Band offset induced threshold variation in strained-Si nMOSFETs

Author

Goo, Jung-Suk ; Xiang, Qi ; Takamura, Yayoi ; Arasnia, Farzad ; Paton, Eric N. ; Besser, Paul ; Pan, James ; Lin, Ming-Ren

Author_Institution

Technol. Dev. Group, Adv. Micro Devices Inc., Sunnyvale, CA, USA

Volume

24

Issue

9

fYear

2003

Firstpage

568

Lastpage

570

Abstract

Due to the offset in the valence band, strained-Si nMOSFETs exhibit a -100 mV threshold shift and 4% degradation of the subthreshold slope per each 10% increase of Ge content in the relaxed SiGe layer. The correlation between the threshold shift and strained layer thickness is investigated based on device simulations. In a certain range of the strained-Si layer thickness, the threshold and subthreshold slope change gradually, posing a concern of larger device parameter variation. A larger threshold distribution is observed in devices fabricated with a strained layer thickness comparable to the depletion depth.

Keywords

MOSFET; elemental semiconductors; silicon; Si; SiGe relaxed layer; strained Si nMOSFET; strained layer thickness; subthreshold slope; threshold voltage shift; valence band offset; Capacitive sensors; Degradation; Electron mobility; Germanium silicon alloys; MOSFETs; Medical simulation; Silicon germanium; Stability; Strain control; Threshold voltage;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2003.815431

Filename

1224520