Analysis of molecular resist distribution in a resist film by using x-ray reflectivity

To obtain high resolution and sensitivity and low line width roughness (LWR), the resist film homogeneity is thought to be the key requirement of extreme ultraviolet lithography (EUVL) resist materials. We have synthesized of a new class of chemically amplified molecular glass resists containing rigid triphenolic cores which are protected by flexible side chains. We analyzed the electron density distribution of resist films (70 nm) by using X-ray reflectivity (XRR). The effects of protection ratio, high and low activation protecting groups, chain lengths have been tested using selected molecular resist. We discuss the effects of the chemical structures of new molecular resists on EUV lithographic performances.