A new theoretical approach to adsorption-desorption behavior of Ga on GaAssurfaces

We propose a new theoretical approach for studying adsorption-desorption be havior of atoms on semiconductor surfaces. The new theoretical approach bas ed on the ab initio calculations incorporates the free energy of gas phase; therefore we can calculate how adsorption and desorption depends on growth temperature and beam equivalent pressure (BEP). The versatility of the new theoretical approach was confirmed by the calculation of Ga adsorption-des orption transition temperatures and transition BEPs on the GaAs(001)-(4 x 2 )beta2 Ga-rich surface. This new approach is feasible to predict how adsorp tion and desorption depend on the growth conditions. (C) 2001 Elsevier Scie nce B.V. All rights reserved.