Silicon film thickness considerations in SOI-DTMOS

We study the body effect in silicon-on-insulator (SDI) devices to determine if enhanced drive currents can be obtained with a body bias equal to the supply voltage. We find that significantly enhanced drive currents are observed only when the film thickness is sufficiently large. We explain this phenomenon using two-dimensional (2-D) device simulations and conclude that a film thickness greater than 100 nm is required. This sets a criterion for SOI devices to be used as dynamic threshold MOSFETs.