Germanium FinFETs having dielectric punch-through stoppers

US8957477B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Cheng-Hung Chang · Riverview Drive, CN
• Yu-Rung Hsu · Tainan, TW
• Chen-Yi Lee · Keelung, TW
• Shih-Ting Hung · New Taipei, TW
• Chen-Nan Yeh · Guoxing Township, TW
• Chen-Hua Yu · Hsinchu, TW

Key dates

• Filing date: Oct 13, 2011
• Grant date: Feb 17, 2015
• Expiry date: Oct 13, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/02617
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of forming a semiconductor structure includes providing a composite substrate, which includes a bulk silicon substrate and a silicon germanium (SiGe) layer over and adjoining the bulk silicon substrate. A first condensation is performed to the SiGe layer to form a condensed SiGe layer, so that the condensed SiGe layer has a substantially uniform germanium concentration. The condensed SiGe layer and a top portion of the bulk silicon substrate are etched to form a composite fin including a silicon fin and a condensed SiGe fin over the silicon fin. The method further includes oxidizing a portion of the silicon fin; and performing a second condensation to the condensed SiGe fin.