Photon-induced anisotropic oxidation along p-n junctions in AlxGa1−xAs-GaAs quantum well heterostructures

Data are presented demonstrating, in ‘‘wet’’ oxidation, anisotropic oxide formation at p-n junction edges in AlxGa1−xAs-GaAs quantum well heterostructures (QWHs). The QWH high gap AlxGa1−xAs upper confining layer is oxidized via H2O vapor at elevated temperatures (425–525 °C). The higher energy portion of ‘‘blackbody’’ radiation (the furnace ambient) at these temperatures generates sufficient electron-hole pairs to drive anodic oxidation at the edge of a QWH p-n junction. The anisotropic oxidation, on the p-type side of the junction, and possible reaction mechanisms are described.