JPH0820641B2 - Liquid crystal display manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid crystal display device that performs display by applying a drive signal to a display pixel electrode via a switching element, and particularly to the liquid crystal display device. The present invention relates to a structure of an active matrix substrate having a storage capacitor used in the above and a manufacturing method thereof.

[Prior Art] Conventionally, in a liquid crystal display device, a display pattern is formed on a screen by selecting display picture elements arranged in a matrix. As a method of selecting display pixels,
There is an active matrix drive system in which individual picture elements are arranged with independent electrodes, and a switching element is connected to each of the picture element electrodes to drive the display. This method enables high-contrast display, such as televisions. Has been put to practical use. As a switching element for selectively driving the pixel electrode, a TFT (thin film transistor) element, a MIM (metal-
Insulating film-metal) elements, MOS transistor elements, diodes, varistors, etc. are generally used, and by switching the voltage signal applied between the picture element electrode and the counter electrode facing it, the liquid crystal intervening between them. Is visually recognized as a display pattern.

FIG. 7A is a cross-sectional perspective view of a liquid crystal display device using the active matrix substrate as described above, and FIG.
FIG. 7B is an arrow view of a portion indicated by a cutting line CC of FIG. 7A, and FIG. 7C is an equivalent circuit diagram of a portion indicated by a cutting line DD of FIG. 7B.

Referring to FIG. 7A, the active matrix liquid crystal display device includes a TFT side substrate 21 on which a TFT is formed and a TFT side substrate 21.
Counter electrode side substrate 22 provided at a position facing the
The liquid crystal layer 26 sandwiched between the side substrate 21 and the counter electrode side substrate 22.
The outer peripheral portion of the liquid crystal layer 26 is sealed with a sealing resin 27 including. The TFT-side substrate 21 has a plurality of gate electrode wirings 28 for transmitting a signal to the gate electrode of the TFT, and a plurality of gate electrode wirings 28 connected in a direction intersecting with the gate electrode wiring 28 for transmitting a video signal to a source electrode of the TFT. The source electrode wiring 29 is formed. The plurality of gate electrode wirings 28 are connected to the plurality of gate electrode terminals 30 at one end of the TFT side substrate 21, and the plurality of source electrode wirings 29 are connected to the plurality of source electrode terminals 31 by the TFT.
It is connected at the end of the side substrate 21. A counter electrode 32 is formed on the counter electrode side substrate 22, and a voltage applied to the counter electrode 32 is supplied from a counter electrode terminal 34 to an end portion of the TFT side substrate 21 via the counter electrode 32 and a terminal connection electrode 33. To be done. TF
T35 is a plurality of gate electrode wirings 28 and a plurality of source electrode wirings 2
It is provided at each intersection with 9.

Referring to FIG. 7B, a plurality of pixel electrodes 36 formed on the TFT side substrate 21 and a counter electrode 32 provided on the counter electrode 22 side substrate sandwich the alignment film 37 and the liquid crystal layer 26 from each other. Facing each other.

Referring to FIG. 7C, TFT 35 is formed at the intersection of gate electrode wiring 28 and source electrode wiring 29. The gate electrode of the TFT 35 is connected to the gate electrode wiring 28, and the drain electrode is connected to the pixel electrode 36.

Next, the electrical operation of the liquid crystal display will be described. A gate-on voltage signal is applied to the gate electrode wiring 28, and all the TFTs 35 connected to the gate electrode wiring 28 are turned on. The voltage of the video signal synchronized with the ON signal of the gate is applied to each pixel electrode 36 via the source electrode wiring 29.
Is applied to The OFF signal of the gate of TFT35 is applied and T
Even when the FT35 is turned off, the electric charge stored in the display electrode is held for the time constant determined by the off resistance of the TFT35 and the capacitance of the liquid crystal cell. In this way, by scanning the gate electrodes one after another, an image can be displayed on the screen.

