Using phase-mask algorithms to direct self assembly

摘要

Recent descriptions of novel directed self assembly (DSA) materials have suggested that exceptional linewidth control may be achieved when imbalanced block co-polymers assemble in a lithographic setting. By laying down initial patterns that serve as a guide for polymer film formation, relatively isolated periodic lines 20-40 nm can be formed. Because the linewidth is dictated by the polymer molecular weight, such a process should be immune to some sources of noise, such as shot noise, that plague other pattern formation methods at these dimensions. This technique can work well for the formation of fine features, but larger patterns need to be formed by other means. This is quite similar to phase-shifting mask (PSM) double exposures, in which periodic patterns are also preferred. We discuss here the applicability of already developed phase mask data parsing algorithms to fine line formation with DSA materials, and propose process flows in which these algorithms can be used directly with little or no modification.