Energy dependence and depth distribution of dry etching-induced damage in III/V semiconductor heterostructures

We have investigated the depth distribution, energy dependence, and the effect of the angle of incidence of ion beam etching (IBE) induced damage. Our technique is based on the partial etching of the upper GaAlAs barrier of a GaAs single quantum well (SQW) layer. The optical emission of the SQW at low temperatures is used as a local probe for the created damage. The dependence of the quantum efficiency on the etch depth can be described by a Gaussian depth distribution with a typical decay length of 5.6 nm and a non-Gaussian long range tail. Our measurements show a strong dependence of the dry etch damage on the angle of incidence of the ion beam and on the sample orientation.