亚90 nm沟道MOSFET亚阈值状态下二维电势和阈值电压的半解析模型

Abstract

A A 2D semi-analytical model for electric potential and threshold voltage of the sub-90 nm channel MOSFET in subthreshold state is presented in this paper. First, a de nite problem is given according to the physical model of the Short Channel MOSFET in sub-threshold state, and then the transcendental equations obtained by using the connected condition of oxide layer and space charge region are expanded by the charac- teristic function. The results are linear algebraic equations about unknown quantities. The 2D electric potential expressions of oxide layer and space charge region, depletion thickness and threshold voltage are obtained by the model. The model is free of adapter parameters, its calculation amount is small, the equation discretion is avoided and the result is as accurate as the numerical solution. The potential distribution, surface potential, depletion thickness and threshold of the MOSFET whose channel length is shorter than 90 nm have been calculated in this paper. It is shown that the calculated results are highly coincident with the 2D numerical simulations.