Extremely high Be doped Ga 0.47In 0.53As growth by chemical beam epitaxy

Abstract

Beryllium-doped Ga 0.47In 0.53As was grown on InP to examine its doping characteristics by chemical beam epitaxy. A net hole concentration as high as 2 × 10 20 cm -3 was obtained with mirror-like surface morphology, while maintaining a constant growth temperature of 540 °C and a growth rate of 3.2 μm/h. Although surface degradation occured for samples doped higher than 2 × 20 20 cm -3, it was possible to dope in GaInAs up to 4.6 × 10 20 cm -3. How surface morphology became degraded is not this time. We also found that the Be incorporation rfficiency increased at lower growth temperatures and hence at lower growth rates, but the upper doping limit was less than that of greater growth rates. If is therefore important to consider growth rates to obtain high hole concentration. Hall mobilities of doped samples were measured and they linearly depended to hole concentration. These mobilities were lower than those of MBE grown samples and slightly higher than GSMBE grown samples. In spite of high doping concentrations, lattice-mismatch ( Δa a > 5 × 10 -4 ) was not observed.