CALIBRATION OF THE MULTIPLE QUANTUM-WELL PROBE TECHNIQUE FOR DRY-ETCH-INDUCED DAMAGE ANALYSIS

The multiple quantum well (MQW) probe technique has provided information of the depth distribution of dry-etch-induced damage. The observed changes in the quantum well cathodoluminescence intensities or peak positions have been uniquely attributed to the dry etching process. There are indications, however, that this premise may not be justified for some applications. Two studies are described, which we have carried out to establish critical calibrations of the MQW probe technique. A slow, carefully controlled wet etch of the starting MQW probe structure allowed us to observe a reduction in luminescence intensity of quantum wells located less than 20 nm from the surface. The other study reveals that the thicknesses and relative ordering of the quantum wells may influence the interpretation of the MQW data.