Cyclic epitaxy process to form air gap isolation for a bipolar transistor

US10186605B1 · kind B1 · utility

Assignee

• STMicroelectronics (Crolles 2) SAS · FR

Inventors

• Alexis Gauthier · Meylan, FR
• Fabien Deprat · Chambéry, FR
• Yves Campidelli · Grenoble, FR

Key dates

• Filing date: Oct 13, 2017
• Grant date: Jan 22, 2019
• Expiry date: Oct 13, 2037

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/401

Abstract

A bipolar transistor is supported by a single-crystal silicon substrate including a collector contact region. A cyclical epitaxy process is performed to provide a collector region of a first conductivity type on the collector contact region that is laterally separated from a silicon layer by an air gap. A second epitaxial region forms a base region of a second conductivity type. Deposited semiconductor material forms an emitter region of the first conductivity type. The collector region, base region and emitter region are located within an opening formed in a stack of insulating layers that includes a sacrificial layer. The sacrificial layer is selectively removed to expose a side wall of the base region. Epitaxial growth from the exposed sidewall forms a base contact region.