GETTERING OF IRON IN SILICON-ON-INSULATOR WAFERS

Gettering of Fe in silicon-on-insulator material has been investigated on both the bonded and separation by implantation of oxygen (SIMOX) p latforms. Reduction of electrically active iron in intentionally conta minated and annealed wafers has been measured by deep level transient spectroscopy. These data, coupled with structural characterization tec hniques, such as transmission electron microscopy and preferential che mical etching, provide evidence that structural postimplantation damag e below the buried oxide (BOX) in SIMOX wafers is an effective site fo r gettering of iron with the iron gettering efficiency varying with th e SIMOX processing. Gettering was not observed in bonded wafers, and t he lower BOX interface did not provide any iron gettering in either bo nded or SIMOX wafers. (C) 1997 American Institute of Physics.