Diffusion and thermal stability of hydrogen in homoepitaxial CVD diamond films

The diffusion and out-diffusion properties of hydrogen have been investigat ed in homoepitaxial layers of CVD boron-doped diamond which have been expos ed to a deuterium microwave plasma. The diffusion experiments show that the onset of (B, H) pair dissociation occurs at 550 degrees C. The hydrogen di ffusion activation energy is 1.4 eV. Hydrogen out-diffuses at 880 degrees C and the diamond surface barrier limits the out-diffusion process. In r.f, plasma exposed diamond epilayers, the hydrogen out-diffusion spectra are co mposed of a peak at 720 degrees C related to the subsurface hydrogen accumu lation layer and another one at 840 degrees C attributed to the hydrogen ad sorbed at the surface. (C) 2000 Elsevier Science S.A. All rights reserved.