Methods and apparatus for a composite collector double heterojunction bipolar transistor

US6563145B1 · kind B1 · utility

Inventors

• Charles E. Chang · Coto De Caza, US
• Richard L. Pierson, Jr. · Thousand Oaks, US
• Peter J. Zampardi, Jr. · Newbury Park, US
• Peter M. Asbeck · San Diego, US

Key dates

• Filing date: Dec 29, 1999
• Grant date: May 13, 2003
• Expiry date: Dec 29, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/85

Abstract

A compound collector double heterojunction bipolar transistor (CCHBT) incorporates a collector comprising two layers: a wide bandgap collector region (e.g., GaAs), and a narrow bandgap collector region (e.g., InGaP). The higher electric field is supported in the wide bandgap region, thereby increasing breakdown voltage and reducing offset voltage. At the same time, the use of wide bandgap material in the depleted portion of the collector, and a higher mobility material toward the end and outside of the depletion region, reduces series resistance as well as knee voltage.