Characteristics of chemical vapor deposition diamond films for x-ray mask substrates

Abstract

In this article we summarize the development and characterization of chemical vapor deposition diamond films used for x-ray mask substrates. Good control of the deposition parameters governing film stress and film thickness has been achieved, and optical transmission greater than 40% has been demonstrated. Novel polishing techniques were employed to reduce the diamond surface roughness to below 3.0 nm Ra. The crystal structure of the diamond material, determined by Raman spectroscopy, transmission electron microscopy and electron diffraction analysis, is polycrystalline, with grain sizes of approximately 10 nm. Accelerated radiation damage testing indicates a correlation between hydrogen content in the films and the degree of distortion. X-ray masks using diamond membranes have been successfully fabricated to provide early learning of image-size and image-placement performance. © 1999 American Vacuum Society.