Analysis of line-and-space resist patterns with sub-20 nm half-pitch fabricated using high-numerical-aperture exposure tool of extreme ultraviolet lithography

Abstract The resolution of resist processes for extreme ultraviolet (EUV) lithography has been steadily improved and has reached the sub-20 nm half-pitch region. Currently, the resist materials capable of resolving 11 nm half-pitch line-and-space patterns are being developed in industrial fields. In this study, the line-and-space resist patterns with sub-20 nm half-pitches were fabricated using a high-numerical-aperture (NA) EUV exposure tool and analyzed by the Monte Carlo simulation.

The scanning electron microscopy (SEM) images of resist patterns after their development were compared with the latent images calculated on the basis of the sensitization and reaction mechanisms of chemically amplified EUV resists. The approximate relationship between resist patterns and latent images was clarified for the sub-20 nm half-pitch region. For the realization of 11 nm half-pitch fabrication, the suppression of the stochastic effects in the development process is an important consideration.