Kinetics of {3 1 1} defect dissolution in silicon-on-insulator (SOI)

The reaction kinetics of {311} defect dissolution in SIMOX, SOITEC and bulk silicon materials have been investigated. The effects of implant energy and surface silicon thickness on the activation energy for {311} dissolution have been measured using quantitative TEM (QTEM). SOI wafers having surface silicon thickness of 750 and 1450Å were implanted with Si+ ions at 15-48.5keV, 1 × 1014cm-2. Furnace and RTA anneals were performed at temperatures ranging from 700 to 825 °C. Quantitative TEM was used to monitor the trapped interstitial dose in {311} defects. The activation energy for {311} dissolution was found to decrease as the surface silicon thickness decreased, suggesting a lower activation barrier as the implant damage approaches the surface silicon/buried oxide (BOX) interface. However, the 1450 Å SOI had similar dissolution kinetics to the bulk silicon for all of the implants studied suggesting the reduced activation barrier is likely due to recombination at the surface Si/BOX interface.