Improvement of electrolessly gap-filled Cu using 2,2'-dipyridyl and bis-(3-sulfopropyl)-disulfide (SPS)

Abstract

The use of bis~3-sulfopropyl! disulfide ~SPS! in Cu electroless deposition resulted in Cu bottom-up filling. However, the high accelerating effect of SPS led to a poor electrical property of the film and generated many voids in the film by increasing the surface roughness and causing unstable deposition behavior. The addition of 2,28-dipyridyl together with SPS substantially improved the film quality of the gap-filled Cu maintaining the bottom-up filling behavior. It lowered the film resistivity by approximately 23% and enhanced the crystallinity. No voids were detected in the as-deposited Cu even after annealing.