A study on the high-temperature subthreshold slope in SOI MOSFETs

In this paper, the validity of a classical expression for the subthreshold swing in SOI MOSFETs is revised for high-temperature conditions. Using numerical simulation, it is demonstrated that at high temperatures (above 150/spl deg/C) the depletion approximation is no longer valid, and the free carriers must be taken into account in the determination of the effective substrate capacitance. Another correction must be introduced into the classical expression to account for the inversion layer broadening caused by lowering the surface electric field in a weak inversion region with temperature.