Method of ensuring adhesion of chemically vapor deposited oxide to gold

Abstract

Adhesion of gold interconnects to silicon dioxide is achieved by forming, through chemical vapor deposition, or plasma enhanced chemical vapor deposition, an extremely thin film of titanium over the entirety of exposed surfaces of an integrated circuit structure on which the gold lines are disposed and over which a silicon dioxide layer is to be formed. This extremely thin film of titanium is then exposed to a flow of an oxidizer to convert the titanium to a film of (insulating) titanium oxide which, unlike gold, strongly adheres to silicon dioxide. Silicon dioxide is then deposited on the titanium oxide film. In the resulting multilayer interconnect structure, the insulator consists of a layer of silicon dioxide adhering to a thin adhesive layer of TiO.sub.x or SiOx--TiO.sub.y at those locations whereat no gold lines are formed, while, on the gold conductor lines, the insulator contains silicon dioxide formed on a thin adhesive layer of SiO.sub.y --TiO.sub.x atop a TiO.sub.y --TiAu interface.