Synthesis and characterization of calixarene derivatives as resist materials for electron-beam lithography

This article describes the electron-beam resist properties of a class of calixarene derivatives for high-resolution electron-beam lithography. The derivatives, which are based on a calix[4]resorcinarene framework, are unique in that the bridging carbon is functionalized with a long chain (C-11) alkyl group. Our studies reveal that the electron-beam sensitivity of the calix[4]resorcinarenes is markedly lower than a standard calix[6]arene material, consistent with the increase in sensitivity that is observed with the number of monomers for these systems. Comparison of the sensitivity of the calix[4]resorcinarenes with four member calix[4]arenes from the literature reveals very similar values, indicating that chemical modification at the bridging carbon has no appreciable effect on sensitivity. The minimum linewidth resolution of the calix[4]resorcinarenes under our experimental conditions was found to be approximately 50 nm at a threshold line dose of 65 nC/cm. Our results also demonstrate the ability to chemically modify calixarene compounds at the bridging carbon position while maintaining electron-beam sensitivity. These findings are intended to open avenues for more extensive modification schemes in developing resist materials for high-resolution electron-beam lithography. (c) 2006 American Vacuum Society.