Plasma-enhanced CVD low-k process enabling global planarity by controlling flowability

Plasma-enhanced CVD (PECVD) flowable low-k process compatible with the conventional UV cure process has been developed. Reduction of shrinkage by the UV cure was critical to ensure gap-filling capability with planarity, which was achieved by deposition condition tuning to reduce hydro-carbon constituent in the film and enhancement of dehydration by applying post-deposition treatment. Complete filling of 45-nm-space trench was achieved with excellent global planarity. The present results suggest applicability of the process for future pre-metal dielectric (PMD) or inter-layer dielectric (ILD) for aggressively scaled devices.