FIG. 8 is an equivalent circuit diagram of one TFT provided at the intersection of the gate electrode wiring 28 and the source electrode wiring 29 and the pixel electrode 36 connected to the drain electrode thereof, and FIG.
It is a schematic plan view of TFT. Referring to FIGS. 8 and 9, T
An overlapping portion S1 is formed between the gate electrode 51 of the FT and the drain electrode 53 formed on the TFT side substrate, and as a result,
A parasitic capacitance C _gd as shown in the figure is formed between the gate electrode 51 and the drain electrode 53. Now, the pixel electrode 36 and the counter electrode 32
_Let C _lc be the liquid crystal capacitance between
The potential of 53 shifts as shown in the following equation.

(V gate: potential difference between ON signal and OFF signal) As described above, the TFT has the gate electrode 51 and the drain electrode 53.
Since there is C _gd between and, when the gate signal changes from the ON signal to the OFF signal, the potential difference between the ON signal and the OFF signal is divided by the ratio of the parasitic capacitance C _gd and the liquid crystal cell capacitance C _lc , which results in the drain , That is, the potential of the pixel electrode shifts by the amount indicated by the V shift in the above equation.

In order to alleviate this drawback, a method has been adopted in which a storage capacitor C _s is added to increase the apparent liquid crystal capacitance as shown in FIG. At this time, the V shift, which is the shift of the drain potential of the TFT, becomes small as shown by the following equation.

The structure of the active matrix substrate having this storage capacitance C _s is shown in FIGS. 11A to 11D. 11th
Figure A is a plan view of the active matrix substrate.
FIG. 11B is a sectional structural view taken along the section line EE of FIG. 11A, FIG. 11C is a sectional structural view taken along the section line FF, and FIG. The cross-sectional structural drawing from the direction along -G is shown. Referring to these drawings, a storage capacitor electrode 38 is formed on the surface of the TFT side substrate 21. Then, the storage capacitor electrode 38 and the pixel electrode 36 are formed so as to surround the gate insulating film 39. Further, the storage capacitor electrode 38 is connected to the counter electrode terminal 34.
With such a configuration, the storage capacitance C _s formed between the storage capacitance electrode 38 and the pixel electrode 36 is formed in parallel with the liquid crystal capacitance C _lc between the pixel electrode 36 and the counter electrode 32.

Next, a method of manufacturing an active matrix substrate having this storage capacitor will be described. 12A to 12D are manufacturing process drawings of the cross-sectional structure shown in FIG. 11B.
FIGS. 13 to 13E are manufacturing process diagrams of the cross-sectional structure shown in FIG. 11C. First, as shown in FIGS. 12A and 13A,
A gate electrode wiring 28 and a TFT gate electrode 51 are integrally formed on the surface of the TFT side substrate 21.

Next, referring to FIGS. 12B and 13B, ITO (Indium-Tin-Oxid) which is a transparent conductive film is further formed on the surface of the TFT side substrate 21.
e: Indium tin oxide) storage capacitor electrode 38 is formed in a predetermined shape.

Thereafter, as shown in FIG. 12C and FIG. 13C, a gate insulating film 39 is formed on the surface of the TFT side substrate 21 to cover the surfaces of the gate electrode wiring 28, the storage capacitor electrode 38 and the like. Next, the TFT manufacturing process is performed. A semiconductor layer 54 is formed on the surface of the gate electrode 51 of the TFT with a gate insulating film 39 interposed.

Then, as shown in FIG. 13D, a source electrode 52 (consisting of a part of the source electrode wiring 29) and a drain electrode 53 are formed on the surface of the semiconductor layer 54.

Thereafter, as shown in FIGS. 12D and 13E, the pixel electrode 36 is formed in a predetermined region on the surface of the gate insulating film 39 covering the surface of the TFT side substrate 21.

Through the above steps, an active matrix substrate having a storage capacitor is manufactured.

