Ultra-Low Damage Chemical Etching of GaAs with a Novel Ion Beam Source

Abstract

ABSTRACTA novel ion beam source has been successfully used in both a CAIBE and RIBE configuration, with chlorine as the chemically active gas, to achieve GaAs etching a rates of around 0.1 µm/hour. The energy of species within the beam from the source is estimated at 10 - 25eV. Under these conditions it can be expected that little or no penetration into the GaAs lattice occurs and that the principle origin of lattice disruption, prior to etching, is chemical; a low damage GaAs etching process results. The source, however, gives rise to a coating, derived from the source liner, which must be washed from all etched samples. The presence of such a coating is likely to be the origin of the slow etch rate achieved. After removal of the coating, smooth, mirror like etched surfaces are apparent. These surfaces perform very well when Schottky diodes are constructed from them showing no deviation from the behaviour of control samples.