# US 7,407,841 B2 · Liquid crystal display panel and method of fabricating thereof

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- Number: US 7,407,841 B2
- Document ID: US7407841B2
- Status: Granted
- Kind: B2
- Application number: 11/527,549
- Filed: 2006-09-27
- Published: 2007-01-25
- Granted: 2008-08-05
- Earliest claimed: 2003-06-28
- Assignees: LG Display Co., Ltd.
- Inventors: Hyun Sik Seo; Hae Yeol Kim
- Web page: https://patentgrep.com/patent/US7407841B2

## CPC

- G02F 1/1368: in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)}
- H10D 86/0225: {using crystallisation-promoting species, e.g. using a Ni catalyst}
- H10D 86/0231: {using masks, e.g. half-tone masks}
- H10P 14/3411: {Silicon, silicon germanium or germanium}
- H10P 14/3806: {using crystallisation-enhancing elements}
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

The present invention relates to a liquid crystal display panel and a fabricating method thereof that is capable of enhancing crystallization efficiency of an active layer and simplifying the fabricating process. A fabricating method of a liquid crystal display panel includes forming a gate electrode on a substrate; forming a gate insulating film on the gate electrode formed thereon; forming an amorphous silicon film on the gate insulating film; forming an insulating pattern on the amorphous silicon film; crystallizing the amorphous silicon film into a polycrystalline silicon film using a derivative metal, the polycrystalline silicon film having source, drain and channel areas, wherein the insulating pattern overlaps the channel area of the polycrystalline silicon film; and forming source and drain electrodes on the polycrystalline silicon film, wherein the source and the drain electrodes contacting the source and drain areas of the polycrystalline silicon film, respectively.

## Claims

### Claim 1

A method of fabricating a liquid crystal display panel, comprising:
forming a gate electrode on a substrate;
forming a gate insulating film on the gate electrode formed thereon;
forming an amorphous silicon film on the gate insulating film;
forming an insulating pattern on the amorphous silicon film;
crystallizing the amorphous silicon film into a polycrystalline silicon film using a derivative metal, the polycrystalline silicon film having source, drain and channel areas, wherein the insulating pattern overlaps the channel area of the polycrystalline silicon film; and
forming source and drain electrodes on the polycrystalline silicon film, wherein the source and the drain electrodes contacting the source and drain areas of the polycrystalline silicon film, respectively;
wherein crystallizing the amorphous silicon film into a polycrystalline silicon film using a derivative metal further includes:
forming the derivative metal on the insulating pattern and the amorphous silicon film;
injecting an impurity ion into the amorphous silicon film having the derivative metal formed thereon; and
applying a heat and an electric field to the amorphous silicon film, wherein the impurity ion injected into the amorphous silicon film is activated during the application of the heat; and
wherein forming source and drain electrodes on the polycrystalline silicon film further includes:
forming sequentially a data metal layer and the photo-resist on the polycrystalline film;
forming a stepped photo-resist pattern with a mask having a partially exposing part:
etching the data metal layer and the polycrystalline silicon film using the stepped photo-resist pattern;
ashing the stepped photo-resist pattern; and
etching the data metal layer using the ashed photo-resist pattern, thereby exposing the insulating pattern overlapping the channel area of the polycrystalline silicon film.

### Claim 2 (depends on 1)

The fabricating method of the liquid crystal display panel according to claim 1, wherein the derivative metal includes nickel (Ni).

### Claim 3 (depends on 1)

The fabricating method of the liquid crystal display panel according to claim 1, wherein forming an insulating pattern on the amorphous silicon film further includes:
forming sequentially an insulating material and an photo-resist on the amorphous silicon film;
irradiating light from the backside of the substrate toward the photo-resist;
developing the photo-resist to form a photo-resist pattern; and etching the insulating material using the photo-resist pattern as a mask.

### Claim 4

A method of fabricating a liquid crystal display panel, comprising:
forming a gate electrode on a substrate;
forming a gate insulating layer on the gate electrode;
depositing an amorphous silicon film on the gate insulating layer;
forming an insulating pattern on the amorphous silicon film;
forming a derivative metal on the insulating pattern and the amorphous silicon film;
crystallizing the amorphous silicon film into a polycrystalline silicon film, the polycrystalline silicon film having source, drain and channel areas; and
forming source and drain electrodes on the polycrystalline silicon film;
wherein crystallizing the amorphous silicon film into a polycrystalline silicon film using a derivative metal further includes:
forming the derivative metal on the insulating pattern and the amorphous silicon film;
injecting an impurity ion into the amorphous silicon film having the derivative metal formed thereon; and
applying a heat and an electric field to the amorphous silicon film, wherein the impurity ion injected into the amorphous silicon film is activated during the application of the heat; and
wherein forming source and drain electrodes on the polycrystalline silicon film further includes:
forming sequentially a data metal layer and the photo-resist on the polycrystalline film;
forming a stepped photo-resist pattern with a mask having a partially exposing part;
etching the data metal layer and the polycrystalline silicon film using the stepped photo-resist pattern;
ashing the stepped photo-resist pattern; and
etching the data metal layer using the ashed photo-resist pattern, thereby exposing the insulating pattern overlapping the channel area of the polycrystalline silicon film.

### Claim 5 (depends on 4)

The fabricating method of the liquid crystal display panel according to claim 4, wherein the insulating pattern is formed by a backside exposure using the gate electrode as a mask.

### Claim 6 (depends on 4)

The fabricating method of the liquid crystal display panel according to claim 4, wherein the insulating pattern overlaps the channel area of the polycrystalline silicon film.

### Claim 7 (depends on 4)

The fabricating method of the liquid crystal display panel according to claim 4, wherein the source and drain electrodes are formed using a mask having a diffractive exposing part.

### Claim 8 (depends on 5)

The fabricating method of the liquid crystal display panel according to claim 5, wherein the liquid crystal display panel is formed with four masks.

### Claim 9 (depends on 4)

The fabricating method of the liquid crystal display panel according to claim 4, further includes forming a passivation layer having a contact hole on the source and drain electrodes and forming a transparent electrode on the passivation layer.