KR100205867B1 - Active matrix substrate and its fabrication method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an active matrix substrate used in a liquid crystal display device and the like, and to an active matrix substrate manufactured by the method. The number is reduced, a polyimide film is formed on the pixel electrode, and a black resin film is formed in a predetermined region on the polyimide film to complete an active matrix substrate having a good alignment state.

Description

Method for manufacturing active matrix substrate and active matrix substrate manufactured by the method

1 is a plan view showing a general active matrix substrate.

2 is a cross-sectional view taken along the line II-II of FIG.

3 is a manufacturing process diagram of an active matrix substrate according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

111, 311: transparent glass substrates 112, 312: gate bus wiring

113, 313: source bus wiring 113a, 313a: source electrode

113b and 313b drain electrodes 114 and 314 gate insulating film

115 and 315: semiconductor layer 116 and 316: impurity semiconductor layer

117, 317: pixel electrode 120: protective insulating film

318: polyimide film 119, 319: black resin film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an active matrix substrate for use in a liquid crystal display device and the like and an active matrix substrate produced by the method.

In general, an active matrix substrate mainly uses a thin film transistor (“TFT”) as a switching element for driving each pixel. FIG. 1 is a plan view showing a general active matrix substrate using a thin film transistor as a switching element, in which a gate bus wiring 112 is formed in parallel in a horizontal direction on a transparent glass substrate, and a front surface of the transparent glass substrate including the gate bus wiring is formed. A gate insulating film is formed over the gate insulating film, and a plurality of source bus wiring 113 intersecting with the respective gate bus wiring 112 is formed in parallel in the vertical direction. A semiconductor layer is formed on the gate insulating film on the gate electrode 112a formed integrally with the gate bus wiring 112 near the intersection of each gate bus wiring 112 and each source bus wiring 113. The drain electrode 113b and the source electrode 113a are formed to face each other so as to form a TFT as an active element. The pixel electrode 117 is electrically connected to the drain electrode 113b.

FIG. 2 is a schematic view of FIG. 1 taken along line II-II. Referring to this, the active matrix substrate is described below.

The semiconductor layer 115 is formed on the gate insulating film 114 covering the gate electrode 112a positioned on the transparent glass substrate 111, and the drain electrode 113b is formed on the impurity semiconductor layer 116 formed on both sides thereof. ) And a source electrode 113a are formed to form a TFT as an active element. The semiconductor layer 115, the transparent glass substrate 111, the drain electrode 113b, and the source electrode 113a are covered with a protective insulating film 120, and the drain electrode 113b is a transparent formed on the protective insulating film 120. It is electrically connected to the pixel electrode 117. On the light shielding film 119 formed on the protective insulating film 120 and showing the boundary of each pixel, an alignment film 118 for orienting liquid crystal molecules is formed. Such an active matrix substrate is repeatedly produced in the manufacturing process of each of the above-described film forming processes, and the films are patterned into a predetermined shape, and the photoetching process for forming the above-mentioned wirings and electrodes is repeated.

Such a method of manufacturing an active matrix substrate in the related art has many processes in various mask processes for pattern formation, such as formation of a mask pattern, advanced mask alignment for accurate pattern description, application and development of resist, and the like. It takes time and yields are low. On the other hand, due to an increase in the level difference due to the formation of the light shielding film, the misalignment worsens and adversely affects the image quality.

SUMMARY OF THE INVENTION An object of the present invention is to produce a source electrode and a drain electrode by etching an impurity semiconductor layer and a second metal layer, which will be described later, using the pixel electrode as a mask, in the manufacture of the above-mentioned general active matrix substrate, thereby shortening the manufacturing time and increasing the yield. There is provided a method of manufacturing an active matrix substrate which can be improved, and an active matrix substrate manufactured by such a method.

It is still another object of the present invention to provide an active matrix substrate and a method of manufacturing the same, which can reduce the misalignment by reducing the step difference.

According to an aspect of the present invention, there is provided a method of manufacturing an active matrix substrate, the method comprising: forming a gate electrode and a gate bus wiring by depositing and patterning a first metal layer on the substrate; Continuously depositing a gate insulating film, a semiconductor layer, an impurity semiconductor layer, and a second metal layer on the gate electrode, the gate bus wiring, and the substrate; Etching the gate insulating film, the semiconductor layer, the impurity semiconductor layer, and the second metal layer in order to form a predetermined pattern; Depositing a transparent metal layer on the second metal layer and the substrate; Selectively etching the transparent metal layer; Etching the second metal layer and the impurity semiconductor layer using the selectively etched transparent metal layer as a mask to form source and drain electrodes; Forming a polyimide film on the selectively etched transparent metal layer and the semiconductor layer; And forming a black resin film in a predetermined region on the polyimide film.

An active matrix substrate made by the method of manufacturing an active matrix substrate of the present invention comprises: a substrate; A first metal layer formed on the substrate to form a gate bus wiring and a gate electrode, and a gate insulating layer formed on the first metal layer and the substrate; A semiconductor layer formed on the gate insulating layer, and an impurity semiconductor layer formed on the semiconductor layer; A second metal layer formed on the impurity semiconductor layer to form a source electrode, a source bus wiring, and a drain electrode; A transparent metal layer formed on the second metal layer and a predetermined region on the substrate; A polyimide film formed on the transparent metal layer and the semiconductor layer; It has a structure which consists of a light shielding film formed in the predetermined area | region on the said polyimide film.

