INFLUENCE OF ETCHING PARAMETERS ON THE DEFECT PROFILE AND THE DEPTH OF DAMAGE OF ALGAAS INDUCED BY ION-BEAM ETCHING

The influence of the dry etching process parameters on the ion induced damage profile was investigated by nitrogen ion beam etching (IBE) of AlGaAs at two different ion energies by spatial resolved confocal pho toluminescence (PL) measurements on specially prepared beveled section s of Al0.35Ga0.65As/GaAs MQW structures. The results reveal that the e xtension of the defect profile is not proportional to the energy of th e nitrogen ions, i.e. the lower ion energy leads to a higher defect pr ofile deep in the material. The difference in both defect profiles can be explained by the different etching rates and defect diffusion coef ficients. The high-energy etching leads to a higher defect concentrati on at the surface measured by RBS/channeling and in accordance with a simple model calculation.