Analytical threshold voltage model for ultrathin SOI MOSFETs including short-channel and floating-body effects

Author

Adan, Alberto O. ; Higashi, Kenichi ; Fukushima, Yasumori

Author_Institution

Lab. of VLSI Dev., Sharp Corp., Nara, Japan

Volume

46

Issue

4

fYear

1999

fDate

4/1/1999 12:00:00 AM

Firstpage

729

Lastpage

737

Abstract

Short-channel effects (SCE) in ultrathin silicon-on-insulator (SOI) fully depleted (FD) MOSFETs are analyzed and an analytical model for threshold voltage, including the kink effect, is presented. The proposed model accounts for (1) a general nonuniform channel doping profile, (2) the drain-induced V_th- lowering enhancement resulting from the interaction of (a) impact ionization, (b) floating-body, and (c) parasitic-bipolar effects. Good agreement between the proposed model and experimental data is demonstrated. Impact ionization and floating-body effects dominate V_th lowering for drain voltages larger than V_dk≃B_i.λ_i/3, where B_i is the impact ionization coefficient, and λ_i is the impact ionization length, a structural parameter which, for a single-drain SOI MOSFET, coincides with the SCE characteristic length λ

Keywords

MOSFET; doping profiles; impact ionisation; semiconductor device models; silicon-on-insulator; Si; analytical threshold voltage model; drain-induced V_th-lowering enhancement; floating-body effects; general nonuniform channel doping profile; impact ionization length; kink effect; parasitic-bipolar effects; short-channel effects; single-drain transistor; ultrathin SOI MOSFETs; Analytical models; CMOS logic circuits; Doping profiles; Fluctuations; Impact ionization; Leakage current; MOSFET circuits; Semiconductor process modeling; Structural engineering; Threshold voltage;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.753707

Filename

753707