[Problems to be Solved by the Invention] However, in the conventional liquid crystal display device, the storage capacitor electrode 38
Is composed of a transparent conductive film such as ITO as described above. The specific resistance of ITO is 1000 μΩcm, and the specific resistance of tantalum (Ta), which is often used for gate electrode materials, is 80 μ.
High resistance compared to Ωcm. Therefore, as the size of the liquid crystal display device becomes larger, the storage capacitor electrode 38 becomes longer and the electrical resistance as an electrode becomes higher. Then, the time constant of the storage capacitor C _s is increased. For this, during the ON signal is applied, it is not performed to accumulate sufficient charge to the storage capacitor C _s, and if the OFF signal is applied, charges accumulated in the storage capacitor C _s is discharged There is a problem in that the rising speed at the time of turning down becomes slow and causes a decrease in contrast.

In addition, when increasing the resolution of the display screen of liquid crystal display devices, the number of gate wirings should be 240 to 480 or even 10
Increase to 00 or more. In this case, the time of the ON signal applied to one gate electrode becomes shorter in inverse proportion to the number of gates. Therefore, it is necessary to reduce the time constant of the storage capacitor C _s , and even in this case, there is a problem that the electrical high resistance of the storage capacitor electrode hinders this.

[Means for Solving the Problems] The present invention includes a thin film transistor on one side of a pair of glass substrates facing each other and a pixel electrode connected to the thin film transistor, and further includes the pixel electrode and the one side. Manufacture of a liquid crystal display device including a storage capacitor electrode formed between a glass substrate and an insulating film, and an auxiliary electrode connected to the storage capacitor electrode for reducing electric resistance of the storage capacitor electrode According to the method. First, a storage capacitor electrode made of a transparent conductive film such as ITO or SnO ₂ is formed on the main surface of the glass substrate. First on the surface of the storage capacitor electrode
An insulating film is formed. An opening is selectively formed in the region of the first insulating film located on the surface of the storage capacitor electrode.
A conductive layer made of tantalum is formed on the surface of the first insulating film and inside the opening. The gate electrode of the thin film transistor and the auxiliary electrode are simultaneously formed by patterning the conductive layer of tantalum into a predetermined shape. An anodized film is simultaneously formed on the surface of the gate electrode of the thin film transistor and the auxiliary electrode. A second insulating film is formed on the surface of the first insulating film on which the auxiliary electrode is formed. A pixel electrode is formed on the surface of the second insulating film.

[Operation] The auxiliary electrode electrically connected to the storage capacitor electrode reduces the apparent electric resistance of the storage capacitor electrode and reduces the time constant of the storage capacitor electrode. As a result, the charge characteristic of the storage capacitor is improved and the display characteristic of the liquid crystal display device is improved.

Further, the auxiliary electrode is formed at the same time as the step of forming the gate electrode wiring on the glass substrate. Accordingly, the liquid crystal display device including the auxiliary electrode can be manufactured by using the conventional manufacturing process without adding a new manufacturing process for the auxiliary electrode. Further, since the anodic oxide film is formed on the surface of the auxiliary electrode, it is possible to secure the insulation between the pixel electrode and the storage capacitor electrode and improve the electrostatic breakdown voltage characteristic.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan structural view of an active matrix substrate of a liquid crystal display device according to an embodiment of the present invention, and FIG. 1B is a sectional structural view from a direction along a cutting line AA in FIG. 1A. , FIG. 1C is a sectional structural view from the direction along the section line B-B. Referring to these drawings, a plurality of gate electrode wirings 28 and source electrode wirings 29 extending in directions orthogonal to each other are arranged on the surface of the TFT side substrate 21. A TFT 35 is formed near the intersection of the gate electrode wiring 28 and the source electrode wiring 29. Further, a pixel electrode 36 is formed in a region on the surface of the TFT side substrate 21 which is partitioned by the gate electrode wiring 28 and the source electrode wiring 29. Further, a storage capacitor electrode 38 is formed between the pixel electrode 36 and the surface of the TFT side substrate 21.

