Influence of oxygen incorporation on beryllium-doped InGaAs grown by molecular beam epitaxy

InGaAs epitaxial layers have been doped with beryllium with concentrations ranging from 1016 to 5×1019 cm−3 as measured by secondary ion mass spectroscopy (SIMS). From electrical measurements we have observed that p-type layers presented a high degree of compensation, and for a doping level below 5×10−7 cm−3, they are often found to be n type. SIMS analysis shows that oxygen is responsible for such behavior. Beryllium doping leads to incorporation of a large amount of oxygen in the epitaxial layers. Investigations on the origin of oxygen incorporation show that it is extremely sensitive to the residual vacuum during the growth and can be reduced by decreasing arsenic pressure.