JP4060125B2 - Substrate for liquid crystal display device, liquid crystal display device including the same, and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate for a liquid crystal display device used in a display unit of information equipment or the like, a liquid crystal display device including the same, and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, liquid crystal display devices of XGA (eXtended Graphics Array; resolution 1024 × 768) to UXGA (Ultra XGA; resolution 1600 × 1200) class with a diagonal size of 15 to 23 inches are popular for desktop PCs (Personal Computers). It's getting on. Accordingly, the demand for an active matrix liquid crystal display device provided with a switching element for each pixel is on an increasing trend. The active matrix liquid crystal display device prevents the occurrence of crosstalk by providing each pixel with a switching element that is turned off when not selected, and blocks the grayscale signal. Compared with a simple matrix liquid crystal display device Excellent display characteristics. In particular, a liquid crystal display device in which a thin film transistor (TFT) is used as a switching element has display characteristics comparable to a CRT (Cathode-Ray Tube) because of its high driving capability.
[0003]
A general TN (twisted nematic) mode liquid crystal display device has a structure in which liquid crystal is sealed between two transparent substrates. On one transparent substrate, a common electrode, a color filter (CF), an alignment film, and the like are formed on surfaces facing each other (opposing surfaces). On the other transparent substrate, a TFT, a pixel electrode, an alignment film, and the like are formed on the opposite surface. A polarizing plate is attached to the surface opposite to the facing surface of each transparent substrate. When the polarizing axes of the two polarizing plates are arranged so as to be orthogonal to each other, light is transmitted when no voltage is applied between the two substrates, and light is blocked when a voltage is applied between the two substrates. That is, the normally white mode is set. Conversely, when the two polarizing plates are arranged so that their polarization axes are parallel to each other, a normally black mode is set.
[0004]
In recent years, higher performance of liquid crystal display devices has been demanded. With the widespread use of cellular phones, portable electronic devices, and the like, there is a strong demand for particularly low power consumption and ease of use outdoors. In order to sufficiently satisfy these low power consumption and outdoor ease of use, there is a demand for the development of a reflective liquid crystal display device that has a light-reflective pixel electrode and does not require a light source device by using external light. ing.
[0005]
A TFT substrate of a reflective liquid crystal display device has a pixel electrode (reflective electrode) formed of a highly reflective metal thin film. The reflection type liquid crystal display device reflects natural light or electric light incident from the display screen side on a TFT substrate, and uses the reflected light as a light source for liquid crystal display. The reflective electrode has an uneven surface. The uneven surface of the reflective electrode can be obtained by previously forming a photosensitive resin film having an uneven surface on the lower layer. A reflection type liquid crystal display device that achieves high luminance and a high viewing angle is realized by irregularly reflecting light incident from the display screen side by the uneven surface of the reflective electrode.
[0006]
Japanese Patent Application Laid-Open No. 2001-194777 (hereinafter referred to as “Document 1”) describes a liquid crystal in which a concavo-convex resist layer is formed under a reflective electrode in order to form concavo-convex on the surface of the reflective electrode made of aluminum (Al). A display device is disclosed. This uneven resist layer is formed directly on the TFT. For this reason, there is a problem that the TFT may be organically contaminated by HMDS (hexamethyldisilazane) used for hydrophobizing the resist or the substrate before the resist is applied. Furthermore, since the process of forming the resist layer is a wet system, there is a problem that moisture or chemicals may permeate into the TFT. Therefore, although not described in Document 1, in order to prevent deterioration of TFT characteristics, it is necessary to form a protective film for preventing contamination on the TFT.
[0007]
Further, in the liquid crystal display device described in Document 1, the uneven resist layer is not formed on the terminal portion. For this reason, if the terminal portion is formed of an Al-based laminated metal film, there is a problem that the terminal layer may be eroded during development of the resist layer. Hereinafter, a conventional substrate for a liquid crystal display device that solves the above problems and a method for manufacturing the same will be described with reference to FIGS.
[0008]
FIG. 25 shows the configuration of a TFT substrate of a conventional reflective liquid crystal display device. 26A shows a cross section of the TFT substrate cut along line XX in FIG. 25, and FIG. 26B shows a cross section of the TFT substrate cut along line YY in FIG. FIG. 26C shows a cross section of the TFT substrate cut along the line ZZ in FIG. As shown in FIGS. 25 and 26A to 26C, the TFT substrate has a plurality of gate bus lines 112 formed on the glass substrate 110 so as to extend in the left-right direction in FIG. is doing. Further, a plurality of drain bus lines 114 extending in the vertical direction in FIG. 25 are formed so as to cross the gate bus line 112 through the insulating film (gate insulating film) 122 formed on the gate bus line 112 and to be parallel to each other. Has been.
[0009]
A TFT 120 is formed near the intersection of the gate bus line 112 and the drain bus line 114. On the gate electrode (gate bus line) 112 of the TFT 120, an operating semiconductor layer 124 made of amorphous silicon (a-Si), a channel protective film 125, n, ⁺ An n-type impurity semiconductor layer 126 made of a-Si is formed in this order. On the n-type impurity semiconductor layer 126, a drain electrode 128 drawn from the drain bus line 114 and a source electrode 130 are formed. The drain electrode 128 and the underlying n-type impurity semiconductor layer 126 are electrically isolated from the source electrode 130 and the underlying n-type impurity semiconductor layer 126. A protective film 136 is formed on the drain electrode 128 and the source electrode 130. A resist layer 152 having an uneven surface is formed on the protective film 136.
[0010]
A reflective electrode 116 made of a light reflective material such as Al is formed in the pixel region arranged in a matrix on the TFT substrate. The reflective electrode 116 is formed in an uneven shape following the surface shape of the resist layer 152. The reflective electrode 116 is electrically connected to the source electrode 130 through the contact hole 138. A storage capacitor bus line 118 is formed across each pixel region substantially parallel to the gate bus line 112. On the storage capacitor bus line 118, a storage capacitor electrode (intermediate electrode) 132 is formed for each pixel region via an insulating film 122. The reflective electrode 116 is electrically connected to the storage capacitor electrode 132 through the contact hole 139.
