DIFFUSION GROWTH OF OXIDE LAYERS ON GAAS SINGLE-CRYSTALS

The thermal surface oxidation of GaAs in dry O2 and in ambient air has been investigated in the temperature range 400-530°C. The studies were carried out using clean, polished (111) substrates. It was found that GaAs single-crystal wafers oxidized parabolically in dry O2 at temperatures from 400 to 450°C. Linear growth occurred at temperatures from 480 to 530°C both in dry O2 and in ambient air. Wagner and Grimley-Trapnell models of metal oxidation are used to identify the growth kinetics. The rate constants kp (parabolic) and k1 (linear) are temperature dependent and satisfy the Arrhenius relationships. The activation enthalpies Hp and H1 are evaluated. © 1990.