MOS-gated power device having segmented trench and extended doping zone and process for forming same

US6433385B1 · kind B1 · utility

Assignee

• FAIRCHILD SEMICONDUCTOR CORPORATION · US

Inventors

• Christopher Boguslaw Kocon · Mountain Top, US
• Thomas E. Grebs · Smethport, US
• Joseph L. Cumbo · West Wyoming, US
• Rodney S. Ridley · Scarborough, US

Key dates

• Filing date: Oct 12, 2000
• Grant date: Aug 13, 2002
• Expiry date: Nov 9, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/516

Abstract

A trench MOS-gated device comprises a doped monocrystalline semiconductor substrate that includes an upper layer and is of a first conduction type. An extended trench in the substrate in the upper layer comprises two segments having differing widths relative to one another: a bottom segment of lesser width filled with a dielectric material, and an upper segment of greater width lined with a dielectric material and substantially filled with a conductive material, the filled upper segment of the trench forming a gate region. An extended doped zone of a second opposite conduction type extends from an upper surface into the upper layer of the substrate only on one side of the trench, and a doped well region of the second conduction type overlying a drain zone of the first conduction type is disposed in the upper layer on the opposite side of the trench.