Heavy carbon doping of GaAs grown by solid-source molecular-beam epitaxy

We study the incorporation of carbon in GaAs at doping levels beyond 1019 cm−3 grown by conventional solid-source molecular-beam epitaxy. The correlation of Hall effect measurements at 77 and 300 K and of double crystal x-ray diffractometry allows us to determine the fraction of carbon incorporated on As sites acting as acceptors. These experiments reveal the onset of compensation at the highest doping levels of 5×1019 cm−3.