The SMART^TM Process for Directed Block Co-Polymer Self-Assembly

Abstract

A new process for directed block co-polymer self-assembly (DSA),AZ^(R) SMART^TM, for high resolution line and space patterning was introduced. The SMART process started with photoresist trench patterns generated through common photolithographic processes on top of a thin crosslinked neutral layer. A reactive ion etching (RIE) process removed the neutral layer at bottom of the resist trenches and followed by a resist stripping step which completely removed the resist material and uncovered the neutral surface protected by the resist film during etching step. DSA performances of the resultant SMART chemical pre-patterns without or with extra pinning material brushing step were compared. Results indicated that pinning material enhanced chemical pre-pattern directing power for DSA performance. The chemical pre-pattern without pinning material provided well aligned DSA performance for some specific pre-pattern structure and DSA multiplication factor, but it lacked general performance stability. On the other hand, process with added pinning material was demonstrated with stable performance for variable pre-pattern pitches with different DSA multiplication factors. SMART DSA pattern profile and its pattern etching transfer into hard masks were investigated.