Surfactant effect of atomic H on Si incorporation in GaAs

The effect of atomic H on Si incorporation in GaAs was studied with different substrate orientations in molecular beam epitaxy process. It is found that with the irradiation of atomic H, the changeover As4/Ga flux ratios for the p- to n-type transition in (111)A and (311)A GaAs are shifted to higher values as if the effective surface As pressure is reduced. The Si-doped (100) GaAs grown at the same time shows n-type conductivity with the electrical activation of almost 100%. Photoluminescence measurements for (311)A samples show great influence by atomic H in the self-compensation region. The irradiation of atomic H helps to lessen the degree of self-compensation in the p-type side but seems to aggravate it in the n-type side of the self-compensation region.