Analytical model of drain current of Si/SiGe heterostructure p-channel MOSFETs for circuit simulation

An analytical model of drain current of Si/SiGe heterostructure p-channel MOSFETs is presented. A simple polynomial approximation is used to model the sheet carrier concentration (p/sub s//sup H/) in the two-dimensional hole gas at the Si/SiGe interface. The interdependence of p/sub s//sup H/ and the hole concentration at the Si/SiO/sub 2/ interface (p/sub s//sup S/) is taken into account in the model, which considers current flow at both the Si/SiGe and the Si/SiO/sub 2/ interfaces. This model is applicable to compressively strained SiGe buried-channel heterostructure PMOSFETs as well as tensile-strained surface-channel PMOSFETs. The model has been implemented in SABER, a circuit simulator. The results from the model show an excellent agreement with the experimental data.