[0011]
A gate bus line terminal 140 is formed at one end of the gate bus line 112 (left side in FIG. 25). A protective conductive film 141 made of the same material as that of the reflective electrode 116 is formed on the gate bus line terminal 140. The protective conductive film 141 is electrically connected to the gate bus line terminal 140 through the contact hole 142. A drain bus line terminal 144 is formed at one end of the drain bus line 114 (upward in FIG. 25). A protective conductive film 145 made of the same material as that of the reflective electrode 116 is formed on the drain bus line terminal 144. The protective conductive film 145 is electrically connected to the drain bus line terminal 144 through the contact hole 146. A storage capacitor bus line terminal 148 is formed at one end of the storage capacitor bus line 118 (left side in FIG. 25). A protective conductive film 149 made of the same material as that of the reflective electrode 116 is formed on the storage capacitor bus line terminal 148. The protective conductive film 149 is electrically connected to the storage capacitor bus line terminal 148 through the contact hole 150.
[0012]
Next, a method for manufacturing a TFT substrate of a conventional reflective liquid crystal display device will be described with reference to FIGS. 27, 28, 30, 31, 33, 34, 36, 37 (a), 39, and 40 are process cross-sectional views showing a conventional TFT substrate manufacturing process. The cross section corresponding to 26 (a) is shown. FIG. 37B is a process cross-sectional view showing a conventional TFT substrate manufacturing process, and shows a cross section corresponding to FIG. FIG. 37 (c) is a process cross-sectional view showing a conventional TFT substrate manufacturing process, and shows a cross-section corresponding to FIG. 26 (c). 29, 32, 35, and 38 show a conventional TFT substrate manufacturing process, in which the TFT substrate is viewed in a direction perpendicular to the substrate surface.
[0013]
As shown in FIG. 27, a metal film 160 is formed on the entire surface of the glass substrate 110. Next, a resist is applied to the entire surface of the substrate over the metal film 160 and patterned using a first photomask to form a resist pattern 161. Next, as shown in FIGS. 28 and 29, etching is performed using the resist pattern 161 as an etching mask to form a gate bus line 112, a storage capacitor bus line 118, a gate bus line terminal 140, and a storage capacitor bus line terminal 148. To do. Next, the resist pattern 161 is removed.
[0014]
Next, as shown in FIG. 30, an insulating film 122, an a-Si layer 124 ', and a silicon nitride film (SiN film) 125' are formed in this order on the entire surface of the substrate. Next, a positive resist is applied to the entire surface of the substrate. Next, back exposure is performed from the back surface (lower side in FIG. 30) of the glass substrate 110 using the gate bus line 112 as a mask, and further exposure using a second photomask is performed so as to be self-aligned on the gate bus line 112. Then, a resist pattern 162 is formed. Next, as shown in FIGS. 31 and 32, etching is performed using the resist pattern 162 as an etching mask to form a channel protective film 125. Next, the resist pattern 162 is removed.
[0015]
Next, as shown in FIG. ⁺ An a-Si layer 126 ′ and a metal film 128 ′ are continuously formed. Next, a resist is applied to the entire surface of the substrate over the metal film 128 ′, and is patterned using a third photomask to form a resist pattern 163. Next, as shown in FIGS. 34 and 35, etching is performed using the resist pattern 163 as an etching mask, Active semiconductor layer 124; A drain bus line 114, a drain electrode 128, a source electrode 130, a drain bus line terminal 144, and a storage capacitor electrode 132 are formed. Thereby, the TFT 120 is formed. Next, the resist pattern 163 is removed.
[0016]
Next, as shown in FIG. 36, a protective film 136 made of a transparent insulating film is formed on the entire surface of the substrate. Next, a resist is applied to the entire surface of the substrate over the protective film 136 and patterned using a fourth photomask to form a resist pattern 164. Next, as shown in FIGS. 37 (a), (b), (c) and FIG. 38, etching is performed using the resist pattern 164 as an etching mask, and contact holes 138 ′, 139 ′, 142 ′, 146 ′, 150 'is formed. Next, the resist pattern 164 is removed.
[0017]
Next, a positive resist is applied to the entire surface of the substrate. Next, in order to form unevenness on the surface, exposure is performed with low-illuminance ultraviolet (UV) light using a fifth photomask having a plurality of circular light-shielding portions. Next, UV light with high illuminance is exposed using a sixth photomask having openings at positions corresponding to the contact holes 138 ′, 139 ′, 142 ′, 146 ′, and 150 ′. Subsequently, as shown in FIG. 39, the regions on the contact holes 138 ′, 139 ′, 142 ′, 146 ′, and 150 ′ exposed with high-intensity UV light are opened, and the contact holes 138, 139, 142, 146, 150 are formed. On the other hand, the film thickness of the resist layer is reduced by a predetermined amount in the area exposed to low-illuminance UV light compared to the area shielded by the light-shielding portion. Thereby, the concavo-convex resist layer 152 having the concavo-convex formed on the surface is formed.
[0018]
Next, as shown in FIG. 40, a metal film 116 ′ made of Al is formed on the entire surface of the uneven resist layer 152. Next, patterning is performed using a seventh photomask, the reflective electrode 116 for each pixel region, the protective conductive film 141 on the gate bus line terminal 140, the protective conductive film 149 on the storage capacitor bus line terminal 148, A protective conductive film 145 is formed on the drain bus line terminal 144. The TFT substrate shown in FIG. 25 and FIGS. 26A to 26C is completed through the above steps.
