Analysis of line-and-space patterns of ZrO2 nanoparticle resist on the basis of EUV sensitization mechanism

Metal oxide nanoparticle resists are promising materials for highly-resolving high-throughput patterning. However, their performance is still inadequate for the application to the production of semiconductor devices. In this study, the dependence of the relationship between chemical gradient and line width roughness (LWR) on the pattern duty, acid generator, and developer was investigated using a zirconia (ZrO2) nanoparticle resist. The line-and-space patterns of ZrO2 nanoparticle resists were analyzed on the basis of the EUV sensitization mechanism. LWR was roughly inversely proportional to the chemical gradient. The proportionality constant decreased with the increase of the ratio of nominal space width to the nominal line width. The proportionality constant for n-butyl acetate was smaller than that for an alternative developer with a high polarity. The proportionality constant decreased by the addition of an acid generator. The improvement of dissolution process and the suppression of secondary electron migration are essential to the suppression of LWR in the ZrO2 nanoparticle resist.