Closed air gap interconnect structure

US7361991B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Simon Karecki · Poughkeepsie, US
• Maheswaran Surendra · Croton-on-Hudson, US
• Satya V. Nitta · Armonk, US
• Sampath Purushothaman · Yorktown Heights, US
• Matthew E. Colburn · Hopewell Junction, US
• Timothy J. Dalton · Ridgefield, US
• Elbert E. Huang · Carmel, US
• Katherine L. Saenger · Ossining, US

Key dates

• Filing date: Sep 19, 2003
• Grant date: Apr 22, 2008
• Expiry date: Sep 30, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A closed air gap interconnect structure is described. The structure includes discrete regions of a permanent support dielectric under the interconnect lines so that the lines are substantially surrounded by air except for the discrete regions of the support dielectric and the optional interconnect vias located underneath. The lines and the lateral gap between them are straddled on top by a cap layer so that a closed air gap is formed. Several embodiments of this structure and methods to fabricate the same are also described.