Analysis of chemical vapour deposited diamond films by X-ray photoelectronspectroscopy

X-ray photoelectron spectroscopy (XPS) for elemental and phase analysis of diamond surfaces is reviewed, including both single crystal natural diamond and polycrystalline chemical vapour deposition (CVD) films. The core Cls p eaks, plasmon losses and valence band spectra Of sp(2) graphite are compare d with those of sp(3) diamond, and briefly with mixed sp(2)/sp(3) hard carb on films. Surface reconstructions are reviewed for diamond in the presence of hydrogen or following thermal annealing. Attention is drawn to the destr uctive effects of argon ion bombardment 'cleaning'. The synthesis of CVD di amond, including the initial nucleation process, is described and the signi ficance of hydrogen is explained. Chemical modification of the surface of d iamond films is discussed, with relevance to sensors and field electron emi ssion. XPS analysis of (111) polycrystalline films treated by atom beams of N, O, H, Cl is described and the influence of unwanted oxygen is emphasise d. For both atom beam and furnace oxidation, the oxygen is incorporated int o the (111) diamond surface as bridging C-O-C. (C) 2001 Elsevier Science B. V. All rights reserved.