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The application of alternative developers for both extreme ultraviolet (EUV) and 193-nm immersion ("ArFi") lithography is investigated by focusing on their effects on the "Defect-Not-Found" (DNF) margins. In case of EUV lithography, defects primarily comprise line bridging at the underdose region and line breaks at the overdose region. The application of a 0.26-N tetrabutylammonium hydroxide (TBAH) developer solution when compared to that of a 0.26-N tetramethylammonium hydroxide (TMAH) developer solution resulted in improved resist sensitivity while maintaining the same DNF margin. In case of ArFi lithography, defects primarily comprise line bridging at the underdose region and pattern collapse at the overdose region. The same improvement that has been mentioned above can be observed with respect to the resist sensitivity using the TBAH developer solution. However, the TBAH developer solution significantly minimizes the pattern collapse at the overdose region, further extending the minimum line pattern size. This translated to significant improvements in both the exposure latitude (EL) and overdose margin (OM) and resulted in a significant increase in the DNF margin. Furthermore, the application of a nonionic surfactant type additive on the TMAH developer solution demonstrates resist sensitivity improvement and pattern collapse mitigation. Increased EL and OM values were observed, which also resulted in increased DNF margin. Results indicate the advantages of utilizing alternative developer solutions in improving the DNF margins.

Directed self-assembly (DSA) lithography is one of the promising next-generation lithography technologies. However, there are two main limitations to the use of DSA. One is the narrowness of the pattern size window and the other is the fabrication of the underlayer. To address the former limitation, wide-range DSA has been applied to expand the applicable patterning size while the latter has been achieved by utilizing the newly developed reactive hemicellulose hardening (R2H) technique. In R2H, the hemicellulose unit is selectively hardened by a chemical reaction. In this study, hemicellulose block copolymers for wide-range DSA lithography and its fabrication technology were newly developed. A hemicellulose high-chi block copolymer (OPAL-BCP) and its underlayer were fabricated using R2H. After reactive ion etching of the underlayer with R2H, a pattern depth of over 300 nm and etching selectivity of 24 were obtained.