Method for preparing a conductive pad for electrical connection and conductive pad formed

US6335104B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Carlos J. Sambucetti · Ossining, US
• Daniel C. Edelstein · White Plains, US
• John G. Gaudiello · Poughkeepsie, US
• Judith M. Rubino · Ossining, US
• George F. Walker · New York, US

Key dates

• Filing date: Feb 22, 2000
• Grant date: Jan 1, 2002
• Expiry date: Feb 22, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/12986
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method for preparing a copper pad surface for electrical connection that has superior diffusion barrier and adhesion properties is provided. In the method, a copper pad surface is first provided that has been cleaned by an acid solution, a protection layer of a phosphorus or boron-containing metal alloy is then deposited on the copper pad surface, and then an adhesion layer of a noble metal is deposited on top of the protection layer. The protection layer may be a single layer, or two or more layers intimately joined together formed of a phosphorus or boron-containing metal alloy such as Ni-P, Co-P, Co-W-P, Co-Sn-P, Ni-W-P, Co-B, Ni-B, Co-Sn-B, Co-W-B and Ni-W-B to a thickness between about 1,000 å and about 10,000 å. The adhesion layer can be formed of a noble metal such as Au, Pt, Pd and Ag to a thickness between about 500 å and about 4,000 å.