双极场引晶体管:Ⅳ.短沟道飘移扩散理论(双MOS栅纯基)

本文描述双极场引晶体管(BiFET)短沟道解析理论,用解析理论分别计算飘移扩散电流.上月文章用单项电化电流描述飘移扩散电流.正如那篇文章里,两维晶体管分成两个区域,源区和漏区.每区在特定外加端电压下既可为电子或空穴发射区又可为电子或空穴收集区.把两维无缺陷Shockley方程分离为两个以表面势为参变量的一维方程,并运用源区和漏区界面处电子电流和空穴电流连续性,得到在源区和漏区内解析方程.典型BiFET包括薄纯基上两个等同金属氧化物硅(MOS)栅.用图形提供实用硅基和氧化层厚度范围内,随直流电压变化,输出和转移电流和电导总量,电子沟道与空穴沟道飘移扩散分量,和两区电学长度.描述两区短沟道理论相对一区长沟道理论偏差.

The Bipolar Field-Effect Transistor:IV.Short Channel Drift-Diffusion Current Theory(Two-MOS-Gates on Pure-Base)

This paper gives the short channel analytical theory of the bipolar field-effect transistor (BiFET) with the drift and diffusion currents separately computed in the analytical theory. As in the last-month paper which represented the drift and diffusion current by the single electrochemical (potential-gradient) current, the two-dimensional transistor is partitioned into two sections, the source and drain sections, each can operate as the electron or hole emitter or collector under specific combinations of applied terminal voltages. Analytical solution is then obtained in the source and drain see-tions by separating the two-dimensional trap-free Shockley Equations into two one-dimensional equations parametrically coupled via the surface-electric-potential and by using electron current continuity and hole current continuity at the bound-ary between the emitter and collector sections. Total and the drift and diffusion components of the electron-channel and hole-channel currents and output and transfer conductances, and the electrical lengths of the two sections are computed and presented in graphs as a function of the D. C. terminal voltages for the model transistor with two identical and con-neeted metal-oxide-silicon-gates (MOS-gates) on a thin pure-silicon base over practical ranges of thicknesses of the silicon base and gate oxide. Deviations of the two-section short-channel theory from the one-section long-channel theory are described.