Langmuir evaporation from the (100), (111A), and (111B) faces of GaAs

Abstract

We have measured the Langmuir evaporation of Ga and As from the (100), (111A), and (111B) faces of GaAs above and below the congruent evaporation temperature Tc. We have found that Tc is lowest for the (111B) face and highest for the (111A) face. These differences can be understood in terms of the different lifetimes of surface Ga on these faces. Furthermore, we have deduced that the evaporation processes are the rate limiting steps in the decomposition of GaAs. Below Tc, decomposition is controlled by the evaporation of Ga; above Tc it is controlled by the evaporation of As. © 1976.