Multi-composition gate dielectric field effect transistors

US9231072B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Emre Alptekin · Fishkill, US
• Unoh Kwon · Fishkill, US
• Wing L. Lai · Williston, US
• Zhengwen Li · Danbury, US
• Vijay Narayanan · New York, US
• Ravikumar Ramachandran · Beacon, US
• Reinaldo Vega · Mahopac, US

Key dates

• Filing date: Feb 12, 2014
• Grant date: Jan 5, 2016
• Expiry date: Mar 3, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/667

Abstract

A first gate structure and a second gate structure are formed over a semiconductor material layer. The first gate structure includes a planar silicon-based gate dielectric, a planar high-k gate dielectric, a metallic nitride portion, and a first semiconductor material portion, and the second gate structure includes a silicon-based dielectric material portion and a second semiconductor material portion. After formation of gate spacers and a planarization dielectric layer, the second gate structure is replaced with a transient gate structure including a chemical oxide portion and a second high-k gate dielectric. A work-function metal layer and a conductive material portion can be formed in each gate electrode by replacement of semiconductor material portions. A gate electrode includes the planar silicon-based gate dielectric, the planar high-k gate dielectric, and a U-shaped high-k gate dielectric, and another gate electrode includes the chemical oxide portion and another U-shaped high-k gate dielectric.