KR0149310B1 - A wafer for active matrix display device and its fabrication method - Google Patents

Abstract

The present invention prevents the gate electrode from being corroded by the etchant during pixel electrode patterning, prevents leakage current from being generated by the source electrode and the drain electrode connecting semiconductor film, and prevents the parasitic current flowing from adjacent pixels through the gate line. In order to provide a substrate for an active matrix display device to prevent deterioration of the image quality, a portion of the semiconductor film corresponding to the end of the gate electrode and a portion of the semiconductor film corresponding to the gate line is photo-etched to stack a transparent conductive material. Has the characteristics.

Description

Substrate for active matrix display device and manufacturing method thereof

1 is a plan view of a substrate for a conventional general active matrix display device,

2 is a cross-sectional view of a substrate for a conventional general active matrix display device,

3 is a plan view of a substrate for an active matrix display device in which a conventional semiconductor film is formed over a data line, a gate electrode and a gate line,

4 is a plan view of a substrate for an active matrix display device in which a conventional semiconductor film is formed on data lines and gate electrodes.

5 is a plan view of a substrate for an active matrix display device according to an embodiment of the present invention,

6 is a cross-sectional view taken along the line AA ′ of FIG. 7;

FIG. 7 is a plan view of the thin film transistor unit of FIG.

8 is a plan view and a cross-sectional view of the B-B 'portion of FIG.

9A to 9G are cross-sectional views illustrating procedures of manufacturing a substrate for an active matrix display device according to an embodiment of the present invention.

The present invention relates to a substrate for an active matrix display device and a method of manufacturing the same. More specifically, the gate electrode is prevented from being corroded by the etchant during the pixel electrode patterning, and the leakage current is prevented from being generated by the semiconductor film between the source electrode and the drain electrode connection portion, and flows in from the adjacent pixel through the gate line. The present invention relates to a substrate for an active matrix display device and a method of manufacturing the same for preventing image quality from being degraded by parasitic currents.

In general, a liquid crystal display device using a thin film transistor as a switching element has been attracting attention as a flat panel display device.

1 is a plan view of a substrate for a conventional general active matrix display device,

2 is a cross-sectional view of a conventional substrate for an active matrix display device.

The semiconductor film 12 of the thin film transistor, as shown in FIGS. 1 and 2, uses amorphous silicon and polysilon, and generally the source as shown in FIGS. It is formed partially under the electrode 16 and the drain electrode 18. However, the above-described conventional technique uses the gate electrode through the pinhole H of the insulating film 8 formed on the gate electrode 4 by the ITO etchant during patterning of the pixel electrode 22. (4) has the disadvantage that the phenomenon of frequent corrosion.

Therefore, as a method for solving the above problem, a technique for preventing the gate electrode 4 from corrosion has been presented by Seiko Instruments in US Pat. No. 4,705,358.

3 is a plan view of a substrate for an active matrix display device in which a conventional semiconductor film is formed over a data line, a gate electrode and a gate line,

4 is a plan view of a substrate for an active matrix display device in which a conventional semiconductor film is formed on data lines and gate electrodes.

As described above with reference to FIGS. 3 and 4, the conventional technique described above includes the semiconductor film 12 being formed under the source electrode 16 and the drain electrode 18 and the data line 20. It is made of a structure formed on the gate line (6).

However, in the conventional technique described above, the source and drain electrodes 16 and 18 are connected to the semiconductor film 12 so that a leakage current flows from the drain electrode 18 to the source electrode 16 so that the off current is increased. There is a drawback to growing.

In addition, the current of the adjacent pixels through the gate line 6 has a disadvantage in that the image quality is reduced.

On the other hand, as shown in FIGS. 5 and 6, the substrate for active matrix display device in which the semiconductor film 12 is formed below the source electrode 16, the drain electrode 18, and the data line 20. FIG. Is also presented.

