Nitride film deposition using ammonia plasma pre-treatment to promote good adhesion of nitride film to copper

Abstract

Over the last decade, there is tremendous amount of technological advances in micro fabrication technology to manufacture devices of high complexities and compact devices to capture global market in semiconductor industry. As the device size shrinks, process integration gets more complicated and interaction between the dielectric layer and metallic layers becomes extremely important. This work presents an integration of a high quality Nitride film to copper. Native copper oxide layer was removed by ammonia plasma pre-treatment using a typical PE CVD (Plasma Enhanced Chemical Vapor Deposition) chamber and a high quality Nitride film deposition was followed on the surface of copper. The copper films exhibited various degrees of haze and discoloration such as dark greenish or dark gold, caused by the copper silicide layer formation at the interface between copper and Nitride. The silicide formation was able to be prevented by maintaining a stable Nitrogen plasma environment prior to introducing SiH4 gas flow into a PE CVD chamber. Results show that Nitride film combined with an in-stiu pre-treatment has excellent film properties in its integration with Copper.