Manufacturing method of self-aligned DMOS body pickup

US11069777B1 · kind B1 · utility

Assignee

• Monolithic Power Systems, Inc. · US

Inventors

• Ji-Hyoung Yoo · Los Gatos, US
• Joel M. McGregor · San Jose, US
• Haifeng Yang · Shanghai, CN
• Deming Xiao · Longbeilingcun, CN

Key dates

• Filing date: Jun 9, 2020
• Grant date: Jul 20, 2021
• Expiry date: Jun 9, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/0289

Abstract

A manufacturing process of a DMOS device in a drift region in a semiconductor substrate, having: forming a polysilicon layer above the drift region; forming a block layer above the polysilicon layer; etching both the block layer and the polysilicon layer, through a window of a first masking layer to expose a window to the drift region; implanting dopants through the window to the drift region to form a body region; forming blocking spacers to wrap side walls of the polysilicon layer; implanting dopants into the body region under a window shaped by the blocking spacers to form a body pickup region; etching away the blocking spacers; performing a masking step to form gates; forming ONO spacers to wrap side walls of the gates; and performing a masking step to form source regions and drain pickup regions.