Utilization of doped glass on the sidewall of the emitter window in a bipolar transistor structure

US7572708B1 · kind B1 · utility

Assignee

• NATIONAL SEMICONDUCTOR CORPORATION · US

Inventors

• Jeff Babcock · Sunnyvale, US
• Steve Adler · Dover, US
• Todd Thiebeault · Gorham, US
• Jamal Ramdani · Gilbert, US

Key dates

• Filing date: Mar 8, 2007
• Grant date: Aug 11, 2009
• Expiry date: Mar 8, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/133

Abstract

A bipolar transistor device architecture and method of manufacture uses doped glass on the sidewall of the emitter window opening to reduce the emitter-base overlap capacitance while at the same time improving the polysilicon plugging effect. The doped glass sidewall also improves dopant loss in the oxide in the case in which an in-situ doped poly emitter is used. By using a doped sidewall glass, the sensitivity of dopant absorption that can potentially occur in un-doped spacers is removed. The proposed technique also provides a simple method for achieving narrow emitter window openings while simultaneously improving doping uniformity compared to implanted poly techniques. The technique also allows a self-aligned base to be performed, thereby allowing tighter spacing between the extrinsic base and the intrinsic base.