the like is formed on the surfaces of the main columnar spacer 26a and the sub columnar spacer 26b. Thereby, the counter substrate 21 side of the liquid crystal display device 100 is formed.

  Next, a bonding step S13 between the TFT substrate 5 and the counter substrate 21 in FIG. 3 is performed. Finally, by performing a liquid crystal sealing step S14 in which the liquid crystal 28 (see FIG. 2) is sealed between the TFT substrate 5 and the counter substrate 21, the liquid crystal display device 100 in the vertical electric field mode is completed.

  In the first embodiment, as described above, a contact hole forming pattern for forming a contact hole provided by removing the planarizing film 12 and a part on the surface side of the planarizing film 12 are removed. A contact hole forming region of the planarizing film 12 using a mask 29 in which a pattern for forming a recess having an opening 31b having a width smaller than the exposure limit resolution is formed to form the recess 12b provided by In addition, the exposure step of forming the contact hole 12a and the recess 12b corresponding to the sub-columnar spacer 26b in the planarizing film 12 by exposing the region corresponding to the sub-columnar spacer 26b, respectively. Thus, unlike the case of using a halftone mask, the width and size of the slit 31b of the mask 29 are adjusted without using a film having a low transmittance, thereby transmitting the slit (semi-transmissive portion) 31b of the mask 29. The rate can be adjusted. As a result, when the exposure step is performed, a contact hole 12a having a depth corresponding to the contact hole forming pattern and a recess 12b having a depth corresponding to the recess forming pattern are formed. Accordingly, the contact hole 12a and the recess 12b having different depths can be easily formed in the planarizing film 12 without using a mask having a complicated structure and suppressing difficulty in adjusting the transmittance. Can be formed. Further, compared to the case where both the contact hole 12a and the depression 12b are formed without using a halftone mask, the contact hole 12a formation process and the depression 12b formation process can be performed simultaneously. Therefore, contact holes 12a and depressions 12b having different depths can be easily formed simultaneously without increasing the number of processes.

  In the first embodiment, as described above, the load is applied to the counter substrate 21 and the TFT substrate 5 by forming the main columnar spacer 26a in the subpixel 3b and the subcolumnar spacer 26b in the subpixels 3a and 3c. When added, the main columnar spacer 26a can regulate the cell gap between the counter substrate 21 and the TFT substrate 5 and improve the surface pressing resistance. Further, when a load is applied to the counter substrate 21 and the TFT substrate 5 or the liquid crystal layer 28 provided between the counter substrate 21 and the TFT substrate 5 contracts at a low temperature, the counter substrate 21 and the TFT substrate 5 When deflected to the liquid crystal layer 28 side, the surface of the alignment film 27 formed on the TFT substrate 5 side of the sub-columnar spacer 26b contacts the surface of the alignment film 14 corresponding to the recess of the recess 12b on the TFT substrate 5 side. By contacting, the cell gap between the counter substrate 21 and the TFT substrate 5 can be regulated, and the generation of low temperature bubbles can be suppressed.

  Further, in the first embodiment, as described above, the pattern for forming the recesses having the opening 31b having a width smaller than the exposure limit resolution is substantially parallel to each other at an interval when viewed in a plan view. By including a plurality of linear slits 31b arranged in a straight line, when the exposure process is performed, the concave and convex recesses 12b can be easily formed in portions corresponding to the plurality of linear slits 31b of the planarizing film 12. Can be formed.

  In the first embodiment, as described above, the height in the direction (Z direction) perpendicular to the surface of the counter substrate 21 of the main columnar spacer 26a is orthogonal to the surface of the counter substrate 21 of the sub columnar spacer 26b. By being substantially equal to the height in the (Z direction), both the main columnar spacers 26a and the sub columnar spacers 26b can be formed at the same time by one exposure step, thereby suppressing an increase in the number of manufacturing steps. be able to.

  In the first embodiment, as described above, the mask 29 in which the contact hole formation pattern and the depression formation pattern having the opening 31b having a width smaller than the exposure limit resolution are formed is used. By forming the recess 12b corresponding to the contact hole 12a and the sub-columnar spacer 26b in the planarizing film 12, both the contact hole 12a and the recess 12b are simultaneously formed in the planarizing film 12 by one exposure process. Since it can form, it can suppress that the number of manufacturing processes increases.

  Further, in the first embodiment, as described above, the top of the convex portion of the concave-convex surface of the recess portion 12b is lower than the upper surface 12c of the planarizing film 12 other than the contact hole 12a and the recess portion 12b. By forming, the portion corresponding to the surface on the TFT substrate 5 side of the sub-columnar spacer 26b of the alignment film 27 and the top portion 12d of the convex portion of the concavo-convex shape surface of the recess portion 12b of the alignment film 14 are easily accommodated. A predetermined interval can be provided between the portions.

