ELECTRON-BEAM-INDUCED PATTERN ETCHING OF ALGAAS USING AN ULTRATHIN GAAS OXIDE AS A RESIST

Electron-beam (EB)-induced pattern etching of AlxGa 1-xAs (0≤x≤0.7) is described. An ultra-thin GaAs oxide at the surface of a GaAs/AlGaAs heterostructure wafer is used as a resist film. The GaAs oxide resist can be selectively removed by EB irradiation in a Cl 2 ambient, which results in pattern etching of GaAs/AlGaAs. The etch rate of AlGaAs is examined as functions of substrate temperature, AlAs mole fraction, and EB flux. The results indicate that pattern etching is realized in the AlAs mole fraction range of 0≤x≤0.7.