Part of the gate electrode wiring 28 is the gate electrode 51 of the TFT 35.
And the source electrode wiring 29 is connected to the source electrode 52 of the TFT 35. Further, the drain electrode 53 of the TFT 35 is connected to the pixel electrode 36. With particular reference to Figure 1C, the TFT3
In the TFT 5, the gate electrode 51 is formed on the surface of the TFT side substrate 21 with the oxide insulating film 55 interposed therebetween. The surface of the gate electrode 51 is covered with the anodic oxide film 56. Further, a gate oxide film 39 is formed on the surfaces of the gate electrode 51 and the oxide insulating film 55.
Further, a semiconductor layer 54 and an etching stop layer 57 are formed on the surface of the gate oxide film 39 located above the gate electrode 51. Further, a source electrode 52 and a drain electrode 53, which are separated and independent of each other, are formed on the semiconductor layer 54 via an amorphous silicon layer 58. Further, a part of the drain electrode 53 is formed on the upper surface of the gate insulating film 39.
A pixel electrode 36 is formed in a predetermined shape so as to cover the upper surface of the pixel electrode 36 as well.

A pixel electrode 36 and a storage capacitor electrode 38 are formed on the surface of the TFT side substrate 21 so as to wrap the oxide insulating film 55 and the gate oxide film 39 from both sides thereof. The storage capacitor C _s is formed by the laminated structure. Further, an auxiliary electrode 40 extending in the plane direction is formed on the surface of the storage capacitor electrode 38. The auxiliary electrode 40 is connected to the storage capacitor electrode 38 through an opening 41 selectively formed in the oxide insulating film 55 located above the storage capacitor electrode 38. The auxiliary electrode 40
The storage capacitor electrodes 38 formed so as to face the pixel electrodes 36 arranged in a matrix on the surface of the TFT side substrate 21 are formed so as to be connected in each row direction, and the ends thereof are formed by the counter electrodes 32 ( (Not shown). The auxiliary electrode 40 is composed of a metal film having low resistance and high conductivity, such as tantalum (Ta). Then, the conductivity of the storage capacitor electrode 38 having a relatively high resistance is supplemented to reduce the time constant of the storage capacitor. Further, an anodic oxide film 56 is formed on the surface of the auxiliary electrode 40 similarly to the surface of the gate electrode wiring 28 and the surface of the gate electrode 51 of the TFT. The anodic oxide film 56 secures the insulation between the pixel electrode 36 and the storage capacitor electrode 38 and improves the electrostatic breakdown voltage characteristic.

Next, a method of manufacturing the above active matrix substrate will be described. 2A to 2D are manufacturing process drawings of the sectional structure shown in FIG. 1B, and manufacturing process drawings of the sectional structure shown in FIGS. 3A to 3D and 1C. First, a description will be given with reference to FIGS. 2A to 2D. As shown in Figure 2A,
On the surface of the TFT side substrate 21 made of a glass substrate, a conductive film made of a transparent conductive material such as ITO or SnO ₂ is formed to a film thickness of about 500Å to 2000Å, and patterned into a predetermined shape to form a storage capacitor electrode.
Form 38.

Next, as shown in FIG. 2B, an oxide insulating film 55 such as SiO ₂ , Ta ₂ O ₅ or Al ₂ O ₃ is formed on the surface of the TFT side substrate 21 on which the storage capacitor electrode 38 is formed. The thickness of the oxide insulating film 55 is 1000 when it is an insulating film having a small relative dielectric constant of 4 such as SiO _2.
It is desirable that the thickness is approximately Å or less.
Further, in the case of an insulating film having a high relative permittivity of 23 to 25 such as Ta ₂ O ₅ , it may be further increased. Next, an opening 41 having a predetermined shape is formed in the oxide insulating film 55 region located on the surface of the storage capacitor electrode 38.

