Method of making crystal silicon semiconductor and thin film transistor

摘要

To provide a crystalline silicon film showing properties preferable to a semiconductor device such as a thin film transistor (TFT) etc., a silicon oxide film is deposited on a glass substrate by a CVD process such as plasma CVD process, thermal CVD process or the like and an amorphous silicon film is continuously deposited thereon without bringing the silicon oxide film into contact with the atmosphere. The amorphous silicon film is annealed at 500 through 600° C. by adding a catalyst element such as nickel thereto and crystallized. A crystal silicon film having improved crystalline property is provided by further irradiating a laser beam thereon. In the provided crystalline silicon film the catalyst element diffuses to silicon oxide under the silicon film and the concentration of the catalyst element in the silicon film is lowered. By using the crystalline silicon film a semiconductor device such as TFT etc. having improved property (especially small off current) can be achieved.