[0019]
[Problems to be solved by the invention]
In the above-described TFT substrate manufacturing method, a protective film 136 made of a SiN film is formed on the TFT 120 after element isolation, and contact holes 138 ′ and 139 ′ are formed in the protective film 136 and the insulating film 122 in advance before forming the concavo-convex resist layer 152. , 142 ′, 146 ′, and 150 ′. Further, in the above-described TFT substrate manufacturing method, the surface of the concavo-convex resist layer 152 is formed using a fifth photomask, and the contact holes 138, 139, 142, 146, and the like are formed using another sixth photomask. 150 is formed. For this reason, seven photomasks are required in the manufacturing process of the reflective TFT substrate. Therefore, the TFT substrate manufacturing process is increased as compared with a transmissive TFT substrate that is normally manufactured using five photomasks, which causes an increase in manufacturing cost and a decrease in manufacturing yield. .
[0020]
An object of the present invention is to provide a substrate for a liquid crystal display device capable of reducing the manufacturing process and obtaining good display quality, a liquid crystal display device including the same, and a method for manufacturing the same.
[0021]
[Means for Solving the Problems]
The object is to provide pixel regions arranged in a matrix on the substrate, a plurality of first bus lines formed in parallel to each other on the substrate, and a first formed on the first bus lines. An insulating film, a plurality of second bus lines that intersect the first bus line via the first insulating film and are formed in parallel to each other, and a thin film transistor formed for each pixel region A second insulating film formed on the thin film transistor; a hook-shaped resin layer having a surface formed in a bowl shape on the second insulating film and having an insulating property; and the pixel on the bowl-shaped resin layer. A plurality of bus line terminals connected to the first and second bus lines, respectively, and a reflective electrode formed of a light-reflective material for each region and having a surface formed in a hook shape following the surface of the hook-shaped resin layer; And the plurality of the reflective electrodes with the same forming material Respectively formed on the Surain terminal is achieved by the plurality of liquid crystal display device substrate and having a plurality of protective conductive film that is connected to the bus line terminal.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
A substrate for a liquid crystal display device according to a first embodiment of the present invention, a liquid crystal display device including the same, and a manufacturing method thereof will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a liquid crystal display device according to the present embodiment. As shown in FIG. 1, the reflective liquid crystal display device includes a TFT substrate 2 in which a TFT, a reflective electrode, and the like are formed for each pixel region, and a CF substrate 4 in which a color filter (CF) is formed. Are bonded together so that liquid crystal is sealed between the substrates 2 and 4.
[0023]
A plurality of gate bus lines and a plurality of drain bus lines are formed on the TFT substrate 2 so as to cross each other through an insulating film. A gate bus line driving circuit 70 on which driver ICs for driving a plurality of gate bus lines are mounted, and a drain bus line driving circuit 72 on which driver ICs for driving a plurality of drain bus lines are mounted are provided. These drive circuits 70 and 72 are configured to output scanning signals and data signals to predetermined gate bus lines or drain bus lines based on predetermined signals output from the control circuit 74. A polarizing plate 76 is bonded to the surface of the CF substrate 4 opposite to the CF forming surface.
[0024]
FIG. 2 shows the configuration of the liquid crystal display substrate according to the present embodiment. 3A shows a cross section of the substrate for a liquid crystal display device taken along line AA in FIG. 2, and FIG. 3B shows a cross section of the substrate for a liquid crystal display device taken along line BB in FIG. Show. FIG. 3C shows a cross section of the substrate for a liquid crystal display device taken along line CC in FIG. 2 and 3A to 3C, the TFT substrate 2 includes a plurality of gate bus lines 12 formed in parallel with each other and extending in the left-right direction in FIG. (Two gate bus lines 12 are shown in FIG. 2). Further, the gate bus line 12 is formed in parallel with each other through an insulating film (gate insulating film) 22 formed on the gate bus line 12 and made of a SiN film, a silicon oxide film (SiO film), or the like. 2, a plurality of drain bus lines 14 extending in the vertical direction are formed (two drain bus lines 14 are shown in FIG. 2).
[0025]
A TFT 20 is formed near the intersection of the gate bus line 12 and the drain bus line 14. On the gate electrode (gate bus line) 12 of the TFT 20, an operation semiconductor layer 24 made of, for example, amorphous silicon (a-Si), a channel protective film 25 made of, for example, an SiN film, and n, for example, are interposed via an insulating film 22. ⁺ An n-type impurity semiconductor layer (ohmic contact layer) 26 made of a-Si is formed in this order. On the n-type impurity semiconductor layer 26, a drain electrode 28 drawn from the drain bus line 14 and a source electrode 30 are formed. The drain electrode 28 and the underlying n-type impurity semiconductor layer 26 are electrically isolated from the source electrode 30 and the underlying n-type impurity semiconductor layer 26. On the drain electrode 28 and the source electrode 30, a protective film 36 made of, for example, a SiN film and having insulating properties is formed. On the protective film 36, a bowl-shaped resin layer 52 having a bowl-shaped surface is formed. The bowl-shaped resin layer 52 is formed of, for example, a single layer resist having photosensitivity and insulation.
[0026]
In the pixel region arranged in a matrix on the TFT substrate 2, a reflective electrode 16 made of a light reflective material such as Al is formed. The reflective electrode 16 is formed in a bowl shape following the surface shape of the bowl-shaped resin layer 52. The reflective electrode 16 is electrically connected to the source electrode 30 through the contact hole 38. A storage capacitor bus line 18 is formed across each pixel region substantially parallel to the gate bus line 12. On the storage capacitor bus line 18, a storage capacitor electrode (intermediate electrode) 32 is formed for each pixel region via an insulating film 22. The reflective electrode 16 is electrically connected to the storage capacitor electrode 32 through the contact hole 39.
