Self-aligned double pattern process using DSA pattern

Directed self-assembly (DSA) is one of the candidates for next generation lithography. Over the past years, many papers and presentation have been reported regarding DSA, and Tokyo Electron Limited (TEL is a registered trademark or a trademark of Tokyo Electron Limited in Japan and /or other countries.) also has presented the evaluation results and the advantages of each1-10. Polystyrene-b-polymethyl methacrylate (PS-b-PMMA) has been used in many report because the polymerization technology is established and it is easy to form vertical patterns. In addition, the chemical epitaxy flow for PS-b-PMMA has established well to improve defectivity, line edge roughness and line width roughness. On the other hand, it is difficult to achieve less than 24nm pitch pattern by PS-b-PMMA because of the low chi parameter. In this paper, the combination process of DSA and SADP (self-aligned double pattern) is proposed for further small pitch pattern by PS-b- PMMA and latest results are reported.