JP2005321837A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display which has a wide viewing angle, is improved in display quality, reduced in the manufacture cost, prevented from generation of electrostatic charges and improved in the yield. <P>SOLUTION: A pixel electrode 19 for driving a liquid crystal is formed on a flattening insulating film 18 covering a thin film transistor, and a vertical alignment layer 31 not subjected to rubbing treatment is formed on the pixel electrode 19. An alignment controlling window 24 where no electrode is present is formed in a common electrode 23, and a vertical alignment layer 32 not subjected to rubbing treatment is formed on the common electrode 23. The liquid crystal having negative dielectric constant anisotropy is initially aligned along the normal direction having no pretilt state. When a voltage is applied, the tilt direction is controlled by the oblique electric field at the end of the pixel electrode 19 and at the end of the alignment controlling window 24 to divide the pixel. Since rubbing treatment is reduced, dielectric breakdown in a TFT is prevented. Since a black matrix is eliminated, the aperture ratio is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vertical alignment 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 in a predetermined shape together with a metal layer 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. 10 is an enlarged plan view of a display pixel portion of the LCD, and FIG. 11 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 subjected to a rubbing treatment 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. A black matrix (61BM) made of a light-shielding film resist is formed at a position corresponding to the gap between the pixel electrode (59) and the TFT. On these color filter (61) 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 subjected to a rubbing treatment. 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 uniformly controlled and aligned 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 inclined in a direction different from the electric field direction. However, by applying a pretilt, the liquid crystal molecules (81) are directed to be inclined toward the pretilt direction by applying a voltage. For this reason, the tilting directions are aligned, the liquid crystal orientation 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 the contrast ratio from being lowered due to birefringence caused by the liquid crystal provided with the pretilt in the region where the voltage between the display pixels is not applied, and unnecessary light being lost. It has been. 13 and 14 show a manufacturing method of the counter substrate. First, in the process of FIG. 13A, R, G, B color filters (61R, 61G, 61B) are formed on a substrate (60). The R color filter (61R) is formed by first attaching an R film resist and exposing and developing it to a shape corresponding to the R display pixels. The G color filter (61G) and the B color filter (61B) are formed in the same manner. These color filters (61R, 61G, 61B) are formed slightly smaller than the corresponding pixel electrodes (59).

  In the subsequent step of FIG. 13 (b), a light-shielding film resist is applied, and in the next step of FIG. 13 (c), the film resist is exposed and developed in a shape corresponding to the space between the pixels. A black matrix (61BM) is formed in the gaps (61R, 61G, 61B). The black matrix (61BM) is formed slightly larger than the region corresponding to the space between the pixel electrodes (59).

  In the next step of FIG. 14D, ITO is deposited to form the common electrode (62).

  Further, in the step shown in FIG. 14E, polyimide is formed into a film by printing, dried by baking, and then rubbed, that is, aligned by rubbing in the direction of the arrow using a cloth or the like to give a pretilt to the liquid crystal. A film (72) is formed.

  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.

  Also, as shown in FIG. 12 and FIG. 14E, conventionally, by subjecting the vertical alignment films (71, 72) to a rubbing process, 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. 11). 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. 11 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.

  According to the present invention, a liquid crystal having negative dielectric anisotropy is sealed between a first substrate and a second substrate which are arranged opposite to each other, and the liquid crystal having a negative dielectric anisotropy is disposed on the opposite surface side of one supporting substrate serving as the first substrate. A plurality of thin film transistors arranged in a matrix, a gate line and a drain line connected to the thin film transistors and intersecting each other, an insulating film covering the plurality of thin film transistors, the gate line and the drain line, and the insulating film formed on the insulating film A plurality of pixel electrodes for driving the liquid crystal connected to each of the thin film transistors through openings formed in the insulating film, and a vertical alignment film formed on the pixel electrodes and not subjected to the rubbing process And a liquid crystal driving common electrode formed on the opposite surface of the other supporting substrate serving as the second substrate, and a rubbing process formed on the common electrode is applied. A polarizing plate is provided on the outer surface of the first substrate and the second substrate, and the polarized light passing through the polarizing plate is modulated by the liquid crystal. In the liquid crystal display device that performs display, the surface of the insulating film is flattened, black display is performed with the initial alignment direction of the liquid crystal being a substantially normal direction of the substrate, and between the pixel electrode and the common electrode. By applying a voltage, an oblique electric field is generated between the periphery of the pixel electrode and the common electrode, and the liquid crystal is substantially tilted according to the electric field action from the normal direction to divide the alignment direction of the liquid crystal. The thin film transistor is crossed. As a result, when the liquid crystal having negative dielectric anisotropy is changed from the vertical alignment when a voltage is applied, good alignment change is performed with good uniformity.

  As is apparent from the above description, in the present invention, good pixel division is performed by electric field control, viewing angle dependency is reduced, and display quality is improved. Further, since the rubbing process is eliminated, the manufacturing cost is reduced, the generation of static electricity is prevented, and the yield is improved.

  Examples of embodiments of the present invention are shown below.

