The effect was studied of hydrogen annealing on the surface roughness and threading dislocation density of germanium films grown on silicon substrates by reduced-pressure chemical vapour deposition. The surface roughness initially decreased with an increase in the annealing temperature. At annealing temperatures greater than 650C the film thickness varied owing to surface undulations, leading to an increase in the surface roughness. Although high-temperature annealing at 850C was effective for reducing threading dislocation density, the surface roughness of a 150-nm-thick Ge film annealed at 650C reaches a minimum value (~0.7nm).

Effect of Isochronal Hydrogen Annealing on Surface Roughness and Threading Dislocation Density of Epitaxial Ge Films Grown on Si. S.Kobayashi, Y.Nishi, K.C.Saraswat: Thin Solid Films, 2010, 518[6], S136-9