Five species (As, B, Ge, P, Si) were implanted, using MeV energies, into (100)-oriented n-type Czochralski material in order to form deep gettering layers for subsequent annealing. The samples were then contaminated with Cu by implanting the impurity into the rear face, and carrying out additional annealing. The resultant Cu depth distributions were measured by means of secondary ion mass spectrometry. A strong gettering of Cu atoms beyond the projected ion range, Rp, and the formation of a well-defined separate Cu gettering band therein, was found for P and As implantation. This was termed the trans-Rp effect. It arose from the presence of a significant number of defects in regions which were much deeper than Rp. Their gettering ability was higher than that of the extended defects around Rp, as the number of Cu atoms gettered beyond Rp was (especially in the case of P implants) much greater than that in the implanted gettering layer at Rp. These deep defects were not detected by transmission electron microscopy, and it was suggested that they were small interstitial clusters.

High-Energy Ion Implantation-Induced Gettering of Copper in Silicon Beyond the Projected Ion Range: the Trans Projected-Range Effect. Y.M.Gueorguiev, R.Kögler, A.Peeva, A.Mücklich, D.Panknin, R.A.Yankov, W.Skorupa: Journal of Applied Physics, 2000, 88[10], 5645-52. See also: Journal of Applied Physics, 2000, 88[11], 6934-6