摘要
重掺杂禁带变窄效应引起异质结导带、价带带阶的扰动,从而使突变HBT异质结界面势垒的形状和高度发生了变化,这将对电流传输特性产生重要的影响.基于热场发射-扩散模型,对这一现象进行了深入的研究.得到的结论是:异质结界面势垒的扰动引起内建势的变化对电流影响的重要性远大于其引起隧道效应发生区域的变化,这是由于内建势的变化对电流的影响反映在指数项;因此对于突变HBT,精确考虑禁带变窄在导带与价带之间的分布对于器件性能的分析是非常重要的.
Heavy impurity doping leads to bandgap narrowing （BGN） and this causes perturbations to the value of the band offsets at the hetero-interface. As a result, the form and height of energy barriers in abrupt HBT is disturbed, which changes the value of the current flowing through its interfaces. The analysis is based on the thermionic field-diffusion model which combines the drift- diffusion transport in the bulk of the transistor with the thermionic emission and tunneling at the base-emitter interface. The calculations reveal a more important role to the transport of carriers played by the modification of the built-in potential than that of the range of barrier energies available for tunneling because the impact of the built-in potential on the current is exponential. Therefore, it is important for a better description of the currents to use an accurate dopant-dependent BGN distribution model between bands.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第5期2890-2894,共5页
Acta Physica Sinica
基金
国家重点基础研究发展计划(973计划)(批准号:2003CB314901)
高等学校博士学科点专项科研基金(批准号:20020013010)资助的课题~~
关键词
HBT
能带带阶
内建势
隧穿因子
HBT, band offsets, built-in potential, tunneling factor
