Synthesis of neutral layer and Implementation of block copolymer nano pattern via initiated chemical vapor deposition

Abstract

Although the self-assembly of block copolymer(BCP) has an advantage of ability to form sub-10 nm patterns, it has greatest limitation that cannot easily orientate the perpendicular structure, which is applicable to nano patterning, due to different surface energies of constituent blocks. Recently the sub-10 nm pattern has been formed by spin-coatable top coat. However, this case cannot have versatility because the top coat and neutral layer should be synthesized respectively. In this study, the top coat and neutral layer were simply synthesized without discrimination by introducing initiated chemical vapor deposition (iCVD) process. Also, due to the rigid property of the iCVD top coat, we found that no hole / island was formed, unlike the spin-coated top coat. By using this fact, it is possible to realize the perpendicular structure by the entropy gain through the thickness control even in the case of the non-neutral top coat. As a result, perpendicular cylinders with a diameter of ~4 nm were implemented through iCVD neutral layer which has no preceding polymer synthesis at all thicknesses. This results are expected to be applicable to various fields such as nanolithography, superhydrophobic surfaces, and nanoporous membranes.