Method of manufacturing a semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsHongyong Zhang, Toru Takayama, Yasuhiko Takemura
Life of this patent
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Abstract
Nickel is introduced to a peripheral circuit section and a picture element section on an amorphous silicon film to crystallize them. After forming gate electrodes and others, a source, drain and channel are formed by doping impurities, and laser is irradiated to improve the crystallization. After that, electrodes/wires are formed. Thereby an active matrix type liquid crystal display whose thin film transistors (TFT) in the peripheral circuit section are composed of the crystalline silicon film crystal-grown in the direction parallel to the flow of carriers and whose TFTs in the picture element section are composed of the crystalline silicon film crystal-grown in the direction vertical to the flow of carriers can be obtained.
Claims11
A method of manufacturing a semiconductor device having at least one thin film transistor, comprising the steps of:
- disposing a catalyst containing material in contact with a selected region of a semiconductor film on an insulating surface of a substrate to be crystallized, said catalyst being capable of promoting crystallization of said semiconductor film;
- crystallizing said semiconductor film by heating where crystals grow from said selected region in parallel with said insulating surface;
- patterning said semiconductor film into an island after the step of crystallization thereof;
- and
- forming source and drain regions in said island with a channel region defined therebetween,
- wherein the step of patterning the semiconductor film is conducted in such a manner that crystals of said semiconductor film extend between said source and drain regions through the channel region in a direction which is in coincidence with a direction in which carriers of the transistor flow.
A method of manufacturing a semiconductor device having at least one thin film transistor, comprising the steps of:
- disposing a catalyst containing material in contact with a selected region of a semiconductor film on an insulating surface of a substrate to be crystallized, said catalyst being capable of promoting crystallization of said semiconductor film wherein said selected region has a rectangular shape lengthened in a first direction;
- crystallizing said semiconductor film by heating where crystals grow from said selected region in a second direction orthogonal to the first direction and parallel with said insulating surface;
- patterning said semiconductor film into an island after the step of crystallization thereof so that said island comprise the crystals extending in the second direction;
- and
- forming source and drain regions in said island with a channel region defined therebetween,
- wherein said island is so arranged that the crystals of the transistor extend between the source and drain regions through the channel region in a direction which is coincidence with a direction in which carriers of the transistor flow.
A method of manufacturing a semiconductor device having a plurality of thin film transistors, comprising the steps of:
- disposing a catalyst containing material in contact with a selected region of a semiconductor film on an insulating surface of a substrate to be crystallized, said catalyst being capable of promoting crystallization of said semiconductor film wherein said selected region has an elongated shape in a first direction;
- crystallizing said semiconductor film by heating where crystals grow from said selected region in a second direction orthogonal to the first direction and parallel with said insulating surface;
- patterning said semiconductor film into a plurality of islands after the step of crystallization thereof so that each of said islands comprises the crystals extending in the second direction;
- and
- forming source and drain regions in each of said islands with a channel region defined therebetween,
- wherein said islands are so arranged that the crystals of the respective transistors extend between the source and drain regions through the channel region in a direction which is in coincidence with a direction in which carriers of the respective transistors flow.
A method of manufacturing a semiconductor device having an active matrix circuit and a driver circuit, said method comprising the steps of:
- preparing a substrate having an active matrix circuit portion and a driver circuit portion on which said active matrix circuit and said driver circuit are to be formed thereon, respectively;
- forming a semiconductor film to be crystallized over the substrate;
- disposing a catalyst containing material selectively in contact with a selected region of the semiconductor film over the driver circuit portion and non-selectively in contact with an entire surface of the semiconductor film over the active matrix circuit portion, said catalyst being capable of promoting crystallization of said semiconductor film;
- crystallizing said semiconductor film by heating where first crystals grow from said selected region in parallel with a major surface of the substrate over the driver circuit portion and second crystals grow vertically to said major surface over the active matrix portion;
- after the step of the crystallization of the semiconductor film, patterning said semiconductor film into a plurality of islands over said active matrix portion and said driver circuit portion;
- forming source and drain regions-in each of said islands with a channel region defined therebetween,
- wherein the islands over the active matrix circuit portion comprise the crystals extending vertically to the substrate and the islands over the driver circuit portion comprise the crystals extending in parallel with the substrate, and
- wherein a crystal extending direction in the driver circuit portion is coincident with a direction linking the source region and the drain region in the island.
Dependencies are inferred from the claim text.