Analysis of V-group molecules sticking to III-V compound surfaces

Previous experiments carried out with the reflection mass spectrometry [12-15] are used to choose an adequate physical model of V-group molecules interaction with III-V-compound surfaces from the set of the possible ones. Comparison to the experimental data shows that a physisorption state plays an important role in the As-4 molecule adsorption on GaAs, AlAs, and InAs surfaces. No evidence of such a state for As-2 molecules was found. On the basis of the data on specie-separated outgoing arsenic fluxes a simple model has been proposed for the analysis of arsenic molecules adsorption, desorption and incident arsenic beam reflection. The desorption rate constant and the maximum sticking coefficient of the arsenic molecules were determined from the experimental data of Brennan et al. [J. Vac. Sci. Technol. A 10 (1992) 33]. It was found that the desorption rate constant was dependent on the surface reconstruction. The results of calculations performed using this model are compared to the data on sticking coefficient and arsenic coverage of the surface obtained in the independent experiments.