Changes in the photoluminescence intensity were used to monitor defect penetration during focussed ion beam implantation at various temperatures. It was found that both the depth and lateral extent of damage were reduced when the sample temperature was changed from 300 to 80K. This result was used to demonstrate that rapid diffusion of non-equilibrium defects took place in the irradiated sample. It was found that this diffusion was highly anisotropic; with a lateral diffusion length that was 10 times greater than that in the depth direction. The results were interpreted in terms of radiation-enhanced diffusion.

Evidence of depth and lateral diffusion of defects during focused ion beam implantation C.Vieu, J.Gierak, M.Schneider, G.Ben Assayag, J.Y.Marzin: Journal of Vacuum Science and Technology B, 1998, 16[4], 1919-27