Method of forming copper interconnections with enhanced electromigration resistance and reduced defect sensitivity

US6287954A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Leon Ashley · Danbury, US
• Hormazdyar M. Dalal · Lagrangeville, US
• Du Nguyen · Danbury, US
• Hazara S. Rathore · Stormville, US
• Richard G. Smith · North Aurora, US

Key dates

• Filing date: Dec 9, 1999
• Grant date: Sep 11, 2001
• Expiry date: Dec 9, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76877
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of providing sub-half-micron copper interconnections with improved electromigration and corrosion resistance. The method includes double damascene using electroplated copper, where the seed layer is converted to an intermetallic layer. A layer of copper intermetallics with hafnium, lanthanum, zirconium or tin, is provided to improve the electromigration resistance and to reduce defect sensitivity. A method is also provided to form a cap atop copper lines, to improve corrosion resistance, which fully covers the surface. Structure and methods are also described to improve the electromigration and corrosion resistance by incorporating carbon atoms in copper interstitial positions.