Base transit time in abrupt GaN/InGaN/GaN HBT´s

Author

Chiu, Shean-Yih ; Anwar, A.F.M. ; Wu, Shangli

Author_Institution

Dept. of Electr. & Syst. Eng., Connecticut Univ., Storrs, CT, USA

Volume

47

Issue

4

fYear

2000

fDate

4/1/2000 12:00:00 AM

Firstpage

662

Lastpage

666

Abstract

Base transit time in an abrupt GaN/InGaN/GaN HBT is reported. Temperature and doping concentration dependence of low field mobility is obtained from an ensemble Monte Carlo simulation. Base transit time, τ_b, decreases with increasing temperature. The low temperature τ_b is dominated by the diffusion constant or, in other words, transport within the neutral base region. However, at elevated temperatures base transit time is dependent more upon the base-collector junction velocity or, in other words, by the transport across the heterointerface. τ_b increases with In-mole fraction showing a stronger dependence at lower temperatures. Unity gain current cut-off frequency, f_T, is a strong function of temperature and base doping concentration. An f_T of 20 GHz is obtained for a 0.05 μm HBT

Keywords

III-V semiconductors; Monte Carlo methods; carrier lifetime; carrier mobility; gallium compounds; heterojunction bipolar transistors; indium compounds; minority carriers; semiconductor device models; wide band gap semiconductors; GaN-InGaN-GaN; abrupt GaN/InGaN/GaN HBT; bandgap narrowing; base doping concentration; base transit time; base-collector junction velocity; carrier degeneracy; diffusion constant; doping concentration dependence; ensemble Monte Carlo simulation; heterointerface transport; linear interpolation; low field mobility; neutral base region transport; temperature dependence; unity gain current cut-off frequency; Cutoff frequency; Gallium nitride; Heterojunction bipolar transistors; Optical devices; Photonic band gap; Semiconductor device doping; Temperature dependence; Thermal factors; Tunneling; Wide band gap semiconductors;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.830977

Filename

830977