Native point defect analysis in non-stoichiometric GaAs: an annealing study

The electronic properties of MBE-grown GaAs at temperatures well below 400 degrees C are governed by its high concentration of native point defects. I t is vital for device applications to understand and control the point defe ct concentrations in this non-stoichiometric III-V compound. In this paper, we present a detailed analysis of the changes of the point defect concentr ations upon thermal annealing in both undoped and p-doped low-temperature-g rown GaAs (LT-GaAs). The temperature-dependent concentration of residual ar senic antisites (AS(Ga)) after annealing is shown. Also the annealing behav ior of the gallium vacancies (V-Ga) is investigated. Their role in the As d iffusion will be discussed. The thermal stabilization of As-Ga Will be demo nstrated in LT-GaAs : Be for annealing temperatures as high as 700 degrees C for 30 min. (C) 1999 Elsevier Science B.V. All rights reserved.