Effect of prior C, Si and Sn implantation on the etch rate of CVD diamond

Diamond films were implanted with C+, Si+ or Sn+ ions at multiple energies in order to generate a uniform layer of implantation-induced disorder. The implant energies of 60, 180, 330 and 525 keV for C+ ions, 200, 500 and 950 keV for Si+ ions and 750 and 2000 keV for Sn+ ions were selected to give an approximately constant vacancy concentration at depths over the range similar to 0-0.5 mu m. An analysis of the C+ implanted surfaces by Raman spectroscopy has shown an increase in non-diamond or sp(2)-bonded carbon at doses in the range 5 x 10(13) to 5 x 10(15) cm(-2). In comparison, a completely non-diamond structure was evident after implantation with either Si+ ions at a dose of 5 x 10(15) ions/cm(2) or Sn+ ions at >= 5 x 10(14) cm(-2). For a given dose, the etch rate of the diamond film was shown to increase with the mass of the implanted species in the order of C+, Si+ and Sn+. For a given implant species, the etch rate increased with the implant dose and the ion-induced vacancy concentration. The etch rate of the implanted diamond in various gases decreased in the order of O-2, CF4/O-2 and CHF3/O-2 plasmas.