Characteristics of MOSFETs fabricated in silicon-on-insulator material formed by high-dose oxygen ion implantation

By implanting a dose of 6×1017 cm¿2 of 32O at 300 keV into a silicon wafer, a buried oxide layer is formed. Crystallinity of the silicon layer above the buried oxide layer is maintained by applying a high (>200°C) substrate temperature during the ion implantation process. A two-step anneal cycle is found to be adequate to form the insulating buried oxide layer and to repair the implantation damage in the silicon layer on top of the buried oxide. A surface electron mobility as high as 710 cm2/Vs has been measured in n-channel MOSFETs fabricated in a 0.5 ¿m-thick epitaxial layer grown on the buried oxide wafer. A minimum subthreshold current of about 10 pA per micron of channel width at VDS=2 V has been measured.