An investigation was made of the radiation-enhanced diffusion of defects during reactive ion-beam etching using the multiple quantum-well probe technique. During low-energy (less than 1keV) Ar+ ion bombardment, illumination with light that had an energy which was above the band-gap was found to reduce substantially the photoluminescence efficiency of multiple quantum-well samples, relative to those which were not laser-illuminated. The degradation of the luminescence efficiency increased with the intensity of the light. Illumination with light that had an energy that was below the band-gap produced a slight increase in the damage profiles. This observation of enhanced defect diffusion due to optical radiation suggested that, in the ion-assisted etching of semiconductors, the generation of excess electron-hole pairs and their subsequent recombination could play a large role in the propagation of defects into the substrate.

C.H.Chen, D.G.Yu, E.L.Hu, P.M.Petroff: Journal of Vacuum Science and Technology B, 1996, 14[6], 3684-7