Verification of a high-resolution PEB parameter extraction methodology based on double exposure technique

Abstract

Resist images printed with sequential double exposures of cross lines are shown to distinguish among chemicallyamplified resist materials and the resulting corner rounding is shown to provide a quantitative means of determining resist model parameters. The experiments are carried out on an ASML stepper with Shipley UV210 and IBM APEX-E resists exposed at 248 nm. The former resist showed notably less corner rounding. Parameters in both Fickean and nonFickean models are determined through simulation interpretation of SEMs with the STORM program. The diffusivity in UV210 is found to be about 35% lower and less nonlinear than that in APEX-E.