[0027]
A gate bus line terminal 40 is formed at one end of the gate bus line 12 (left side in FIG. 2). A protective conductive film 41 made of the same material as that of the reflective electrode 16 is formed on the gate bus line terminal 40. The protective conductive film 41 is electrically connected to the gate bus line terminal 40 through a contact hole 42 in which the protective film 36 and the insulating film 22 are opened. A drain bus line terminal 44 is formed at one end of the drain bus line 14 (upward in FIG. 2). A protective conductive film 45 made of the same material as that of the reflective electrode 16 is formed on the drain bus line terminal 44. The protective conductive film 45 is electrically connected to the drain bus line terminal 44 through a contact hole 46 in which the protective film 36 is opened. A storage capacitor bus line terminal 48 is formed at one end of the storage capacitor bus line 18 (left side in FIG. 2). A protective conductive film 49 made of the same material as that of the reflective electrode 16 is formed on the storage capacitor bus line terminal 48. The protective conductive film 49 is electrically connected to the storage capacitor bus line terminal 48 through a contact hole 50 in which the protective film 36 and the insulating film 22 are opened. On the outer periphery of the gate bus line terminal 40 and the drain bus line terminal 44, a bowl-shaped resin layer 52 is formed. Further, a bowl-shaped resin layer 52 is formed on the outer periphery of the storage capacitor bus line terminal 48.
[0028]
Next, a substrate for a liquid crystal display device according to the present embodiment and a method for manufacturing a liquid crystal display device including the same will be described with reference to FIGS. 4, FIG. 5, FIG. 7, FIG. 8, FIG. 10, FIG. 11, FIG. 13, FIG. 14, FIG. 15 (a), FIG. FIG. 4 is a process cross-sectional view showing the cross section corresponding to FIG. FIG. 15B is a process sectional view showing a manufacturing process of the substrate for a liquid crystal display device according to the present embodiment, and shows a section corresponding to FIG. FIG. 15C is a process cross-sectional view showing the manufacturing process of the substrate for a liquid crystal display device according to the present embodiment, and shows a cross section corresponding to FIG. 6, FIG. 9, FIG. 12 and FIG. 16 show the manufacturing process of the substrate for a liquid crystal display device according to this embodiment, and are views of the TFT substrate viewed in the direction perpendicular to the substrate surface.
[0029]
As shown in FIG. 4, for example, a PVD (Physical Vapor Deposition) method is used to form, for example, an Al film having a thickness of 100 nm and a titanium (Ti) film having a thickness of 50 nm on the entire surface of the glass substrate 10 in this order. Then, a metal film (gate metal layer) 60 is formed. The metal film 60 may be formed of a chromium (Cr) film, an Al alloy film, or a molybdenum (Mo) film. Next, a resist (photosensitive resin) is applied to the entire surface of the substrate on the metal film 60, and is patterned using a first photomask to form a resist pattern 61 having a predetermined shape.
[0030]
Next, as shown in FIGS. 5 and 6, dry etching with a Cl-based gas is performed using the resist pattern 61 as an etching mask. If the metal film 60 is formed of a Cr film, wet etching using a Cr etchant is performed. If the metal film 60 is formed of an Al alloy film or a Mo-based film, wet etching using an Al etchant is performed. Thereby, the gate bus line 12, the storage capacitor bus line 18, the gate bus line terminal 40, and the storage capacitor bus line terminal 48 are formed. Next, the resist pattern 61 is removed.
[0031]
Next, as shown in FIG. 7, for example, by using a plasma CVD (Chemical Vapor Deposition) method, the insulating film 22 made of a transparent and insulating SiN film having a thickness of, for example, 350 nm, and an a− film having a thickness of, for example, 30 nm An Si layer 24 ′ and, for example, a 120 nm-thickness SiN film 25 ′ are successively formed on the entire surface of the substrate in this order. Next, a positive resist that solubilizes the photosensitive portion is applied to the entire surface of the substrate. Next, back exposure is performed from the back surface (downward in FIG. 7) of the glass substrate 10 using the gate bus line 12 as a mask, and further exposure using a second photomask is performed so as to be self-aligned on the gate bus line 12. Then, a resist pattern 62 is formed.
[0032]
Next, as shown in FIGS. 8 and 9, etching is performed using the resist pattern 62 as an etching mask to form a channel protective film 25 in the TFT 20 formation region on the gate bus line 12. Next, the resist pattern 62 is removed.
[0033]
Next, as shown in FIG. 10, for example, PVD method is used, for example, n having a film thickness of 30 nm. ⁺ An a-Si layer 26 'and a metal film (drain metal layer) 28' made of, for example, a 20 nm thick Ti film, a 75 nm thick Al film, and a 20 nm thick Ti film are successively formed in this order. . The metal film 28 'may be formed of an Al alloy film, a laminated film of other low resistance metals, or the like. Next, a resist is applied to the entire surface of the substrate on the metal film 28 ′ and patterned using a third photomask to form a resist pattern 63 having a predetermined shape.
[0034]
Next, as shown in FIGS. 11 and 12, using the resist pattern 63 as an etching mask, the metal film 28 ′, n ⁺ The a-Si layer 26 'and the a-Si layer 24' are collectively dry-etched. This etching is performed by an RIE (Reactive Ion Etching) method using a Cl-based gas. In this etching, the channel protective film 25 functions as an etching stopper, and the underlying a-Si layer 24 'remains without being etched. This Active semiconductor layer 24, The drain bus line 14, the drain electrode 28, the source electrode 30, the drain bus line terminal 44, and the storage capacitor electrode 32 are formed. Next, the resist pattern 63 is removed.
[0035]
Next, as shown in FIG. 13, a protective film 36 made of, for example, a SiN film having a thickness of 330 nm is formed on the entire surface of the substrate by using, for example, a plasma CVD method. Next, for example, a positive resist having a thickness of about 3.5 μm is applied to the entire surface of the substrate on the protective film 36 and patterned using a fourth photomask to form a resist pattern 64 having a predetermined shape.
