Copper-rich complexes in irradiated silicon

Abstract

Only copper-related deep-level centers are produced by room-temperature MeV-electron irradiation in silicon doped with a high concentration of mobile interstitial copper atoms. In oxygen-lean FZ-Si, the well-known CuPL centers of four copper atoms show up in the DLTS, Laplace-DLTS, and photoluminescence measurements. In oxygen-rich Cz-Si, two new centers appear due to the irradiation at the expense of the CuPL defect. Reaction kinetics analysis correlates the new defects with oxygen, copper, and the irradiation-induced vacancy. The new defects are annealed at temperatures of 150–250 °C and, after passing through two more new configurations, are transformed into CuPL. The strong similarities to CuPL suggest that all four new defects are CuPL-like complexes of four copper atoms perturbed by a nearby oxygen.