Vapor phase assisted polymer deposition for generating hierarchical block copolymer nanostructures

The ability of block copolymers (BCPs) to self-assemble into uniform nanostructures has rendered them highly attractive for a wide variety of technologies. Many applications such as information technology require the assembly of BCPs in thin films with different regions containing different features (domain spacing and morphology). Previous methods for generating complex nanopatterns on one substrate usually rely on either multiple processing steps or locally controlling the orientation/degree of ordering of polymer patterns, which are challenging with increasing complexity of the desired nanopatterns. Here, we adapt common BCP solvent vapor annealing processes to develop a vapor-phase photo-controlled deposition technique for producing homopolymers in BCP film matrices. The amount of deposited homopolymers and their molecular weight can be controlled by the processing time and irradiation energy. The synthesized homopolymers blend with BCPs, which change the underlying polymer chemistry and alter the BCP morphology and domain spacing. This method can be applied to different BCP systems. We will also demonstrate how to generate different nanopatterns (both sizes and shapes) from one block copolymer on different regions of one substrate using this technique.