考虑二维量子力学效应的MOSFET解析电荷模型

Analytical Charge Mode l for MOSFETs with 2-D Quantum Mechanical Effects

在亚 5 0 nm的 MOSFET中 ,沿沟道方向上的量子力学效应对器件特性有很大的影响。基于 WKB理论 ,考虑MOSFET中该效应对垂直沟道方向上能级的影响 ,引入了其对于阈电压的修正。在此基础上 ,对沟道方向的子带作了抛物线近似 ,从而建立了一个考虑二维量子力学的电荷解析模型。根据该模型 ,得到二维量子力学修正和沟道长度以及其他工艺参数的关系。与数值模拟结果的比较表明 ,该解析模型的精度令人满意 ,并且得出以下结论 :二维量子力学效应使阈电压下降 ,并且在亚 5 0 nm的 MOSFET中 ,这个修正不可忽略。

In sub-50-nanomet er(nm)MOSFETs,the Quantum Mechanical(QM) effects,particularly along the channel,h ave a significant influence on device ch aracteristics.Based on the WKB theory,th e QM effects in the transport direction of a MOSFET are taken into account to re vise the energy levels in the carrier co nfinement direction.This semi-analytical scheme introduces a threshold voltage s hift,which is then used to establish a f ully analytical 2-D QM charge model with the usage of p arabolic approximation to subband edge p rofiles and numerical fitting.The relati on of 2-D QM corrections to channel leng ths and other material parameters is asc ertained.Comparing to numerical 2-D QM s imulation,the correction must not be ign ored in sub-50 nm MOSFETs and the fully- analytical charge model renders satisfac tory results.