Anodic Oxidation and MOS Devices of GaAs and GaP

Chemical and electric properties of the anodic oxide films of GaAs and GaP are investigated under various annealing conditions. Analysis of the oxidation current proves that the oxide grows at constant field condition on p-GaAs and at constant resistivity condition on n-GaAs under the pseudo constant voltage biasing. Proper annealing improves C-V curves of a p-GaAs MOS diode to almost the ideal case, while the improvement is small for an n-GaAs diode. It is found that the change of the C-V and G-V curves is influenced by annealing temperatures rather than by annealing gases. Effects of the Bias-Temperature (BT) treatment are also shown.