Trench MOSFET device with polycrystalline silicon source contact structure

US6822288B2 · kind B2 · utility

Assignee

• General Semiconductor, Inc. · US

Inventors

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

Key dates

• Filing date: Nov 20, 2001
• Grant date: Nov 23, 2004
• Expiry date: Nov 20, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/62

Abstract

A trench MOSFET transistor device and a method of making the same. The device comprises: (a) a silicon substrate of first conductivity type; (b) a silicon epitaxial layer of first conductivity type over the substrate, the epitaxial layer having a lower majority carrier concentration than the substrate; (c) a trench extending into the epitaxial layer from an upper surface of the epitaxial layer; (d) an insulating layer lining at least a portion of the trench; (e) a conductive region within the trench adjacent the insulating layer; (f) a body region of second conductivity type provided within an upper portion of the epitaxial layer and adjacent the trench; (g) a source region of first conductivity type provided within an upper portion of the body region and adjacent the trench; (h) an upper region of second conductivity type within an upper portion of the body region and adjacent the source region, the upper region having a higher majority carrier concentration than the body region; and (i) a source contact region disposed on the epitaxial layer upper surface, wherein the source contact region comprises a doped polycrystalline silicon contact region in electrical contact with the sou…