JP2013047829A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device with wide viewing angle.SOLUTION: A pixel electrode 19 for driving a liquid crystal is formed on a flattened insulating film 18 covering a thin-film transistor, a vertical alignment film 31 which is not to be subjected to rubbing process is formed on the pixel electrode 19, an orientation control window 24 having no electrode is formed in a common electrode 23, and a vertical alignment film 32 which is not to be subjected to the rubbing process is formed on the common electrode 23. The liquid crystal having negative dielectric anisotropy is initial-orientation-controlled along a normal direction without having pre-tilt, an inclination direction is controlled by inclined electric fields in an end of the pixel electrode 19 and an end of the orientation control window 24, by applying voltage, and pixels are divided. A black matrix between the pixels is omitted, a light shielding film 21BL is formed only in an area corresponding to a TFT, and light leak current is prevented.

Description

  The present invention relates to a semiconductor device, and more particularly to a liquid crystal display (LCD).

  In recent years, flat panel displays such as LCDs, organic electroluminescence (EL) displays, plasma displays, etc. have been actively developed and put into practical use. Above all, LCDs are excellent in terms of thinness and low power consumption, and have already become mainstream in the field of OA equipment and AV equipment. In particular, an active matrix LCD in which TFTs are arranged as switching elements for controlling the pixel information rewriting timing for each pixel enables large-screen, high-definition video display, so that various televisions, personal computers, It is often used for monitors of portable computers, digital still cameras, video cameras and the like.

  A TFT is a field effect transistor (FET) obtained by forming a semiconductor layer together with a metal layer in a predetermined shape on an insulating substrate. In the active matrix LCD, the TFT is connected to each capacitance for driving the liquid crystal formed between a pair of substrates sandwiching the liquid crystal.

  FIG. 13 is an enlarged plan view of a display pixel portion of the LCD, and FIG. 14 is a cross-sectional view taken along the line BB. A gate electrode (51) such as Cr, Ti, or Ta is formed on the substrate (50), and a gate insulating film (52) is formed so as to cover it. On the gate insulating film (52), an amorphous silicon, that is, an a-Si film (53) is formed in an island shape so as to pass over the gate electrode (51). On the a-Si film (53), an N + type a-Si film (53N) doped with impurities at both ends is formed to form an ohmic layer. An etch stopper (54) is left on the channel region of the a-Si film (53). A drain electrode (56) and a source electrode (57) are formed on the N + a-Si film (53N), respectively. An interlayer insulating film (58) is formed so as to cover them, and a pixel electrode (59) made of ITO (indium tin oxide) or Al is formed on the interlayer insulating film (58), and the interlayer insulating film (58 ) Is connected to the source electrode (57) through the contact hole opened in the above. On top of this, an alignment film (71) such as polyimide is formed, and a rubbing process is performed as shown in FIG. The TFT substrate is configured as described above.

  On the substrate (60) disposed opposite to the TFT substrate (50), R, G, B color filters (61) made of film resist are formed, and positions corresponding to the respective pixel electrodes (59). Is provided. Also, a black matrix (61BM) made of a light-shielding film resist is formed between the color filters (61) without any gaps at positions corresponding to the gaps between the pixel electrodes (59) and the TFTs. On these color filter layers, a common electrode (62) such as ITO is formed. On the common electrode (62), the same alignment film (72) as that on the substrate (50) side is provided, and a rubbing process is performed as shown in FIG. The counter substrate is configured as described above.

  A liquid crystal layer (80) is loaded between the TFT substrate (50) and the counter substrate (60), and the electric field strength formed by the voltage applied between the pixel electrode (59) and the common electrode (62) is increased. Accordingly, the direction, that is, the orientation of the liquid crystal molecules (81) is controlled. Although not shown, a polarizing plate is provided outside the substrates (50) and (60), and the polarization axes are orthogonal to each other. The linearly polarized light passing between the polarizing plates is modulated when passing through the liquid crystal layer (80) controlled to have a different orientation for each display pixel, and is controlled to a desired transmittance.

