Lithographic performance of a chemically-amplified resist developed for synchrotron radiation lithography in the sub-100-nm region

Chemically-amplified resists are crucial for making synchrotron radiation (SR) lithography practical for the mass production of future LSIs. It offers not only high resolution but also high sensitivity to X-rays and high etching durability in LSI fabrication processes. In this article, we evaluate the lithographic performance of a newly developed SR resist in the sub-100-nm region. It is a three-component chemically-amplified negative resist which utilizes polyhydroxystyrene partially protected by t-Boc groups as a base polymer to enhance the quality of casting and to control the dissolution rate, alicyclic-bromides with a ketonic group as a highly efficient acid generator to improve the sensitivity, and hexamethoxymethylmelamine as a cross linker. To enhance the discrimination in the dissolution rate between exposed and unexposed films, basic compounds were added.