Thin film semiconductor and method for manufacturing the same, semiconductor device and method for manufacturing the same
First Claim
1. A method for manufacturing a thin film semiconductor comprising the steps of:
- forming a silicon oxide film by sputtering on a surface of a substrate having an insulating surface;
intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a shape;
forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film;
forming a metallic element which accelerates the crystallization to said silicon oxide film and/or said amorphous silicon film;
crystallizing said amorphous silicon film into a crystalline silicon film by heat treatment; and
irradiating a laser light or an intense light having an energy equivalent to that of said laser light to said crystalline silicon film,wherein said crystalline silicon film is formed into a monodomain region by irradiating a laser light or an intense light having an energy equivalent to that of said laser light.
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Accused Products
Abstract
The present invention is related to a thin film semiconductor which can be regarded as substantially a single crystal and a semiconductor device comprising an active layer formed by the thin film semiconductor. At least a concave or convex pattern is formed intentionally on a insulating film provided in contact with the lower surface of an amorphous silicon film, whereby at least a site is formed in which a metal element for accelerating crystallization can be segregated. Therefore, a crystal nuclei is selectively formed in a portion where the concave or convex pattern is located, which carries out controlling a crystal diameter. Thus, a crystalline silicon film is obtained. A crystallinity of the crystalline silicon film is improved by the irradiation of a laser light or an intense light having an energy equivalent to that of the laser light, whereby a monodomain region in which no grain boundary substantially exit is formed.
300 Citations
27 Claims
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1. A method for manufacturing a thin film semiconductor comprising the steps of:
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forming a silicon oxide film by sputtering on a surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a shape; forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates the crystallization to said silicon oxide film and/or said amorphous silicon film; crystallizing said amorphous silicon film into a crystalline silicon film by heat treatment; and irradiating a laser light or an intense light having an energy equivalent to that of said laser light to said crystalline silicon film, wherein said crystalline silicon film is formed into a monodomain region by irradiating a laser light or an intense light having an energy equivalent to that of said laser light. - View Dependent Claims (2, 3, 4)
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5. A method for manufacturing a semiconductor device having an active layer comprising the thin film semiconductor, said method comprising the steps of:
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forming a silicon oxide film by sputtering on the surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a shape; forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates the crystallization to the amorphous silicon film; crystallizing said amorphous silicon film into a crystalline silicon film by means of heat treatment; and irradiating a laser light or an intense light having an energy equivalent to that of said laser light to said crystalline silicon film, wherein; said crystalline silicon film is modified into a monodomain region by the step of irradiating a laser light or an intense light having an energy equivalent to that of said laser light; and said active layer is formed by using only said monodomain region. - View Dependent Claims (7, 8, 9)
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6. A method for manufacturing a semiconductor device having an active layer comprising a thin film semiconductor, said method comprising the steps of:
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forming a silicon oxide film by sputtering on the surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a shape; forming an amorphous silicon film by means of low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates the crystallization to said amorphous silicon film; crystallizing said amorphous silicon film into a crystalline silicon film by heat treatment; modifying said crystalline silicon film into a monodomain region by irradiating a laser light or an intense light having an energy equivalent to that of said laser light to said crystalline silicon film; forming an active layer by using said monodomain region alone; forming an insulating film covering said active layer and containing silicon as a main component by vapor phase method; performing heat treatment in an atmosphere containing a halogen element for gettering and removing the metallic element which accelerates the crystallization and, at the same time, forming a thermal oxide film at the interface between the active layer and said insulating film containing silicon as a main component; and performing heat treatment under gaseous nitrogen atmosphere to thereby improve the film quality of said insulating film containing silicon as a main component inclusive of said thermal oxide film.
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10. A method for fabricating a thin film transistor comprising:
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forming an insulating film on a surface of a substrate; forming at least a concave or a convex pattern intentionally on said insulating film; forming a semiconductor film in contact with an upper surface of said insulating film; forming a catalyst for promoting crystallization of said semiconductor film in contact with said semiconductor film; crystallizing said semiconductor film to form a plurality of columnar or needle-like crystals in parallel with said substrate therein; irradiating said semiconductor film with a laser light or an intense light having an energy equivalent to said laser light to aggregate said plurality of columnar or needle-like crystals so that at least a monodomain region is formed, said monodomain region being regarded as substantially a single crystal. - View Dependent Claims (11, 14, 15, 16, 17, 18)
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12. A method for fabricating a thin film transistor comprising:
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forming an insulating film on a surface of a substrate; forming at least a concave or a convex pattern intentionally on said insulating film; forming a semiconductor film in contact with an upper surface of said insulating film; forming a catalyst for promoting crystallization of said semiconductor film in contact with said semiconductor film; crystallizing said semiconductor film to form a plurality of columnar or needle-like crystals substantially in parallel with said substrate therein; irradiating said semiconductor film with a laser light or an intense light having an energy equivalent to a laser light to aggregate said plurality of columnar or needle-like crystals so that at least a monodomain region is formed, said monodomain region being substantially free of crystal grain boundaries.
