An in situ deep level transient spectroscopic technique was used to investigate n-type material which had been implanted with protons at low temperatures. Two signals, E3' and E3”, originated from H-related donor centres. The electron emission rates of the donors were similar, and the 2 signals were separable only because they were created and annealed out differently. In n-type samples, the centres transformed into negatively charged centres at 100 and about 65K, respectively. Both signals could be regenerated at 65K: E3' via the forward-bias injection of holes, and E3" via illumination with band-gap light under reversed-bias conditions. During E3' regeneration, long-range migration of H occurred. On the other hand, E3" regenerated without migration. In the space-charge layers of reverse-biased diodes, E3' converted into E3" with an activation enthalpy of 0.44eV in O-rich material. The E3" converted into E3' with an activation enthalpy of 0.72eV in O-poor material. The density of H sites which was associated with E3" was approximately equal to the O concentration, whereas the density of E3' sites was equal to about 1023/cm3. The results provided further evidence for the previous attribution of E3' to isolated H at a bond center site, and led to the attribution of E3" to bond-centered H which was perturbed by a nearby O atom. It was suggested that dilated Si-Si bonds, in the strain fields around impurities and defects, were trapping sites for H.

Bond-Centered Hydrogen in Silicon Studied by in situ Deep-Level Transient Spectroscopy K.Bonde Nielsen, B.Bech Nielsen, J.Hansen, E.Andersen, J.U.Andersen: Physical Review B, 1999, 60[3], 1716-28