JPS61226731A - Manufacture of thin film transistor liquid crystal display - Google Patents

Abstract

PURPOSE:To prevent opacification of a film formed by plasma CVD and deterioration of film quality by successively forming interlayers by the plasma CVD process on a transparent conductive film covered with a protective film, and removing the protective film after removing the plasma CVD films on the electrode film. CONSTITUTION:A lower gate electrode 12 of Cr and a transparent conductive electrode 13 are formed on a glass base 11, and the electrode 13 is covered with a thin Cr protective film 14. Next, an SiN film 15 and an a-Si film 16 are successively formed on these surfaces by the P-CVD process with a glow discharge device to form the interlayers, an upper source electrode 17, a drain electrode 18 corresponding to the gate electrode 12 is formed to separate the elements, and the film 16 and the film 15 formed on the electrode 13 are etched off, and then, the protective layer 14 is also etched off, thus permitting the P-CVD to be executed in a state of the electrode 13 covered with the film 14, therefore, the electrode 13 not to be exposed to the plasma at the time of film formation by P-CVD operation, and opacification and deterioration of quality of the P-CVD film to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to the effects of the underlying transparent conductive film on the formation of P-CVD (plasma-chemical vapor deposition) films during the manufacturing process of thin film transistor liquid crystal displays. - This is to prevent clouding of the CVD film and deterioration of film quality, and after covering the transparent conductive film with a protective film, C2P-CV
We are trying to solve the problem by forming a D film.

[Industrial application field]

The present invention relates to a method of manufacturing a thin film transistor liquid crystal display.

Some liquid crystal displays are of an active matrix type that use thin film transistors as switching elements and transparent conductive films as display electrodes.

[Conventional technology]

The manufacturing process of this type of conventional thin film transistor liquid crystal display is shown in FIG. This figure shows one pixel of one substrate equipped with a thin film transistor.When manufacturing a liquid crystal display, first a Cr gate electrode 2 is placed on a glass substrate 1, as shown in FIG. 2(a). A transparent electrode (a transparent conductive 1LIC film corresponding to a display electrode) 3 is formed. Next, I: As shown in Figure 2(b), 42, the silicon nitride (SIN) film of the P-CVD film (
Insulator layer)4. Amorphous silicon (a-81) film (
Semiconductor layer) 5 is continuously formed. Thereafter, as shown in FIG. 2(e), the source electrode 6. A drain electrode 7 is formed to perform element isolation, and the SIN on the transparent electrode 5 is 5% v.
The a-+3i film is removed by etching C;. Thereafter, a liquid crystal display is constructed by sandwiching two liquid crystals between this substrate and the other substrate on which a transparent conductive film, an insulating film, and an alignment film are formed.

[Problem that the invention seeks to solve]

In this way, conventionally, two P-CV (two P-CV)
Since the D film is formed, impurities such as incidium and tin contained in the transparent conductive film ζ have an adverse effect on the initial stage of film formation, causing the P-CVD film to become cloudy and the film quality to deteriorate. I end up.

[Means for solving problems]

The present invention is intended to solve the above-mentioned problems, and as shown in FIG. When forming a layer, plasma CV on a transparent conductive film
After removing the D film, a step of removing the protective film is adopted. The protective film is made of a material that is selectively etched with the transparent conductive film, such as Cr, Ta, Mo, or the like. Also a-8i
membrane, 810. It is also possible to form a reflection film using an insulating film such as.

[Effect]

The plasma CVD film is formed on the protective film 62 times, and the transparent conductive film is not exposed to the plasma during the formation period, so that cloudiness and film quality deterioration of the formed plasma CVD film can be prevented.

〔Example〕

The present invention will now be described in detail with reference to FIG.

FIG. 1 is a manufacturing process diagram (showing one pixel) of the thin film transistor liquid crystal display of the present invention.

Manufacture of thin film transistor liquid crystal display
First, as shown in FIG. 1(a), a Cr gate electrode (upper electrode) 12 and a transparent electrode (ITO transparent conductive film corresponding to a display electrode) 13 are formed on a glass substrate 11. do.

Next, as shown in FIG. 1(b) ζ2, a protective film 14 of a thin Cr film covering the transparent electrode 16 is formed.

Next, as shown in Figure (e)≦2, the P-CVD film SiN film (insulator layer) 15 and A-8L film (semiconductor layer) 16 are formed using these surface area discharge devices. The intermediate layer is formed by continuous film formation.

Next ζ;, FIG. 1(d) (2) As shown in 1;, on top of this (= gate electrode + lA121 = corresponding upper electrode source electrode 417° drain electrode 18 is formed to perform element isolation,
It is removed from a-8116 on the transparent electrode, 5 on the SIN film 1 and 12 on the SIN film.

Thereafter, as shown in FIG. 1(-), C2, the protective film 14 on the transparent electrode 13 is removed by etching.

Thus, in the present invention, the transparent electrode 16 is protected by the protection 1114.
Since the P-CVD film is formed while being covered with the plasma 6, the transparent electrode 13 is not exposed to the plasma 6 during film formation. Therefore, clouding of the P-CVD film and deterioration of film quality, which have been problems in the past, can be prevented, and a high quality film can be formed.

In the above description, Example C is described in which a Cr thin film is used as the protective film, but in addition to this, a transparent conductive film (transparent electrode) and a selectively etchingable material such as Ta, Mo, etc. can be used as the protective film.

Further, as the protective film, not only a metal thin film but also an α-8t film, an 810° insulating film, etc., which has selective etching properties with a transparent conductive film, can be used.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent clouding of the P-CVD film and deterioration of the film quality due to the influence of the transparent conductive film, so it is possible to form a high-quality P-CVD film. This makes it possible to significantly increase the fabrication yield by two orders of magnitude.

[Brief explanation of the drawing]

Figures 1 (&) to (6) are manufacturing process diagrams of a thin film transistor liquid crystal display showing an embodiment of the present invention, and Figure 2 (ta)
~(c) is a manufacturing process diagram of a conventional thin film transistor liquid crystal display, in which 11 is a glass substrate, 12 is a gate IIE electrode (lower electrode), 13 is a transparent electrode (transparent conductive film that is a display electrode), and 14 is a Protective layer, 15 is a SIN film (insulator layer), 16 is an a-81 film (semiconductor layer) that forms a ζ2 intermediate layer with the SIN film, 17 is a source electrode (upper electrode), 1 is a drain electrode ( upper electrode). Craftsmanship of the Atsuhara transistor liquid bird display of the present invention!
I-Figure 1

Claims (1)

[Claims] A thin film transistor is used as a switching element, a transparent conductive film is used as a display electrode, and an intermediate layer formed by continuous deposition and etching of a plasma CVD film is provided between the upper and lower electrodes of the thin film transistor. In the manufacturing process of an active matrix liquid crystal display, the intermediate layer is formed by covering the transparent conductive film with a protective film that is selectively etched to prevent the transparent conductive film from being exposed to plasma; A method for manufacturing a thin film transistor liquid crystal display, comprising the step of subsequently removing the protective film.