Method of Fabricating Thin, Crystalline Silicon Film and Thin Film Transistors

A method of forming a crystalline silicon layer of a TFT device having a gate, a gate insulator, and an active layer, the active layer comprising source, drain, and channel regions formed in the crystalline silicon layer, the method comprising:

• forming a first silicon film, the first silicon film being amorphous at formation;
• forming a phosphorus doped silicon film on the first silicon film, the phosphorous doped silicon film being amorphous at formation;
• forming a nickel film on the phosphorus doped silicon film;
• and
• annealing the structure to crystallize the phosphorus doped silicon film and the first silicon film, wherein crystallization propagates by a combination of lateral crystal growth and vertical crystal growth.

A method of forming polycrystalline silicon TFT, comprising:

• forming a first intrinsic silicon film on a substrate, the first intrinsic silicon film being amorphous initially;
• forming a phosphorus doped silicon film on the first intrinsic silicon film, the phosphorous doped silicon film being amorphous initially;
• forming nickel patterns on the phosphorus doped silicon film;
• annealing the structure to cause crystallization of the phosphorus doped silicon film and the first intrinsic silicon film, wherein the crystallization propagates by a combination of lateral crystal growth between the nickel patterns and vertical crystal growth;
• removing the phosphorus doped silicon film from the first intrinsic silicon film after the crystallization;
• forming a gate insulator film over the crystallized first intrinsic silicon film;
• forming a gate electrode pattern over the gate insulator film;
• and
• doping into the selected areas of the crystallized first intrinsic silicon film to form source and drain regions separated by a channel region.