Method of forming low resistance and reliable via in inter-level dielectric interconnect

US7223691B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Cyril Cabral, Jr. · Ossining, US
• Lawrence A. Clevenger · Saratoga Springs, US
• Timothy J. Dalton · Ridgefield, US
• Patrick W. DeHaven · Poughkeepsie, US
• Chester T. Dziobkowski · Hopewell Junction, US
• Sunfei Fang · Lagrangeville, US
• Terry A. Spooner · Clifton Park, US
• Tsong-Lin Tai · Stormville, US
• Kwong Hon Wong · Wappingers Falls, US
• Chin-Chao Yang · Beacon, US

Key dates

• Filing date: Oct 14, 2004
• Grant date: May 29, 2007
• Expiry date: Oct 14, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76888
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A novel interlevel contact via structure having low contact resistance and improved reliability, and method of forming the contact via. The method comprises steps of: etching an opening through an interlevel dielectric layer to expose an underlying metal (Copper) layer surface; and, performing a low energy ion implant of an inert gas (Nitrogen) into the exposed metal underneath; and, depositing a refractory liner into the walls and bottom via structure which will have a lower contact resistance due to the presence of the proceeding inert gas implantation. Preferably, the inert Nitrogen gas reacts with the underlying exposed Copper metal to form a thin layer of CuN.