Patent ID: 8878295

Claim:
A DMOS transistor comprising: a semiconductor structure having: a top surface of a semiconductor substrate; a rectangular shaped opening that extends from the top surface into the semiconductor structure, the opening having a bottom surface and a side wall surface, wherein the side wall surface is slanted; a drain region of a first conductivity type that touches the bottom surface of the opening; a body region of a second conductivity type that touches the top surface; a drift structure that touches the side wall surface of the opening, the drift structure having a first region of the first conductivity type and a second region of the second conductivity type, the first region directly touching the drain region and having a first region surface that lies substantially in parallel with the side wall surface of the opening, the second region separated from the drain region by a portion of the semiconductor substrate, the second region touching the body region and having a second region surface that touches the first region surface; a source region of the first conductivity type that touches the body region; a channel region in the top surface of the body region that lies horizontally between and touches the drift structure and the source region; a non-conductive region that fills the rectangular shaped opening; and a metal drain contact that extends through the non-conductive region to the top surface, contacting and connecting to the drain region.