In this paper we describe the concept of electroless dilute copper alloy deposition for ULSI applications. First, we describe the chemistry and the deposition conditions of of Cu deposition solutions with added Sn, Zn, Ni and Co atoms. Next, we present the deposition rates, the solid films characterization, the thin film resistivity and its topography as observed by STM and AFM. Finally, we discuss the application of Cu alloy in general as a way to improve Cu metallization reliability and the role of electroless Cu alloy in particular. Few applications are possible such as Cu seed enhancement or repair, and improving the adhesion of seedless Cu electro-deposition.
- Cu alloy
- Electroless deposition