US 7,144,793 B2 · Method of producing crystalline semiconductor material and method of fabricating semiconductor device

Abstract

Disclosed are a method of producing a crystalline semiconductor material capable of improving the crystallinity and a method of fabricating a semiconductor device using the crystalline semiconductor material. An amorphous film is uniformly irradiated with a pulse laser beam (energy beam) emitted from an XeCl excimer laser by 150 times so as to heat the amorphous film at such a temperature as to partially melt crystal grains having the {100} orientations with respect to the vertical direction of a substrate and melt amorphous film or crystal grains having face orientations other than the {100} orientations. Silicon crystals having the {100} orientations newly occur between a silicon oxide film and liquid-phase silicon and are bonded to each other at random, to newly form crystal grains having the {100} orientations. Such a crystal grain creation step is repeated, to form a crystalline film which has crystal grains preferentially grown in the {100} orientations with respect to the vertical direction of the substrate and thereby has sharp square-shaped crystal grain boundaries.

Claims20

Dependent claims

A method of producing a crystalline semiconductor material, comprising:

(a) a first step of forming a starting material on a substrate, wherein said starting material is selected from the group consisting of amorphous semiconductor material and polycrystalline semiconductor material;
(b) a second step of forming a first crystalline material comprising crystal grains preferentially grown in the {100} orientation with respect to the vertical direction of the substrate by uniformly heat-treating said starting material by a plurality of times;
(c) a third step of forming a second crystalline material by heat-treating said first crystalline material by a plurality of times so as to form, on said first crystalline material, a high temperature region and a low temperature region, wherein:
(i) the temperature of said low temperature region is lower than the temperature of said high temperature region;
and
(ii) the temperature of said low temperature region is such as to partially melt said crystal grains having said specific face orientation with respect to the vertical direction of the surface of said substrate.

3 more elements

Dependencies are inferred from the claim text.

Method of producing crystalline semiconductor material and method of fabricating semiconductor device

Life of this patent

Method of producing crystalline semiconductor material and method of fabricating semiconductor device

Life of this patent

Abstract

Claims20