SURFACE CLEANING OF C-DOPED P-CYCLOTRON-RESONANCE PLASMA( GAAS WITH HYDROGEN ELECTRON)

We report surface cleaning of C-doped p+-GaAs epilayers with hydrogen electron cyclotron resonance plasma. Native oxides on the surface of t he p+-GaAs layer can be removed at a very low substrate temperature of 150-degrees-C. In addition, carrier concentrations decrease after cle aning at about 300-degrees-C, which is attributed to the hydrogenation of carbon acceptors caused by hydrogen plasma exposure. A cleaning te mperature of about 400-degrees-C, a cleaning time of about 5 min, and microwave power of about 30 W appear to be optimum for the regrowth pr ocess.