Microdomain orientation control of PS-b-PMMA films enabled by wettability relay of graphene

Abstract

Orientation control of block copolymer (BCP) microdomains in thin films is an important step for robust pattern transfer in BCP-based nanolithography. The established orientation control of BCP films relies on neutral surface modification using a random copolymer brush covalently bonded to substrates with proper anchoring groups, which is limited to specific substrates. Herein, we reported the utilization of monolayer graphene to physically separate a neutral random copolymer layer and a BCP film, and at the same time, relay the wettability of the neutral interface to achieve a perpendicularly oriented control of self-assembly of PS-b-PMMA microdomains. We demonstrate that the method is widely applicable to achieve the orientation control of the BCP film on various substrates.