  FIG. 1 is a plan view of a display pixel portion of an LCD according to an embodiment of the present invention, and FIG. 2 is a 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 (53) is formed in an island shape so as to pass over 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 to cover the drain electrode (16) and the source electrode (17), and ITO (indium tin) is formed on the flattening insulating film (18). A pixel electrode (19) made of 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 protective film (22) made of a flattening insulating film such as acrylic resin is formed on these color filter (21) layers, and a common electrode (23) such as ITO is formed on the protective film (22). 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) cuts the center part of the pixel vertically and is divided into two branches at an angle of about 45 ° from there, and is directed to the corner part 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 improve the flatness 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, considering the relatively large unevenness of the TFT or the color filter layer (31), by relaxing these steps, the contact interface with the liquid crystal layer (40) 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 black matrix (61BM) as shown in FIGS. 10 and 11 is not provided on the counter substrate (20) side. 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 is suppressed between the pixel electrodes (19). This is because it is shielded from light. For this reason, it is not necessary to form a large light-shielding film in consideration of the bonding deviation on the counter substrate (20) side, so that 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.

  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. And the pixel electrode (4) connected to the TFT (3) is formed to form a display 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 display unit, 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). 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.

  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 SiO ₂ is formed on the entire surface covering the gate electrode (11) by plasma CVD. Subsequently, amorphous silicon ( a-Si) (13a) is deposited. The a-Si (13a) is formed by decomposing and depositing monosilane SiH ₄ or disilane Si 2 H _{4 as} a material gas 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. 5D, SiO ₂ is formed on the substrate on which p-Si (13) is formed, and this is etched using the backside exposure method, so that the upper portion of the gate electrode (11) is obtained. An injection stopper (14) is formed on the substrate. The backside exposure is performed by applying a resist on SiO ₂ and exposing it from below the substrate (10) to expose and develop a shape using the shadow of the gate electrode (11). . 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 forming an Al / Mo film 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. These color filters (21R, 21G, 21B) are formed at least larger than the corresponding pixel electrodes (19).

  In the step of FIG. 8B, the protective film (22) of these color filters (21R, 21G, 21B) is formed by covering these color filters (21R, 21G, 21B) and forming an acrylic resin. . The protective film (22) also serves as a planarizing film for the base of the common electrode (23).

  In the step of FIG. 9C, ITO is deposited by sputtering, and this is etched to form the common electrode (23) and the orientation control window (24) which is an electrode absent portion in the common electrode (23). To do.

  In the step of FIG. 9 (d), polyimide is formed into a liquid film by printing, pre-baked at 80 ° for 10 minutes, and then finally baked at 180 ° for 30 minutes and dried to obtain a vertical alignment film. (32) is formed.

  The counter substrate is completed through the above steps.

  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 the step of FIG. 9 (d) for manufacturing the counter substrate (20). That is, the rubbing process is not performed in the step of forming the alignment film (32). 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. In particular, in the driver built-in type, TFTs are densely arranged in the driver portions (5, 6), and the number of TFTs is much larger than that of the pixel portion. However, by reducing the rubbing process, such problems can be prevented and the yield can be improved.

  Further, in the process of FIG. 8A for manufacturing the counter substrate (20), the black matrix is not formed even after the color filters (21R, 21G, 21B) are formed. That is, light shielding is performed between display pixels by a combination of a liquid crystal and a polarizing plate. Thus, by eliminating the black matrix, the effective display area is enlarged and the aperture ratio is increased.

It is a top view of the liquid crystal display device concerning embodiment of this invention. It is sectional drawing along the AA line of FIG. It is a block diagram of a liquid crystal display device. 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 conventional liquid crystal display device. It is sectional drawing along the BB line of FIG. It is process sectional drawing which shows the conventional manufacturing method. It is process sectional drawing which shows the manufacturing method of the opposing board | substrate of the conventional liquid crystal display device. It is process sectional drawing which shows the manufacturing method of the opposing board | substrate of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 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 22 protective film 23 common electrode 24 alignment control electrode 31, 32 vertical alignment film 40 liquid crystal layer 41 liquid crystal molecule 42 electric field

Claims (1)

A liquid crystal having a negative dielectric anisotropy is sealed between the first substrate and the second substrate that are arranged to face each other,
A plurality of thin film transistors arranged in a matrix on the opposite surface side of the one supporting substrate to be the first substrate, gate lines and drain lines connected to the thin film transistors and intersecting with each other, the plurality of thin film transistors, the gate lines, and An insulating film covering the drain line; a plurality of pixel electrodes for driving the liquid crystal connected to each of the thin film transistors through openings formed on the insulating film and opened in the insulating film; and the pixels A vertical alignment film not subjected to rubbing treatment formed on the electrode, a liquid crystal driving common electrode formed on the opposite surface of the other supporting substrate serving as the second substrate, and formed on the common electrode And a vertical alignment film that has not been subjected to rubbing treatment,
In the liquid crystal display device in which a polarizing plate is provided on the outer surface of the first substrate and the second substrate, and display is performed by modulating the polarized light passing through the polarizing plate with the liquid crystal.
The insulating film has a planarized surface,
Black display with the initial alignment direction of the liquid crystal as the normal direction of the substrate,

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, and the liquid crystal is tilted in accordance with the electric field action from the normal direction. A liquid crystal display device characterized by dividing an alignment direction and intersecting the thin film transistor with the division boundary.