Reduction of residual doping in molecular-beam epitaxial GaAs

Abstract

Unintentionally doped GaAs molecular beam epitaxial layers were grown using MBE equipment developed for research purposes. The process of surface treatment of the GaAs substrates is described. The MBE grown layers were characterized using temperature dependent Hall effect measurements, and low temperature photoluminescence spectroscopy. The occurrence of unintentional doping elements (C and Mn) are studied too. A novel method is proposed to reduce the amount of unintentional C resulting in an estimated concentration of C less than about a few times 10¹⁴ cm^-3.