A novel molecular resist for EUV lithography

Abstract

The continued request for miniaturization of feature sizes in microelectronic, optoelectronic, and microelectromechanical systems places strong demands on the lithographic and patterning processes used to fabricate such devices. A EUV lithography, using low wavelength region (13.4 nm) so small size pattern obtained. Because EUV source is relatively low, the novel EUV resist required low sensitivity needed. A novel molecular resist was synthesized with the core material is bisphenol A oligomer and substitute is 7-membered lactone. This 7-membered lactone moiety was synthesized from camphor by Bayer-Villiger oxidation. 7-membered lactone group of the matrix bisphenol A oligomer was cleaved and the carboxylic acid functionality was formed by acid-catalyzed ring-opening reaction in the exposure region after post-exposure bake. This cyclic lactone group do not produce volatile byproduct and the molecular resist have low sensitivity, thus can be used for EUV resist. And eventually, we successfully obtained the positive tone images featuring micro-size line and space patterns..