Method of plasma preparation of metallic contacts to enhance mechanical and electrical integrity of subsequent interconnect bonds

Abstract

A method of removing oxidation from certain metallic contact surfaces utilizing a combination of relatively simple and inexpensive off-the-shelf equipment and specific chemistry. The method being a very rapid dry process which does not require a vacuum or containment chamber, or toxic gasses/chemicals, and does not damage sensitive electronic circuits or components. Additionally, the process creates a passivation layer on the surface of the metallic contact which inhibits further oxidation while allowing rapid and complete bonding, even many hours after surface treatment, without having to remove the passivation layer. The process utilizes a room-ambient plasma applicator with hydrogen, nitrogen, and inert gasses.

1 . A method of preparing metallic contacts for interconnect bonding, the method comprising the steps of:
 applying an activated chemical reducing agent, via a room-ambient plasma applicator, to at least a first metallic contact supported by a substrate, to remove oxidation from the first metallic contact; and   applying an activated chemical passivation agent, via the room-ambient plasma applicator, to the first metallic contact to create a passivation layer on the first metallic contact to inhibit oxidation of the first metallic contact.   
     
     
         2 .- 20 . (canceled)