Patent ID: 6638825
Filing Date: 2003-10-28
Classification: H01L

Abstract:
A method for fabricating a high voltage device comprising the steps of:forming drift regions in a semiconductor substrate; forming source and drain ion injection regions within the drift regions; forming a trench having a depth greater than the drift regions in one region of the semiconductor substrate; forming a first insulating film on an entire surface including the trench; forming a first conductive film on the first insulating film; selectively removing the first conductive film to form buffer conductive films at both sides of the trench; forming a second insulating film having a thickness at a lower portion of the trench; forming a third insulating film on the entire surface including the buffer conductive films; forming a second conductive film on the third insulating film; and selectively removing the second conductive film and the third insulating film to form a gate electrode on the trench and the buffer conductive films adjacent to the trench.