Replacement gate with reduced gate leakage current

US8809176B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Takashi Ando · Tuckahoe, US
• Michael P. Chudzik · Beacon, US
• Rishikesh Krishnan · Poughkeepsie, US
• Siddarth A. Krishnan · Newark, US
• Unoh Kwon · Fishkill, US
• Keith Kwong Hon Wong · Wappingers Falls, US

Key dates

• Filing date: Mar 15, 2013
• Grant date: Aug 19, 2014
• Expiry date: Mar 15, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/792
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Replacement gate work function material stacks are provided, which provides a work function about the energy level of the conduction band of silicon. After removal of a disposable gate stack, a gate dielectric layer is formed in a gate cavity. A metallic compound layer including a metal and a non-metal element is deposited directly on the gate dielectric layer. At least one barrier layer and a conductive material layer is deposited and planarized to fill the gate cavity. The metallic compound layer includes a material having a work function about 4.4 eV or less, and can include a material selected from tantalum carbide and a hafnium-silicon alloy. Thus, the metallic compound layer can provide a work function that enhances the performance of an n-type field effect transistor employing a silicon channel.