The evolution of the interstitials and vacancies, formed during the implantation of Si crystals with protons and Cu ions, during annealing at 100 to 800C was investigated by means of photoluminescence measurements. In the case of samples annealed below 400C, only the familiar W and I3 center peaks were observed following proton and Cu implantation. Some 6 no-phonon photoluminescence peaks, thought to be due to interstitial clusters, were found between 1.2 and 1.4µm for samples that were heavily implanted with both protons and Cu ions; after annealing at between 500 and 600C. This indicated the existence of several self-interstitial clusters having a stability which lay between that of the W center and {311} defects. On the basis of the dependences of their photoluminescence intensities upon the densities of displaced atoms formed by implantation and upon the annealing temperatures, these clusters were suggested to be composed of larger numbers of self-interstitials than was the W center. In addition to these peaks (W, I3, new centers), some broad peaks which seemed to have several causes were observed after annealing the heavily implanted samples at between room temperature and 600C. They vanished completely upon annealing at 700C. Evolution of a photoluminescence peak at 1.376µm, which was and known to be due to {311} defects, was not observed following annihilation of the preceding peaks; that were presumed to be precursors of the {311} peak.

Evolution of Photoluminescent Defect Clusters in Proton- and Copper-Implanted Silicon Crystals during Annealing. M.Nakamura, S.Murakami: Journal of Applied Physics, 2003, 94[5], 3075-81