Use of superlattices to realize inverted GaAs/AlGaAs heterojunctions with lowhyphen;temperature mobility of 2times;106cm2/Vthinsp;s

摘要

Reproducible realization of high quality inverted interfaces (GaAs on AlGaAs) grown by molecular beam epitaxy is reported. Effective use of thin‐layer GaAs/AlAs superlattices in place of an AlGaAs barrier was made to reduce the number of impurities and the roughness at these interfaces. The low‐temperature (&bartil;4 K) mobility for electrons at these interfaces is as high as 2×106cm2/V s for an electron density of &bartil;5×1011cm−2—a factor of four improvement over the highest mobility reported for inverted interfaces.