GAP STATES CAUSED BY OXYGEN PRECIPITATION IN CZOCHRALSKI SILICON-CRYSTALS

Deep level transient spectroscopy measurements have been made on both n- and p-type silicon crystals containing various types of the oxygen precipitates to investigate the associated gap states. A new signal in the gap- state density was observed at about E-c - 0.25 eV, as well a s the previously reported peak at about E-upsilon + 0.3 eV. Both peaks are attributed to a defect generated by oxygen precipitation. The obs erved distribution of the gap- state density is very similar to that o f the well-known P-b center due to a dangling bond of a silicon atom a t the interface between the silicon and silicon dioxide at the surface of the sample. The measured gap states could be passivated by hydroge n, as found for the P-b center. (C) 1998 American Institute of Physics . [S0021-8979(98)08120-1].