Substrate damageless tri-layer process for advanced ArFi lithography

The importance of multi-layer process with spin-on hard masks increases for various processes on the next generation of logic and memory devices. The tri-layer process with spin-on glass (SOG) and spin-on carbon (SOC) is mainly used for ArFi multi-patterning lithography process, in order to provide wide process window by suppressing substrate reflectivity as well as etch-transfer fine pattern to substrate by enhancement of etch selectivity. However, conventional tri-layer process in advanced node device has the critical issue on substrate damage in SOG removal process because of vulnerability of topography wafers which contain smaller pattern features and thinner ALD/CVD films. In order to solve this problem, we developed novel SOG removal process with unique SOG/SOC materials for substrate damage mitigation. We will report Thin SOG Process for substrate damage-less SOG removal process.