摘要
本文根据MOS器件沟道区离子注入引起的衬底杂质非均匀分布情况，提出了一个简单的衬底杂质分布的近似．并以此导出了非均匀掺杂下开启电压的衬偏效应模型．模型中采用了一个双曲函数解决了在不同掺杂区域的边界处，电流（或开启电压）对衬偏VBS的导数的不连续问题，并可通过调整参数δ计及实际器件中衬底掺杂的缓变过程．本文还给出一个与村偏相关的短沟道效应公式，准确地反应了深亚微米器件衬偏效应减小的现象．模型计算的结果与数值模拟的结果十分一致．
A simple substrate-bias dependent threshold voltage model of deep-submicorn MOSFET with nonuniform doping substrate is presented. In this model, a new simplified substrate doping profile according to the channel implantation is assumed. We apply a hyperbola function to avoid the discontinuous problem at the boundary between different doping regions. By adjusting the parameters 3, the real gradual doping profile in the devices can be obtained. A substrate-bias dependent formula of short channel effect is also introduced which describes the reducing substrate-bias effect in deep-submicron devices. A good fitting has been achieved between the model and numerical simulation.
