Crystallization pattern and method for crystallizing amorphous silicon using the same

Abstract

Disclosed are a crystallization pattern, and a method for crystallizing amorphous silicon. The method includes the steps of forming an amorphous silicon film on a glass substrate, forming a crystallization pattern by patterning the amorphous silicon film, and crystallizing the crystallization pattern into polycrystalline silicon by irradiating a laser onto the crystallization pattern. The crystallization pattern includes a peripheral region located within a first distance from an edge of the crystallization pattern, and an internal region located away from the edge of the crystallization pattern by more than the first distance. The internal region is divided into at least one sub-region, each sub-region includes one crystallization inducement pattern, and an edge of each sub-region is located within a second distance from the crystallization inducement pattern.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an SEM picture showing a fine crystallization structure obtained after a laser has been irradiated onto a conventional amorphous silicon pattern;

FIGS. 2A and 2B are sectional views for explaining the crystallization state of an amorphous silicon pattern according to the size of a crystallization pattern;

FIGS. 3A and 3B are plan views for explaining the crystallization state of an amorphous silicon pattern according to the size of a crystallization pattern;

FIG. 4 is a plan view illustrating a crystallization pattern according to one embodiment of the present invention;

FIG. 5 is a sectional view taken along line A-A′ shown in FIG. 4; and

FIG. 6 is a view illustrating a mask used in a method for crystallizing amorphous silicon according to one embodiment of the present invention.

Claims

1. A crystallization pattern including amorphous silicon, which is crystallized into polycrystalline silicon as a laser is irradiated thereto, the crystallization pattern comprising: a peripheral region located within a first distance from an edge of the crystallization pattern; andan internal region located away from the edge of the crystallization pattern by more than the first distance, whereinthe internal region is divided into at least one sub-region,each sub-region includes one crystallization inducement pattern, andan edge of each sub-region is located within a second distance from the crystallization inducement pattern.

2. The crystallization pattern as claimed in claim 1, wherein the first distance corresponds to a critical lateral growth length.

3. The crystallization pattern as claimed in claim 1, wherein the second distance is identical to or shorter than the first distance.

4. The crystallization pattern as claimed in claim 1, wherein the crystallization inducement pattern includes a hole pattern or a dimple pattern.

5. A method for crystallizing amorphous silicon in order to fabricate a polycrystalline silicon thin film transistor, the method comprising the steps of: forming an amorphous silicon film on a glass substrate;forming a crystallization pattern by patterning the amorphous silicon film in a form of an active pattern of the thin film transistor; andcrystallizing the crystallization pattern into polycrystalline silicon by irradiating a laser onto the crystallization pattern, whereinthe crystallization pattern includes a peripheral region located within a first distance from an edge of the crystallization pattern, and an internal region located away from the edge of the crystallization pattern by more than the first distance, the internal region is divided into at least one sub-region, each sub-region includes one crystallization inducement pattern, and an edge of each sub-region is located within a second distance from the crystallization inducement pattern.

6. The method as claimed in claim 5, wherein the first distance corresponds to a critical lateral growth length.

7. The method as claimed in claim 5, wherein the second distance is identical to or shorter than the first distance.

8. The method as claimed in claim 5, wherein the crystallization inducement pattern includes a hole pattern or a dimple pattern.

9. The method as claimed in claim 5, wherein the laser is irradiated onto the crystallization pattern through an SLS (sequential lateral solidification) scheme.

10. The method as claimed in claim 9, wherein, when the laser is irradiated through the SLS scheme, a box type mask is used so as to expose an entire area of the crystallization pattern.

11. The method as claimed in claim 9, wherein laser irradiation is performed only one time by using the box type mask.