A complex heterostructure to achieve a single-crystalline MgO film on GaAs(001)

A single-crystalline MgO film was grown on GaAs(001) by constructing a comp lex heterostructure with two alkali halide buffer layers. The growth temper ature was decreased to 150 degrees C as compared with direct growth of MgO on GaAs(001). Electron energy loss spectrum of the grown film agreed well w ith that of bulk MgO, indicating that surface stoichiometry was maintained. The structure was stable up to 600 degrees C against heating in UHV condit ion. The concept of a complex heterostructure will help fabrication of func tional oxide layers on GaAs substrates and lead to oxide/semiconductor inte grated devices.