Surface cleaning of C-doped p+ GaAs with hydrogen electron cyclotron resonance plasma

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