  In the example given here, the liquid crystal has negative dielectric anisotropy, and the alignment films (71, 72) are vertical alignment films in which the initial alignment of the liquid crystal is controlled in the vertical direction of the substrate. In this case, when no voltage is applied, the linearly polarized light passing through one polarizing plate passes through the liquid crystal layer (80) and is blocked by the other polarizing plate, and the display is recognized as black. When a voltage is applied, the linearly polarized light that has passed through one polarizing plate undergoes birefringence in the liquid crystal layer (80), changes to elliptically polarized light, passes through the other polarizing plate, and the display approaches white. This method is called normally black (NB) mode. In particular, the vertical alignment films (71, 72) are rubbed, and the orientation of the liquid crystal molecules (81) in the initial state is controlled with a slight inclination (pretilt) from the normal direction. This pretilt angle (θ) is normally set to 1 ° to 5 °. The liquid crystal molecules (81) are electrically uniaxial, and the angle formed with the electric field direction is determined by the electric field strength, but the azimuth angle about the electric field direction is not controlled. The liquid crystal molecules (81) having negative dielectric anisotropy are tilted in a direction different from the electric field direction. However, by applying a pretilt, the liquid crystal molecules (81) are directed to be uniformly tilted in the pretilt direction by applying a voltage. In this way, by providing a pretilt angle and controlling the liquid crystal molecules (81) to be aligned, the orientation of the liquid crystal is prevented from varying in the plane direction and the display quality is prevented from deteriorating. .

  In addition, the black matrix (61BM) is provided for the purpose of preventing light leakage due to birefringence caused by liquid crystal to which a pretilt is applied in a region where a voltage between display pixels is not applied.

  The liquid crystal having negative dielectric anisotropy changes the orientation so that the orientation direction is perpendicular to the electric field direction. At this time, the liquid crystal generates an action against an electric field, but such a change from the vertical alignment of the liquid crystal is generally more than the case where the liquid crystal having positive dielectric anisotropy such as TN changes from the parallel alignment. The stability is bad. In particular, the unevenness at the contact interface with the alignment films (71, 72) due to the steps of the TFT and the color filter layer affects the alignment change and causes the display quality to deteriorate.

  Further, as shown in FIGS. 15 and 16, conventionally, by applying a rubbing process to the vertical alignment films (71, 72), a pretilt (θ) is imparted to the initial alignment of the liquid crystal as shown in FIG. Therefore, when a voltage is applied, all the liquid crystal molecules (81) are tilted in the pretilt direction (rightward in FIG. 14). For this reason, for example, the angle of inclination of the liquid crystal molecules (81) with respect to the optical path is relatively different between the viewing from the upper right direction in FIG. 14 and the viewing from the upper left direction, and the transmittance appears to change. For this reason, there is a problem of so-called viewing angle dependency in which the luminance or contrast ratio changes depending on the viewing direction.

  Further, since the black matrix (61BM) formed on the counter substrate (60) side must cover the area between the pixel electrodes (59) without omission, there is no deviation at the time of bonding to the TFT substrate (50) side. Considering this, it is formed larger. For this reason, there is a problem that the effective display area is reduced and the aperture ratio is lowered. Further, the rubbing treatment for forming the vertical alignment film (71) on the TFT substrate side causes the electrostatic breakdown of the TFT, resulting in a display defect and a decrease in yield.

A liquid crystal having a negative dielectric anisotropy is sealed between the first substrate and the second substrate which are arranged to face each other, and polarized light is polarized on the outer surface of the first substrate and / or the second substrate. In a vertical alignment type liquid crystal display device provided with a plate and performing display by modulating polarized light that has passed through the polarizing plate with the liquid crystal, an opposing surface of one support substrate serving as the first substrate A plurality of thin film transistors arranged in a matrix, a pixel electrode for driving a liquid crystal, and a vertical alignment film that is formed on the pixel electrode and is not subjected to rubbing treatment, A color filter layer, a common electrode for driving a liquid crystal, and a vertical alignment film that has not been rubbed are provided on the opposite surface side of the other support substrate to be the substrate, and the opposite surface of the second substrate On the side, facing the area between the pixel electrodes And a light-shielding film smaller than a region between the pixel electrodes is further provided, and the color filter layer is opposed to the corresponding pixel electrode and in the region between the pixel electrodes around the pixel electrode. The pixel electrode is formed larger than the corresponding pixel electrode so as to face a region where no light-shielding film is provided, and a voltage is applied between the pixel electrode and the common electrode to surround the pixel electrode and the common electrode. By generating an oblique electric field therebetween, the alignment direction of the liquid crystal is inclined from the end of the pixel electrode toward the inside of the pixel electrode.

