异质结界面电荷对突变InP/InGaAs异质结双极晶体管热场发射影响研究

The impact of interface charges at the heterojunction on the carriers transport in abrupt InP/InGaAs heterojunction bipolar transistor

异质结界面电荷的存在改变了异质结的内建势,这引起了界面势垒尖峰高度和形状的扰动,从而使异质结界面载流子的输运产生相应的变化,最终导致异质结双极晶体管(HBT)性能的改变.基于热场发射-扩散模型,对异质结界面电荷对InP/InGaAs HBT性能的改变做了研究,得到结论是正极性的界面电荷有利于InP/InGaAs HBT的直流和高频特性的改善,而负极性的界面电荷则使器件的直流和高频特性变差.

The carriers transport at the base-emitter interface of abrupt heterojunction bipolar transistors （HBTs） is controlled by thermionic emission and tunneling, which depends on the form and height of the energy barriers. The interface charges at the heterojunction disturb the energy barriers, thus bringing about the change of the electrical characteristics of HBT. Based on thermionic-field-diffusion model which combines the dri^diffusion transport in the bulk of the transistor with the thermionic emission and tunneling at the interface, a conclusion can be drawn that the positive interface charges can improve the electrical characteristics of abrupt InP/InGaAs HBT, while the negative interface charges deteriorate the devices.