New materials for directed self-assembly for advanced patterning

Directed Self-Assembly (DSA) of block copolymers is a candidate advanced patterning technology at future technology nodes. Although DSA promises resolution and cost benefits, a number of constraints and challenges remain for its implementation. Poly(styrene-block-methyl methacrylate) (PS-b-PMMA) has been widely studied in DSA and applied in various applications to demonstrate the potential of DSA to extend optical lithography, including line space and contact hole patterning and uniformity repair,. However, the relatively weak segregation strength of PS-b-PMMA limits its capability to pattern sub-10 nm features. This paper presents the use of strongly segregated high chi block copolymers to enable sub-10 nm patterning. Chemoepitaxy DSA with high chi lamellar block copolymers is demonstrated with two different strategies based on thermal annealing process and no top coat. These technologies hold promise to enable the implementation of DSA at future technology nodes.