Method of forming topcoat for patterning

Disclosed is a method for the fabrication of polymeric topcoat via initiated chemical vapor deposition (iCVD) or photoinitiated chemical vapor deposition (piCVD) in conjunction with directed self-assembly (DSA) of block copolymers to generate high resolution patterns. A topcoat deposited by iCVD or piCVD allows for conformal, ultra-thin, uniform, pinhole-free coatings. iCVD or piCVD topcoat enables the use of a diversity of block copolymer (BCP) materials for DSA and facilitates the direct and seamless integration of the topcoats for a pattern transfer process.