  Accordingly, in the second substrate, at least a region corresponding to the pixel electrode and the region between the pixel electrodes is translucent, and at least a part of the region corresponding to the region between the pixel electrodes includes the liquid crystal and the polarizing plate. And is shielded from light. This eliminates the need to form a light-shielding film larger than between the pixel electrodes in consideration of the difference in bonding between the first substrate and the second substrate, enlarges the effective display area, and increases the aperture ratio.

  As is apparent from the above description, in the present invention, the aperture ratio is increased by forming the light shielding film smaller than between the pixel electrodes, and the contrast ratio is further improved by shielding the light between the pixel electrodes. it can.

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 AA line of FIG.1 and FIG.9. It is a top view which shows the structure of LCD. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is a top view of the liquid crystal display device concerning the 2nd Embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is process sectional drawing which shows the manufacturing method concerning embodiment of this invention. It is a top view of the liquid crystal display device which concerns on the conventional form. It is sectional drawing along the BB line of FIG. It is process sectional drawing which shows the manufacturing method of the conventional liquid crystal display device. It is process sectional drawing which shows the manufacturing method of the conventional liquid crystal display device.

FIG. 1 is a plan view of a display pixel portion of the LCD according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA. On the substrate (10), a gate electrode (11) made of Cr, Ti, Ta or the like is formed, and a gate insulating film (12) is formed covering the gate electrode (11). On the gate insulating film (12), a p-Si film (13) is formed in an island shape so as to pass above the gate electrode (11). In the p-Si film (13), a region immediately above the gate electrode (11) is a non-doped channel region (CH), and both sides of the channel region (CH) are doped with N-type impurities such as phosphorus at a low concentration. An LD (lightly doped) region (LD) and the outside thereof are a source region (NS) and a drain region (ND) doped with the same impurity at a high concentration, and have an LDD structure.

  On the channel region (CH), an implantation stopper (14) used as a mask at the time of ion implantation when the LD region (LD) is formed is left. An interlayer insulating film (15) is formed to cover the p-Si film (13), and a drain electrode (16) and a source electrode (17) are formed on the interlayer insulating film (15). ) Is connected to the drain region (ND) and the source region (NS) of the p-Si film (13) through the contact hole opened in. A flattening insulating film (18) such as SOG, BPSG, or acrylic resin is formed so as to cover the drain electrode (16) and the source electrode (17), and ITO (indium) is formed on the flattening insulating film (18). A pixel electrode (19) made of tin oxide) or Al is formed and connected to the source electrode (17) through a contact hole opened in the planarization insulating film (18). A vertical alignment film (31) such as polyimide is formed thereon.

At a position facing the TFT substrate (10), a substrate (20) serving as a counter substrate is disposed with a liquid crystal layer (40) interposed therebetween. On the substrate (20), R, G and B color filters (21) made of a film resist are formed and provided at positions corresponding to the respective pixel electrodes (19). A light shielding film (21BL) made of a non-translucent film resist is formed in a region facing the TFT, and is located between the color filters (21). A protective film (22) made of a flattening insulating film such as acrylic resin is formed on the color filter (21) and the light shielding film (21BL), and further, a common material such as ITO is formed on the protective film (22). An electrode (23) is formed. In the common electrode (23), an orientation control window (24) formed by the absence of ITO is provided. As shown in FIG. 1, the orientation control window (24) is formed in a shape that vertically cuts through the central portion of the pixel and then divides into two branches at an angle of about 45 ° from the central portion toward the corner of the pixel. Yes. On the common electrode (23), the same vertical alignment film (32) as that on the substrate (10) side is provided.

  In the present invention, the planarization insulating film (18) on the TFT substrate side and the planarization protective film (22) on the counter substrate side serve to enhance the planarity as the base of the pixel electrode (19) and the common electrode (23), respectively. doing. In particular, when a liquid crystal having negative dielectric anisotropy changes from the vertical alignment, a favorable alignment change is promoted when an interaction with the electric field, that is, an action against the electric field is generated. Further, in the high-definition LCD, in consideration of the relatively large unevenness of the TFT or the color filter layer (21), by relaxing these steps, the contact interface with the liquid crystal layer (80) can be reduced. Display quality is improved by improving flatness and improving uniformity of orientation.

