The diffusion of H in homo-epitaxial layers of chemical vapor deposited B-doped material was investigated as a function of the diffusion temperature, the B dopant concentration and the nature of the H source (radio-frequency or microwave-plasma). It was shown that, for both types of plasma, H diffusion was limited by trapping at B acceptors for diffusion temperatures below 500C. The dissociation of B-H pairs occurred at 550C; thus implying a significantly higher stability of these pairs in diamond as compared with Si. However, a higher H diffusion activation energy was found in microwave plasma-exposed samples as compared with radio-frequency plasma-exposed samples. There was also an absence of the sub-surface H accumulation layer which was observed after radio-frequency plasma treatment. The results of H effusion experiments showed that, in radio-frequency plasma-exposed samples, an effusion peak at 720C could be attributed to the sub-surface H-accumulation layer. Another effusion peak, at 850C, was attributed to the desorption of H which was adsorbed at the surface.

Hydrogen in Monocrystalline CVD Boron Doped Diamond. J.Chevallier, D.Ballutaud, B.Theys, F.Jomard, A.Deneuville, E.Gheeraert, F.Pruvost: Physica Status Solidi A, 1999, 174[1], 73-81