Scientists at Tokyo Institute of Technology and Tokyo Ohka Kogyo have developed a novel block copolymer (BCP) that could significantly advance semiconductor manufacturing by enabling finer circuit patterns through directed self-assembly (DSA). This new BCP, derived from a chemically tailored version of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), self-assembles into lamellar structures with a half-pitch size of just 7.6 nanometers. This surpasses the capabilities of conventional BCPs, which struggle to achieve sub-10 nm features, and represents one of the smallest reported half-pitch sizes in the world for thin-film lamellar structures.
a Schematic of the DSA process using a PS-b-PGFM on a chemically patterned Si substrate. AFM phase images of a b PS-b-PGFM19-23 film on an NL35-modified DSA substrate (Ls = 90 nm) after annealing at 240 °C for 5 min, c PS-b-PGFM19-10 film on an NL38-modified DSA substrate (Ls = 84 nm) after annealing at 230 °C for 5 min, and d PS-b-PGFM18-11 film on an NL38-modified DSA substrate (Ls = 90 nm) after annealing at 230 °C for 5 min. All thin films are 19-nm thick and were etched using O2 plasma for 10 s prior to AFM.
The research, published in *Nature Communications*, highlights the potential of this new BCP to push the boundaries of miniaturization in electronics, which is crucial for the continued advancement of semiconductor technology. The tailored copolymer, PS-b-PGFM, exhibits reliable and reproducible self-assembly into extremely small nanometric patterns, making it a promising template for lithographic processes. As the demand for smaller feature sizes in semiconductor devices grows, this breakthrough could pave the way for next-generation Logic and Memory components that all need to continuously scale to smaller critical dimensions.
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