Base transit time of a Heterojunction Bipolar Transistor with Gaussian doped base

Author

Islam, S. M Moududul ; Arafat, Yeasir ; Chowdhury, Iqbal Bahar ; Khan, M. Ziaur Rahman ; Hassan, M. M. Shahidul

Author_Institution

Dept. of Electr. & Electron. Eng., United Int. Univ., Dhaka, Bangladesh

fYear

2010

fDate

18-20 Dec. 2010

Firstpage

127

Lastpage

130

Abstract

Base transit time for an npn SiGe HBT is calculated assuming Gaussian doped base and a generalized trapezoidal Ge profile considering field dependent mobility in excess to doping dependent mobility and diffusivity. Band-gap narrowing (BGN) due to heavy doping, due to presence of Ge and due to change in the density of states (DOS) are also considered. For presence of Ge, a different saturation velocity has been used. Ge profile variation has been incorporated by a single parameter. Base transit time of SiGe HBT is calculated and computed for different Ge contents. The calculated base transit time shows similar variations as found in literature for BJT.

Keywords

Ge-Si alloys; heterojunction bipolar transistors; semiconductor doping; Gaussian doped base; SiGe; bandgap narrowing; base transit time; density of states; doping dependent diffusivity; doping dependent mobility; field dependent mobility; generalized trapezoidal profile; heterojunction bipolar transistor; npn HBT; saturation velocity; Base transit time; Gaussian doping; HBT; bandgap narrowing; density of states; velocity saturation;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical and Computer Engineering (ICECE), 2010 International Conference on

Conference_Location

Dhaka

Print_ISBN

978-1-4244-6277-3

Type

conf

DOI

10.1109/ICELCE.2010.5700643

Filename

5700643