Passivation of bulk and surface defects in GaAs grown on Si substrate by radio frequency phosphine/hydrogen plasma exposure

The effects of PH₃/H₂ plasma exposure on GaAs grown on Si substrate (GaAs/Si) were investigated. It found that incorporation of P atoms in H₂ plasma not only hydrogenated the defect-related recombination centers of GaAs/Si epilayer, but also phosphidized the surface region of GaAs/Si epilayer by forming a phosphidized layer. Electron beam-induced current measurement directly proved that the defect-related dark spot density was effectively reduced by adding P atoms into the pure H₂ plasma. In addition, PH₃/H₂ plasma exposure greatly increased the minority carrier lifetime properties and decreased the saturation current of the GaAs p⁺-n junction structure grown on Si substrate.