Masami Hayashida

Comparison Among Multilayer Soft X-Ray Mirrors Fabricated By Electron Beam, Dc-, Rf-Magnetron Sputtering And Ion Beam Sputtering Deposition

Multilayer Mo/Si mirrors have been fabricated by various physical vapor deposition methods. The best mirror fabricated by RF-magnetron sputtering showed a reflectivity of 57.8% at an incident angle of 25° and at a wavelength of 12.66 nm with synchrotron radiation reflectometer. The characteristics of fabricated multilayer mirrors have been measured using transmission electron microscope for surface and cross-sectional micrographs, electron diffraction for crystalline nature, small-angle x-ray diffractometer and synchrotron radiation reflectometer for reflectivity. Particularly, the dependencies of deposition parameters of Ar pressure and input power in RF-magnetron sputtering and substrate temperature in electron beam deposition in ultra high vacuum, have been investigated. The crystalization of Mo layers is clearly admitted for the mirrors by DC-and RF-magnetron sputtering. Surface roughness is minimum for the mirrors by RF-magnetron sputtering and ion beam sputtering. A possible reason of low reflectivity for the mirrors by ion beam sputtering is discussed from the resluts of additional analysis.

Suppression of columnar-structure formation in Mo-Si layered synthetic microstructures

We have previously reported that columnar-structures were formed in electron beam (EB) deposited and DCmagnetron sputtered Mo-Si layered synthetic microstructures (LSMs). The columnar structures reduced x-ray reflectivity by roughing layer interfaces of the LSMs. We here investigated the conditions to suppress columnar structure formation, by varying the substrate temperature (T9) in EB deposition and the argon pressure (PAT ) in D C- and RF-sputtering. In the EB deposited LSMs, the columnar structure disappeared and almost uniform LSMs were obtamed both at T□ 400°C and T9< -155°C. In the DC- and RF-sputtered LSMs, the columnar structure formation was suppressed by lowering PAr. The measured x-ray reflectivity of the LSMs increased according to the suppression of the columnar structure formation.