JPH03174517A - Production of liquid crystal display with thin film transistor - Google Patents

Abstract

PURPOSE:To prevent the occurrence of defects due to a short circuit by successively forming a gate insulating film, a first semiconductor film and a patterned etching stopper, further forming a second semiconductor film having low resistance and patterning the second and first semiconductor films. CONSTITUTION:A display pixel electrode 8 is formed on a glass substrate 1 and patterned, an SiO2 film is grown as an interlaminar insulating film 10 and Cr is formed and patterned to form gate metal wiring 2. A gate insulating film 3, a semiconductor Si film 4 and a silicon nitride film are successively formed and the silicon nitride film is patterned to form an etching stopper 5. An n<+>Si film 6 is grown, the films 6, 4 are patterned, a through hole 11 is pierced in the films 10, 3 on the electrode 8 and a source-drain metal 7 is formed. The film 6 is etched up to the etching stopper 5 under self-matching to pierce a channel opening 9 and a thin film transistor is completed. The occurrence of defects due to a short circuit between drain wiring and display pixel is prevented in a lithographing stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a thin film transistor (TPT) liquid crystal display (LCD), and particularly relates to a manufacturing method for obtaining a TFTLCD that is free from defects due to short circuits and has a high yield.

[Conventional technology]

Conventionally, bottom gate type T in this type of TFTLCD
The schematic steps of the method for manufacturing the FT and display pixel section are shown in FIGS. 3(a) to 3(f). That is, first, a gate metal wiring 2 is formed on a glass substrate (FIG. 3(a)). A gate insulating film 3, a semiconductor Si film 4 and an etching stopper 5 are provided thereon (FIG. 3(b)).
). Next, an n'' Si film 6 is formed and patterned together with the semiconductor Si film 4 (FIG. 3(C)).Next, a source/drain metal 7 is formed (FIG. 3(d)).Next, the display pixel electrode 8 (Fig. 3(e)), and finally provide a channel etching opening 9 to complete the TPT (Fig. 3(e)).
f)〉.

FIG. 4 is a plan view showing one pixel of the TFTLCD manufactured in this manner, in which 21 is a gate wiring, 22 is a drain wiring, 23 is a TFT section, and 24 is a display pixel section.

[Problem to be solved by the invention]

In the conventional TFTLCD manufacturing method shown in FIG. 3, the gate wiring is separated between layers over the entire surface by a gate insulating film. There are no short circuit defects. but,
Since there is no interlayer film between the drain wiring and the display pixel part,
There is a drawback that pattern defects occur due to dust and the like during the phosphorography process, leading to defects. For example, a short circuit between the drain wiring and one display pixel becomes a point defect.
A short circuit between two adjacent drain wires via one display pixel portion becomes a line defect.

[Means to solve the problem]

The method for manufacturing a TFTLCD of the present invention includes a step of providing a display pixel electrode on a glass substrate, a step of providing an interlayer insulating film and a patterned gate wiring thereon, and a step of providing a gate insulating film, a first semiconductor film and a patterned gate wiring thereon. A step of providing a patterned etching stopper, a step of providing a second low resistance semiconductor film thereon and patterning it together with the first semiconductor film, and opening a through hole on the display pixel electrode to form a source/drain electrode. It is characterized by including the step of providing. Note that the interlayer insulating film and the gate insulating film may have the same composition.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) to (f) show the first embodiment of the present invention.
FIG. 3 is a longitudinal cross-sectional view showing a method for manufacturing an FTLCD. First, the display pixel electrode 8 is made of ITD (Indium Tin).
oxide) on the glass substrate 1 and patterned (FIG. 1(a)). Next, as the interlayer insulating film 10, S
The i02 film is grown, and then a CR is formed and patterned to form the gate metal wiring 2 (FIG. 1(b)).
. Next, a gate insulating film 3, a semiconductor Si film 4, and a silicon nitride film are formed, and the silicon nitride film is patterned to form an etching stopper 5 (FIG. 1(C)). Then n
"The Si film 6 is grown and patterned together with the semiconductor Si film 4 (FIG. 1(d)). Next, through holes 11 are opened on the display pixel electrodes and source/drain metals 7 are formed (FIG. 1(e) ).Finally, the n''Si film 6 is self-aligned and etched to the etching stopper 5 to form a channel etching opening 9 to complete the TPT (Fig. 1(f)).
.

Note that since the opening of the through hole to the display pixel electrode can be performed in the same process as the opening of the through hole to the gate wiring, the number of phosphorography operations is the same as in the conventional method.

FIGS. 2(a) to (f) show the second embodiment of the present invention.
FIG. 3 is a longitudinal cross-sectional view of the FTLCD. In this embodiment, an interlayer insulating film having the same composition as the gate insulating film [10'] is used as the interlayer insulating film formed on the display pixel electrode 8. For example, when a silicon nitride film of 200 OA is used as the gate insulating film by plasma vapor deposition. , 200O under the same conditions for the interlayer insulating film 10'.
A and a silicon nitride film are grown. In this embodiment, the openings of the through holes 11 on the display pixel electrodes 8 are formed by etching a film of the same composition, so that there is little overetching, and the opening shape can be easily controlled, which has the advantage of reducing disconnection defects at step portions.

〔Effect of the invention〕

As described above, in the present invention, the gate wiring, display pixel electrode, source/drain, and their wiring are separated from each other by an interlayer insulating film. Therefore, there is no defect caused by a short circuit between the drain wiring and the display pixel during the lithography process, which is a drawback of the conventional method. Also, after forming display pixel electrodes on and in contact with the glass substrate,
Since the gate wiring, source/drain portions, and their wiring are formed, the TPT can be manufactured in exactly the same manner as the conventional method, and there is a degree of freedom. The stability and reliability of TFT'Pf properties can be guaranteed to the same extent as the conventional method.

Furthermore, the ITO film of the display pixel electrode is generally 100%
Because it is thin and around 0A, it is easy to break at the step. Therefore, the present invention in which patterning is performed on the element surface of a glass substrate has the advantage that there is no disconnection failure at the stepped portion.

[Brief explanation of the drawing]

Figures 1 (a) to (f) are TFTLCD diagrams (a) of the present invention.
~(f) is a vertical cross-sectional view showing an example of a conventional manufacturing method, No. 4
The figure is a schematic plan view of a TFTLCD. 1...Glass substrate, 2...Gate metal wiring, 3...
・Gate insulating film, 4... Semiconductor Si film, 5... Etching stopper 6... n'' Si film, 7... Source/drain metal, 8... Display pixel electrode, 9... Channel etching Opening, 10...Interlayer insulating film, 10'
...Interlayer insulating film with the same composition as the gate insulating film, 11...
・Through hole.

Claims (1)

[Claims] 1. Providing a display pixel electrode on a glass substrate;
A step of providing an interlayer insulating film and a patterned gate wiring thereon, a step of providing a gate insulating film, a first semiconductor film, and a patterned etching stopper thereon, and a step of providing a second low-resistance semiconductor film thereon. A method for manufacturing a thin film transistor liquid crystal display, comprising the steps of forming and patterning the first semiconductor film together with the first semiconductor film, and forming a source/drain electrode by opening a through hole on the display pixel electrode. 2. The method of manufacturing a thin film transistor liquid crystal display according to claim 1, wherein the interlayer insulating film and the gate insulating film have the same composition.