Insulated gate bipolar transistor having a trench and a method for production thereof

US5763902A · kind A · utility

Assignee

• ABB RESEARCH LTD. · CH

Inventors

• Christopher Harris · Sollentuna, SE
• Ulf Gustafsson · Linköping, SE
• Mietek Bakowski · Gately Drive, SE

Key dates

• Filing date: Apr 24, 1996
• Grant date: Jun 9, 1998
• Expiry date: Apr 24, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/393

Abstract

An insulated gate bipolar transistor comprises a drain which supports a highly doped p-type substrate layer; a low doped n-type drift layer supported over the substrate layer; a base layer supported over the drift layer including a trench extending into the base layer, and supporting an insulated gate on an upper surface thereof separated from the trench by a highly doped n-type source region, the trench having a highly doped p-type layer at the bottom thereof vertically separated from the source region; and a source layer disposed over the n-type source region and extending into the trench covering the highly doped p-type layer in the trench bottom, wherein an applied voltage to the gate forms a conducting inversion channel in the base layer for electron transport from the source region to the drain, and the highly doped p-type layer in the bottom of the trench collects holes injected from the substrate layer into the drift layer thereby improving latch up immunity for the transistor.