Deep level transient spectroscopy of CVD diamond: the observation of defect states in hydrogenated films

Hydrogenated polycrystalline CVD diamond films support a number of defect s tates within the range 0.03-1.0 eV, as determined by charge-based deep leve l transient spectroscopy (Q-DLTS). The observation of a 30-meV state is dir ect evidence for such a shallow level in this material, and is most likely to be the acceptor state that gives rise to the p-type character of these f ilms. Deeper levels, at 0.11 eV, 0.39 eV, 0.65 eV and 0.70 eV-1.0 eV can al so be observed and again appear to be associated with the hydrogenation lev el within the near surface region of the CVD diamond film. The loss of the 0.11 eV level at temperatures greater than 417 K is most easily explained i f adsorbates are being removed from the surface at this temperature. (C) 20 01 Elsevier Science B,V. All rights reserved.