Patent ID: 9721806
Date: 2017-08-01
CPC Classifications: H01L

Claim:
1. A method for fabricating a lateral double-diffused MOSFET (LDMOS) device, comprising: forming a drift region and a body region in a semiconductor substrate; forming a first shallow trench isolation structure in the drift region and in the semiconductor substrate between the drift region and the body region; removing a portion of the first shallow trench isolation structure to provide a first trench having a first portion in the semiconductor substrate between the drift region and the body region and a second portion in the drift region next to a remaining portion of the first shallow trench isolation structure, a side surface of the first trench being connected to a top surface of the body region; forming a gate dielectric layer on a side surface and a bottom surface of the first trench; forming a gate electrode on the gate dielectric layer and filling up the first trench to provide a top surface above a top surface of the semiconductor substrate; forming a first sidewall spacer and a second sidewall spacer on both side surfaces of the gate electrode, the first sidewall spacer being on a portion of the gate dielectric layer and a portion of the body region and the second sidewall spacer being on another portion of the gate dielectric layer and a portion of the first shallow trench isolation structure; and forming a source region in the body region on one side of the gate electrode and a drain region in the drift region on another side of the gate electrode.