Dissolution kinetics of main-chain-scission-type resist in organic developers

Abstract Main-chain-scission-type resists have been widely used for the fabrication of nanodevices. A copolymer consisting of methyl α -chloroacrylate and α -methylstyrene, known as the ZEP series of ZEON, is a popular main-chain-scission-type positive-tone resist. In this study, the dissolution kinetics were investigated using the ZEP series to clarify the effects of the molecular weight distribution and developer on the dissolution kinetics of the main-chain-scission-type resist. The thickness of the transiently swelling layer in hexyl acetate development was less than that in pentyl acetate development. The thickness of the transiently swelling layer depended on the molecular weight distribution of resist polymers.