[0036]
Next, after irradiating the surface of the resist pattern 64 with UV light, the resist pattern 64 is baked at a baking temperature of 200 ° C. or more, for example. The UV light is preferably irradiated with an irradiation wavelength (specifically, 170 to 260 nm) of i-line or less and an irradiation energy of about 30 mJ, for example. As a result, as shown in FIG. 14, only the surface of the resist pattern 64 undergoes a crosslinking reaction to form bowl-shaped irregularities, and the bowl-shaped resin layer 52 is obtained. At this time, a resist sublimate or the like generated when the resist is baked is formed in the region α.
[0037]
Next, as shown in FIGS. 15A, 15C, and 16, the protective film 36 is etched using the bowl-shaped resin layer 52 as an etching mask to form contact holes 38, 39, and 46, respectively. As shown in FIGS. 15B and 16, the protective film 36 and the insulating film 22 are collectively etched to form contact holes 42 and 50, respectively. This etching is, for example, dry etching by an RIE method using a fluorine-based gas. Etching conditions are 6.7 Pa, SF ₆ / O ₂ = 200/200 (sccm), 600 W. Resist sublimates and the like formed in the region α are removed by this etching.
[0038]
Next, as shown in FIG. 17, for example, by using the PVD method, an Al film having a film thickness of, for example, 150 nm is formed on the entire surface of the substrate on the bowl-shaped resin layer 52 to form a metal film 16 ′. Next, a resist is applied on the entire surface of the metal film 16 ′. Next, patterning is performed using a fifth photomask to form a resist pattern 65. Next, as shown in FIG. 18, using the resist pattern 65 as an etching mask, wet etching is performed with a mixed acid of phosphoric acid, nitric acid, acetic acid, or the like, so that the reflective electrode 16 for each pixel region and each gate bus line terminal 40 are formed. The protective conductive film 41, the protective conductive film 49 on each storage capacitor bus line terminal 48, and the protective conductive film 45 on each drain bus line terminal 44 are formed. Next, the resist pattern 65 is removed. Through the above steps, the TFT substrate 2 of the liquid crystal display device substrate according to the present embodiment is completed. Thereafter, the TFT substrate 2 and the CF substrate 4 are bonded together to seal the liquid crystal, whereby the liquid crystal display device according to the present embodiment is completed.
[0039]
In the present embodiment, bowl-shaped irregularities are formed on the surface of the bowl-shaped resin layer 52 formed on the protective film 36. The reflective electrode 16 formed on the bowl-shaped resin layer 52 is formed in a bowl shape following the shape of the surface of the bowl-shaped resin layer 52. For this reason, the reflective electrode 16 can diffusely reflect light incident from the display screen side, and a reflective liquid crystal display device with high luminance and high viewing angle can be obtained.
[0040]
In the present embodiment, the contact holes 38, 39, 42, 46, and 50 are formed after the bowl-shaped resin layer 52 is formed. For this reason, when the contact holes 38, 39, 42, 46, and 50 are formed, resist sublimates generated during resist baking can be removed. Further, since the metal film is not exposed when the resist is baked, a thermal oxide film is not formed on the surface of the metal film. Therefore, it is possible to avoid contact failure between metal films due to resist sublimates and thermal oxide films. Further, since the protective film 36 made of the SiN film is formed on the TFT 20 after the element separation, the TFT 20 can be prevented from being contaminated by a resist or the like.
[0041]
Furthermore, according to the present embodiment, since no photomask is used when forming irregularities on the surface of the bowl-shaped resin layer 52, one photomask can be reduced. Further, since the bowl-shaped resin layer 52 is used as an etching mask, one photomask can be further reduced. Therefore, the required number of photomasks is reduced from 7 to 5. For this reason, the manufacturing process of the TFT substrate 2 is reduced, and accordingly, the manufacturing cost can be reduced and the manufacturing yield can be improved.
[0042]
Next, a substrate for a liquid crystal display device according to a second embodiment of the present invention, a liquid crystal display device including the same, and a manufacturing method thereof will be described with reference to FIGS. FIG. 19 shows a cross section corresponding to FIG. 3A of the substrate for a liquid crystal display device according to the present embodiment. In addition, about the component which has the same function effect | action as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. As shown in FIG. 19, the surface of the source electrode 30 in a region connected to the reflective electrode 16 through the contact hole 38 is removed by etching. Similarly, the surface of a region of the storage capacitor electrode 32 connected to the reflective electrode 16 through the contact hole 39 is removed by etching. Although not shown, the surface of the region connected to the protective conductive film 41 through the contact hole 42 in the gate bus line terminal 40 is removed by etching. Of the drain bus line terminal 44, the surface of the region connected to the protective conductive film 45 through the contact hole 46 is removed by etching. Of the storage capacitor bus line terminal 48, the surface of the region connected to the protective conductive film 49 through the contact hole 50 is removed by etching.
[0043]
Next, a substrate for a liquid crystal display device according to the present embodiment and a method for manufacturing a liquid crystal display device including the same will be described. Note that the steps until the TFT 20 is formed are the same as those in the first embodiment described with reference to FIGS. As shown in FIG. 20, a protective film 36 made of, for example, a 330 nm-thickness SiN film is formed on the entire surface of the substrate on the drain electrode 28, the source electrode 30 and the storage capacitor electrode 32 by using, for example, plasma CVD. Next, a resist is applied to the entire surface of the substrate on the protective film 36 and patterned using a fourth photomask to form a resist pattern 64 having a predetermined shape.
[0044]
Next, as shown in FIG. 21, the protective film 36 and the insulating film 22 are collectively etched using the resist pattern 64 as an etching mask to form contact holes 38, 39, 42, 46, 50 (in FIG. 21, the contact holes 42, 42, 46 and 50 are not shown), respectively. This etching is, for example, dry etching by an RIE method using a fluorine-based gas. Etching conditions are, for example, 6.7 Pa, SF ₆ / O ₂ = 200/200 (sccm), 600 W. Next, the resist pattern 64 is removed.
