VERTICAL MOS POWER TRANSISTOR

摘要

A transistor (10) such as a DMOS transistor is formed on a semiconductor substrate (12) with a first surface (19) for forming a channel (40). A gate dielectric (22) has a first thickness overlying a first portion of the channel, and a dielectric film (20) overlies a second portion of the channel and has a second thickness greater than the first thickness. The second thickness reduces the drain to gate capacitance of the transistor, thereby improving its switching speed and frequency response.