3D defect distribution induced by focused ion beam irradiation at variable temperatures in a GaAs/GaAlAs multi quantum well structure.

In this study, we propose a new characterisation method of the damage distribution using a GaAs/GaAlAs multi quantum well structure (MQW). Three quantum wells are used as high sensibility sensors, in relation to the damage created during the FIB irradiation through photoluminescence (P.L.) intensity measurements. We have compared the effect of a Ga+ focused ion beam irradiation on the MQW structure, which was kept either at room temperature, or near the liquid nitrogen temperature (80 K) during the bombardment. The surface ion dose was kept constant at 10(15) ions/cm(2). No subsequent annealing was performed. Irradiated samples were characterised using low temperature (1.7 K) and spatially resolved photoluminescence experiments.