Aluminum-based metallization exhibiting reduced electromigration and method therefor

US6448173B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Lawrence A. Clevenger · Saratoga Springs, US
• Ronald G. Filippi · Wappingers Falls, US
• Kenneth P. Rodbell · Sandy Hook, US
• Roy Iggulden · Newburgh, US
• Chao-Kun Hu · Somers, US
• Lynne M. Gignac · Beacon, US
• Stefan Weber · Fishkill, US
• Jeffrey P. Gambino · Gresham, US
• Rainer Florian Schnabel · Weilmünster, DE

Key dates

• Filing date: Jun 7, 2000
• Grant date: Sep 10, 2002
• Expiry date: Jun 7, 2020

Classification

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

Abstract

A dual damascene process capable of reliably producing aluminum interconnects that exhibit improved electromigration characteristics over aluminum interconnects produced by conventional RIE techniques. In particular, the dual damascene process relies on a PVD-Ti/CVD-TiN barrier layer to produce aluminum lines that exhibit significantly reduced saturation resistance levels and/or suppressed electromigration, particularly in lines longer than 100 micrometers. The electromigration lifetime of the dual damascene aluminum line is strongly dependent on the materials and material fill process conditions. Significantly, deviations in materials and processing can result in electromigration lifetimes inferior to that achieved with aluminum RIE interconnects. In one example, current densities as high as 2.5 MA/cm2 are necessary to induce a statistically relevant number of fails due to electromigration.