JPS5890689A - Manufacture of matrix type liquid crystal display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention provides a matrix type liquid crystal display device comprising a plurality of gate lines and a plurality of source lines orthogonal to the gate lines, and an active element such as a TPT, a storage capacitor, etc. at each intersection point. The present invention relates to a manufacturing method.

FIG. 1 is a cross-sectional structural diagram for explaining the configuration of a TFT array, and FIG. 2 is a cross-sectional structural diagram for explaining the configuration of a matrix type color liquid crystal display device.

In the figure, (1) is a gate line, (2) is a source line, (
3) is the drain electrode, (4) is the TPT, (5) is the display electrode, (6) is the storage capacitor, (7) is the liquid crystal, (8)
is a TFT array, (9) is a TFT array substrate, 0 is a transparent conductive film, 0υ is a color filter, (6) is a counter substrate,
α4 indicates a matrix type color liquid crystal display device, and 04 indicates external light.

Conventionally, there have been devices of this type as shown in FIGS. 8 and 4. FIG. 8 is a partial plan view of the TFT array pixel,
The figure shows a cross-sectional structural diagram of the section A-A' in FIG. 8.

In the figure, (1) is a gate line, (2) is a source line, (
3) is the drain electrode, (5) is the display electrode, and (9) is the TF.
T array substrate, α average is semiconductor, a6 is 5iOz, αη is gate insulating film % (to) doped polysilicon, α is source region.

The pen is the drain area, C! υ is a PSG film, 2) is an insulating film between 1 and 2, (to) is a storage capacitor electrode, and 2 is a dielectric.

First, the structure of a matrix type color liquid crystal display device will be explained with reference to FIGS. 1 and 2. The matrix type color liquid crystal display device α] has a plurality of gate lines (1).

and a source line (2) orthogonal to these gate lines, and an active element, for example T P T (4) 4, is formed at the intersection thereof, and its drain electrode (3) and display electrode (5) are provided.
, a TFT array substrate (9) on which a TFT array (8) having a structure having a signal storage capacitor (6) is formed, and an opposing transparent conductive film (10) having a color filter αυ of red, green, blue, etc. It has a structure in which a liquid crystal (7) is sandwiched between a substrate (6) and both substrates (9) and (2), and is irradiated with external light (141).

Next, the conventional TFT array (8) will be explained with reference to FIGS. 8 and 4. The TFT array (8) is formed by forming 0G of a semiconductor such as polysilicon on the surface of a TFT array substrate (9) made of an insulating substrate such as glass by low pressure CVD or the like.
TPT forming part OG using a mask of SiN etc.
5i02αG with selective oxidation of polysilicon in other parts
After forming the gate insulating film 07) by, for example, a thermal oxidation method, and subsequently forming a film of doped polysilicon (T) doped with an impurity such as boron, the gates αη,
(to) Perform patterning.

Thereafter, ions of impurity such as arsenic are implanted into the source region and the drain region (e). Subsequently, a phosphorus, glass ωSG) film (2) is formed and patterned by a CVD method or the like, and AI, which will become a source line (2) and a drain electrode (3), is formed by, for example, a vapor deposition method.

Also, ITO, which will later become the storage capacitor
(indium, tin oxide) was formed by a vapor deposition method, and the interlayer insulating film (2) between the gate line (1) and the source line (2) and the dielectric material i of the storage capacitor were formed by, for example, a 5i01+ sputtering method. Later, a transparent electrode made of ITO, which serves as the upper electrode of the storage capacitor and the display electrode (5), is formed by, for example, vapor deposition, and connected to the drain electrode (3) formed earlier, forming the gate line A1 (gate line +1). is formed by, for example, a vapor deposition method to complete the TFT array (8).

Since the conventional TFT array (8) is constructed as described above, after etching the AI with a phosphorus-oxygen etching solution to form the source line (2) and drain electrode (3), the TFT array (8) containing ferric chloride is etched. The storage capacitor electrode (c) and display electrode (5) must be formed by etching the ITO with a hydrochloric acid-based etching solution.

The salt-oxygen etching solution containing ferric chloride corrodes and oxidizes the electrodes, resulting in defects such as poor electrical contact between the drain electrode and the display electrode, or frequent disconnections. TFT arrays and matrix type liquid crystal display devices using these TFT arrays have drawbacks such as poor manufacturing yields and short lifespans.

This invention was made in order to eliminate the drawbacks of the conventional ones as mentioned above.
We provide TFT arrays and matrix-type liquid crystal display devices with high reproducibility, high manufacturing yield, and long life by using a method in which the etching of the electrode formation part, such as AI, is actually performed after the etching of the TO formation part is completed. It is intended to.

An embodiment of the present invention will be described below with reference to FIGS. 5 and 6.

FIG. 5 is a partial plan view of a TFT array pixel according to an embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along line A-A' in FIG.

