光リソグラフィー技術の限界と極端紫外リソグラフィー技術への期待―その開発の経緯と今後の展開―

摘要

The development of ultralarge scale integration (ULSI) has been promoted by the miniaturization of ULSI devices. This miniaturization has been supported by the development of lithography. We have been using optical lithography for the fabrication of ULSI devices. However optical lithography is now facing its resolution limit. To overcome this limitation, various tricks for resolution enhancement are widely adopted. However, we have to restrict the pattern layout flexibility strictly. By the introduction of extreme ultraviolet (EUV) lithography, the patter layout will be set free from these restrictions and get higher resolution. Still there are many issues in EUV lithography. In this paper, firstly the history of lithography is reviewed and the issues of current optical lithography are discussed. The issues of EUV lithography are summarized in the next. The history of EUV development is also shown. Then the remaining issues and future prospects are introduced.