Growth of high-purity GaAs layers by molecular beam epitaxy

Abstract

High‐purity GaAs layers were grown by molecular beam epitaxy using carefully controlled procedures for source and substrate preparation as well as the growth itself. The layers grown without intentional doping were semi‐insulating with resistivities consistently greater than 10⁶ Ω cm. The layers doped with Si in the 10¹⁴ cm⁻³ range gave record Hall mobilities, the highest value being 140 000 cm²/Vs at 55 K with a net charge carrier concentration of 1×10¹⁴ cm⁻³. The results suggest that the use of prolonged growth period or AsH₃ source is not a necessary condition for high‐purity growth.