Structural Design of Resin Matrix and Acid-labile Dissolution Inhibitor of Chemical Amplification Positive Electron-beam Resist for Gigabit Lithography

The effect of m/p-cresol novolak molecular-weight-distribution (MWD) and dissolution inhibitor structure on resist performance were investigated. A novolak resin richer in p-cresol ratio gave a large dissolution inhibition capability of polymeric dissolution inhibitor, tetrahydropyranyl (THP) protected-polymeric dissolution inhibitor. In particular, a high molecular-weight novolak resin richer in p-cresol ratio was regarded as an effective matrix of a chemical amplification (CA) positive resist. THP protected phenolic compounds with extended backbone structures showed a large dissolution inhibition. The resist with MWD controlled resin and a THP-protected phenolic compound can achieve high resolution patterns (100-nm contact holes ) with high sensitivity (6.0μC/cm2).