  Further, the vertical alignment films (31, 32) are not rubbed, and as shown in FIG. 2, the pretilt angle is within 1 °, ideally 0 °. That is, the orientation vector indicating the average orientation within the minute range coincides with the normal direction in the initial state, or is within the range of 1 °. Therefore, even when a voltage is applied, the liquid crystal molecules (41) are oriented in the normal direction or within a range of 1 ° from the normal direction between display pixels.

  In this configuration, when a voltage is applied, an electric field (42) is formed between the pixel electrode (19) and the common electrode (23), and the liquid crystal molecules (41) tilt, but at the end of the pixel electrode (19), The electric field (42) is inclined obliquely from the pixel electrode (19) toward the common electrode (23). For this reason, the orientation of the liquid crystal molecules (41) changes so as to incline from the electric field (42) at the shortest. That is, it is inclined toward the inner side of the pixel electrode (19) by the action of the oblique electric field without depending on the directivity imparted by the pretilt as in the prior art. As shown in FIG. 1, the four sides of the pixel electrode (19) are similarly inclined inward.

Further, in the alignment control window (24), since the common electrode (23) is absent, an electric field is not formed even when voltage is applied, and the liquid crystal molecules (41) are in the initial alignment state in the region of the alignment control window (24). Fixed to. The alignment controlled by the four sides of the pixel electrode (19) extends to the central region of the pixel electrode (19) due to the continuity of the liquid crystal. (24) Fixed above. That is, in FIG. 1, in each small region in the display pixel partitioned by the orientation control window (24), the liquid crystal orientations are directed in four different directions, and so-called pixel division is performed. Accordingly, since each small region having different transmittance is averaged and recognized with respect to one display pixel, it is visually recognized at a constant luminance at any viewing angle, and the problem of viewing angle dependency is solved.

  In particular, in the structure of the present invention, since the planarization insulating film (18) is used as the base of the pixel electrode (19), the alignment of the liquid crystal in the initial state is the normal direction or the normal direction with high uniformity. Within 1 °. Further, the planarization insulating film (18) is formed as thick as about 1 μm, and the liquid crystal is not easily affected by the electric field of the TFT below and the electrode lines (1, 2, 16, 17), As described above, the pixel division by the combined action of the oblique electric field (42) at the end of the pixel electrode (19) and the no electric field in the alignment control window (24) is performed very well.

Here, by sufficiently increasing the width of the orientation control window (24), an oblique electric field (42) is generated at the end of the orientation control window (24) as shown in FIG. In this case, in the shape of the alignment control window (24) as shown in FIG. 1, the inclination direction of the liquid crystal molecules (41) at the end of the pixel electrode (19) and the liquid crystal at the end of the alignment control window (24). The tilt direction of the molecule (41) is the same for any region, or at least within 45 °, and the alignment control action at the end of the pixel electrode (19) and the end of the alignment control window (24). The orientation control action in is almost the same, and the controllability is improved. That is, in each small area of the display pixel partitioned by the alignment control window (24), the same alignment control is applied from the end of the pixel electrode (19) and the end of the alignment control window (24), and the alignment is performed with high uniformity. Are aligned.

  On the other hand, the conventional substrate (20) is not provided with a black matrix (61BM) that covers the entire area between the pixels as shown in FIGS. In the present invention, since the liquid crystal molecules (41) are in the normal direction or within 1 ° from the normal direction in the initial state, light leakage due to the pretilt angle between the pixels is suppressed and light is completely blocked. It is. However, in the present invention, a light shielding film (21BL) is provided only on the TFT in order to suppress a leakage current due to light incident on the TFT. For this reason, since it is not necessary to form a large black matrix in consideration of the bonding deviation on the counter substrate (20) side, it is possible to prevent the effective display area from being reduced by the light shielding film and the aperture ratio from being lowered.

The TFT described here uses polycrystalline silicon (p-Si) instead of amorphous silicon (a-Si) which has been widely used as a semiconductor layer used as an active layer. This p-Si TFT has a large on-current, the size of the TFT is reduced, and the aperture ratio is improved and the definition is increased. Further, the p-Si TFT has a high operating speed, and not only the pixel portion but also a peripheral drive circuit (driver) can be integrally formed on the same substrate, and a driver built-in type LCD has been manufactured. Note that the peripheral driver portion is configured by a CMOS composed of N-ch and P-ch TFTs having the same structure as in FIG. However, the LD region (LD) is not formed for the P-ch TFT.

