Sputtered tungsten diffusion barrier for improved interconnect robustness

US6245668A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Stephen Bruce Brodsky · Beacon, US
• William J. Murphy · North Ferrisburgh, US
• Matthew J. Rutten · Colchester, US
• David C. Strippe · Waterbury Center, US
• Daniel S. Vanslette · South Burlington, US

Key dates

• Filing date: Sep 18, 1998
• Grant date: Jun 12, 2001
• Expiry date: Sep 18, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76876
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method of forming inter-level contacts or vias between metal layers using a tungsten film deposited into the via using non-collimated sputter deposition. The sputter chamber is configured with a pressure of about 1 mTorr to about 10 mTorr with an inert gas flow of at least at least 25 cm.sup.3 /min to about 150 cm.sup.3 /min. Shielding inside the chamber is coated with a material, preferably, aluminum oxide, that promotes adhesion of tungsten to the shielding. An adhesion layer of titanium may be included prior to deposition of the tungsten film. Non-collimated sputter deposition increases the target to substrate distance inside the sputter chamber; reduces the heating effect associated with traditional collimated sputtering; and provides more robust diffusion barriers.