Base transit time of a heterojunction bipolar transistor (HBT) with Gaussian doped base under high-level of injection

Author

Islam, Shekh Md Mahmudul ; Chowdhury, M.I.B. ; Arafat, Yeasir ; Khan, Md Ziaur Rahman

Author_Institution

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

fYear

2012

fDate

15-16 March 2012

Firstpage

114

Lastpage

118

Abstract

Base transit time for an npn SiGe HBT has been analysed assuming Gaussian doped base considering doping dependent mobility. Band-gap narrowing (BGN) effects due to heavy doping, due to presence of Germanium and due to change in the density of states (DOS) have also been considered. The presence of Ge has been incorporated by using a different saturation velocity for the SiGe alloy. A generalized profile for Ge mole fraction distribution is used, where Ge profile variation has been illustrated by varying a single parameter for box, trapezoidal and triangular forms. Base transit time of SiGe HBT has been calculated for these three Ge profiles under high level of injection.

Keywords

Ge-Si alloys; carrier mobility; heterojunction bipolar transistors; semiconductor doping; BGN effects; Gaussian doped base; HBT; SiGe; band gap narrowing effects; base transit time; density of states; doping dependent mobility; heterojunction bipolar transistor; mole fraction distribution; profile variation; saturation velocity; Band gap narrowing; Base transit time; Density of states; Gaussian doping; HBT;

fLanguage

English

Publisher

ieee

Conference_Titel

Devices, Circuits and Systems (ICDCS), 2012 International Conference on

Conference_Location

Coimbatore

Print_ISBN

978-1-4577-1545-7

Type

conf

DOI

10.1109/ICDCSyst.2012.6188685

Filename

6188685