Native-oxide-masked Si impurity-induced layer disordering of AlxGa1−xAs-AlyGa1−yAs-AlzGa1−zAs quantum-well heterostructures

Abstract

Data are presented showing that the native oxide that can be formed on high Al composition Al_xGa_1−xAs (x≳0.7) confining layers commonly employed on Al_xGa_1−xAs‐Al_yGa_1−yAs‐Al_zGa_1−zAs (y≳z) superlattices or quantum‐well heterostructures serves as an effective mask against Si diffusion, and thus impurity‐induced layer disordering. The high‐quality native oxide is produced by the conversion of high‐composition Al_xGa_1−xAs (x≳0.7) confining layers via H₂O vapor oxidation (≳400 °C) in N₂ carrier gas.