Neutralisation of point defects in Ge and GaAs by hydrogen incorporation.

Abstract

Deep level transient spectroscopy has been used to observe the passivation of copper-related centres in Ge, y-radiation induced centres in Ge and residual defects in GaAs by reaction with atomic hydrogen. Data are presented on the efficiency of passivation as a function of the duration and temperature of the exposure to hydrogen. A 3-hour exposure in a H plasma at 300oC passivated >90% of the copper centres in Ge to a depth of ~80 μm; 3 hours at 250oC passivated 3 x 1015 donor defects cm-3 to a depth of ~1.1 μm in GaAs. An estimate of 3.5 x 10-9 cm2 s-1 at 300oC was obtained for the diffusion coefficient of H in Ge; at 225oC the corresponding number for GaAs is estimated to be ~3 x 10-13 cm2 s-1.