Trench DMOS transistor having lightly doped source structure

US6445037B1 · kind B1 · utility

Assignee

• General Semiconductor, Inc. · US

Inventors

• Fwu-Iuan Hshieh · Saratoga, US
• Koon Chong So · Fremont, US
• Yan Man Tsui · Union City, US

Key dates

• Filing date: Sep 28, 2000
• Grant date: Sep 3, 2002
• Expiry date: Sep 28, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/661

Abstract

A trench DMOS transistor cell includes a substrate of a first conductivity type and a body region located on the substrate, which has a second conductivity type. At least one trench extends through the body region and the substrate. An insulating layer lines the trench and a conductive electrode is placed in the trench overlying the insulating layer. A source region of the first conductivity type is located in the body region adjacent to the trench. The source region includes a first layer and a second layer disposed over the first layer. The first layer has a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.