Efficient Si Planar Doping in GaAs by Flow-Rate Modulation Epitaxy

During the growth of GaAs layers by flow-rate modulation epitaxy (FME), triethyl gallium and arsine are alternately supplied on the GaAs substrate. Thus, the Ga atomic surface and As atomic surface appear alternately at the growing surface. These atomic surfaces exhibit very different characteristics in capturing impurity atoms. By supplying 10% silane diluted with hydrogen gas at a flow-rate of 20 cc/min for one second, we have succeeded in obtaining extremely high Si planar doping levels with the maximum sheet carrier density of 1.1×10 13 cm -2 occurring at the low growth temperature of 550°C.