Study of threshold voltage modeling for small-scaled strained Si nMOSFET

In this paper, based on the distribution of electric field in the channel which follows the Guass Law, an analytical expression of Quasi-2D threshold voltage model for strained Si nMOSFET with Polycrystalline SiGe gate was established. With this model, the variation threshold voltage with its design physical and geometric parameters can be predicted, such as Ge content, oxide thickness, doping concentration, gate length, and drain bias. The validity of the model was proved by ISE TCAD simulation. This model is significant for the design of high performance strained Si nMOSFET.