Solubility and diffusion of hydrogen in hydrogenated crystalline and amorphous silicon

Hydrogen diffusion and solubility effects in hydrogenated crystalline and amorphous silicon prepared by hydrogen implantation with approximately equal hydrogen concentrations are compared. Hydrogen diffusion is found to be limited by hydrogen solubility in both cases. Between 300 and 450 degrees C, an agreement of the hydrogen diffusion coefficients for the two Si:H materials approximately within a factor of ten is observed. With increasing hydrogen concentration, hydrogen diffusion increases for amorphous Si:H but decreases for crystalline Si:H. This latter decrease is attributed to a hydrogen related microstructure which appears in crystalline Si:H at about a factor of ten smaller hydrogen concentration than in amorphous Si:H. (C) 1998 Elsevier Science B.V. All rights reserved.