Deuterium effusion from crystallinen-type GaAs(Si)

Several experiments involving deuterium effusion are performed on ${\mathrm{Si}}_{\mathrm{Ga}}$-doped crystalline GaAs. The out-diffusion rates of deuterium are studied for different temperatures and durations of plasma treatment, and also, as functions of doping level, etch-back surface layer, heating rate, and prior isothermal anneals. We establish the correlation between the effusion spectra, the corresponding secondary-ion-mass spectroscopy depth profiles and infrared spectroscopy measurements. From a comparative analysis of the data obtained by these different techniques, we are able to identify several distinct bonding configurations that are ascribed to weak deuterium bonds near the surface due to plasma-induced defects, dopant-deuterium complexes, and diatomic molecular complexes. The strong influence of the prior annealings on the D-bonding states and their evolution rates is carefully investigated. A description of the effusion process is proposed and the role of the thermal rupture energy of the bonds is examined. Particular annealing-related aspects such as recovery of plasma-induced strain fields and passivation extent are also evidenced and commented on. Some estimates about the thermal stability of the suggested D-bonding configurations in the passivated material are reported and discussed.