VACUUM-ARC DEPOSITION OF MULTILAYER X-RAY MIRRORS

A vacuum arc deposition technique for the production of multilayer structures is described. In the preliminary work described here, we used carbon as the low Z element and a heavy metal such as W or Pt as the high Z species to obtain periodic multilayers which can be used for X-ray reflectors. The plasma necessary for the deposition was produced by two vacuum arc plasma sources, each coupled to magnetic filters to prevent macroparticle transport to and contamination of the films. The multilayer structures were investigated by Auger spectroscopy and Rutherford backscattering spectrometry, and several multilayer samples were tested by measuring the specular reflectance and off-specular scattering, and by comparing these data with calculations using a Fresnel reflectance model. Analysis of X-ray results indicate that smooth, well defined layers are formed with reasonably small interface widths. With improvements in layer thickness reproducibility, it appears that vacuum arc deposition could produce useful multilayer X-ray interference mirrors.