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13. A method of manufacturing a thin film transistor comprising:
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forming a silicon oxide film by sputtering on a surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a predetermined shape; forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates crystallization to said silicon oxide film and/or said amorphous silicon film; crystallizing said amorphous silicon film into a crystalline silicon film by heat treatment; and irradiating a laser light or an intense light having an energy equivalent to that of the laser light to said crystalline silicon film to thereby modify said crystalline silicon film into a monodomain region.
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19. A method for fabricating a thin film transistor comprising:
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forming an insulating film on a surface of a substrate; forming at least a concave or a convex pattern intentionally on said insulating film; forming a semiconductor film in contact with an upper surface of said insulating film; forming a catalyst for promoting crystallization of said semiconductor film in contact with said semiconductor film; crystallizing said semiconductor film to form a plurality of columnar or needle-like crystals in parallel with said substrate therein; irradiating said semiconductor film with a laser light or an intense light having an energy equivalent thereto to aggregate said plurality of columnar or needle-like crystals so that at least a monodomain region is formed, said monodomain region being substantially a single crystal, wherein an active layer of said thin film transistor is formed by said monodomain region alone. - View Dependent Claims (20, 25, 26)
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21. A method for fabricating a thin film transistor comprising:
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forming an insulating film on a surface of a substrate; forming at least a concave or a convex pattern intentionally on said insulating film; forming a semiconductor film in contact with an upper surface of said insulating film; forming a catalyst for promoting crystallization of said semiconductor film in contact with said semiconductor film; crystallizing said semiconductor film to form a plurality of columnar or needle-like crystals in parallel with said substrate therein; irradiating said semiconductor film with a laser light or an intense light having an energy equivalent to said laser light to aggregate said plurality of columnar or needle-like crystals so that at least a monodomain region is formed, said monodomain region being substantially free of crystal grain boundaries; and patterning said monodomain region to form an active layer on said thin film transistor, wherein said active layer of said thin film transistor includes no grain boundary.
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22. A method of manufacturing a semiconductor device comprising:
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forming a silicon oxide film by sputtering on a surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a predetermined shape; forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates the crystallization to said amorphous silicon film; crystallizing the amorphous silicon film into a crystalline silicon film by heat treatment; and irradiating a laser light or an intense light having an energy equivalent to that of said laser light to said crystalline silicon film to thereby modify said crystalline silicon film into a monodomain region, wherein an active layer is formed by said monodomain alone.
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23. A method of manufacturing a semiconductor device having an active layer made from a thin film semiconductor, said method comprising:
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forming a silicon oxide film by sputtering on the surface of a substrate having an insulating surface; intentionally forming at least a concave or convex pattern by patterning said silicon oxide film into a shape; forming an amorphous silicon film by low pressure thermal CVD on said silicon oxide film; forming a metallic element which accelerates crystallization to said amorphous silicon film; crystallizing said amorphous silicon film into a crystalline silicon film by heat treatment; irradiating a laser light or an intense light having an energy equivalent to that of said laser light to the crystalline silicon film, to thereby modify said crystalline silicon film into a monodomain region; forming an active layer by using said monodomain region alone; forming an insulating film covering said active layer and containing silicon as a main component by vapor phase method; performing heat treatment in an atmosphere containing a halogen element for gettering and removing metallic element which accelerates said crystallization of said active layer and, at the same time, forming a thermal oxide film at the interface between said active layer and said insulating film having silicon as a main component; and performing heat treatment under gaseous nitrogen atmosphere to thereby improve the film quality of said insulating film containing silicon as a main component including said thermal oxide film. - View Dependent Claims (24)
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27. A method for fabricating a semiconductor device having an active layer made from a thin film semiconductor on an insulating film formed on the upper side of active circuits being integrated on a silicon substrate, said method comprising:
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forming at least a concave or a convex pattern intentionally on said insulating film; forming a semiconductor film in contact with an upper surface of said insulating film; forming a catalyst for promoting crystallization of said semiconductor film in contact with said semiconductor film; crystallizing said semiconductor film to form a plurality of columnar or needle-like crystals in parallel with said substrate therein; irradiating said semiconductor film with a laser light or an intense light having an energy equivalent to a laser light to aggregate said plurality of columnar or needle-like crystals so that at least a monodomain region is formed, said monodomain region being substantially free of crystal grain boundaries, and forming an active layer of said thin film transistor from only said monodomain region.
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Specification