异质结晶体管的设计与性能

本文较详细地讨论了异质结晶体管的设计原理、材料选用和结构设计。在能带设计方面对宽发射区、缓变基区和多种收集区分别进行了讨论,比较了不同能带结构的优缺点。文章以晶体管的特征频率f_T和最高振荡频率f_(max)为例分析和比较了Ge/GaAs,Si/α-Si,GaAs/GaAlAs,InGaAsP/InP四种异质结晶体管的频率特性潜力。文章最后对目前常用的台面结构、平面结构、倒置结构作了介绍,并分析了它们的优缺点,简介了异质结的发展现状和发展方向。

Designs and Performances of HBTs

In this paper, the design principle of heterojunction bipolar transistors (HBTs), including energy band gap design and semiconductor material selection as well as device structure design, are discussed in more detail. The energy band design focuses on wide gap emitter, graded base and various type of wide gap collector. As an example of the material selection, the potentials of the cutoff frequency fT and the maximum frequency of oscillation fmax for Ge/GaAs, Si/a-Si, GaAs/GaAlAs and InGaAsP/InP HBTs are analyzed and compared. Finally, conventional mesa, planar and up-side-down structures for HBTs are analysed and compared for their advantages. The state -of-art and the new development of HBTs are briefly described as well.