基于二维电势的超短沟道MOSFET亚阈值电流模型

随着器件工艺的更新。亚阈值电流对MOSFET的亚阔值特性的影响越来越大，但是目前的计算均是基于一维或者准二雏电势模型，计算量小但是误差大。基于二维电势模型，使用最小二乘法将二维电势解析式转化为二次抛物线方程，并用泰勒级数展开法计算得到二维电势的指数函数积分。并且考虑在沟道超短的情况下，热电子发射电流已经无法忽略，因而考虑了热电子发射电流并联的影响，最终得到了适用于超短沟道的精确的亚阈值电流模型。通过将计算结果与Medici仿真结果对比，验证了该模型能够准确模拟超短沟道下的MOSFET在亚阚值区的电流。

Sub-threshold Current Model for the Ultra Short Channel MOSFETs Based on the 2-D Potential Model

Decreased MOSFETs device dimension makes the sub-threshold current seriously affect the threshold characteristics,which results in the need of a more accurate sub-threshold current model. The calculation of current is also based on the 1-D or quasi-2-D potential model which has less calculation but obvious errors. In this paper,the 2-D potential model converts to the quadratic parabolic equation by using the least square method and the exponential integral of 2-D potential has been solved by the Taylor series expansion method. The model of the sub-threshold current for Ultra Short Channel MOSFETs is presented and the thermionic emission current is considered as well. Comparing the Medici simulation results with the calculated value, it is shown that the model can accurately simulate the sub-threshold current of ultra short channel MOSFETs.