Phosphorus site after CIRA implantation of type IIa diamond

A set of type IIa diamond crystals was processed by cold implantation and r apid annealing at 1050 degreesC ex situ annealing at 1400 degreesC and inve stigated by ESR measurement. The ESR spectra of CIRA and post-annealed samp les show an isotropic line at g = 2.003, a set of anisotropic hyperfine lin es, and a pair of isotropic hyperfine lines centred at g = 2.003 with Delta H = 28 G. The intensities of each signal increase with the implantation dos e. After the second annealing step the intensities of all signal was reduce d, excepted for the centre with DeltaH= 28 G which increases. This signal w as ascribed to a new centre related to phosphorus, probably neutral substit utional phosphorus. (C) 2001 Elsevier Science B.V. All rights reserved.