Mechanism of compensation in heavily silicon-doped gallium arsenide grown by molecular beam epitaxy

Abstract

Silicon-doped GaAs grown by molecular beam epitaxy has been characterized by Hall measurements, infrared local vibrational mode (LVM) absorption, secondary ion and laser source mass spectroscopy. Highly doped samples with [Si]∼3×1019 cm−3 show only a low carrier concentration of 8×1017 cm−3. LVM spectroscopy shows that SiGa donors are compensated predominantly by [Si-X] complexes, where X has been assigned previously to a gallium vacancy (VGa). Other compensating impurities are not present in the layers at significant concentrations.