The effects of base dopant outdiffusion and undoped Si/sub 1-x/Ge/sub x/ junction spacer layers in Si/Si/sub 1-x/Ge/sub x//Si heterojunction bipolar transistors

Author

Prinz, E.J. ; Garone, P.M. ; Schwartz, P.V. ; Xiao, X. ; Sturm, James C.

Author_Institution

Dept. of Electr. Eng., Princeton Univ., NJ, USA

Volume

12

Issue

2

fYear

1991

Firstpage

42

Lastpage

44

Abstract

The effects of base dopant outdiffusion and nominally undoped Si/sub 1-x/Ge/sub x/ spacer layers at the junction interfaces of Si/Si/sub 1-x/Ge/sub x//Si n-p-n heterojunction bipolar transistors (HBTs) have been studied. It has been found that small amounts of boron outdiffusion from heavily doped bases of nonabrupt interfaces cause parasitic barriers in the conduction band, which drastically reduce the collector current enhancement in the HBTs. Undoped interface spacers can remove the parasitic barriers, resulting in a strongly improved collector current enhancement.<>

Keywords

Ge-Si alloys; elemental semiconductors; heterojunction bipolar transistors; semiconductor materials; semiconductor technology; silicon; HBTs; Si-Si/sub 1-x/Ge/sub x/-Si; conduction band; effects of base dopant outdiffusion; heavily doped bases; heterojunction bipolar transistors; improved collector current enhancement; n-p-n transistors; nonabrupt interfaces; parasitic barriers; semiconductors; undoped Si/sub 1-x/Ge/sub x/ spacer layers; Bipolar transistors; Boron; Degradation; Doping; Electron emission; Germanium silicon alloys; Heterojunction bipolar transistors; Photonic band gap; Silicon germanium; Voltage;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.75698

Filename

75698