Studies of defects and annealing behavior of silicon irradiated with 70 MeV 56Fe ions

The effects of 70 MeV irradiation of iron ions in p-type silicon at fluences between 1 x 10(12) and 5 x 10(14) ions cm(-2) were investigated by high resolution X-ray diffraction (HRXRD), electron spin resonance (ESR) and current-voltage measurements. The irradiated samples were isochronally annealed in nitrogen ambient up to 973 K for 2 min using the rapid thermal annealing (RTA) system. The screw dislocation density of the annealed sample (5 x 101 4 ions cm(-2)) estimated at each stage of annealing from the broadening of the HRXRD peak was observed to change from 8.70 x 10(7) to 1.58 x 10(7) cm(-2) with increasing temperatures. The strain and stress parameters estimated at each stage of annealing using the FWHM of omega-scan clearly indicate relative trend towards the un-irradiated silicon sample. The electron spin resonance studies indicate the presence of the dangling bond state of silicon (Si equivalent to Si) and complex defects. The annealing at 873 K was found to be sufficient for complete removal of the defect centers induced due to irradiation. The I-V studies performed on the irradiated samples before and after annealing indicate that the defects created as a consequence of irradiation trap the charge carriers. (c) 2005 Elsevier B.V. All rights reserved.