Hydrogen incorporation depths of more than 25µm were obtained in bulk monocrystalline samples during exposure to 2H plasmas for 0.5h at 300C. This produced an estimated diffusivity of about 8 x 10–10cm2/Vs at that temperature. The activation energy for diffusion was 0.17eV; thus indicating an interstitial mechanism. Subsequent annealing at 500 to 600C was sufficient to evolve all of the H; at least within the sensitivity of secondary ion mass spectrometry (below 5 x 1015/cm3). The thermal stability of H retention was slightly greater when the H was incorporated by direct implantation relative to plasma exposure, due to trapping at residual damage in the former case.

Hydrogen Incorporation and Diffusivity in Plasma-Exposed Bulk ZnO. Ip, K., M.E.Overberg, Y.W.Heo, D.P.Norton, S.J.Pearton, C.E.Stutz, B.Luo, F.Ren, D.C.Look, J.M.Zavada: Applied Physics Letters, 2003, 82[3], 385-7