基于二维电势分布的一种新型复合多晶硅栅LDMOS阈值电压模型

本文提出了一种新型的复合多晶硅栅LDMOS结构.该结构引入栅工程的概念,将LDMOST的栅分为n型多晶硅栅和p型多晶硅栅两部分,从而提高器件电流驱动能力,抑制SCEs(short channel effects )和DIBL(drain-induced barrier lowering).通过求解二维泊松方程建立了复合多晶硅栅LDMOST的二维阈值电压解析模型.模型考虑了LDMOS沟道杂质浓度分布和复合栅功函数差的共同影响,具有较高的精度.与MEDICI数值模拟结果比较后,模型得以验证.

Threshold Voltage Model of a Novel Dual Polysilicon Material Gate LDMOS Based on Two Dimensional Potential Distribution

A novel lateral double-diffused metal oxide semiconductor field effect transistor(LDMOSFET) structure,using an effective concept of dual Polysilicon material gate,is proposed.The conventional polysilicon gate applied in LDMOSFET is divided into S-gate and D-gate by gate engineering.The special gate structure can improve driveability,suppress SCEs(short channel effects) and screen DIBL(drain-induced barrier lowering).The threshold voltage model is solved by two dimensional(2D) Poisson's equation.The difference of workfunction and doping concentration distribution are also taken into account in the surface potential function.The results predicted by the model are compared with those obtained by 2D simulating to verify the accuracy of the proposed analytical model.