Self-aligned self-assembled organosilicate line patterns of ~20nm half-pitch from block-copolymer mediated self assembly

Abstract

We report the formation of robust organosilicate line patterns of ~20nm half-pitch on surfaces from the self-assembled lamellar phase of a diblock copolymer of polystyrene and poly(ethylene oxide), PS-b-PEO, and an oligomeric organosilicate precursor mixtures. We could control the orientation and alignment of microdomains of this hybrid to the same degree of the thin films of organic block copolymers. By controlling the surface energy of substrates using dense organosilicate, the perpendicular orientation of lamellae to the surface was achieved. Topographic prepatterns were generated by E-beam lithography and used for alignment of the line patterns from lamellar phase. Upon removing the organic component (i.e. PS-b-PEO) by thermal treatment, the organosilicate microdomains remain as periodic line patterns with global alignment on surfaces. This method gives well-aligned silicon-containing line patterns with sublithographic length scales on surface. The self-assembled organosilicate line patterns were successfully transferred into underlying silicon substrate using anisotropic plasma etching.