US 12,456,619 B2 · Method of fabricating thin, crystalline silicon film and thin film transistors

Abstract

A method of producing a reduced-defect density crystalline silicon film includes forming a Six1Ge1-x1 film on a substrate, forming a Six2Ge1-x2 film on the Six1Ge1-x1 film, forming a silicon film on the Six2Ge1-x2 film, and annealing to crystallize the Six1Ge1-x1, Six2Ge1-x2, and silicon films. The values of x1 and x2 are between zero and one. The Six1Ge1-x1 and Six2Ge1-x2 films are amorphous at formation, having a first thermal budget and a second thermal budget, respectively, for crystallization, the second thermal budget lower than the first thermal budget, the Six2Ge1-x2 film spaced apart from the substrate by the Six1Ge1-x1 film. A crystalline silicon TFT device includes a substrate, a crystallized Six1Ge1-x1 layer on the substrate, a crystallized Six2Ge1-x2 layer on the crystallized Six1Ge1-x1 layer, a crystallized silicon layer on the Six2Ge1-x2 layer, a gate insulator layer on the crystallized silicon layer, and a gate electrode on the gate insulator layer.

Claims18

Dependent claims

A method of producing a reduced-defect density crystalline silicon film, comprising:

forming a Six1Ge1-x1 film on a substrate, x1 having a value between zero and one not including zero, the Six1Ge1-x1 film being amorphous at formation and having a first thermal budget for crystallization;
forming a Six2Ge1-x2 film on the Six1Ge1-x1 film, x2 having a value between zero and one including zero, the value of x2 being smaller than the value of x1, the Six2Ge1-x2 film being amorphous at formation and having a second thermal budget for crystallization, the second thermal budget being lower than the first thermal budget, the Six2Ge1-x2 film being spaced apart from the substrate by the Six1Ge1-x1 film;
forming a silicon film on the Six2Ge1-x2 film, the silicon film being amorphous at formation;
and
annealing to crystallize the Six1Ge1-x1 film, the Six2Ge1-x2 film, and the silicon film, such that crystallization is initiated within the Six2Ge1-x2 film and propagates through the silicon film and the Six1Ge1-x1 film, transforming the silicon film to a reduced-density, crystallized silicon film.

2 more elements

A method of producing a reduced-defect density crystalline silicon film, comprising:

forming a first SixGe1-x film on a substrate, where x has a value between zero and one, including zero, the SixGe1-x film being amorphous at formation and having a first thermal budget for crystallization;
forming a second SixGe1-x film on the first SixGe1-x film, the second SixGe1-x film being doped, the second SixGe1-x film being amorphous at formation and having a second thermal budget for crystallization, the second thermal budget being lower than the first thermal budget, the second SixGe1-x film being spaced from the substrate by the first SixGe1-x film;
forming a silicon film on the second SixGe1-x film, the silicon film being amorphous at formation;
and
annealing to crystallize the first SixGe1-x film, the second SixGe1-x film, and the silicon film, such that crystallization is initiated within the second SixGe1-x film and propagates through the silicon film and the first Six1Ge1-x1 film, transforming the silicon film to a reduced-density, crystallized silicon film.

2 more elements

Dependencies are inferred from the claim text.

Method of fabricating thin, crystalline silicon film and thin film transistors

Life of this patent

Method of fabricating thin, crystalline silicon film and thin film transistors

Life of this patent

Abstract

Claims18