Large area nanolithographic templates by selective etching of chemically stained block copolymer thin films

Magnetic nanodot arrays were prepared from thin film templates of cylinder-forming polystyrene-polylactide diblock copolymers by first annealing the films to obtain PLA cylinders oriented perpendicular to the surface, then selectively staining the PS matrix with RuO4 vapors, followed by etching the cylinders by O2-reactive ion etching. Metal was then deposited by molecular beam deposition and finally the polymer mask was lifted off.