Parasitic energy barriers in SiGe HBTs

Author

Slotboom, Jan W. ; Streutker, G. ; Pruijmboom, A. ; Gravesteijn, D.J.

Author_Institution

Philips Res. Lab., Eindhoven, Netherlands

Volume

12

Issue

9

fYear

1991

Firstpage

486

Lastpage

488

Abstract

Parasitic energy barriers can easily be introduced during processing. Measurements and calculations of experimental n-p-n HBTs (heterojunction bipolar transistors) are presented, showing that a parasitic conduction-band barrier at the base-collector junction reduces the collector current and the cutoff frequency. A simple analytical model explains the f/sub T/ degradation, caused by the reduction of the collector current and a pileup of minority carriers in the base. With the model the effective height and width of the barrier can also be derived from the measured collector current enhancement factor I/sub C/(SiGe)/I/sub C/(Si).<>

Keywords

Ge-Si alloys; conduction bands; heterojunction bipolar transistors; minority carriers; secondary ion mass spectra; semiconductor device models; semiconductor materials; SIMS profiles; SiGe-Si; analytical model; base-collector junction; collector current; collector current enhancement factor; cutoff frequency; minority carrier pileup; n-p-n HBTs; parasitic conduction-band barrier; parasitic energy barriers; Analytical models; Current measurement; Cutoff frequency; Degradation; Electron mobility; Energy barrier; Germanium silicon alloys; Heterojunction bipolar transistors; Photonic band gap; Silicon germanium;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.116926

Filename

116926