Method to fabricate SiGe HBTs with controlled current gain and improved breakdown voltage characteristics

US6787427B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• David R. Greenberg · White Plains, US
• Basanth Jagannathan · Beacon, US
• Shwu-Jen Jeng · Wappingers Falls, US
• Joseph T. Kocis · Pleasant Valley, US
• Samuel C. Ramac · Beacon, US
• David M. Rockwell · Fayetteville, US

Key dates

• Filing date: Oct 1, 2003
• Grant date: Sep 7, 2004
• Expiry date: Oct 1, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D10/891

Abstract

A method of fabricating a SiGe heterojunction bipolar transistor (HBT) is provided which results in a SiGe HBT that has a controllable current gain and improved breakdown voltage. The SiGe HBT having these characteristics is fabricated by forming an in-situ P-doped emitter layer atop a patterned SiGe base structure. The in-situ P-doped emitter layer is a bilayer of in-situ P-doped a:Si and in-situ P-doped polysilicon. The SiGe HBT structure including the above mentioned bilayer emitter is also described herein.