Patent ID: 6461918
Filing Date: 2002-10-08
Classification: H01L

Abstract:
A method of fabricating a double-diffused metal oxide semiconductor (DMOS) device, the method comprising:forming a body region of a first conductivity type in a semiconductor substrate having a drain region of a second conductivity type; forming a source region of the second conductivity type in the body region; forming a trench in the semiconductor substrate; lining the trench with a dielectric layer; forming a first polysilicon gate portion to an intermediate depth of the trench; implanting a dopant of the first conductivity type into the first polysilicon gate portion; forming a second polysilicon gate portion in the trench over the first polysilicon gate portion to a level substantially equal to a top surface of the silicon substrate; implanting a dopant of the second conductivity type into the second polysilicon gate portion; etching away an intermediate portion of the second polysilicon gate portion down to the first polysilicon gate portion; and forming a polycide strap layer over the first polysilicon gate portion in the intermediate portion and on opposite side walls of the second polysilicon gate portion.