Ultrahigh-<i>χ</i> Block Copolymer Materials with Versatile Etch Selectivity for Sub-10 nm Pattern Transfer

Studies of block copolymer (BCP) materials and their phase separation in bulk and thin-film have exploded over the last decades due to the wide range of accessible morphologies and feature sizes. The basic BCP self-assembly principles have enabled the community to control the domain size and target the smallest sizes possible using BCPs with high interaction parameter. Accessing sub-5 nm feature size is not a challenge anymore. Transferring the BCP features to a substrate over a large area with high fidelity presents additional challenges, especially at the 10 nm length scale. In this work, the highly polar poly(3-hydroxystyrene) (P3HS) is incorporated with poly(dimethylsiloxane) (PDMS). We explore both P3HS/PDMS-based diblocks and triblocks. The BCPs show various well-ordered structures with the smallest lameallar domain of 7.4 nm. Mean-field theory analysis of the temperature-dependent correlation-hole scattering gives χ_(T) = 33.491/T + 0.3126. Thin-film self-assembly is studied and the domains are aligned vertically by solvent annealing. These new BCPs not only exhibit high interaction parameter, but also present high etch contrast and versatility to facilitate pattern transfer.