Further, as shown in FIG. 2C, a highly anodic metal film such as Ta is formed on the surface of the oxide insulating film 55 and inside the opening 41, and patterned into a predetermined shape. By this step, the auxiliary electrode 40 formed inside the gate electrode wiring 28 and the opening 41 is formed. In this patterning step, for example, when Ta is used for the metal film and the oxide insulating film 55 is SiO ₂ , a selective process can be performed by the dry etching method. Further, when the oxide insulating film 55 is Ta ₂ O ₅ , the wet etching method enables a selective process.

Next, as shown in FIG. 2D, anodic oxidation is performed to form an anodic oxide film 56 on the surfaces of the auxiliary electrode 40 and the gate electrode wiring 28. For example, when Ta is used as the wiring material, the anodic oxide film 56 is anodized in an aqueous solution of ammonium borate, an aqueous solution of citric acid, or an aqueous solution of ammonium tartrate to form Ta ₂ O ₅ . Through the above steps, the main part of the sectional structure shown in FIG. 1B is formed.

Next, the TF shown in FIG. 1C will be described with reference to FIGS. 3A to 3D.
A method of manufacturing the T35 sectional structure will be described.

First, as shown in FIG. 3A, a TFT is formed on the surface of the TFT side substrate 21 through the oxide insulating film 55 by the steps up to the above FIG. 2D.
A gate electrode 51 of 35 and an anodized film 56 covering the surface thereof are formed. Next, on the surface of the oxide insulating film 55 on which the gate electrode 51 is formed, the gate insulating film 39 made of SiNx, the amorphous silicon layer 54a forming the semiconductor layer 54, and the etching stopper layer 57 are formed by using the plasma CVD method. The SiNx layer 57a is sequentially grown. The thickness of each layer is 3000
Å, 300Å, 1000Å.

Next, as shown in FIG. 3B, the second SiNx layer 57a is patterned into a predetermined shape to form an etching stopper layer 57.

Further, as shown in FIG. 3C, the amorphous silicon layer 54a and the patterned etching stop layer 5 are formed.
Amorphous silicon (n ⁺ ) film thickness of about 1000Å is grown on the surface of 7 by plasma CVD method. Then, the amorphous silicon layer 58 and the underlying amorphous silicon layer 54a are simultaneously patterned to form the semiconductor layer 54 and the amorphous silicon layer 58.

Further, as shown in FIG. 3D, a source electrode wiring material such as Ti and Mo is deposited on the entire surface by using a sputtering method and patterned into a predetermined shape. In this patterning step, the amorphous silicon layer 58 formed on the surface of the etching stop layer 57 is also etched at the same time to form independent amorphous silicon 58, 58. In this etching step, the etching stop layer 57 defines the end point of etching. Further, the source electrode wiring 29 (leasing electrode 52) and the drain electrode 53 are formed on the upper surfaces of the independent amorphous silicon layers 58, 58.

Next, referring to FIGS. 1B and 1C, ITO, which is a pixel electrode material, is deposited on the entire surface by a sputtering method to form an ITO film having a film thickness of about 1000 Å and processed into a predetermined shape. The pixel electrode 36 is formed. In addition, in order to reinforce the pattern of the source electrode wiring 29, the ITO film may be formed into the same pattern as the source electrode wiring 29 except for the portion forming the pixel electrode 36.

Next, a second embodiment of the present invention will be described. Fourth A
FIG. 4 is a plan view of an active matrix substrate of a liquid crystal display device according to a second embodiment, and FIGS. 4B and 4C are sectional views taken along section lines AA-AA and BB-BB in FIG. 4A, respectively. FIG. 3 is a cross-sectional structure view from a vertical direction. With reference to these figures, the second embodiment is characterized in that an auxiliary electrode 40 is formed between the TFT side substrate 21 and the storage capacitor electrode 38. The auxiliary electrode 40 and the storage capacitor electrode 38 are directly connected. Even in such a structure, the auxiliary electrode 40 supplements the conductivity of the storage capacitor electrode 38 and reduces the time constant of the storage capacitor, as in the first embodiment.

Next, the manufacturing method of the second embodiment will be described. 5A
5 to 5C are manufacturing process diagrams of the sectional structure shown in FIG. 4B. 6A to 6D are manufacturing process diagrams of the sectional structure shown in FIG. 4C.

