Patent ID: 7638394
Filing Date: 2009-12-29
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, comprising: forming a hard mask on an upper surface of a semiconductor substrate; forming an opening in the hard mask to expose a portion of the semiconductor substrate; forming a trench in the semiconductor substrate by etching the semiconductor substrate using the hard mask as an etch mask; forming a gate insulating film on inner walls of the trench; forming a conductive film on the gate insulating film and at least a portion of the hard mask, the conductive film filling the trench; forming a patterned conductive film in the trench by etching the conductive film; removing the hard mask; and forming a gate electrode by polishing only the patterned conductive film until an upper surface of the patterned conductive film aligns with the upper surface of the semiconductor substrate.