Graded-SiGe-base, poly-emitter heterojunction bipolar transistors

Author

Patton, Gary L. ; Harame, David L. ; Stork, Johannes M C ; Meyerson, B.S. ; Scilla, G.J. ; Ganin, E.

Author_Institution

IBM T.J. Watson Res. Center, Yorktown Heights, NY, USA

Volume

10

Issue

12

fYear

1989

Firstpage

534

Lastpage

536

Abstract

Si/Si/sub 1-x/Ge/sub x/ heterojunction bipolar transistors (HBTs) fabricated using a low-temperature epitaxial technique to form the SiGe graded-bandgap base layer are discussed. These devices were fabricated on patterned substrates and subjected to annealing cycles used in advanced bipolar processing. These devices, which have base widths under 75 mm, were found to have excellent junction qualities. Due to the small bandgap of SiGe, the collector current at low bias is ten times higher than that for Si-base devices that have a pinched base resistance. This collector current ratio increases to more than 40 at LN/sub 2/ temperature resulting in current gains of 1600 for the SiGe-base transistors despite base sheet resistances as low as 7.5 k Omega / Square Operator .<>

Keywords

Ge-Si alloys; heterojunction bipolar transistors; semiconductor technology; 75 nm; 77 K; HBTs; Si-Si/sub 1-x/Ge/sub x/ transistors; SiGe graded-bandgap base layer; annealing cycles; base widths; collector current ratio; current gains; heterojunction bipolar transistors; junction qualities; low bias; low temperature operation; low-temperature epitaxial technique; pinched base resistance; room temperature operation; sheet resistances; Annealing; Bipolar transistors; Chemical technology; Germanium silicon alloys; Heterojunction bipolar transistors; Microwave transistors; Photonic band gap; Silicon germanium; Substrates; Temperature;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.43131

Filename

43131