ANALYTICAL 2-DIMENSIONAL MODELING FOR POTENTIAL DISTRIBUTION AND THRESHOLD VOLTAGE OF THE SHORT-CHANNEL FULLY DEPLETED SOI (SILICON-ON-INSULATOR) MOSFET

A two-dimensional analytical model for fully depleted Sol MOSFETs is presented. An extensive study of potential distribution in the silicon film is carried out for non-uniform doping distribution and extended to find an expression for threshold voltage in the sub micrometer region. The results so obtained are verified with experimental data. The present model calculates a critical gate voltage (for short channel fully depleted SOI devices) beyond which gate losses its control on drain current. The advantages of SOI MOSFETs over the bulk counterparts are explained on the basis of drain induced barrier lowering [DIBL]. It is also shown that the threshold voltage for the thin film SOI MOSFET is less than that of bulk MOSFET The short-channel effects, DIBL and threshold voltage reduction, are well predicted in the present model.