Embedded sigma-shaped semiconductor alloys formed in transistors by applying a uniform oxide layer prior to cavity etching

US8728896B2 · kind B2 · utility

Assignee

• GlobalFoundries Inc. · KY

Inventors

• Stephan Kronholz · Dresden, DE
• Andreas Ott · Erfurt, DE
• Ina Ostermay · Berlin, DE

Key dates

• Filing date: Sep 21, 2011
• Grant date: May 20, 2014
• Expiry date: Apr 4, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L22/12
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

When forming sophisticated transistors requiring an embedded semiconductor alloy, the cavities may be formed with superior uniformity on the basis of, for instance, crystallographically anisotropic etch steps by providing a uniform oxide layer in order to reduce process related fluctuations or queue time variations. The uniform oxide layer may be formed on the basis of an APC control regime.