Formation and depth distribution of optically active centers in diamond implanted with high energy xenon ions

Abstract

The depth distributions of the spectral parameters of Raman and luminescence features of diamond implanted with Xe ions of an energy 167 MeV have been studied in as-irradiated state and after post-irradiation annealing. The Raman data show that the distribution of radiation defects in the as-irradiated layer follows the nuclear stopping power of the ions. It has been found that the two major mechanisms determining the distribution of intensity of the luminescence centers are the quenching due to crystal lattice damage and the instantaneous heating due to intense electronic stopping. It has been shown that the strong nuclear stopping at the end of the ion penetration produces a highly disordered buried layer. The atomic structure of this layer completely loses its crystallinity for ion fluences above 3 × 1014 cm−2. This atomic structure does not collapse into graphite during high temperature annealing and can be regarded as amorphous diamond. It has been shown that the post-irradiation annealing produces secondary radiation defects far deeper than the depth of the ion penetration. This deep defect production is explained by the dislocations propagating from the disordered layer into the diamond bulk during heating.