However, in the active matrix display substrate as shown in FIGS. 5 and 6, the semiconductor film 12 is not formed on the gate line 6, so that the corrosion of the gate line 6 is prevented. There is a limit that cannot be prevented and only corrosion of the gate electrode 4 can be prevented.

Accordingly, the present invention is to solve the problems of the prior art, to prevent the gate electrode from being corroded by the etching solution during the pixel electrode patterning, and to prevent the leakage current generated by the semiconductor film of the source electrode and drain electrode connection portion And a semiconductor film is formed on the upper part of the gate line and the upper part of the gate electrode in order to prevent the current of adjacent pixels from flowing through the gate line and causing the deterioration of image quality. SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate for an active matrix display device which is not formed and is formed with a transparent conductive material and a method of manufacturing the same.

The structure of the board | substrate for active matrix display apparatuses of this invention for achieving this objective is

Board;

A gate electrode formed on the substrate,

A gate insulating film overlying the gate electrode,

A semiconductor film formed on the insulating film,

A source electrode and a drain electrode formed of a conductive material formed on the semiconductor film;

A thin film transistor unit including a pixel electrode formed of a transparent conductive material connected to the drain electrode;

A gate line extending to the gate electrode and extending in a row direction;

A substrate for an active matrix display device, comprising a data line extending from the source electrode and extending in a column direction.

The semiconductor layer is formed such that an end portion corresponding to the gate electrode formed on the opposite side of the gate line is exposed.

The semiconductor film formed on the gate line is not connected to the semiconductor film formed on the gate line of an adjacent pixel.

The upper end portion corresponding to the gate electrode on which the semiconductor film is not formed and the portion of the gate line are covered with the same material as the pixel electrode.

The structure of the manufacturing method of the common electrode substrate of the liquid crystal cell of this invention for achieving this objective is

A first step of forming a gate electrode and a gate line by photo-etching the conductive material after laminating a conductive material on a substrate;

A second process of forming a gate insulating film on the gate wiring;

A third process of laminating a semiconductor film on the gate insulating film,

An end portion of the gate electrode and the gate insulating layer is exposed to the opposite side when the gate line is referenced, and is formed on the gate line.

A fourth process of photo etching the semiconductor film to expose a portion of the gate insulating film;

A fifth process for forming a source electrode, a drain electrode, and a data line after stacking a conductive material on the passivation layer;

A sixth step of forming and patterning a protective film on the data line;

An ITO layer is formed of a transparent conductive material on an end portion formed of the gate electrode and the gate insulating layer on the opposite side of the protective layer and the gate line, and a portion of the gate insulating layer exposed by etching the semiconductor layer on the gate line. It consists of a 7th process of forming and patterning.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

5 is a plan view of a substrate for an active matrix display device according to an embodiment of the present invention,

6 is a cross-sectional view taken along the line AA ′ of FIG. 7;

FIG. 7 is a plan view of the thin film transistor unit of FIG.

8 is a plan view and a cross-sectional view of the B-B 'portion of FIG.

9A to 9G are cross-sectional views illustrating procedures of manufacturing a substrate for an active matrix display device according to an embodiment of the present invention.

First, as shown in FIG. 9A, a conductive material such as aluminum is formed on the glass substrate 2, and the gate electrode 4 and the gate line 6 are formed by photolithography.

Next, as shown in FIG. 9B, the upper portion of the gate electrode 4 is anodized to form an anodic oxide film 8.

Next, as shown in FIG. 9C, the gate insulating film 10, the amorphous silicon film 12, and the n + amorphous silicon film 14 are successively applied and patterned on top of the gate wiring. .

In this case, the pattern shape is a photo-etched portion of the portion corresponding to the end of the gate electrode, which is the portion A shown in FIG. 11, and the portion corresponding to the gate line, which is the portion B shown in FIG.

