Bipolar junction transistors with self-aligned terminals

US9059196B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• John Benoit · Montpelier, US
• James R. Elliot · South Burlington, US
• Peter B. Gray · Jericho, US
• Alvin J. Joseph · Williston, US
• Qizhi Liu · South Burlington, US
• Christa R. Willets · Jericho, US

Key dates

• Filing date: Nov 4, 2013
• Grant date: Jun 16, 2015
• Expiry date: Nov 4, 2033

Classification

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

Abstract

Device structures, design structures, and fabrication methods for a bipolar junction transistor. A first layer comprised of a first semiconductor material and a second layer comprised of a second semiconductor material are disposed on a substrate containing a first terminal of the bipolar junction transistor. The second layer is disposed on the first layer and a patterned etch mask is formed on the second layer. A trench extends through the pattern hardmask layer, the first layer, and the second layer and into the substrate. The trench defines a section of the first layer stacked with a section of the second layer. A selective etching process is used to narrow the section of the second layer relative to the section of the first layer to define a second terminal and to widen a portion of the trench in the substrate to undercut the section of the first layer.