Direct Measurement of the Potential Spike Energy in AlGaAs/GaAs Single-Heterojunction Binolar Transistors
Journal
IEEE Electron Device Letters
Journal Volume
6
Journal Issue
8
Pages
431-433
Date Issued
1985
Author(s)
Abstract
A balanced two-step current transport theory, i.e., thermionic emission followed by Shockley diffusion, is applied to study the emitter-base (EB) potential spike energy in the AlGaAs/GaAs single-heterojunction bipolar transistor. It is found, surprisingly, that when the transistor is operated in the active region the I-V characteristics of the collector current (Ic) versus base-emitter applied voltage (VBE) exhibits an ideality factor of 1.237. This non-1kT transfer characteristics is due to the bias-dependent potential spike energy at the emitter-base heterojunction. The reverse I-Vcharacteristics of emitter current (IE) versus base-collector bias (FBC), however, shows the traditional 1kT behavior. The difference between lclEat the same applied voltage (VBE= VBC) determines the potential spike energy (ΔE). It turns out that ΔE/q = 0.19 (VBE- 0.48) where q is the unit charge. This indicates that the potential spike appears only when the applied voltage VBE> 0.48 V. © 1985 IEEE
SDGs
Type
journal article