High-Sensitivity Molecular Organometallic Resist for EUV (MORE)

摘要

We have developed organometallic carboxylate compounds [R_nM(O_2CR')_2] capable of acting as negative-tone EUV resists. Overall, the best and fastest resists contain antimony, are pentavalent and the carboxylate group contains a polymerizable olefin (e.g. acrylate, methacrylate or styrenecarboxylate). Evidence suggests that high sensitivity is achieved through the polymerization of olefins in the exposed region. We have performed a systematic sensitivity study of molecules of the type R_nM(O_2CR')_2 where we have studied seven R groups, four main group metals (M), and three polymerizable carboxylate groups (O_2CR'). We found that the greatest predictor of sensitivity of the R_nSb(O_2CR')_2 resists is their level of polymerizable olefins. We mathematically define the polymerizable olefin loading (POL) as the ratio of the number of olefins vs. the number of non-hydrogen atoms. Linear and log plots of E_(max) vs. POL for a variety of molecules of the type R_3Sb(O_2CR')_2 lend insight into the behaviour of these resists.