Hole trap investigations in supplemental oxygen SIMOX wafers by opposite channel based charge injection

摘要

It is well known that excess silicon exists in the buried oxide of SIMOX wafers, and that its presence introduces a variety of carrier traps at increased densities, as compared to thermal SiO/sub 2/. To combat this, a supplemental oxygen implantation has been applied to finished SIMOX wafers for the reduction of excess Si in the BOX. Previous results from UV and VUV electron injection, and X-ray cryogenic irradiation studies on SIMOX supplemental versus control wafers have indicated a reduction in both electron and hole trap levels for supplemental material. However, practical difficulties in performing hole injection with these techniques (requirement of a vacuum, low injection fluences, cryogenic temperatures, and mixed carrier generation/transport) invite the need for additional hole injection techniques to fully characterize the BOX. The work presented here uses the recently discovered opposite channel based charge injection technique which makes it now possible to inject "pure" hole pulses into the buried oxide, and thus to study the hole traps.