EFFECTS OF BURIED OXIDE STRESS ON THIN-FILM SILICON-ON-INSULATOR METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR

Thin-film silicon-on-insulator (SOI) device characteristics have been investigated in terms of stress in the buried oxide interface by both simulation and experiment. Bonded SOI wafer with a 400 nm buried oxide and SOI wafer with a 100 nm buried oxide which is made by implanted o xygen are used as a substrate for device fabrication. From the simulat ion, it is demonstrated that the 100 nm buried oxide has higher compre ssive stress than the 400 nm counterpart after the local oxidation of silicon process. With the highly compressive-stressed buried oxide, bo ron atoms may accumulate at the silicon side, especially at the silico n edge, under tensile stress so that these accumulated boron atoms inc rease threshold voltage of the edge channel. Therefore, it is found th at there is no hump of the drain current in the subthreshold drain cur rent-rate-voltage characteristics of thin-film SOI n-channel metal-oxi de-semiconductor field-effect transistors (MOSFET) with the highly com pressed buried oxide. (C) 1998 American Institute of Physics.