N. Watanabe et al., SURFACE CLEANING OF C-DOPED P-CYCLOTRON-RESONANCE PLASMA( GAAS WITH HYDROGEN ELECTRON), Journal of applied physics, 73(12), 1993, pp. 8146-8150
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.