Enhancement of the etch rate of CVD diamond by prior C and Ge implantation

Polycrystalline diamond films have been irradiated with C⁺ or Ge⁺ ions at doses in the range 5 × 10¹³-5 × 10¹⁵ ions/cm². Analysis of the implanted surfaces by Raman spectroscopy has shown that the proportion of non-diamond or amorphous carbon increased with implant dose. For implantation with Ge⁺ ions, a complete amorphisation was evident at a dose of 5 × 10¹⁵ Ge/cm². We have examined the effect of prior implant species and doses on the subsequent ion beam etch rate of the films. The ion beam etching (IBE) was performed in either Ar or Ar/O₂ gases at a bias energy of 500-1000 eV. In Ar gas, the etch rate of the diamond increased steadily with implant dose with a similar dependence for both the Ge⁺ and the C⁺ implanted samples. In Ar/O₂ gases, the etch rate was greater than in pure Ar with comparatively higher rates for Ge⁺ than the C⁺ implants.