Deviation From Proportional Relationship Between Emitter Charging Time and Inverse Current of Heterojunction Bipolar Transistors Operating at High Current Density

Author

Yamada, Masayuki ; Uesawa, Takafumi ; Miyamoto, Yasuyuki ; Furuya, Kazuhito

Author_Institution

Dept. of Phys. Electron., Tokyo Inst. of Technol., Tokyo, Japan

Volume

32

Issue

4

fYear

2011

fDate

4/1/2011 12:00:00 AM

Firstpage

491

Lastpage

493

Abstract

We investigated the relationship between the emitter charging time and the inverse current of heterojunction bipolar transistors. A proportional relationship assuming the Boltzmann approximation and constant capacitances is often used to separate the components of the total delay time; however, without the aforementioned assumption, the theoretical calculations show that the relationship is not proportional but has an intercept. This deviation causes a nonnegligible error in the results obtained at high current densities. Additionally, we show the possibility of reducing the total delay time beyond that inferred from the conventional linear characteristics by a high-current-density operation.

Keywords

approximation theory; heterojunction bipolar transistors; Boltzmann approximation; HBT; constant capacitances; conventional linear characteristics; emitter charging time; heterojunction bipolar transistors; high-current-density operation; inverse current; total delay time; Capacitance; Current density; Delay; Heterojunction bipolar transistors; Indium phosphide; Junctions; Neodymium; Emitter charging time; Fermi–Dirac distribution; heterojunction bipolar transistors (HBTs); high-current-density operation;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2011.2107497

Filename

5719625