Sharp Kabushiki Kaisha Corporation

Semiconductor Energy Laboratory Co., Ltd.

Takashi Funai

Naoki Makita

Yoshitaka Yamamoto

Tadayoshi Miyamoto

Toru Takayama

Masahiro Adachi

Yasuhiro Mitani

Katsumi Nomura

Akihiro Hata

Takamasa Kosai

Tatsuo Morita

Masashi Maekawa

Takamasa Kousai

In a fabrication of a semiconductor device, an amorphous semiconductor film is first formed on a substrate having an insulating surface. Then, a minute amount of catalyst elements for accelerating crystallization of the amorphous semiconductor film is supplied to at least a portion of a surface of the amorphous semiconductor film. A heat treatment is further conducted so that the supplied catalyst elements are diffused into the amorphous semiconductor film. Thus, the catalyst elements are introduced uniformly into the amorphous semiconductor film in a very minute amount or at a low concentration, resulting in polycrystallization of at least a portion of the amorphous semiconductor film. Utilizing the thus obtained crystalline semiconductor film on the substrate surface as an active region, a semiconductor device such as a TFT is fabricated. The introduction of the catalyst elements are conducted by various methods such as: a formation of a film containing a minute amount of the catalyst elements; application of a solution containing the catalyst elements in several spin coating cycles; diffusion of the catalyst elements through a buffer layer; dipping into a solution in which the catalyst elements are dissolved or dispersed; or formation of a plating layer containing the catalyst elements.

Method for fabricating thin film transistors

The semiconductor device of this invention includes a substrate having an insulating surface and a thin film transistor formed on the substrate, wherein the thin film transistor has a semiconductor island including a channel region and source/drain regions, a gate insulating film formed on the semiconductor island and a gate electrode covering the channel region of the semiconductor island interposing the gate insulating film therebetween, and wherein a distance between an edge of the channel region of the semiconductor island and the gate electrode is larger than a distance between a central portion of the channel region of the semiconductor island and the gate electrode.

Semiconductor device with increased distance between channel edges and a

A semiconductor device comprising a substrate having thereon an amorphous silicon film fabricated by a reduced pressure chemical vapor deposition, characterized in that a thin film transistor is provided by using a crystalline silicon film obtained by effecting crystal growth in parallel with the surface of the substrate at the periphery of a region containing a selectively introduced metallic element, the region being obtained by selectively introducing a metallic element capable of accelerating the crystallization of the amorphous silicon film and heating the region thereafter.

Method of fabricating a thin film transistor

The semiconductor device of the invention includes: a substrate having an insulating surface; an active region formed on the insulating surface of the substrate, the active region being formed by a crystalline silicon film; and an insulating thin film formed on the active region. In the semiconductor device, the active region contains a catalyst element for promoting a crystallization of an amorphous silicon film by a heat treatment.

Semiconductor device and method for producing the same

Into an amorphous silicon film, catalyst elements for accelerating the crystallization are introduced. After patterning the amorphous silicon films in which the catalyst elements have been introduced into an island pattern, a heat treatment for the crystallization is conducted. Thus, the introduced catalyst elements efficiently diffuse only inside the island-patterned amorphous silicon films. As a result, a high-quality crystalline silicon film, having the crystal growth direction aligned in one direction and having no grain boundaries, is obtained. Using the thus formed crystalline silicon film, semiconductor devices having a high performance and stable characteristics are fabricated efficiently over the entire substrate, irrespective of the size of the devices.

Semiconductor device formed within asymetrically-shaped seed crystal

In a substrate having an insulating surface in which an amorphous semiconductor film is deposited on the insulating surface, a predetermined under-heating portion of the amorphous semiconductor film is partially heated with a heating source emitting heating rays. While heating, the under-heating portion is shifted by moving the heating source or the substrate. Accordingly, the amorphous semiconductor film is sequentially heat-treated and polycrystallized. As the under-heating portion shifts, the polycrystallization sequentially proceeds using the already polycrystallized portion by irradiation with the heating rays, which is adjacent to the under-heating portion, as seed crystal. Thus, the growth condition of crystal grains is uniformly controlled in the shifting direction of the under-heating portion.

Method and an apparatus for fabricating a semiconductor device

The semiconductor device of this invention includes a substrate having an insulating surface and a thin film transistor formed on the substrate, wherein the thin film transistor has a semiconductor island including a channel region and source/drain regions, a gate insulating film formed on the semiconductor island and a gate electrode covering the channel region of the semiconductor island interposing the gate insulating film therebetween, and wherein a distance between an edge of the channel region of the semiconductor island and the gate electrode is larger then a distance between a central portion of the channel region of the semiconductor island and the gate electrode.

Method for fabricating a semiconductor device using a catalyst

A method for producing a semiconductor film, includes the steps of: (a) forming an amorphous semiconductor film on a substrate having a surface with an insulating property; (b) introducing a material for accelerating crystallization of the amorphous semiconductor film into at least a part of the amorphous semiconductor film; (c) crystallizing the amorphous semiconductor film by heating to obtain a crystalline semiconductor film from the amorphous semiconductor film; and (d) oxidizing a surface of the crystalline semiconductor film to form a semiconductor oxide film containing a part of the material for accelerating the crystallization on the surface of the crystalline semiconductor film.

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Tenri, Japan

Takashi Funai