The H effusion spectra of oxidized samples were investigated, and the characteristic activation energies which were associated with the rupture of H bonds were estimated. A dislocation-enhanced H solubility was found for deformed crystals, and macroscopic (mm) diffusion depths could be achieved. Hydrogenation was carried out by exposing crystals to H2 at 800C. As well as the desorption of H which was bound close to the Si surface, rupture of the H-H bonds of molecules which were stored in deformed crystals was observed. The storage of H2 molecules required the presence of dislocations or deformation-induced point defects, and the H-H binding energy ranged from 2.7 to 3.8eV. It was suggested that this energy variation probably arose from the differing local strains around dislocations. Atomic H was found to dominate the effusion kinetics.

Hydrogen Desorption from Crystalline Silicon and its Modification due to the Presence of Dislocations. C.Kisielowski-Kemmerich, W.Beyer: Journal of Applied Physics, 1989, 66[2], 552-8