In the figure (ri is the gate line, (2) is the source line, (3)
is the drain electrode, (5) is the display electrode, (9) is the TFT array substrate, α is the semiconductor, αG is Sing, 07) is the gate insulating film, α is the doped polysilicon, 0 is the source region, ( 1) 1 drain region, 2) PSG film, 1 insulating film, (to) storage capacitor electrode, 2) dielectric.

The structure will be explained next.

The TFT array is made of an insulating substrate such as glass.

A semiconductor (c) such as polysilicon is provided on the surface of the TFT7 lay substrate (9) by a low pressure CVD method, etc., and using a mask such as SiN, selectively oxidizes the polysilicon etc. in areas other than the TPT forming area a8. After forming Lll, a gate insulating film αη is formed by, for example, a thermal oxidation method.

After successively forming a film of doped polysilicon doped with impurities such as boron, the gate 0η, (to) is formed.
Perform patterning.

Thereafter, impurity ions such as arsenic are ion-implanted into the source region QQ and drain region. Subsequently, a phosphor glass (PSG) film Q is formed by a CVD method or the like.

After this, ITO, which will become the electrode (2) of the storage capacitor, is formed into a film by, for example, a vapor deposition method, and then pattern-etched with a hydrochloric acid-based etching solution containing ferric chloride, which will subsequently become the dielectric material (material) of the storage capacitor. For example, after forming 5i02 by sputtering method etc., is there a variable display? After forming a transparent electrode made of ITO, which also serves as the void electrode (6) and the upper electrode of the storage capacitor, by, for example, a vapor deposition method, pattern etching is performed using a hydrochloric acid-based etching solution I containing ferric chloride. After this, after forming a film of AI that will become the saw X-ray (2) and the drain electrode (3) by, for example, a vapor deposition method, pattern etching is performed using a phosphoric acid etching solution to form the drain electrode (3).
is connected to the previously formed display electrode (5). After this, for example, 5i02, which will become the glabellar insulation/Ill between the source line (2) and the gate line (1), is formed by sputtering, etc., and then AI, which will become the gate line (1), is again formed by vapor deposition, etc. Then pattern-etch the TFT using a phosphoric acid etching solution.
Array (8) is completed.

As described above, the TFT array according to the present invention uses IT for the storage capacitor electrode (5) and the display electrode (5).
After pattern etching O with a hydrochloric acid etching solution containing ferric chloride, the source line Q) and drain electrode (
3), and the gate line (11) was pattern-etched using a phosphoric acid-based etching solution, so the AI used for the source line 2) and the drain electrode E electrode (3) was changed as in the conventional example. The drain electrode ( 3) and the display [The electrical contact between the pole (5) is good and stable, and there is no disconnection.

Therefore, the TFT array according to the method of the present invention and the TFT
Matrix type liquid crystal display devices using FT arrays have a frustrating feature of good manufacturing yield and long life.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the configuration of a TFT array, Figure 2 is a cross-sectional structural diagram of a matrix type color liquid crystal display device, Figure 8 is a partial plan view of a conventional TFT array pixel, and Figure 4 is directed to Figure 8. 5 is a partial plan view of the TFT array pixel of the present invention, and FIG. 6 is a sectional structural diagram of the section A-A' in FIG. :In A, (1) is the gate line, (2) is the source line, (3)
1 is the drain pole, (5) is the display electrode, and @ is the storage capacitor (4 poles). Note that the same lines in Figure 1 indicate the same or equivalent parts. Agent Ge Shu Xin - Figure 1, Figure 8, Figure 2, Figure 3, Figure 4, Procedure amendment (voluntary) Showa 5η 1 River 1-1, Indication of case Relationship to patent application Showa 511-11111 case No. 6 Patent Representative Hitoshi Katayama, Department 4, Agent Address: 2-2-3-6, Marunouchi 2-chome, Chiyoda-ku, Tokyo, Detailed Description of the Invention and Drawing 6 in the Specification Subject to Amendment, Contents of the Amendment (11 Specifications) "Phosphorous oxygen" on page 6, line 4 of the book is corrected to "phosphoric acid type". (2) "Salt oxygen" on page 6, line 1θ of the same book is corrected as "hydrochloric acid type". (3 ) Correct "Example" in line 6 of page 6 to "Example of Example". (4) Correct Figure 2 of the drawings to indicate that it has not been placed in the attached copy. ?, List of attached documents (1 drawing (Fig. 2) 1 copy or more Fig. 2)

Claims (1)

[Claims] It has a plurality of gate lines and a plurality of source lines orthogonal to the gate lines, and a thin film transistor (hereinafter referred to as TPT) is installed at the intersection point.
A matrix type having a structure in which a substrate is formed with a TFT array consisting of active elements such as (referred to as ) and storage capacitors, and a counter substrate is formed with a transparent conductive film and a color filter, and a liquid crystal is sandwiched between the side substrates. In the manufacturing method of a liquid crystal display device, after completing the etching of the indium and tin oxides that make up the display electrodes, storage capacitor electrodes, etc., the aluminum that makes up the gate lines, source lines, and train electrodes of the TPT is etched. A method of manufacturing a matrix type liquid crystal display device characterized by performing etching.