Ion beam smoothing of CVD diamond thin films by etchback method

Abstract

Smoothing of chemical vapor deposited (CVD) diamond thin films with argon ion beams, and oxygen ion beams, and with both ion beams by the etchback method was investigated. Diamond thin films synthesized by the hot filament CVD method were used as samples. The samples were etched using an ion beam etching apparatus with a Kaufman-type ion source. Consequently, the surface roughness is extremely improved from 0.38 μm R a (as-grown) to 0.18 μm R a at the etched depth of 7.2 μm for 1000 eV argon ions at an ion incident angle of 0°. For 1000 eV oxygen ions at an ion incident angle of 80°, the surface roughness is also extremely improved from 0.38 μm R a (as-grown) to 0.18 μm R a at the etched depth of 5.5 μm. With the use of the etchback method, the surface roughness decreases rapidly with increasing etched depth and is reduced from 0.38 μm R a (as-grown) to 0.06 μm R a at the etched depth of 4.0 μm.