Directed self-assembly (DSA) lithography, which combines self-assembling materials and lithographically defined prepatterns, is a candidate to extend optical/EUV lithography beyond sub-10 nm.1,2 DSA of block copolymer (BCP) films on chemically or topologically patterned substrates is an attractive patterning technique that combines the ability of BCPs to self-assemble into nanoscale features with the use of lithographic tools.3–7 One of the important problems concerning practical application of DSA lithography is a “defect” problem. So far, the typical defect densities remain orders of magnitude away from the target concentration of proposed by the International Technology Roadmap for Semiconductors.8 Therefore, it is crucially important to minimize defect levels and maximize DSA lithography process margin by carefully designing lithographically defined prepatterns and precisely adjusting process conditions. Applying polystyrene-polymethylmethacrylate (PS-b-PMMA) diblock copolymer in a full-pitch size of around 25 nm, such a defect investigation has been reported.9 On the other hand, the domain size of self-organization is basically determined by the Flory–Huggins parameter and the polymerization index.10,11 To realize sub-10 nm feature size patterns, a higher parameter diblock copolymer is required. For example, polystyrene-b-poly 2-vinylpyridine and polystyrene-b-polydimethylsiloxane are well known as high materials with a potential for sub-10 nm patterns.12–14 However, to apply such materials for the lithographic process, high etching selectivity between the two composite polymers is required in order to transfer the pattern to the substrate.15 In this work, we report a fabrication process of sub-10 nm line-and-space patterns using the DSA materials featuring high parameter and high etch selectivity. We applied one of the most promising DSA materials, namely, POSS containing DSA materials, to realize sub-10 nm line-and-space patterning processes.16 In addition, we report the evaluation process of a new neutral layer (NL) material for Si containing high material.