  In the first embodiment, as described above, the depression 12b is formed on the surface of the planarization film 12 located above the formation region of the thin film transistor 4, so that the sub-columnar spacer 26b is located above the depression 12b. Therefore, when the upper side of the thin film transistor 4 is shielded by the black matrix 22, the thin film transistor 4 and the sub-columnar spacer 26b can be shielded simultaneously.

  Further, in the first embodiment, as described above, the depression 12b is formed in the vicinity of the contact hole 12a for electrical connection with the source electrode 9 / drain electrode 10 of the thin film transistor 4, whereby the thin film transistor 4 In the vicinity, the contact hole 12a and the recess 12b can be simultaneously formed by one exposure process.

  Further, in the first embodiment, as described above, by forming the recess 12b in the planarizing film 12 formed in the transmission region, by using the planarizing film 12 made of a photosensitive material, A recess 12b can be formed in the planarizing film 12 formed in the transmission region. Thereby, in the transmissive liquid crystal display device 100, the sub-columnar spacer 26b for suppressing the generation of bubbles in the liquid crystal layer 28 can be formed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, unlike the first embodiment in which one of the main columnar spacers 26a and the sub columnar spacers 26b is arranged in one subpixel 3, the main columnar spacer 26a in one subpixel 3 is arranged. The liquid crystal display device 110 in which both the sub-columnar spacers 26b are arranged will be described.

  In the liquid crystal display device 110 according to the second embodiment, as shown in FIG. 12, a main columnar spacer 26a and a sub columnar spacer 26b are formed for each subpixel 3 (subpixels 3a to 3c). In addition, a recess 12b is formed on the side of the TFT substrate 5 facing the sub-columnar spacer 26b of the sub-pixel 3 (sub-pixels 3a to 3c). That is, the depression 12b is formed in all the subpixels 3. In addition, the other structure of 2nd Embodiment is the same as that of 1st Embodiment mentioned above.

  Next, with reference to FIG. 13 and FIG. 14, the mask 129 used for the exposure process of contact hole and hollow part formation process S4 is demonstrated.

  As shown in FIG. 13, the mask 129 is formed with a rectangular opening 31a for forming the contact hole 12a and a plurality of slits 31b having a width smaller than the exposure limit resolution for forming the recess 12b. Has been. Unlike the first embodiment described above, the mask 129 has openings 31a and slits 31b corresponding to all the subpixels 3 (subpixels 3a to 3c). Thereby, when the exposure process of the contact hole / depression portion forming step S4 is performed, the contact holes 12a and the depression portions 12b are formed in all the subpixels 3 (subpixels 3a to 3c).

  In addition, the other manufacturing method of 2nd Embodiment is the same as that of 1st Embodiment mentioned above.

  In the second embodiment, as described above, the main columnar spacer 26a and the sub columnar spacer 26b are formed in the sub-pixels 3 (3a to 3c), so that the main column disposed between the counter substrate 21 and the TFT substrate 5 is formed. Since the number of columnar spacers 26a and sub-columnar spacers 26b (spacer density) can be adjusted, surface pressing resistance when an excessive load is applied to the counter substrate 21 and the TFT substrate 5 and low-temperature bubbles are generated. Can be suppressed.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. 2, FIG. 15, and FIG. In the third embodiment, unlike the first embodiment in which the exposure process is performed using the mask 33 in which a plurality of linear slits 31b arranged in the X direction at intervals are arranged in parallel with each other. A method for manufacturing the liquid crystal display device 120 that performs an exposure process using a mask 229 in which a plurality of linear slits 131 arranged in the Y direction in parallel with each other at intervals will be described. The configuration of the third embodiment is the same as that of the first embodiment described above.

  As shown in FIG. 15, the mask 229 has a rectangular opening 31a for forming the contact hole 12a (see FIG. 2) and an exposure limit resolution for forming the recess 12b (see FIG. 2). A plurality of slits 131 having a small width are formed. Further, as shown in FIG. 16, in the sub-pixel 3c, the slit 131 of the mask 229 is disposed in a region overlapping the region where the sub-columnar spacer 26b on the counter substrate 21 side is formed in plan view. .

  In addition, the other manufacturing method of 3rd Embodiment is the same as that of 1st Embodiment mentioned above.

  In the third embodiment, as described above, the pattern for forming the recesses having the opening 131 having a width smaller than the exposure limit resolution is arranged in the Y direction substantially parallel to each other with a space when seen in a plan view. By including the plurality of linear slits 131 formed, the concave and convex portions 12b having the concavo-convex shape are easily formed in portions corresponding to the plurality of linear slits 131 of the planarizing film 12 when the exposure process is performed. be able to.

