Semiconductor device and process for producing same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Toru Mitsuki
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Abstract
To provide a semiconductor device utilizing a semiconductor film having a high crystallinity by a production process having a high mass productivity. Upon crystallizing an amorphous silicon film 106, germanium is used as a catalyst element for accelerating the crystallization. A heat treatment is conducted in a condition in that a germanium film 107 is formed on the amorphous silicon film 106, and thus a polysilicon film 108 is obtained by the catalytic function of germanium. The polysilicon film 108 thus obtained has crystallinity that can be substantially regarded as a single crystal.
Claims24
A semiconductor device comprising a circuit comprising plural TFTs formed on a substrate having an insulating surface, wherein
- a channel forming region of said plural TFT comprises a crystalline semiconductor film having a main orientation plane of a {111} plane, and
- germanium is present in a higher concentration with closer to a vicinity of a primary surface of said crystalline semiconductor film.
A semiconductor device comprising a circuit comprising plural TFTs formed on a substrate having an insulating surface, wherein
- a channel forming region of said plural TFT comprises a crystalline semiconductor film having a main orientation plane of a {111} plane, which is substantially regarded as a single crystal, and
- germanium is present in a higher concentration with closer to a vicinity of a primary surface of said crystalline semiconductor film.
A semiconductor device comprising a circuit comprising plural TFTs formed on a substrate having an insulating surface, wherein
- a channel forming region of said plural TFT comprises a crystalline semiconductor film having a main orientation plane of a {111} plane, and
- germanium is present in said crystalline semiconductor film in a concentration of from 1×1014 to 1×1020 atoms/cm3, and said crystalline semiconductor film has a spin density of 5×1017 spins/cm3 or less.
A semiconductor device comprising a circuit comprising plural TFTs formed on a substrate having an insulating surface, wherein
- a channel forming region of said plural TFT comprises a crystalline semiconductor film having a main orientation plane of a {111} plane, which is substantially regarded as a single crystal, and
- germanium is present in said crystalline semiconductor film in a concentration of from 1×1014 to 1×1020 atoms/cm3, and said crystalline semiconductor film has a spin density of 5×1017 spins/cm3 or less.
A semiconductor device having at least one active matrix type display panel, said panel comprising:
- a substrate having an insulating surface;
- a plurality of pixel electrodes arranged in a matrix form formed over said substrate, each of said pixel electrodes being electrically connected to at least one first thin film transistor, wherein said first thin film transistor comprising a channel forming layer comprising crystal silicon, a gate insulating layer adjacent to the channel forming layer and a gate electrode adjacent to said gate insulating layer;
- a driving circuit comprising at least one second thin film transistor for driving said first thin film transistor, wherein said second thin film transistor comprising a channel forming layer comprising crystal silicon, a gate insulating layer adjacent to the channel forming layer and a gate electrode adjacent to said gate insulating layer,
- wherein the channel forming layer of each of said first and second thin film transistors has a {111} orientation and contains germanium, and a concentration of said germanium is higher in an upper portion of said channel forming layer than a lower portion thereof.
A semiconductor device having at least one active matrix type display panel, said panel comprising:
- a substrate having an insulating surface;
- a plurality of pixel electrodes arranged in a matrix form formed over said substrate, each of said pixel electrodes being electrically connected to at least one first thin film transistor, wherein said first thin film transistor comprising a channel forming layer comprising crystal silicon, a gate insulating layer adjacent to the channel forming layer and a gate electrode adjacent to said gate insulating layer;
- a driving circuit comprising at least one second thin film transistor for driving said first thin film transistor, wherein said second thin film transistor comprising a channel forming layer comprising crystal silicon, a gate insulating layer adjacent to the channel forming layer and a gate electrode adjacent to said gate insulating layer,
- wherein the channel forming layer of each of said first and second thin film transistors contains germanium at a concentration not higher than 1×1020 atoms/cm3 and has a spin density not higher than 5×1017 spins/cm3.
Dependencies are inferred from the claim text.