  FIG. 3 shows the configuration of the driver built-in type LCD. A gate line (1) connected to the gate electrode (11) and a drain line (2) connected to the drain electrode (16) are arranged to intersect at the center, and the TFT (3) is arranged at the intersection. A pixel electrode (4) connected to the TFT (3) is formed to form a pixel portion. A gate driver (5) for supplying a scanning signal to the gate line (1) and a drain driver (6) for supplying a pixel signal to the drain line (2) are formed around the pixel portion. The pixel portion, the gate driver (5) and the drain driver (6) are formed on the same substrate. On the other hand, a common electrode (7) is formed on another substrate sandwiching the liquid crystal. The display pixel is configured such that the common electrode (7) and the liquid crystal are partitioned by the pixel electrode (4).

  4 to 7 show a manufacturing method of the TFT substrate of the LCD according to the embodiment of the present invention. First, in the process of FIG. 4A, a gate electrode (11) is formed by depositing Cr on the substrate (10) by sputtering and etching it.

  In the step of FIG. 4B, a gate insulating film (12) made of SiNx and SiO2 is formed on the entire surface covering the gate electrode (11) by plasma CVD, and then amorphous silicon (a -Si) (13a) is deposited. The a-Si (13a) is formed by decomposing and depositing monosilane SiH4, which is a material gas, or disilane Si2H4 by heat and plasma of about 400 °.

  In the step of FIG. 4C, laser annealing is performed to crystallize a-Si (13a) to form p-Si (13). Laser annealing is performed by, for example, pulse laser line beam scanning. Since the substrate temperature can be performed at a relatively low temperature of 600 ° C. or less, a relatively inexpensive non-alkali glass substrate can be used as the substrate (10). A low cost process is realized.

  In the step of FIG. 5 (d), SiO2 is deposited on the substrate on which p-Si (13) is formed, and this is etched using the backside exposure method, so that it is above the gate electrode (11). An injection stopper (14) is formed. The backside exposure is performed by applying a resist on SiO2 and exposing it from below the substrate (10) to expose and develop the gate electrode (11) in a shape utilizing a shadow. Using this implantation stopper (14) as a mask, ion implantation of phosphorus (P) showing N-type conductivity is performed on p-Si (13) at a low dose of about 10 13. The region other than the region where (14) is formed is doped at a low concentration (N−). At this time, the region immediately below the injection stopper (14), that is, the region directly above the gate electrode (11) is maintained in the intrinsic layer and becomes the channel region (CH) of the TFT. The resist when the implantation stopper (14) is etched may be left at the time of ion implantation and may be removed after the ion implantation.

  In the step of FIG. 5E, a resist (RS) larger than the gate electrode (11) is formed at least in the channel length direction, and using this as a mask, phosphorus (P) ions are implanted into p-Si (13). A high dose of about 10 to the 15th power is performed, and a region other than the resist (RS) is doped at a high concentration (N +). At this time, the low concentration region (N−) and the channel region (CH) are maintained in the region immediately below the resist (RS). As a result, an LDD structure is formed in which the high-concentration source and drain regions (NS, ND) are located on both sides of the channel region (CH) with the low-concentration LD region (LD) interposed therebetween.

  After the resist (RS) is stripped, activation annealing such as heating or laser irradiation is performed for the purpose of restoring the crystallinity of the p-Si film doped with impurity ions and replacing the impurity lattice.

  In the step of FIG. 6F, this p-Si (13) is etched to leave only the necessary region of the TFT to form an island, and then an interlayer insulating layer (15) made of SiNx or the like is formed. A portion corresponding to the drain region (NS, ND) is removed by etching to form a contact hole (CT), and a part of p-Si (13) is exposed.

  In the step of FIG. 6G, a source electrode (17) connected to the source region (NS) through the contact hole (CT) by depositing Al / Mo by sputtering and etching it, and A drain electrode (16) connected to the drain region (ND) is formed. The TFT is completed here.

  Further, in the step of FIG. 7 (h), a planarization insulating film (18) is formed by covering a TFT and covering with a photosensitive acrylic resin, and exposing and developing this to form a contact hole in the display pixel portion. After forming and exposing the upper part of the source electrode (17), ITO is formed into a film by sputtering, and this is etched to form the pixel electrode (19) connected to the source electrode (17).

