Designing new materials and processes for directed self-assembly applications

Directed self-assembly (DSA) of block copolymers (BCPs) is a promising technology for advanced patterning at future technology nodes, but significant hurdles remain for commercial implementation. The most widely studied material for DSA is poly(styrene- block -methyl methacrylate) (PS-PMMA), but this material has a relatively weak segregation strength that has limited its utility to patterns above 24 nm pitch. This paper reports on some of Dow's efforts to develop new materials capable of extending DSA to smaller pitch by development of new BCP copolymer materials with stronger segregation strength. Some preliminary efforts are reported on new substrate treatments that stabilize perpendicular orientations in a high-c block copolymer that also incorporate an etch-resistant block to facilitate patterning at small dimensions. In addition, development of new block copolymer materials that have a c-parameter that is large enough to drive defect reduction and but not so high that it precludes thermal annealing are also presented. DSA of these new materials is demonstrated using thermal annealing processes at pitch ranging from 40 to 16 nm, and etch capability is also demonstrated on a material with 18 nm pitch. These technologies hold promise for the extension of DSA to sub 24 nm pitch.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.