Method of making an aluminum contact

US5854140A · kind A · utility

Assignees

• Siemens Aktiengesellschaft · DE
• International Business Machines Corporation · US

Inventors

• Mark A. Jaso · Yorktown Heights, US
• Herbert Palm · Hohenkirchen, DE
• Hans W. Poetzlberger · Munich, DE

Key dates

• Filing date: Dec 13, 1996
• Grant date: Dec 29, 1998
• Expiry date: Dec 13, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76807
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of forming aluminum contacts of submicron dimensions wherein, after formation of both vias and line openings in a silicon oxide layer, a metal stop layer is deposited, followed by deposition of aluminum. Alternatively, the metal stop layer is deposited prior to forming the vias and line openings. The excess aluminum is removed by chemical-mechanical polishing, the stop layer providing high selectivity to the chemical mechanical polishing. The stop layer is then removed. The resultant silicon oxide-aluminum surface is planar and undamaged by the chemical-mechanical polishing step.