Effects of buried oxide thickness on electrical characteristics of LOCOS-isolated thin-film SOI MOSFETs

It is known that the electrical characteristics of thin-film SOI MOSFETs depend on many physical parameters, such as Si film thickness and process conditions. Several researchers have reported the effects of the buried oxide and its interface on redistribution of boron atoms (Crowder et al. 1993; Park et al. 1995). In this work, we have investigated the stress behaviour in the buried oxide (BOX) interface relative to BOX thickness and its effects on LOCOS-isolated thin-film SOI MOSFET (i.e. both n- and p-MOSFETs) characteristics by experiment and simulation. It was noted that thin-film SOI MOSFETs with a thin BOX show a higher threshold voltage and hole mobility than those with a thick BOX due to the silicon film stress.