First, as shown in FIGS. 5A and 6A, tantalum (Ta) is deposited on the surface of the TFT-side substrate 21 made of a glass substrate by a sputtering method, and then a predetermined shape is formed by a photolithography method. Pattern. By this step, the gate electrode wiring 28, the gate electrode 51 of the TFT 35 and the auxiliary electrode 40 are simultaneously formed. Then, the TFT-side substrate 21 on which these wiring layers are formed is immersed in an aqueous solution containing about 1 to 5% ammonium tartrate, and is subjected to a predetermined anodic oxidation process on the surfaces of the gate electrode wiring 28 and the TFT gate electrode 51. An anodic oxide film 56 is formed.

Further, as shown in FIGS. 5B and 6B, the TFT side substrate 2
After forming an ITO film on the entire surface of 1 by using a sputtering method, this is patterned into a predetermined shape. As a result, the storage capacitor electrode 38 is formed on the surface of the TFT side substrate 21 at a position where a pixel should be formed so as to cover the upper surface of the auxiliary electrode 40.

Further, as shown in FIGS. 5C and 6C, a gate insulating film 39 made of a silicon nitride (SiNx) film is deposited on the entire surface of the TFT side substrate 21 by using the plasma CVD method. Further, a- is formed on the gate insulating film 39 at a position overlapping the gate electrode 51.
A Si (amorphous silicon) layer is formed by using the plasma CVD method and is patterned to form the semiconductor layer 54 of the TFT 35.

Further, as shown in FIG. 6D, molybdenum (Mo) is deposited on the entire surfaces of the gate insulating film 39 and the semiconductor layer 54 by using the sputtering method. Then, the Mo layer is patterned to form the source electrode 29, the source electrode 52 and the drain electrode 53 of the TFT 35. The source electrode wiring 29 and the source electrode 52 are integrally formed. The source electrode 52 is formed so that a part thereof overlaps with one side of the semiconductor layer 54, and the drain electrode 53 is still formed so that a part thereof overlaps with the other side of the semiconductor layer 54.

Finally, an ITO film is deposited on the entire surface by a sputtering method and patterned to form a pixel electrode 36. The pixel electrode 36 is formed so that a part thereof is in contact with the upper portion of the drain electrode 53. Through the above steps, the liquid crystal display device having the sectional structure shown in FIGS. 4B and 4C is manufactured.

Thus, in the above manufacturing process, the gate electrode wiring 28, the gate electrode 51 of the TFT 35, and the auxiliary electrode 40 are formed using the same deposition process and patterning process. Therefore, it is possible to manufacture a liquid crystal display device which can be increased in size without causing a reduction in contrast and the like in a simple manufacturing process without adding a new manufacturing process to the conventional manufacturing process.

EFFECTS OF THE INVENTION As described above, in the liquid crystal display device according to the present invention, since the auxiliary electrode having higher conductivity is connected to the storage capacitor electrode forming the additional capacitance, the time constant of the storage capacitor electrode is It is possible to realize a liquid crystal display device having a smaller size, improved charging characteristics, and improved display characteristics such as contrast.

In addition, since the liquid crystal display device having the auxiliary electrode is configured such that the gate electrode wiring and the auxiliary electrode are manufactured at the same time in the same process, the display characteristics are easily improved without adding a new complicated manufacturing process. A liquid crystal display device that can be upsized can be manufactured. Further, since the anodic oxide film is formed on the surface of the auxiliary electrode, it is possible to manufacture a liquid crystal display device in which the insulation between the pixel electrode and the storage capacitor electrode is secured and the electrostatic breakdown voltage characteristic is improved. .

