Influence of etching parameters on the defect profile and the depth of damage of AlGaAs induced by ion beam etching

Abstract

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 photoluminescence (PL) measurements on specially prepared beveled sections of Al 0.35Ga 0.65As/GaAs MQW structures. The results reveal that the extension of the defect profile is not proportional to the energy of the nitrogen ions, i.e. the lower ion energy leads to a higher defect profile deep in the materal. The difference in both defect profiles can be explained by the different etching rates and defect diffusion coefficients. The high-energy etching leads to a higher defect concentration at the surface measured by RBS/channeling and in accordance with a simple model calculation.