Effects of hydrogen ion bombardment and boron doping on (001) polycrystalline diamond films

Hydrogen ion bombardment was carried out by applying a negative bias voltag e to the substrate during a microwave plasma chemical vapor deposition proc ess, using only hydrogen as reactant gas. The sine of (0 0 1) faces increas es after hydrogen ion etching while other grains are etched off. The surfac es of [0 0 1] directionally oriented films after boron doping were investig ated by scanning electron microscopy (SEM) and cathodoluminescent (CL) spec tra. The absence of the band-A emission in the CL spectra indicates a low d ensity of dislocations in the films. It is the first indication that the pe ak at 741.5 Nn and the broad peak at around 575 and 625 nm in the CL spectr a are reduced efficiently after boron doping in (0 0 1) polycrystalline dia mond films. We propose that these phenomena could be explained in simple te rms by penetration or adsorption through the lattice nets of the [0 0 1] di rectionally oriented surfaces model. (C) 2000 Elsevier Science B.V. All rig hts reserved.