The mean concentrations, CD, of aggregated vacancy-type point-defect structures in float-zone Si implanted with H+, B+, Si+, O+ and Ge2+ ions at energies between 0.45 and 4.0MeV were measured as a function of ion dose, φ, at depths of about half of the projected ion range, using beam-based positron spectroscopy. Adjusting φ to φA, using factors given by a computer code, gave the universal expression, CD(/cm3) = (2.79 x 1010)φA0.63. The value of CD could be estimated to within ±50% for MeV ions implanted for φA from 109 x 1013/cm2. This corresponded to an upper limiting dose which approached 1014/cm2 for 2MeV Si+ implantation.

Simple Expression for Vacancy Concentrations at Half Ion Range Following MeV Ion Implantation of Silicon. P.G.Coleman, C.P.Burrows, A.P.Knights: Applied Physics Letters, 2002, 80[6], 947-9