[0045]
Next, as shown in FIG. 22, for example, a positive resist (for forming the bowl-shaped resin layer 52) having a film thickness of about 3.5 μm is applied to the entire surface of the protective film 36, and a fifth photomask is used. By patterning, a resist pattern 66 having openings on the contact holes 38, 39, 42, 46, 50 is formed. The contact holes 38, 39, 42, 46 and 50 can be formed only by exposure and development. Next, after irradiating the surface of the resist pattern 66 with UV light, the resist pattern 66 is baked at a baking temperature of 200 ° C. or more, for example. The UV light is preferably irradiated with an irradiation wavelength (specifically, 170 to 260 nm) of i-line or less and an irradiation energy of about 30 mJ, for example. As a result, as shown in FIG. 23, only the surface of the resist pattern 66 undergoes a crosslinking reaction to form bowl-like irregularities, and the bowl-like resin layer 52 is obtained. At this time, a thermal oxide film on the surface of the metal film, a resist sublimate, a resist residue, or the like formed when the resist is baked is formed in the region α.
[0046]
Next, as shown in FIG. 24, using the bowl-shaped resin layer 52 as an etching mask, the surface of the region of the source electrode 30 where the contact hole 38 is formed and the contact hole 39 of the storage capacitor electrode 32. The surface of the region where the film is formed is removed by etching. Although not shown, the surface of the gate bus line terminal 40 in the region where the contact hole 42 is formed, and the drain bus line terminal 44 in the region where the contact hole 46 is formed, Of the storage capacitor bus line terminal 48, the surface of the region where the contact hole 50 is formed is simultaneously etched away. This etching is, for example, dry etching using the RIE method. Etching conditions are, for example, 6.0 Pa, SF ₆ / O ₂ = 150/150 (sccm), 600 W. This etching is performed to remove the thermal oxide film, resist sublimate and the like formed in the region α.
[0047]
Next, for example, a PVD method is used to form a metal film made of, for example, an Al film having a thickness of 150 nm on the entire surface of the substrate on the bowl-shaped resin layer 52. Next, a resist is applied on the entire surface of the metal film. Next, patterning is performed using a sixth photomask to form a resist pattern. Next, using the resist pattern as an etching mask, wet etching is performed with phosphoric acid, nitric acid, mixed acid of acetic acid, or the like, and the reflective electrode 16 for each pixel region, the protective conductive film 41 on each gate bus line terminal 40, A protective conductive film 49 on each storage capacitor bus line terminal 48 and a protective conductive film 45 on each drain bus line terminal 44 are formed. Next, the resist pattern is removed. Through the above steps, the TFT substrate 2 of the liquid crystal display device substrate according to the present embodiment is completed. Thereafter, the TFT substrate 2 and the CF substrate 4 are bonded together to seal the liquid crystal, whereby the liquid crystal display device according to this embodiment is completed.
[0048]
In the present embodiment, bowl-shaped irregularities are formed on the surface of the bowl-shaped resin layer 52 formed on the protective film 36. The reflective electrode 16 formed on the bowl-shaped resin layer 52 is formed in a bowl shape following the shape of the surface of the bowl-shaped resin layer 52. For this reason, the reflective electrode 16 can diffusely reflect light incident from the display screen side, and a reflective liquid crystal display device with high luminance and high viewing angle can be obtained.
[0049]
In this embodiment, the thermal oxide film on the surface of the metal film, resist sublimate, resist residue, and the like generated in the region α during resist baking are removed by etching after the ridge-like resin layer 52 is formed. Therefore, it is possible to avoid contact failure between metal films due to a thermal oxide film, resist sublimate, or the like. Further, since the protective film 36 made of the SiN film is formed on the TFT 20 after the element separation, the TFT 20 can be prevented from being contaminated by a resist or the like.
[0050]
Furthermore, in this embodiment, since no photomask is used when forming irregularities on the surface of the bowl-shaped resin layer 52, one photomask can be reduced. Therefore, the required number of photomasks is reduced from 7 to 6. For this reason, the manufacturing process of the TFT substrate 2 is reduced, and accordingly, the manufacturing cost can be reduced and the manufacturing yield can be improved.
[0051]
The present invention is not limited to the above embodiment, and various modifications can be made.
For example, although the bowl-shaped resin layer 52 is formed of a positive resist in the above embodiment, the present invention is not limited to this, and the bowl-shaped resin layer 52 may be formed of a negative resist.
In the above embodiment, the resist pattern 64 is baked after the surface of the resist pattern 64 made of a photosensitive resin is irradiated with ultraviolet light to form the bowl-shaped resin layer 52. However, the present invention is limited to this. Absent. The resin for forming the resist pattern 64 may be selected as appropriate, and the resist pattern 64 may be subjected to other processing to form the bowl-shaped resin layer 52.
[0052]
The substrate for a liquid crystal display device according to the above-described embodiment, the liquid crystal display device including the substrate, and the manufacturing method thereof are summarized as follows.
(Appendix 1)
Pixel regions arranged in a matrix on the substrate;
A plurality of first bus lines formed in parallel with each other on the substrate;
A first insulating film formed on the first bus line;
A plurality of second bus lines formed in parallel with each other, intersecting the first bus lines via the first insulating film;
A thin film transistor formed for each pixel region;
A second insulating film formed on the thin film transistor;
A hook-shaped resin layer having a surface formed in a bowl shape on the second insulating film and having an insulating property;
A reflective electrode that is formed of a light-reflective material for each of the pixel regions on the bowl-shaped resin layer, and has a bowl-like surface that follows the bowl-shaped resin layer surface;
A plurality of bus line terminals respectively connected to the first and second bus lines;
A plurality of protective conductive films respectively formed on the plurality of bus line terminals with the same forming material as the reflective electrode and connected to the plurality of bus line terminals;
A substrate for a liquid crystal display device, comprising:
[0053]
(Appendix 2)
In the substrate for a liquid crystal display device according to appendix 1,
The plurality of bus line terminals have an outer peripheral portion on which the bowl-shaped resin layer is formed.
