KR100193652B1 - Method of manufacturing thin film transistor of liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to simultaneously form a semiconductor layer and a doped semiconductor layer of a liquid crystal display device, and fabricate a gate electrode wiring and a source electrode wiring on the same line, thereby reducing process steps. The present invention relates to a method for manufacturing a liquid crystal display device capable of forming a liquid crystal display device, wherein the liquid crystal display device formed by the present invention can reduce the metal wiring process by one step by forming a data electrode wiring including a source and a drain at the same time as the gate electrode is formed. Instead of the conventional deposition process of the doped semiconductor layer, only a portion of the undoped amorphous silicon is ion implanted to replace the two-stage semiconductor layer forming process with one-stage CVD process, which reduces the process step, resulting in manufacturing yield. Increase and cost reduction.

Description

Method of manufacturing thin film transistor of liquid crystal display device

1 is a cross-sectional view of a thin film transistor manufactured according to a method of manufacturing a thin film transistor of a conventional liquid crystal display device.

2 is a perspective view of a thin film transistor of a liquid crystal display device according to the present invention.

* Explanation of symbols for main parts of the drawings

11 Insulation Substrate 12 Gate Electrode

13 source electrode 14 drain electrode

15 pixel electrode 16 gate insulating film

17 amorphous semiconductor layer 18 etching stopper

19: ohmic area

The present invention relates to a method for manufacturing a thin film transistor of a liquid crystal display device, and more particularly, while simultaneously forming a semiconductor layer and a doped semiconductor layer of a liquid crystal display device, while forming a gate electrode wiring and a source electrode wiring on the same plane, The present invention relates to a method for manufacturing a thin film transistor of a liquid crystal display device capable of reducing process steps.

Recently, as the retention of the liquid crystal display device value is increased, there is a tendency of thinning, and the development of a technology in which the display unit constituting the liquid crystal display device and the driving retrospective are integrally formed.

Herein, a method of manufacturing a lower substrate of a liquid crystal display device including a conventional thin film transistor and a pixel electrode will be described with reference to FIG. 1 of the accompanying drawings. In order to form a gate electrode 3 by depositing a metal and etching a predetermined portion, a gate insulating layer 3 is formed on the entire surface of the device to prevent a short circuit with an upper layer wiring. Thereafter, the semiconductor layer 4 of the amorphous silicon layer is deposited on both sides of the gate insulating film 3 to a predetermined thickness, and there is no loss of the semiconductor layer 4 during the patterning process for forming subsequent source and drain electrodes thereon. In order to prevent the silicon nitride film formed by the plasma enhanced chemical vapor deposition (PECVD) method is deposited to a thickness of 2000 to 3000Å. Thereafter, a predetermined portion of the silicon nitride film is etched to form an etching stopper 5, and an amorphous silicon layer 6 doped with N ⁺ impurities is formed on the semiconductor layer 4 and the etching stopper 5. Then, the semiconductor layer 4 and the amorphous silicon layer 6 doped with impurities are etched to a predetermined size to define an active region, that is, a liquid crystal display device thin film transistor region. Then, an indium tin oxide (ITO) electrode material is formed by a sputtering method to form a pixel electrode on the body structure, and then a region of the thin film transistor including the gate electrode (the region where the semiconductor layer is formed). It is etched so as to exist only at one side end portion of) to form the ITO electrode 7. Then, a metal layer for forming an electrode on the entire structure, for example, a metal layer such as aluminum or chromium is formed, and predetermined portions of the metal layer and the doped semiconductor layer are etched to form the source 8 and the drain electrode 9. By forming, the lower substrate of the liquid crystal display element provided with the thin film transistor and the pixel electrode is completed.

However, in manufacturing the thin film transistor of the liquid crystal display device according to the conventional method as described above, even though both of the amorphous semiconductor layer which is the null region and the semiconductor layer doped with the impurities constituting the ohmic region are the same amorphous silicon layer, the ohmic region is the same. Because of the doping, it was cumbersome to deposit in different chambers. In addition, although the gate electrode (gate electrode wiring), the source and the drain electrode (data electrode wiring) of the thin film transistor are similarly the same metal film, the gate electrode forming process and the source and drain electrode forming process must be performed separately. There was a problem that the number increases.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, by simultaneously forming a portion made of the same material in the thin film transistor value forming process to reduce the number of manufacturing process, thereby reducing the manufacturing yield and manufacturing cost of the device It is an object of the present invention to provide a method for manufacturing a thin film transistor of a liquid crystal display device.