  The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. 2, FIG. 17, and FIG. In the fourth embodiment, unlike the first embodiment in which the exposure process is performed using a mask in which a plurality of linear slits 31b arranged in the X direction and spaced apart from each other are arranged in parallel in the X direction, Specifically, a method of manufacturing the liquid crystal display device 130 that performs an exposure process using a mask having a slit 231 formed in a hexagonal shape (honeycomb shape) will be described. The configuration of the fourth embodiment is the same as that of the first embodiment described above.

  As shown in FIG. 17, the mask 329 has a rectangular opening 31a for forming the contact hole 12a (see FIG. 2) and an exposure limit resolution for forming the recess 12b (see FIG. 2). A plurality of slits 231 having a small width are formed. Further, as shown in FIG. 18, in the sub-pixel 3c, the slit 231 of the mask 329 is disposed in a region overlapping the region where the sub-columnar spacer 26b on the counter substrate 21 side is formed in plan view. .

  In addition, the other manufacturing method of 4th Embodiment is the same as that of 1st Embodiment mentioned above.

  In the fourth embodiment, as described above, the recess forming pattern having the opening 231 having a width smaller than the exposure limit resolution is formed in a hexagonal shape (honeycomb shape) in a plan view. By including 231, when the exposure process is performed, the concave-convex recess 12 b can be easily formed in the portion corresponding to the slit 231 formed in the hexagonal shape of the planarizing film 12.

  The remaining effects of the fourth embodiment are similar to those of the aforementioned first embodiment.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described with reference to FIG. 2, FIG. 19, and FIG. In the fifth embodiment, unlike the first embodiment in which the exposure process is performed using a mask in which a plurality of linear slits 31b arranged in the X direction and spaced apart from each other are arranged in parallel in the X direction, Specifically, a manufacturing method of the liquid crystal display device 140 that performs an exposure process using a mask 429 in which an opening (hole) 331 formed in a circular shape is formed will be described. The configuration of the fifth embodiment is the same as that of the first embodiment described above.

  As shown in FIG. 19, the mask 429 has a rectangular opening 31a for forming the contact hole 12a (see FIG. 2) and an exposure limit resolution for forming the recess 12b (see FIG. 2). A plurality of openings (holes) 331 having a small diameter are formed. As shown in FIG. 20, in the sub-pixel 3c, the opening (hole) 331 of the mask 429 overlaps with the region where the sub-columnar spacer 26b on the counter substrate 21 side is formed in plan view. Placed in.

  In addition, the other manufacturing method of 5th Embodiment is the same as that of 1st Embodiment mentioned above.

  In the fifth embodiment, as described above, an opening (hole) 331 in which a pattern for forming a recess having an opening 331 having a width smaller than the exposure limit resolution is formed in a circular shape when seen in a plan view. Thus, when the exposure process is performed, the concave and convex portion 12b can be easily formed in a portion corresponding to the opening (hole) 331 formed in the circular shape of the planarizing film 12.

  The remaining effects of the fifth embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to fifth embodiments, the example using the liquid crystal display device in the vertical electric field mode is shown, but the present invention is not limited to this. For example, a liquid crystal display device other than the vertical electric field mode may be used.

  In the first to fifth embodiments, the example in which the recessed portion is formed for every two subpixels or for every one subpixel is shown, but the present invention is not limited to this. For example, one recess may be formed for every three or more subpixels.

  Moreover, in the said 1st-5th embodiment, although the example which forms a hollow part above the formation area of a thin-film transistor was shown, this invention is not restricted to this. For example, you may form a hollow part in areas other than the formation area of a thin-film transistor.

  Moreover, in the said 1st-5th embodiment, although the linear slit, the hexagonal-shaped slit, and the hole formed in circular shape were shown as an example of the pattern for hollow part formation, this invention is shown to this. Not exclusively. For example, as long as the opening has a width smaller than the exposure limit resolution, a shape other than a straight slit, a hexagonal slit, and a hole formed in a circular shape, such as a triangular shape or a quadrangular shape (square shape), may be used. .

  Moreover, in the said 1st-5th embodiment, although the planarization film | membrane consisting of an acrylic photosensitive resin was shown as an example of the insulating film which consists of photosensitive materials, this invention is not restricted to this. For example, as long as it is an insulating film capable of performing an exposure process, it may be other than a planarizing film made of an acrylic photosensitive resin.

  In the first to fifth embodiments, an example in which a positive acrylic photosensitive resin is used as the material of the planarizing film has been described. However, the present invention is not limited to this. For example, a negative acrylic photosensitive resin may be used. In this case, the photosensitive resin film corresponding to the region where the light shielding film is formed is removed, and a contact hole and a depression are formed. Further, the photosensitive resin film corresponding to the region where the light shielding film is not formed is left without being removed.

