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US 6,664,144 B2Granted
Method of forming a semiconductor device using a group XV element for gettering by means of infrared light
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsSetsuo Nakajima, Hisashi Ohtani
Life of this patent
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Abstract
There is disclosed a method of fabricating TFTs using a silicon film crystallized with the aid of nickel. The nickel is removed from the crystallized silicon film. The method starts with maintaining nickel in contact with the surface of an amorphous silicon film. Then, a heat treatment is performed to form a crystalline silicon film. At this time, nickel promotes the crystallization greatly, and nickel diffuses into the film. A mask is formed. A silicon film heavily doped with phosphorus is formed. Thereafter, a heat treatment is performed to move the nickel from the crystalline silicon film into the phosphorus-rich silicon film. This reduces the concentration of nickel in the crystalline silicon film.
Claims51
A method of fabricating a microprocessor comprising:
- forming a semiconductor film comprising silicon and crystallized by the action of a metal for promoting crystallization of silicon;
- forming a film comprising XV group element in contact with said semiconductor film;
- irradiating an infrared light to said semiconductor film to getter said metal from said semiconductor film into said film comprising XV group element;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the infrared light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands.
3 more elements
A method of fabricating a microprocessor comprising:
- forming a semiconductor film comprising silicon and crystallized by the action of a metal for promoting crystallization of silicon;
- forming a mask for exposing a part of said semiconductor film;
- forming a film comprising XV group element so as to cover said mask and the exposed part of said semiconductor film;
- irradiating an infrared light to said semiconductor film to getter said metal from said semiconductor film into said film comprising XV group element;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the infrared light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands.
4 more elements
A method of fabricating a microprocessor comprising:
- forming an amorphous semiconductor film comprising silicon and crystallized by the action of a metal for promoting crystallization of silicon;
- forming a mask for exposing a part of said semiconductor film;
- forming a gettering film comprising an amorphous silicon so as to cover said mask and the exposed part of said semiconductor film;
- irradiating an infrared light to said semiconductor film to getter said metal from said semiconductor film into said gettering film;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the infrared light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands.
4 more elements
A method of fabricating a microprocessor comprising:
- providing a semiconductor film comprising silicon with a metal for promoting crystallization of silicon;
- crystallizing said semiconductor film provided with said metal into a crystalline semiconductor film;
- forming a film comprising a gettering element over said crystalline semiconductor film;
- gettering said metal from said crystalline semiconductor film into said film comprising the gettering element by irradiation of an infrared light;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the infrared light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands.
4 more elements
A method of fabricating a microprocessor comprising:
- providing a semiconductor film comprising silicon with a metal for promoting crystallization of silicon;
- crystallizing said semiconductor film provided with said metal into a crystalline semiconductor film;
- forming a film comprising a gettering element over said crystalline semiconductor film;
- gettering said metal from said crystalline semiconductor film into said film comprising the gettering element by irradiation of an infrared light;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the infrared light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands,
- wherein said gettering is conducted in an atmosphere comprising nitrogen.
5 more elements
A method of fabricating a microprocessor comprising:
- providing a semiconductor film comprising silicon with a metal for promoting crystallization of silicon;
- crystallizing said semiconductor film provided with said metal into a crystalline semiconductor film;
- forming a film comprising a gettering element over said crystalline semiconductor film;
- heating said film comprising the gettering element formed over said crystalline semiconductor film to getter said metal from said crystalline semiconductor film into said film comprising the gettering element;
- patterning said semiconductor film to form at least first and second semiconductor islands after the heating;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands,
- wherein said heating is conducted in an atmosphere comprising nitrogen.
5 more elements
A method of fabricating a microprocessor comprising:
- providing a semiconductor film comprising silicon with a metal for promoting crystallization of silicon;
- crystallizing said semiconductor film provided with said metal into a crystalline semiconductor film;
- forming a film comprising a gettering element over said crystalline semiconductor film;
- gettering said metal from said crystalline semiconductor film into said film comprising the gettering element by irradiation of a light;
- patterning said semiconductor film to form at least first and second semiconductor islands after the irradiation of the light;
- and
- forming at least one CMOS device including at least an n-channel thin film transistor and a p-channel thin film transistor, using said at least first and second semiconductor islands.
4 more elements
Dependencies are inferred from the claim text.