In order to achieve the above object of the present invention, the present invention is a process for depositing a metal film on the transparent insulating substrate and etching a predetermined portion in the form of a gate electrode, a source electrode and a drain electrode, and contacting the drain electrode, Forming a pixel electrode on a predetermined portion, forming a gate insulating film on a surface of the gate electrode, forming an amorphous semiconductor layer on a predetermined portion of the gate electrode, the source electrode, and the drain electrode; Forming an etching stopper on a predetermined portion of the semiconductor layer, and forming an ohmic region by implanting impurities into the amorphous semiconductor layer exposed by the ping stopper.

In addition, the amorphous silicon layer is characterized in that formed by the PECVD method.

As described above, according to the present invention, there is an effect of cost reduction due to the reduction of the manufacturing yield and the manufacturing process time of the liquid crystal display device.

EXAMPLE

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a liquid crystal display device formed according to the present invention. First, an opaque metal film constituting a gate electrode (gate electrode wiring), a source, and a drain electrode (data electrode hood) on the transparent insulation engine 11. For example, a metal film such as aluminum or chromium is formed on the insulating substrate 11 to a thickness of about 2500 to 3500 mm by a conventional deposition method, and the gate electrode 12 and both sides thereof are formed by a known photolithography process. The source electrode 13 and the drain electrode 14 are formed by etching with a predetermined electrode pattern. At this time, the gate electrode 12 is integral with the gate electrode wiring, and the source electrode 13 is integrally formed with the data electrode wiring so that these wirings can define a pixel shape.

Thereafter, an indium tin oxide (ITO) layer is formed on the entire structure, and then connected to the drain electrode 14 and disposed in a space formed of a gate electrode wiring (not shown) and a data electrode wiring (not shown). Etching is performed to form the pixel electrode 15.

Then, an insulating film is formed on the entire structure, and the gate insulating film 16 is formed by etching to exist only on the surface of the gate electrode 12, that is, the upper side and both sidewall portions. Thereafter, an amorphous silicon layer having a predetermined thickness is formed in an appropriate temperature range in which the silicon film is amorphous by PECVD, and then etched into a predetermined shape so as to remain only in a region defined by the thin film transistor to form the amorphous semiconductor layer 17. Subsequently, an insulating film for protecting the amorphous semiconductor layer 17 is formed on the structure, for example, a silicon nitride layer is formed to have a predetermined thickness, and the etching is performed so as to exist only on the amorphous semiconductor layer including the gate electrode 12. The stopper 18 is formed. Preferably, the etch stopper 18 has a width equal to the predetermined channel width. Then, the formed N-type impurity is ion-implanted on the exposed amorphous semiconductor layer by using the formed etching stopper 18 as an ion implantation mask. As a result, an ohmic region 19 of the thin film transistor, that is, a semiconductor layer into which impurities are injected, is formed, thereby completing the thin film transistor.

As described in detail above, the liquid crystal display device formed according to the present invention can reduce the metal wiring process by one step by forming a data electrode wiring including a gate electrode and a source and a drain. Instead of deposition deposition of the semiconductor layer, only a portion of the undoped amorphous silicon can be ion implanted to replace the two-stage semiconductor layer forming process with one-stage CVD process, which reduces the process step, resulting in increased production yield and cost. There is a saving effect.

Claims (5)

Depositing a metal film on the transparent insulating substrate and etching a predetermined portion in the form of a gate electrode, a source electrode, and a drain electrode; forming a pixel electrode on a predetermined portion of the substrate to be in contact with the drain electrode; Forming a gate insulating film on a surface, forming a amorphous semiconductor layer on a predetermined portion of the gate electrode source electrode and a drain electrode, forming an etching stopper on the predetermined portion of the amorphous semiconductor layer, and A method of manufacturing a thin film transistor of a liquid crystal display device, comprising the step of forming an ohmic region by implanting impurities into an amorphous semiconductor layer exposed by an ping stopper. The method of claim 1, wherein the amorphous silicon layer is formed by PECVD. The method of claim 1, wherein the etching stopper is formed of a silicon nitride film. The method of claim 1, wherein the etching stopper is formed on the amorphous silicon layer including the gate electrode. The method of claim 1, wherein the impurities implanted into the amorphous silicon layer exposed by the etching stopper are N-type impurities.