Next, as shown in (d) of FIG. 9, a metal film such as Cr, Ta, Ti or the like is coated on the n + amorphous silicon film 14, and then patterned to form a source electrode 16 and a drain electrode. 18 and the data line 20 is formed.

Next, as shown in FIG. 9E, the n + amorphous silicon film 14 formed between the source electrode 16 and the drain electrode 18 is removed by dry etching.

Next, as shown in FIG. 9F, a protective film 21 such as SiNx is applied to the upper portion including the source / drain electrodes 16 and 18 and then patterned.

Next, as shown in (g) of FIG. 9, after coating ITO (ITO), which is a transparent conductive material, on the protective film 21, part A of FIG. 7, part B of FIG. 7 and pixel electrode The Ithio film is patterned so that only the portion of the upper portion of the drain electrode serving as the Ithio film remains.

Therefore, the present invention prevents the gate electrode from being corroded by the etchant during pixel electrode patterning, prevents leakage current from being generated by the semiconductor film of the source and drain electrode connecting portions, and parasitic current flowing from adjacent pixels through the gate line. This has the effect of preventing image quality from being lowered.

Claims (9)

Agency; A gate electrode formed over the substrate, a gate insulating film overlying the gate electrode, a semiconductor film formed over the insulating film, a source electrode and a drain electrode formed of a conductive material formed over the semiconductor film, and A thin film transistor unit including a pixel electrode formed of a transparent conductive material connected to the drain electrode; A gate line extending from the gate electrode and extending in a row direction; A substrate for an active matrix display device comprising a data line extending from the source electrode and extending in a column direction, wherein the semiconductor film has an end portion corresponding to the gate electrode formed on the opposite side of the gate line. The semiconductor film is formed to be exposed and is formed on the gate line so as not to be connected to the semiconductor film formed on the gate line of the adjacent pixel, and corresponds to the gate electrode on which the semiconductor film is not formed. A substrate for an active matrix display device overlying an end portion and a portion of the gate line with the same material as the pixel electrode. 2. The substrate of claim 1, further comprising an n + silicon film formed between the semiconductor film, the source electrode, and the drain electrode. 2. The substrate of claim 1, further comprising an anodization film formed over the gate electrode. The substrate of claim 1, wherein the gate electrode forms aluminum or an aluminum alloy. The substrate of claim 1, wherein the source electrode, the drain electrode, and the data line are formed of Cr, Ta, Ti, or the like. A first step of forming a gate electrode and a gate line by laminating a conductive material on a substrate and then etching the conductive material to form a gate electrode and a gate line; a second step of forming a gate insulating film on the gate wiring; The third step of stacking the semiconductor film on the upper side, the end portion of the gate electrode and the gate insulating film is exposed to the other side when the gate line as a reference and the portion of the gate insulating film formed on the gate line is exposed A fourth step of photolithography a semiconductor film, a fifth step of forming a source electrode, a drain electrode and a data line after filling a conductive material on the passivation layer, and a sixth step of forming and patterning a passivation layer on the data line On the passivation layer and on the gate line. And a seventh step of forming and patterning an Ithio film made of a transparent conductive material on a portion where the gate film and the gate insulating film are oppositely formed, and a semiconductor film is etched on the gate line to expose the gate insulating film. The manufacturing method of the board | substrate for active matrix display apparatuses which exists. The method of claim 6, further comprising: forming an exogenous semiconductor film on the semiconductor film after forming the semiconductor film of the third step; and sequentially photographing the exogenous semiconductor film during the photolithography etching of the fourth step; And dry etching the exogenous semiconductor film between the source electrode and the drain electrode after the formation of the source electrode and the drain electrode in step 5. The method of manufacturing a substrate for an active matrix display device according to claim 6 or 7, wherein the semiconductor film and the exogenous semiconductor film are formed of amorphous silicon and n + amorphous silicon. The method of manufacturing a substrate for an active matrix display device according to claim 6, wherein the protective film is formed of SiNx.