非简并半导体中费米能级的简单计算及应用

A simple calculationand application of the Fermi level of non-degenerated semiconductors

本文基于半导体器件物理的教学实践,从非简并半导体的玻尔兹曼统计规律出发,总结了载流子浓度变化与费米能级之间的简明规律,即室温下当载流子浓度改变1个数量级,则其对应的费米能级改变60 meV.为深入理解该规律,本文通过对非平衡状态下的准费米能级、半导体的功函数、MIS结构的阈值电压及PN结的内建电势等实例,对重要参数进行了分析和计算.该规律有助于学生在学习过程中加深感性认识,培养和提高分析和设计半导体器件的能力.

Based on the teaching practice of semiconductor device physics,a simple law between the carrier concentration and the Fermi level from the Boltzmann statistical law of non-degenerated semiconductor is summarized in this paper.When its carrier concentration is changed by one order of magnitude,its corresponding Fermi level should change by 60 meV.In order to understand this law deeply,this paper analyzes and calculates the important parameters,such as the quasi-Fermi level in non-equilibrium state,the work function of semiconductor,the threshold voltage of an MIS structure and the built-in potential of a PN junction.This facilitates students not only to deepen their perceptual knowledge in the process of mastering the physical knowledge of semiconductor devices,but also to develop and enhance the ability in analyzing and designing semiconductor devices.