A combination of high-resolution Laplace deep-level transient spectroscopy and direct capture cross-sectional measurements was used to investigate whether deep electronic states related to interstitial-type defects introduced by ion implantation originated from point or extended defects, prior to any annealing. n-type Si was implanted with doses of 109/cm2 of Si, Ge or Er, and comparison was made with proton- and electron-irradiated material. When measured by Laplace deep-level transient spectroscopy at 225K, the region of the implant thought to contain mostly vacancy-type defects exhibited a complex spectrum with 5 closely spaced defect-related energy levels, with energies close to Ec-0.4eV. The region nearer the tail of the implant, which should be dominated by interstitial-type defects, exhibited a simpler Laplace deep-level transient spectroscopy spectrum with three closely spaced levels being recorded, again with energies centered on

EC-0.4eV. Annealing at 180C did not completely remove any of the defect peaks, suggesting that the energy levels were not due to the simple vacancy-P center. Direct electron capture cross-section measurements revealed that the defects in the tail of the implanted volume, prior to any annealing, were not simple point defects, as they exhibited non-exponential capture properties. This was attributed to the presence of extended defects in this region. By contrast, defects with the same activation energy in proton- and electron-irradiated Si exhibited point-defect-like exponential capture.

High Resolution Electrical Studies of Vacancy-Rich and Interstitial-Rich Regions in Ion-Implanted Silicon. N.Abdelgader, J.H.Evans-Freeman: Journal of Applied Physics, 2003, 93[9], 5118-24