Native‐oxide masked impurity‐induced layer disordering of AlxGa1−xAs quantum well heterostructures

Data are presented showing that the native oxide that can be formed on high Al composition AlxGa1−xAs (x≳0.7) confining layers on AlyGa1−yAs‐AlzGa1−zAs (y≳z) superlattices or quantum well heterostructures serves as an effective mask against impurity diffusion (Zn or Si), and thus against impurity‐induced layer disordering. The high quality native oxide is produced by the conversion of high Al composition AlxGa1−xAs (x≳0.7) confining layers, which can be grown on a variety of heterostructures, via H2O vapor oxidation (≳400 °C) in an N2 carrier gas.