Mitsuo Sumiya

Soft X-ray multilayers fabricated by electron-beam deposition

We have investigated the optimum deposition conditions for fabricating Mo/Si multilayers on Si wafers by means of electron-beam deposition, taking the substrate temperature and deposition rate as parameters. Mo/Si multilayers made at substrate temperatures Of room ternperature to 420°C and at deposition rates of 0.02 to 1.0 nm/s were evaluated by transmission electron micrographs of their cross sections, x-ray diffraction patterns, and their spectral reflectances for soft x rays of 10 to 17 nm. The optimum deposition parameters were found to be 100 to 150°C and 0.02 to 0.2 nm/s, respectively, for substrate temperature and deposition rate. The Mo/Si multilayer made under the optimum condition showed fairly smooth layered structure and a reflectance of ~30% for unpolarized soft x ray of 14.6 nm at an incident angle of 20 deg.

A Soft X-Ray Microscope Using an Imaging Detector

An X-ray microscope, consisting of a Wolter-type mirror and an imaging detector, was constructed. The configuration of the mirror was optimized by the ray-tracing procedure. The resolution of the imaging detector was estimated to be better than 1 µm from the spot diagram of the electron lenses. A photocathode made of a CsI layer as a photoemitter and a SiNx membrane as a support for the CsI layer is presented. The fundamental performance of the X-ray microscope has been evaluated, and its resolution has been estimated to be better than 2 µm.