Straightforward Integration Flow of a Silicon-Containing Block Copolymer for Line–Space Patterning

A promising alternative for the next-generation lithography is based on the directed self-assembly of block copolymers (BCPs) used as a bottom-up tool for the definition of nanometric features. Herein, a straightforward integration flow for line-space patterning is reported for a silicon BCP system, that is, poly­(1,1-dimethylsilacyclobutane)-b-poly­(styrene) (PDMSB-b-PS), able to define sub 15 nm features. Both in-plane cylindrical (L 0 = 20.7 nm) and out-of-plane lamellar structures (L 0 = 23.2 nm) formed through a rapid thermal annealing10 min at 180 °Cwere successfully integrated using graphoepitaxy to provide a long-range ordering of the BCP structure without the use of underlayers or top coats. Subsequent deep transfer into the silicon substrate using the hardened oxidized PDMSB domains as a mask is demonstrated. Combining a rapid self-assembly behavior, straightforward integration, and an excellent etching contrast, PDMSB-b-PS may become a material of choice for the next-generation lithography.