Gap states caused by oxygen precipitates and their hydrogen passivation inCzochralski silicon crystals

In order to investigate the gap states caused by the oxygen precipitation, we performed deep level transient spectroscopy measurements on silicon crys tals containing various types of oxygen precipitates. For all types of the oxygen precipitates, a new signal in the gap-state density was observed at about E-c - 0.25 eV, as well as the previously reported peak at about E-v 0.3 eV. Both peaks were attributed to the defect due to oxygen precipitati on. This distribution of the gap-state density is very similar to that of t he well-known P-b center originating from the dangling bond of a silicon at om at the interface between the silicon and silicon dioxide. These gap stat es were further found to be passivated by hydrogen, similarly to the case o f the P-b center.