Oxygen on diamond surfaces

Studies into the effect of hydrogen and oxygen on the growth of CVD diamond s have been in progress for a number of years. Surface oxygen studies on na tural diamond using Rutherford backscattering spectrometry have yielded par tial monolayer coverage on low index planes. To increase the sensitivity of the measurements, elastic scattering using the O-16(alpha,alpha)O-16 reson ance at 3.045 MeV has been performed. This resonance can enhance, by up to 30 times, the Rutherford cross-section. The samples are natural diamonds wi th either (111) or (100) surfaces. These have been cleaned using aqueous an d acidic solvents to study the effect cleaning has on the oxygen coverage. We have found the coverage to be dependent on the vacuum level of the targe t chamber, with no effect being shown by the cleaning methods. (C) 1999 Els evier Science S.A. All rights reserved.