A substrate for a liquid crystal display device.
[0054]
(Appendix 3)
In the substrate for a liquid crystal display device according to appendix 1 or 2,
The bowl-shaped resin layer is formed of a resist
A substrate for a liquid crystal display device.
[0055]
(Appendix 4)
In the liquid crystal display substrate according to any one of appendices 1 to 3,
The bowl-shaped resin layer is formed as a single layer.
A substrate for a liquid crystal display device.
[0056]
(Appendix 5)
The substrate for a liquid crystal display device according to any one of appendices 1 to 4,
The second insulating film is formed of a silicon nitride film or a silicon oxide film.
A substrate for a liquid crystal display device.
[0057]
(Appendix 6)
The substrate for a liquid crystal display device according to any one of appendices 1 to 5,
Of the source electrode of the thin film transistor, the surface of the region connected to the reflective electrode is etched away.
A substrate for a liquid crystal display device.
[0058]
(Appendix 7)
The substrate for a liquid crystal display device according to any one of appendices 1 to 6,
Of the bus line terminal, the surface of the region connected to the protective conductive film is etched away.
A substrate for a liquid crystal display device.
[0059]
(Appendix 8)
In a liquid crystal display device having two substrates opposed to each other and a liquid crystal sealed between the two substrates,
The substrate for a liquid crystal display device according to any one of appendices 1 to 7 is used on one of the two substrates.
A liquid crystal display device.
[0060]
(Appendix 9)
Forming a first bus line and a first bus line terminal connected to the first bus line on the substrate;
Forming a first insulating film on the first bus line and the first bus line terminal;
A second bus line and a second bus line terminal connected to the second bus line are formed on the first insulating film, and connected to one of the first and second bus lines. Forming a thin film transistor having a gate electrode and a drain electrode connected to the other;
Forming a second insulating film on the second bus line and the second bus line terminal;
Resin is applied on the second insulating film and patterned to form a resin layer having openings on the source electrode of the thin film transistor and on the first and second bus line terminals,
A predetermined treatment is performed on the resin layer to form a bowl-shaped resin layer having a bowl-shaped surface,
Etching the first and second insulating films using the bowl-shaped resin layer as an etching mask;
A reflective electrode having a hook-like surface following the surface of the hook-shaped resin layer, which is connected to the source electrode and patterned to form a light-reflective material on the hook-shaped resin layer, and is patterned. Forming a protective conductive film on the bus line terminal
A method for manufacturing a substrate for a liquid crystal display device.
[0061]
(Appendix 10)
In the method for manufacturing a substrate for a liquid crystal display device according to appendix 9,
The second insulating film is formed of a silicon nitride film or a silicon oxide film formed using a CVD method,
The first and second insulating films are etched by dry etching using a fluorine-based gas.
A method for manufacturing a substrate for a liquid crystal display device.
[0062]
(Appendix 11)
In the method for manufacturing a substrate for a liquid crystal display device according to appendix 9 or 10,
The resin layer is a photosensitive resin layer,
The predetermined treatment includes firing the photosensitive resin layer at a predetermined firing temperature after irradiating the surface of the photosensitive resin layer with ultraviolet light.
A method for manufacturing a substrate for a liquid crystal display device.
[0063]
(Appendix 12)
Forming a first bus line and a first bus line terminal connected to the first bus line on the substrate;
Forming a first insulating film on the first bus line and the first bus line terminal;
A second bus line and a second bus line terminal connected to the second bus line are formed on the first insulating film, and connected to one of the first and second bus lines. Forming a thin film transistor having a gate electrode and a drain electrode connected to the other;
Forming a second insulating film on the second bus line and the second bus line terminal;
A resin is applied on the second insulating film and patterned to form a first resin layer having openings on the source electrode of the thin film transistor and the first and second bus line terminals,
Etching the first and second insulating films using the first resin layer as an etching mask;
Resin is applied on the second insulating film and patterned to form a second resin layer having openings on the source electrode of the thin film transistor and the first and second bus line terminals,
A predetermined treatment is performed on the second resin layer to form a bowl-shaped resin layer having a bowl-shaped surface,
Sublimates and / or thermal oxide films formed on the source electrode and on the first and second bus line terminals when forming the bowl-shaped resin layer using the bowl-shaped resin layer as an etching mask. Etching away,
A reflective electrode having a hook-shaped surface following the surface of the hook-shaped resin layer, which is connected to the source electrode and patterned to form a light-reflective material on the hook-shaped resin layer, is patterned. Forming a protective conductive film on the bus line terminal
A method for manufacturing a substrate for a liquid crystal display device.
[0064]
(Appendix 13)
In the method for manufacturing a substrate for a liquid crystal display device according to appendix 12,
The second insulating film is formed of a silicon nitride film or a silicon oxide film formed using a CVD method,
The first and second insulating films, or the sublimates and / or the thermal oxide film are removed by dry etching using a fluorine-based gas.
A method for manufacturing a substrate for a liquid crystal display device.
[0065]
(Appendix 14)
In the method for manufacturing a substrate for a liquid crystal display device according to appendix 12 or 13,
The second resin layer is a photosensitive resin layer;
The predetermined treatment includes firing the photosensitive resin layer at a predetermined firing temperature after irradiating the surface of the photosensitive resin layer with ultraviolet light.
A method for manufacturing a substrate for a liquid crystal display device.
[0066]
(Appendix 15)
In the method for manufacturing a substrate for a liquid crystal display device according to appendix 11 or 14,
The firing temperature is 200 ° C. or higher.
A method for manufacturing a substrate for a liquid crystal display device.
[0067]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a liquid crystal display device capable of reducing the manufacturing process and obtaining good display quality.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a liquid crystal display device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a liquid crystal display substrate according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a configuration of a substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 4 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 5 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 6 is a diagram showing a method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 7 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 8 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 9 is a diagram showing a method of manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 10 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 11 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention.
