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US 8,999,823 B2Granted
Semiconductor device, method for manufacturing same, and display device
AssigneeSharp Kabushiki Kaisha
InventorsNaoki Makita, Hiroshi Nakatsuji
Life of this patent
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Abstract
A semiconductor device according to the present invention includes a thin-film transistor and a thin-film diode. The respective semiconductor layers and of the thin-film transistor and the thin-film diode are crystalline semiconductor layers that have been formed by crystallizing the same crystalline semiconductor film. Ridges have been formed on the surface of the semiconductor layer of the thin-film diode. And the semiconductor layer of the thin-film diode has a greater surface roughness than the semiconductor layer of the thin-film transistor.
Claims20
A method for fabricating a semiconductor device, the method comprising the steps of:
- (a1) providing a substrate, of which the surface is already covered with an amorphous semiconductor film;
- (b) forming an oxide layer on a portion of the amorphous semiconductor film;
- (c) irradiating and crystallizing the amorphous semiconductor film with a laser beam that has come from over the oxide layer, thereby obtaining a crystalline semiconductor film including a first crystallized region, in which the rest of the amorphous semiconductor film that is not covered with the oxide layer has been crystallized, and a second crystallized region, in which the portion of the amorphous semiconductor film that is covered with the oxide layer has been crystallized and which has a greater surface roughness than the first crystallized region;
- and
- (d) patterning the crystalline semiconductor film into a first semiconductor island to define the active region of a thin-film transistor and a second semiconductor island to define the active region of a thin-film diode, the first semiconductor island having the first crystallized region, the second semiconductor island having the second crystallized region.
2 more elements
A method for fabricating a semiconductor device, the method comprising the steps of:
- (a1) providing a substrate, of which the surface is already covered with an amorphous semiconductor film;
- (a2) irradiating the amorphous semiconductor film with a laser beam, thereby crystallizing and turning the amorphous semiconductor film into a crystalline semiconductor film;
- (b) forming an oxide layer locally on the crystalline semiconductor film;
- (c) irradiating the crystalline semiconductor film with a laser beam that has come from over the oxide layer and reducing the surface roughness of a part of the crystalline semiconductor film that is not covered with the oxide layer, thereby turning that part of the crystalline semiconductor film that is not covered with the oxide layer into a first crystallized region and the rest of the crystalline semiconductor film that is covered with the oxide layer into a second crystallized region with a greater surface roughness than the first crystallized region;
- and
- (d) patterning the crystalline semiconductor film into a first semiconductor island to define the active region of a thin-film transistor and a second semiconductor island to define the active region of a thin-film diode, the first semiconductor island having the first crystallized region, the second semiconductor island having the second crystallized region.
3 more elements
A method for fabricating a semiconductor device, the method comprising the steps of:
- (a1) providing a substrate, of which the surface is already covered with an amorphous semiconductor film;
- (a2′) adding a catalyst element that promotes crystallization to at least a part of the amorphous semiconductor film and then heating the amorphous semiconductor film, thereby crystallizing and turning the amorphous semiconductor film into a crystalline semiconductor film;
- (b) forming an oxide layer locally on the crystalline semiconductor film;
- (c) irradiating the crystalline semiconductor film with a laser beam that has come from over the oxide layer, thereby further crystallizing or re-crystallizing and turning a part of the crystalline semiconductor film that is not covered with the oxide layer into a first crystallized region and the rest of the crystalline semiconductor film that is covered with the oxide layer into a second crystallized region with a greater surface roughness than the first crystallized region;
- and
- (d) patterning the crystalline semiconductor film into a first semiconductor island to define the active region of a thin-film transistor and a second semiconductor island to define the active region of a thin-film diode, the first semiconductor island having the first crystallized region, the second semiconductor island having the second crystallized region.
3 more elements
A method for fabricating a semiconductor device, the method comprising the steps of:
- (a1) providing a substrate, of which the surface is already covered with an amorphous semiconductor film;
- (a2′) adding a catalyst element that promotes crystallization to at least a part of the amorphous semiconductor film and then heating the amorphous semiconductor film, thereby crystallizing and turning the amorphous semiconductor film into a crystalline semiconductor film;
- (a3′) irradiating and farther crystallizing or re-crystallizing the crystalline semiconductor film with a laser beam;
- (b) forming an oxide layer locally on the crystalline semiconductor film;
- (c) irradiating the crystalline semiconductor film with a laser beam that has come from over the oxide layer and reducing the surface roughness of a part of the crystalline semiconductor film that is not covered with the oxide layer, thereby turning that part of the crystalline semiconductor film that is not covered with the oxide layer into a first crystallized region and the rest of the crystalline semiconductor film that is covered with the oxide layer into a second crystallized region with a greater surface roughness than the first crystallized region;
- and
- (d) patterning the crystalline semiconductor film into a first semiconductor island to define the active region of a thin-film transistor and a second semiconductor island to define the active region of a thin-film diode, the first semiconductor island having the first crystallized region, the second semiconductor island having the second crystallized region.
4 more elements
A display device comprising:
- a display area including a plurality of display units;
- and
- a frame area, which surrounds the display area,
- wherein the device further includes a photosensor unit with a thin-film diode, and
- wherein each said display unit includes an electrode and a thin-film transistor that is connected to the electrode, and
- wherein the thin-film transistor and the thin-film diode have been formed on the same substrate, and
- wherein the thin-film transistor includes a crystalline semiconductor layer with a channel region and source and drain regions, a gate insulating film that is arranged to cover the crystalline semiconductor layer, and a gate electrode that is arranged on the gate insulating film to control the conductivity of the channel region, and
- wherein the thin-film diode includes a crystalline semiconductor layer that has at least an n-type region and a p-type region, and
- wherein the respective semiconductor layers of the thin-film transistor and the thin-film diode are crystalline semiconductor layers that have been formed by crystallizing the same amorphous semiconductor film, and
- wherein ridges have been formed on the surface of the semiconductor layer of the thin-film diode, and
- wherein the semiconductor layer of the thin-film diode has a greater surface roughness than the semiconductor layer of the thin-film transistor.
8 more elements
Dependencies are inferred from the claim text.