Suppression of hillock growth through multiple thermal cycles by argon implantation

摘要

A technique for suppressing hillock growth in metal films on integrated circuits through multiple thermal cycles by argon implantation. Although it was known that ion implantation of many species such as arsenic suppressed the growth of hillocks in metal films through one thermal cycle, it was discovered that only one of the proposed ions, argon, would suppress hillock formation for multiple subsequent thermal cycles. For the other species, hillock formation would reoccur after multiple cycles. This characteristic is important for double layer metal (DLM) processes to prevent interlayer shorting.