Study of lithographic characteristics due to differences in novolac resin structure

Our earlier studies pointed to a strong correlation between the molecular weight of novolac resin and lithographic characteristics. In particular, they showed that the resolution and DOF characteristics of resists may be improved by controlling molecular weight distribution. The present study focuses on photoactive compound (PAC) structure and resin structure. This paper discusses the effects of differences in PAC ballast structure and the composition of m-cresol (metacresol), p-cresol (para-cresol), and xylenol, phenolic monomers that constitute novolac resin, on resolution and lithographic characteristics, based on development rates and resist pattern simulations.