The successful synthesis, characterization, and directed self-assembly of a silicon-containing block copolymer, poly(styrene-block-trimethylsilylisoprene) (P(S-b-TMSI)), which has much higher oxygen etch contrast than the de facto standard, poly(styrene-block-methyl methacrylate) is reported. A Sakurai, Grignard-type coupling reaction provided the key monomer in good yield. Living anionic polymerization was employed to prepare the block copolymer, which has very low polydispersity. P(S-b-TMSI) was successfully ordered and oriented by directed self-assembly. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013