Effect of native oxide on the interface property of GaAs MIS structures

Interface native oxide has been found to cause anomalous frequency dispersion of capacitance in the accumulation region of n-GaAs MIS structures. Sputter etching by nitrogen is effective to remove the native oxide layer and obtain normal C-V characteristics by probably reducing surface-state density. The present results indicate that native oxide would not be essentially suitable for passivation of GaAs with low surface-state density.