Schwarzschild microscope for carbon Kα radiation.

A Schwarzschild objective (magnification, ×32; numerical aperture, 0.2), which has a 0.1-µm resolution within 30 µm of the object height, was designed and fabricated. We have developed new normalincidence multilayer mirrors for carbon Kα radiation (wavelength, 44.8 Å), NiCr (80-20 wt. %)/C multilayers (thickness period, 22.5 Å; number of layers, 50), which are deposited by ion-beam sputtering with the thickness distribution corrected by deposition masks. Magnified images were taken on photographic film with the Schwarzschild objective by using an electron impact carbon Kα radiation source, and a resolution of < 0.5 µm was confirmed.