FIG. 12 is a diagram showing a method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention;
FIG. 13 is a process cross-sectional view illustrating the method for manufacturing the substrate for a liquid crystal display device according to the first embodiment of the present invention.
FIG. 14 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention.
FIG. 15 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention;
FIG. 16 is a diagram showing a method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention;
FIG. 17 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention;
FIG. 18 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the first embodiment of the present invention;
FIG. 19 is a cross-sectional view showing a configuration of a substrate for a liquid crystal display device according to a second embodiment of the present invention.
FIG. 20 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the second embodiment of the present invention;
FIG. 21 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the second embodiment of the present invention;
FIG. 22 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the second embodiment of the present invention;
FIG. 23 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the second embodiment of the present invention;
FIG. 24 is a process cross-sectional view illustrating the method for manufacturing the substrate for liquid crystal display device according to the second embodiment of the present invention;
FIG. 25 is a diagram illustrating a configuration of a conventional substrate for a liquid crystal display device.
FIG. 26 is a cross-sectional view showing a configuration of a conventional substrate for a liquid crystal display device.
FIG. 27 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 28 is a process cross-sectional view illustrating a method for manufacturing a conventional substrate for a liquid crystal display device.
FIG. 29 is a diagram showing a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 30 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 31 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 32 is a diagram showing a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 33 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 34 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 35 is a diagram showing a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 36 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 37 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 38 is a diagram showing a conventional method for manufacturing a substrate for a liquid crystal display device.
FIG. 39 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for liquid crystal display device.
FIG. 40 is a process cross-sectional view illustrating a conventional method for manufacturing a substrate for a liquid crystal display device.
[Explanation of symbols]
2 TFT substrate
4 CF substrate
10 Glass substrate
12 Gate bus line
13 Gate electrode
14 Drain bus line
16 Reflective electrode
16 ', 28' metal film
18 Storage capacity bus line
20 TFT
22 Insulating film
24 Operating semiconductor layer
24 'a-Si layer
25 channel protective film
26 n-type impurity semiconductor layer
26 'n ⁺ a-Si layer
28 Drain electrode
30 Source electrode
32 Storage capacitor electrode
34 Storage capacity
36 Protective film
38, 39, 42, 46, 50 Contact hole
40 Gate bus line terminal
41, 45, 49 Protective conductive film
44 Drain bus line terminal
48 Storage capacitor bus line terminal
52 Saddle-shaped resin layer
61, 62, 63, 64, 65, 66 resist pattern
70 Gate bus line drive circuit
72 Drain Bus Line Drive Circuit
74 Control circuit
76 Polarizer

Claims (4)

Forming a first bus line and a first bus line terminal connected to the first bus line on the substrate;
Forming a first insulating film on the first bus line and the first bus line terminal;
A second bus line and a second bus line terminal connected to the second bus line are formed on the first insulating film, and connected to one of the first and second bus lines. Forming a thin film transistor having a gate electrode and a drain electrode connected to the other;
Forming a second insulating film on the second bus line and the second bus line terminal;
A photosensitive resin is applied on the second insulating film and patterned to form a photosensitive resin layer having openings on the source electrode of the thin film transistor and the first and second bus line terminals,
After irradiating the entire surface of the photosensitive resin layer with ultraviolet light, the photosensitive resin layer is baked at a predetermined baking temperature to form a bowl-shaped resin layer having a bowl-shaped surface;
Etching the first and second insulating films using the bowl-shaped resin layer as an etching mask;
A reflective electrode having a hook-like surface following the surface of the hook-shaped resin layer, which is connected to the source electrode and patterned to form a light-reflective material on the hook-shaped resin layer, and is patterned. And a protective conductive film on the bus line terminal. A method for producing a substrate for a liquid crystal display device. In the manufacturing method of the board | substrate for liquid crystal display devices of Claim 1 ,
The second insulating film is formed of a silicon nitride film or a silicon oxide film formed using a CVD method,
The method for manufacturing a substrate for a liquid crystal display device, wherein the first and second insulating films are etched by dry etching using a fluorine-based gas. Forming a first bus line and a first bus line terminal connected to the first bus line on the substrate;
Forming a first insulating film on the first bus line and the first bus line terminal;
A second bus line and a second bus line terminal connected to the second bus line are formed on the first insulating film, and connected to one of the first and second bus lines. Forming a thin film transistor having a gate electrode and a drain electrode connected to the other;
Forming a second insulating film on the second bus line and the second bus line terminal;
A resin is applied on the second insulating film and patterned to form a first resin layer having openings on the source electrode of the thin film transistor and the first and second bus line terminals,
Etching the first and second insulating films using the first resin layer as an etching mask;
A photosensitive resin is applied and patterned on the second insulating film to form a second resin layer having openings on the source electrode of the thin film transistor and on the first and second bus line terminals,
After irradiating the entire surface of the second resin layer with ultraviolet light, the second resin layer is fired at a predetermined firing temperature to form a bowl-shaped resin layer having a bowl-shaped surface;
Sublimates and / or thermal oxide films formed on the source electrode and on the first and second bus line terminals when forming the bowl-shaped resin layer using the bowl-shaped resin layer as an etching mask. Etching away,
A reflective electrode having a hook-like surface following the surface of the hook-shaped resin layer, which is connected to the source electrode and patterned to form a light-reflective material on the hook-shaped resin layer, and is patterned. And a protective conductive film on the bus line terminal. A method for producing a substrate for a liquid crystal display device. In the manufacturing method of the board | substrate for liquid crystal display devices of Claim 3 ,
The second insulating film is formed of a silicon nitride film or a silicon oxide film formed using a CVD method,
The method for manufacturing a substrate for a liquid crystal display device, wherein the first and second insulating films, the sublimate and / or the thermal oxide film are removed by dry etching using a fluorine-based gas.

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