[Brief description of drawings]

FIG. 1A is a plan structural view of an active matrix substrate of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 1B is a sectional view taken along a section line AA in FIG. 1A. It is a structural drawing and FIG. 1C is a cross-sectional structural drawing similarly from the direction along the cutting line BB. 2A, 2B, 2C,
FIG. 2D is a manufacturing process diagram of a cross-sectional structure of the liquid crystal display device shown in FIG. 1B. 3A, 3B, 3C and 3D are manufacturing process diagrams of the cross-sectional structure of the liquid crystal display device shown in FIG. 1C. FIG. 4A is a plan structure view of an active matrix substrate of a liquid crystal display device according to a second embodiment of the present invention, and FIG. 4B is a sectional structure taken along the line AA-AA in FIG. 4A. Similarly, FIG. 4C is a sectional structural view taken along the line BB-BB. Figures 5A, 5B and 5C
FIG. 4C is a manufacturing process sectional view of a sectional structure of the liquid crystal display device shown in FIG. 4B. Figures 6A, 6B, 6C and 6D show 4C.
FIG. 9 is a manufacturing process diagram of a cross-sectional structure of the liquid crystal display device shown in the drawing. FIG. 7A is a perspective view of a sectional structure of a conventional liquid crystal display device. FIG. 7B is a sectional structural view of the liquid crystal display device shown in FIG. 7A. FIG. 7C is an equivalent circuit diagram on an active matrix substrate of a conventional liquid crystal display device. FIG. 8 is an equivalent circuit diagram of a portion corresponding to one pixel of the liquid crystal display device shown in FIG. 7C. FIG. 9 is an enlarged view of the periphery of the TFT of the liquid crystal display device shown in FIG. 7A. FIG. 10 is an equivalent circuit diagram of a portion corresponding to one pixel of a liquid crystal display device to which a storage capacitor is added. FIG. 11A is a plan structural view of a liquid crystal display device corresponding to the equivalent circuit diagram shown in FIG. 10, and FIG. 11B is a sectional structural view from a direction along a cutting line EE in FIG. 11A. , 11th
Similarly, FIG. 11C is a sectional structural view taken along the section line FF, and FIG. 11D is a sectional structural view taken along the section line GG. 12A, 12B, 12C and 12D are manufacturing process diagrams of the cross-sectional structure of the liquid crystal display device shown in FIG. 11B. 13A, 13B, 13C, 13D
FIG. 13 and FIG. 13E are manufacturing process drawings of a cross-sectional structure of the liquid crystal display device shown in FIG. 11C. In the figure, 21 is a TFT side substrate, 22 is a counter electrode side substrate, 26
Is a liquid crystal layer, 28 is a gate electrode wiring, 29 is a source electrode wiring,
32 is a counter electrode, 35 is a TFT, 36 is a pixel electrode, 38 is a storage capacitor electrode, 39 is a gate insulating film, 40 is an auxiliary electrode, and 55 is an oxide insulating film. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A thin film transistor and a picture element electrode connected to the thin film transistor are provided on one side of a pair of glass substrates facing each other, and the picture element electrode and the glass substrate on the one side are provided between the picture element electrode and the one side glass substrate. A method of manufacturing a liquid crystal display device, comprising: a storage capacitor electrode formed via an insulating film; and an auxiliary electrode connected to the storage capacitor electrode for reducing the electric resistance of the storage capacitor electrode, Forming a storage capacitor electrode made of a transparent conductive film such as ITO or SnO ₂ on the main surface of the glass substrate; forming a first insulating film on the surface of the storage capacitor electrode; A step of selectively forming an opening in a region of the first insulating film located on a surface, and a step of forming a conductive layer made of tantalum on the surface of the first insulating film and inside the opening, From the tantalum Forming a gate electrode of the thin film transistor and the auxiliary electrode at the same time by patterning a conductive layer formed into a predetermined shape, and forming an anodized film on the surface of the gate electrode of the thin film transistor and the auxiliary electrode at the same time. A liquid crystal comprising: a step of forming a second insulating film on the surface of the first insulating film on which the auxiliary electrode is formed; and a step of forming a pixel electrode on the surface of the second insulating film. Manufacturing method of display device.