Hereinafter, an embodiment of a method of manufacturing an active matrix substrate according to the present invention will be described with reference to FIG.

EXAMPLE

A first metal layer made of Cr, Al, Al-Ta, or the like is deposited on the transparent glass substrate 311 by sputtering or the like. After the photoprocessing, the first metal layer is selectively etched with an etching solution to form a gate bus wiring (not shown in the figure) and a gate electrode 312a branching off from the gate bus wiring. (Figure 3a)

If necessary, the gate bus wiring 312 may be anodized to increase chemical resistance and heat resistance, in particular, bonding with the gate insulating layer formed next, and an anodizing film may be formed on the gate bus wiring. The oxide film serves as a silicon nitride layer and a two-layer insulating layer of the gate insulating layer formed later, thereby improving the interlayer insulation between the gate bus wiring 312 and the signal line (source bus wiring).

Subsequently, ammonia gas, silane gas, nitrogen gas, hydrogen gas, or the like is introduced onto the transparent glass substrate 311 by a sputtering method or a plasma CVD apparatus to form a gate insulating layer 314 and an amorphous silicon (a-Si) semiconductor. A layer 315, an impurity semiconductor layer 316 of n + a-Si, and a second metal layer 313 made of metal such as Pd, Al-Si, Al-Si-Ti, Al-Si-Cu, etc. are continuously deposited. (Figure 3b)

After coating and exposing the photoresist on the second metal layer 313, the second metal layer 313, the impurity semiconductor layer 316, the semiconductor layer 315, and the gate insulating layer 314 are sequentially etched to form a predetermined pattern. (Figure 3c)

On the second metal layer 313 and the transparent glass substrate 311, a transparent metal layer 317, such as indium tin oxide (ITO), which forms a pixel electrode is deposited, and a photosensitive film is applied on the transparent metal layer, exposed, and then etched. A pattern of the transparent metal layer is formed. By etching, a predetermined portion is removed and the electrode isolation region of the second metal layer 313 is exposed. (Figure 3d)

Etching is performed using the etched transparent metal layer as a mask to remove the electrode isolation region of the exposed second metal layer and the impurity semiconductor under the exposed portion to form the source electrode 313a and the drain electrode 313b. (Figure 3e)

Next, the polyimide film 318 is applied. The polyimide film 318 functions as a protective insulating film and as an alignment film. (Figure 3f)

A black resin film 319, which is a light shielding film, is formed in a predetermined region on the polyimide film 318 to separate the boundaries between the pixels. (Figure 3g)

Since the black resin film 319 is formed on the polyimide film 318, the thin film transistor can be protected from external light without deterioration of transistor characteristics due to direct contact between the semiconductor layer 315 and the black resin film 319. Can be. In addition, a black resin film 319 functioning as a light shielding film is formed on the polyimide film 318, which is an alignment film, so that the level difference as much as the black resin film 319 is reduced and uniformity during rubbing is ensured. The alignment state can be obtained.

In the act matrix matrix according to the present invention, the source and drain electrodes are formed using a transparent metal layer as a mask, and the transparent metal layer is formed on the second metal layer forming the source electrode and the drain electrode and extends onto the transparent glass substrate. To form a pixel electrode. A light shielding film is formed on a portion of the black resin film as the alignment film to show the boundary between the pixels.

According to the present invention, since the source electrode and the drain electrode are formed using the pixel electrode as a mask, the number of mask patterns and the number of pattern formations are reduced, and a black resin film as an alignment film is coated on the pixel electrode, and then on the polyimide film. By forming a black resin film, which is a light shielding film, an active matrix substrate having no good deterioration of a transistor and having a good alignment state can be obtained with a high yield in a shorter time.

Claims (2)

Depositing and patterning a first metal layer on the substrate to form a gate electrode and a gate bus wiring; Continuously depositing a gate insulating film, a semiconductor layer, an impurity semiconductor layer, and a second metal layer on the gate electrode, the gate bus wiring, and the substrate; Etching the gate insulating film, the impurity semiconductor layer, and the second metal layer in order to form a predetermined pattern; Depositing a transparent metal layer on the second metal layer and the substrate; Selectively etching the transparent metal layer, etching a second metal layer and the impurity semiconductor layer using the selectively etched transparent metal layer as a mask to form source and drain electrodes; Forming a polyimide film on the transparent metal layer and the semiconductor layer; And forming a black resin film in a predetermined region on the polyimide film. A gate insulating layer, a semiconductor layer, an impurity semiconductor layer, a source electrode, and a drain electrode are sequentially stacked to cover the gate electrode formed on the substrate, and form an island shape. The impurity semiconductor layer and the source electrode are separated on both sides of the semiconductor layer. A switching element configured to expose a portion of the surface of the semiconductor layer; A transparent metal layer covering the source electrode and the drain electrode based on the exposed surface of the semiconductor layer and extending to the surface of the substrate to be separated from each other; A polyimide film covering the surfaces of the transparent metal layer and the exposed semiconductor layer; A light shielding film formed on the polyimide film so as to cover the switching device; An active matrix substrate comprising a.