Analytical modeling of base transit time for a Si1−yGey heterojunction bipolar transistor

Author

Arafat, Yeasir ; Khan, Md Ziaur Rahman ; Hassan, M. M Shahidul

Author_Institution

Dept. of EEE, Bangladesh Univ. of Eng. & Technol. (BUET), Dhaka, Bangladesh

fYear

2009

fDate

25-27 Dec. 2009

Firstpage

358

Lastpage

361

Abstract

An analytical model for base transit time of an exponentially doped base npn Si_1-yGe_y HBT has been developed. The model is valid in all levels of injection before the onset of Kirk effect. In this analysis, bandgap-narrowing effect, high-injection effect, carrier velocity saturation at the base edge of the base collector junction and doping dependent mobility are incorporated. It is found that base transit time depends on the Ge profiles in the base. The increase of Ge content for the same profile results in a decrease of transit time. Results of this work are compared with results available in literature.

Keywords

heterojunction bipolar transistors; silicon compounds; Kirk effect; Si_1-yGe_y; bandgap-narrowing effect; base collector junction; base transit time; carrier velocity saturation; doping dependent mobility; heterojunction bipolar transistor; high-injection effect; Analytical models; Current density; Doping; Electron mobility; Equations; Germanium silicon alloys; Heterojunction bipolar transistors; III-V semiconductor materials; Semiconductor process modeling; Silicon germanium; Base transit time; HBT; SiGe; high injection;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices and Solid-State Circuits, 2009. EDSSC 2009. IEEE International Conference of

Conference_Location

Xi´an

Print_ISBN

978-1-4244-4297-3

Electronic_ISBN

978-1-4244-4298-0

Type

conf

DOI

10.1109/EDSSC.2009.5394245

Filename

5394245