Air gap spacer between contact and gate region

US9716158B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Kangguo Cheng · Schenectady, US
• Nicolas Loubet · Guilderland, US
• Xin Miao · Guilderland, US
• Alexander Reznicek · Troy, US

Key dates

• Filing date: Mar 21, 2016
• Grant date: Jul 25, 2017
• Expiry date: Mar 21, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/834
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Unfilled gaps are provided as spacers between gate stacks and electrically conductive source/drain contacts to reduce parasitic capacitance in CMOS structures. Sidewall spacers are removed partially or entirely from portions of the gate stacks and replaced by materials such as amorphous semiconductor materials. Source/drain contacts subsequently formed on source/drain regions adjoin the spacer replacement material. Selective removal of the spacer replacement material leaves unfilled gaps between the source/drain contacts and the gate stacks. The unfilled gaps are then sealed by a dielectric layer that leaves the gaps substantially unfilled.