Wet etch process for high-resolution DSA patterning for advanced node DRAM

Abstract

For adopting DSA patterning technology to implementation of upcoming DRAM nodes, a novel, unique, and user-friendly wet etch process was introduced. Our concept performs for good etch selectivity in design which facilitates high resolution patterning, and potentially offers an alternative solution to conventional dry etch techniques especially where CD goes smaller with a higher aspect ratio. This paper will discuss more in detail the concept of wet chemistry and design strategy which were developed for processing PS-b-PMMA (polystyrene-b-polymethyl methacrylate) hole patterns for advanced nodes. Besides, we further open perspectives of our wet etch strategy to new process development which does not require UV cure. Preliminary experiment and successful demonstration on PS-b-PMMA-based hole patterns will also be discussed in this paper.