  In the step of FIG. 7 (i), a polyimide film is formed into a liquid state by printing, pre-baked at 80 ° for 10 minutes, followed by main baking at 180 ° for 30 minutes and drying to obtain a vertical alignment film ( 31).

  The TFT substrate is completed through the above steps.

  Next, a manufacturing method on the counter substrate side will be described with reference to FIGS. First, in the process of FIG. 8A, R, G, and B color filters (21R, 21G, and 21B) are formed on the substrate (20). The R color filter (21R) is formed by first attaching a photosensitive R film resist, exposing it to a shape corresponding to the R display pixel, and developing it. The G color filter (21G) and the B color filter (21B) are formed in the same manner.

  In the step of FIG. 8B, a non-translucent film resist is attached.

  In the step of FIG. 8C, the film resist is exposed to a shape corresponding to the pixel only in the region facing the TFT, and developed, for example, a light shielding film (21BL) is formed in the gap between the color filters (21R, 21B). Form.

  In the step of FIG. 9 (d), these color filters (21R, 21G, 21B) and the light shielding film (21BL) are covered to form an acrylic resin, thereby protecting the color filters (21R, 21G, 21B). (22) is formed. The protective film (22) also serves as a planarizing film for the base of the common electrode (23).

  In the step of FIG. 9 (e), ITO is formed into a film by sputtering, and this is etched to form the common electrode (23) and the alignment control window (24) which is an electrode absent portion in the common electrode (23). To do.

  In the step of FIG. 9 (f), a polyimide film is formed into a liquid form by printing, pre-baked at 80 ° for 10 minutes, followed by main baking at 180 ° for 30 minutes and drying to obtain a vertical alignment film. (32) is formed.

  The counter substrate is completed through the above steps.

Next, a second embodiment of the present invention will be described. In addition, the overlapping description is omitted. FIG. 10 is a plan view of the display pixel portion. The cross-sectional structure along the line AA in FIG. 10 is the same as FIG. In the present embodiment, a black matrix (21BM) that covers the TFT region and slightly covers the space between the pixel electrodes (19) is provided on the counter substrate side. As described above, since the liquid crystal is not given a pretilt angle, there is almost no light leakage in the region between the pixels. However, in some cases, a small amount of light leakage may occur due to wraparound of light inside the panel. For this reason, the black matrix (21BM) is used to cover not only the TFT but also the inter-pixel region.
) Can be completely shielded between pixels, and the contrast ratio can be further improved.

  However, the black matrix (21BM) is formed slightly smaller than between the pixels so that the black matrix (21BM) does not interrupt the pixel electrode (19) due to a shift at the time of bonding.

  11 and 12 show a manufacturing method on the counter substrate side according to the present embodiment. First, in the step of FIG. 11A, R, G, and B color filters (21R, 21G, and 21B) are formed on the substrate (20) so as to be slightly larger than the corresponding pixel electrodes (19).

  In the step of FIG. 11B, a non-translucent film resist is pasted.

  In the step of FIG. 11C, the film resist is exposed and developed in a shape corresponding to the region facing the TFT and the region between the pixels, so that, for example, a black matrix is formed in the gap between the color filters (21R, 21B). (21BM) is formed.

  In the step of FIG. 12D, the color filters (21R, 21G, 21B) and the black matrix (21BM) are covered and an acrylic resin is formed, thereby protecting the color filters (21R, 21G, 21B). (22) is formed. The protective film (22) also serves as a planarizing film for the base of the common electrode (23).

  In the step of FIG. 12 (e), ITO is formed by sputtering, and this is etched to form the common electrode (23) and the alignment control window (24) which is an electrode absent portion in the common electrode (23). To do.

  In the step of FIG. 12 (f), a polyimide film is formed into a liquid form by printing, prebaked at 80 ° for 10 minutes, and subsequently baked at 180 ° for 30 minutes and dried to obtain a vertical alignment film. (32) is formed.

  In the present invention, as described above, the step of FIG. 7 (i) for manufacturing the TFT substrate (10), that is, the step of forming the vertical alignment film (31), and FIG. 9 (f) and FIG. In the step 12 (f), that is, the formation step of the alignment film (32), the rubbing treatment is not performed. Therefore, the liquid crystal is contained in the normal direction or within a range of 1 ° from the normal direction without having a pretilt in the initial alignment. In particular, by not performing the rubbing treatment on the TFT substrate side, the electrostatic breakdown of the TFT can be prevented. For this reason, in the driver built-in type, TFTs are densely packed in the driver part (5, 6), and even if the structure is much larger than the pixel part, it is prevented from causing electrostatic breakdown of the TFT and the yield is improved. can do.