  In the first to fifth embodiments, the negative acrylic photosensitive resin film is used as the material for the main columnar spacer and the sub columnar spacer. However, the present invention is not limited to this. For example, a positive acrylic photosensitive resin film may be used. In this case, the photosensitive resin film corresponding to the region where the light shielding film is formed remains without being removed, and the main columnar spacer and the sub columnar spacer are formed. Further, the photosensitive resin film corresponding to the region where the light shielding film is not formed is removed.

  In the first to fifth embodiments, an example in which a pixel is configured by sub-pixels of three colors of red, green, and blue has been described. However, the present invention is not limited to this. For example, a pixel may be configured by sub-pixels of two colors or four colors or more.

  Moreover, although the example which applied the opening part 31a as a pattern for contact hole formation was shown in the said 1st-5th embodiment, this invention is not limited to this. For example, the opening 31a, which is a contact hole forming pattern, may be used not for forming the contact hole but for removing (completely) all the photosensitive resin film 26 around the display area.

3, 3a, 3b, 3c Subpixel 4 Thin film transistor 5 TFT substrate (second substrate) 9 Source electrode 10 Drain electrode 12 Planarizing film (insulating film) 12a Contact hole 12b Depressed portion 12c Flat surface (upper surface) 12d Top portion 21 Opposite substrate (First substrate) 26a Main columnar spacer (first spacer) 26b Sub columnar spacer (second spacer) 29, 129, 229, 329, 429 Mask 31b, 131, 231 Slit (opening) 331 Opening 100, 110, 120, 130, 140 Liquid crystal display device

Claims (10)

Forming a first spacer and a second spacer on the first substrate side of the first substrate and the second substrate arranged to face each other;
Forming an insulating film made of a photosensitive material on the second substrate side;
Exposure limit resolution for forming a contact hole forming pattern for forming a contact hole provided by removing the insulating film and a recess provided by removing a part of the surface side of the insulating film By exposing the contact hole forming region of the insulating film and the region corresponding to the second spacer using a mask in which a pattern for forming a recess having an opening having a smaller width is formed, A method of manufacturing a liquid crystal display device, comprising: an exposure step of forming a contact hole and a depression corresponding to the second spacer in the insulating film. A plurality of subpixels are provided on the first substrate and the second substrate,
2. The liquid crystal display according to claim 1, wherein the step of forming the first spacer and the second spacer includes a step of forming at least one of the first spacer and the second spacer in the sub-pixel. Device manufacturing method.   The pattern for forming the dent portion having an opening having a width smaller than the exposure limit resolution includes a plurality of linear slits arranged substantially parallel to each other at an interval when seen in a plan view. 3. A method for producing a liquid crystal display device according to 1 or 2.   The pattern for forming the dent part having an opening having a width smaller than the exposure limit resolution includes a slit or a hole formed in a polygonal shape or a circular shape when seen in a plan view. The manufacturing method of the liquid crystal display device of description.   5. The height of the first spacer in a direction orthogonal to the surface of the first substrate is substantially equal to a height of the second spacer in a direction orthogonal to the surface of the first substrate. The manufacturing method of the liquid crystal display device of description. The step of forming an insulating film made of a photosensitive material on the second substrate side includes a step of forming a planarizing film made of a photosensitive material on the second substrate side,
In the exposure step, a contact hole is formed in the planarization film using a mask in which the contact hole forming pattern and the recess forming pattern having an opening having a width smaller than the exposure limit resolution are formed. The manufacturing method of the liquid crystal display device of any one of Claims 1-5 including the process of forming the hollow part corresponding to a said 2nd spacer. The exposure step includes a step of forming a surface of the recess corresponding to the second spacer of the planarization film in a concavo-convex shape,
7. The liquid crystal display device according to claim 6, wherein a top portion of a convex portion of the concave-convex surface of the concave portion is formed to be lower than an upper surface other than the contact hole and the concave portion of the planarizing film. Manufacturing method. Forming a thin film transistor on the second substrate side;
8. The method of manufacturing a liquid crystal display device according to claim 6, wherein the exposing step includes a step of forming the depression portion on a surface of a planarizing film located above the formation region of the thin film transistor.   9. The method of manufacturing a liquid crystal display device according to claim 8, wherein the exposing step includes a step of forming the recess in the vicinity of a contact hole for establishing electrical connection with the source / drain electrode of the thin film transistor.   10. The method of manufacturing a liquid crystal display device according to claim 1, wherein the exposing step includes a step of forming the depression in the insulating film formed in the transmission region.

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