Patent ID: 7615442

Claim:
A method for fabricating a trench metal-oxide-semiconductor field effect transistor, comprising steps of: (a) providing a substrate, forming an epitaxy layer on said substrate and etching said epitaxy layer to form a trench structure; (b) forming a gate oxide layer on a surface of said epitaxy layer and inner sidewalls of said trench structure and depositing a polysilicon layer to fill said trench structure; (c) introducing a nitrogen gas and performing a driving-in procedure to form a body structure in said epitaxy layer; (d) performing an implantation procedure to form a source layer between said body structure and said gate oxide layer; (e) forming a dielectric layer on said trench structure and said source layer; (f) etching said dielectric layer and said source layer downwardly to a surface of said body structure to define a source structure and form a contact region; (g) filling said contact region with a contact structure layer; and (h) forming a conductive metal layer on said contact structure layer and said dielectric layer to form said trench metal-oxide-semiconductor field effect transistor.