Reduction imaging at 14 nm using multilayer-coated optics: Printing of features smaller than 0.1 μm

Abstract

We demonstrate high resolution reduction imaging in the soft x-ray spectral region using multilayer-coated reflective optics. In particular, a Schwarzschild objective was used at 20:1 reduction with 14 nm radiation to image line and space features from a transmission mask onto a resist-coated silicon wafer with a resolution better than 0.1 μm. The mirrors of the objective were coated with Mo/Si multilayers to provide nearly 40% reflectance at near-normal incidence for the 14 nm radiation. Our results demonstrate that multilayer coatings are capable of enhancing the reflectance of optical components at soft x-ray wavelengths without significantly degrading their imaging performance.