  Further, in the process of FIGS. 8C and 11C for manufacturing the counter substrate 20, the formation of the light shielding film 21BL and the black matrix 21BM is as shown in FIGS. Further, only the region corresponding to the TFT and the narrow region between the pixels are not formed in the entire region between the pixels. That is, light shielding is performed between pixels by a combination of a liquid crystal and a polarizing plate. For this reason, the loss of the effective display area due to the enlargement of the black matrix is eliminated, and the aperture ratio is increased.

1 gate line, 2 drain line, 10 substrate, 11 gate electrode, 13 p-Si, 16 drain electrode, 17 source electrode, 18 planarization insulating film, 19 pixel electrode, 20 substrate, 21 color filter, 21BL light shielding film, 21BM Black matrix, 22 protective film, 23 common electrode, 24 alignment control window, 31, 32 vertical alignment film, 40 liquid crystal layer, 41 liquid crystal molecule, 42 electric field.

Claims (9)

A liquid crystal having a negative dielectric anisotropy is sealed between the first substrate and the second substrate which are arranged to face each other, and polarized light is polarized on the outer surface of the first substrate and / or the second substrate. In a vertical alignment type liquid crystal display device comprising a plate and performing display by modulating polarized light that has passed through the polarizing plate with the liquid crystal,
On the opposite surface side of one support substrate that is the first substrate,
A plurality of thin film transistors arranged in a matrix, a pixel electrode for driving a liquid crystal, and a vertical alignment film that is formed on the pixel electrode and is not subjected to rubbing treatment are provided,
On the opposite surface side of the other support substrate to be the second substrate,
A color filter layer, a common electrode for driving liquid crystal, and a vertical alignment film not subjected to rubbing treatment,
On the opposite surface side of the second substrate, a light-shielding film that is opposite to the region between the pixel electrodes and smaller than the region between the pixel electrodes is further provided, and the color filter layer includes the corresponding color filter layer. It is formed larger than the corresponding pixel electrode so as to face the pixel electrode and also face the region where the light shielding film is not provided in the region between the pixel electrodes around the pixel electrode,
By applying a voltage between the pixel electrode and the common electrode, an oblique electric field is generated between the periphery of the pixel electrode and the common electrode, so that the alignment direction of the liquid crystal is changed from the end of the pixel electrode. A liquid crystal display device, wherein the liquid crystal display device is inclined toward the inner side of the pixel electrode.   An alignment control unit is provided in a region facing the pixel electrode in the common electrode on the opposite surface side of the second substrate, and the alignment control unit, the periphery of the pixel electrode, and between the common electrodes 2. The liquid crystal display device according to claim 1, wherein the alignment direction of the liquid crystal is inclined toward the inner side of the pixel electrode by a joint action with the oblique electric field generated in the pixel electrode.   An electrode wiring connected to the thin film transistor is provided on the opposite surface side of the first substrate, covers the thin film transistor and the electrode wiring, and smoothes the unevenness caused by the thin film transistor and the electrode wiring. The liquid crystal display device according to claim 1, further comprising: The alignment direction of the liquid crystal controlled by the oblique electric field generated between the periphery of the pixel electrode and the common electrode and the alignment direction of the liquid crystal controlled by the alignment control unit are the same or within 45 °. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device. The planarization insulating film is formed on an interlayer insulating film formed so as to cover a semiconductor layer of the thin film transistor, and a source electrode of the thin film transistor is formed on the interlayer insulating film and opened in the interlayer insulating film. And the pixel electrode is formed on the planarization insulating film and connected to the source electrode through the opening of the planarization insulating film. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a liquid crystal display device.   The liquid crystal display device according to claim 1, wherein the common electrode is formed on the color filter layer.   The liquid crystal display device according to claim 6, wherein a protective film is formed on the color filter layer, and the common electrode is formed on the protective film.   The liquid crystal display device according to claim 7, wherein the protective film is a flattening film that relieves unevenness caused by the color filter layer. 9. The liquid crystal display device according to claim 1, wherein the light shielding film is further formed in a region opposed to a region where the thin film transistor is formed.