Mechanically strained Si-SiGe HBTs

Author

Yuan, F. ; Jan, S.-R. ; Maikap, S. ; Liu, Y.-H. ; Liang, C.-S. ; Liu, C.W.

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan

Volume

25

Issue

7

fYear

2004

fDate

7/1/2004 12:00:00 AM

Firstpage

483

Lastpage

485

Abstract

The current gain (β=I_C/I_B) variations of the mechanically strained Si-SiGe heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) devices are investigated experimentally and theoretically. The β change of HBT is found to be 4.2% and -7.8 under the biaxial compressive and tensile mechanical strain of 0.028%, respectively. For comparison, there are 4.9% and -5.0 β variations for BJT under the biaxial compressive and tensile mechanical strain of 0.028%, respectively. In HBT, the mechanical stress is competing with the compressive strain of SiGe base, inherited from the lattice misfit between SiGe and Si. The current change due to externally mechanical stress is the combinational effects of the dependence of the mobility and the intrinsic carrier concentration on strain.

Keywords

compressive testing; heterojunction bipolar transistors; semiconductor device measurement; semiconductor device testing; Si-SiGe; biaxial compressive strain; bipolar junction transistor; current gain variation; heterojunction bipolar transistor; intrinsic carrier concentration; lattice misfit; mechanical stress; tensile mechanical strain; Bipolar transistors; Boron; Capacitive sensors; Compressive stress; Germanium silicon alloys; Helium; Heterojunction bipolar transistors; Lattices; Silicon germanium; Tensile strain; BJT; Bipolar junction transistor; HBT; heterojunction bipolar transistor; mechanical strain;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2004.831223

Filename

1308427