Samples of n-type crystalline material were exposed to 90MeV Si-ion fluences which ranged from 1.25 x 1014 to 5 x 1014/cm2. The disorder which was introduced in the surface region was studied by using grazing-angle X-ray diffraction and optical reflection spectroscopic techniques, while that in the bulk was studied by measuring the lifetime of the excess minority carriers which were generated by a 1MeV pulsed electron beam. In the surface region, as well as in the bulk, the number of induced lattice defects was found to increase with increasing ion fluence. The value of the damage coefficient, as estimated from the lifetime of the minority carriers, increased from 1.2 x 10-10 to 8.9 x 10-10cm2/s over the above range of ion fluences. The results indicated that 90MeV Si ions created an appreciable number of defects, in crystalline material, whose concentration increased from the surface to a projected range of about 31. At higher fluences, secondary defects were also produced in the bulk. Even at the highest fluence which was used, the energy which was deposited via electronic losses had no observable effect upon the annealing of the induced defects.

S.T.Chavan, P.S.Bhave, V.N.Bhoraskar, D.Kanjilal: Journal of Applied Physics, 1995, 78[4], 2328-32