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

Sotoodeh, M., Khalid, A.H. , Sheng, H., Amin, F.A., Gokdemir, T., Rezazadeh, A.A., Knights, A.P. and Button, C.C. (1999) Direct extraction and numerical simulation of the base and collector delay times in double heterojunction bipolar transistors. IEEE Transactions on Electron Devices, 46(6), pp. 1081-1086. (doi: 10.1109/16.766867)

Abstract

A new method is presented to evaluate the base and collector transit times, τB and τC 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 τB and τC 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

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Khalid, Dr Ata-Ul-Habib
• Authors: Sotoodeh, M., Khalid, A.H., Sheng, H., Amin, F.A., Gokdemir, T., Rezazadeh, A.A., Knights, A.P., and Button, C.C.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: IEEE Transactions on Electron Devices
• ISSN: 0018-9383