Direct extraction and numerical simulation of the base and collector delay times in double heterojunction bipolar transistors

Author

Sotoodeh, Mohammad ; Khalid, A.H. ; Sheng, Hong ; Amin, Farid A. ; Gokdemir, Tacar ; Rezazadeh, Ali A. ; Knights, Andy P. ; Button, Christopher C.

Author_Institution

Dept. of Electron. Eng., King´´s Coll., London, UK

Volume

46

Issue

6

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

1081

Lastpage

1086

Abstract

A new method is presented to evaluate the base and collector transit times, τ_B and τ_C in heterojunction bipolar transistors (BBT´s) from the phase and magnitude of the common-base current gain, α(ω), which itself was directly extracted from measured S-parameter data. The method is applied to InGaP/GaAs single and double HBT´s. A smaller cutoff frequency in the latter device is attributed to τ_B and τ_C due to two effects: trapping of electrons in the conduction band triangular barrier existing at the base-collector (B-C) heterojunction and smaller saturation velocity of electrons in InGaP as compared to GaAs. Finally, a new B-C design of InGaP/GaAs DNBT´s is proposed to partially compensate the transit time effects. Numerical simulation of the cutoff frequency demonstrates the superiority of the proposed structure for high-frequency applications

Keywords

III-V semiconductors; S-parameters; UHF bipolar transistors; delays; electron traps; gallium arsenide; gallium compounds; heterojunction bipolar transistors; indium compounds; microwave bipolar transistors; semiconductor device models; III-V semiconductors; InGaP-GaAs; S-parameter data; base delay times; collector delay times; common-base current gain; conduction band triangular barrier; cutoff frequency; double heterojunction bipolar transistors; electron trapping; high-frequency applications; numerical simulation; saturation velocity; transit times; Current measurement; Cutoff frequency; Data mining; Electrons; Gain measurement; Gallium arsenide; Heterojunction bipolar transistors; Numerical simulation; Phase measurement; Scattering parameters;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.766867

Filename

766867