Crystal surface stoichiometry and the Fermi level effects on outdiffusion of Si in GaAs
GaAs samples doped with Si to a concentration of approximately 2.7×1018 cm-3 were annealed at temperatures between 800 and 1000 °C for 3 to 20 hours under As-rich and As-poor conditions for Si outdiffusion which were then measured using the capacitance-voltage method employing an electrochemical profiler. The deduced Si diffusivity showed strong dependencies on the As4 vapor phase pressure, PAs(4), and on the electron concentration, n. When reduced to that under intrinsic conditions, activation enthalpies of 3.91 eV and 4.19 eV were obtained for As-rich and As-poor annealing cases, respectively. From these results, it is concluded that Si outdiffusion in GaAs is governed by the triply-negatively-charged Ga vacancies, VGa3-.
You, HM; Gosele, UM; Tan, TY
Materials Research Society Symposium Proceedings
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