The threshold-voltage model of MOSFET devices with localized interface charge

Author

Jean, Yuh-Sheng ; Wu, Ching-Yuan

Author_Institution

Adv. Semicond. Device Res. Lab., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

44

Issue

3

fYear

1997

fDate

3/1/1997 12:00:00 AM

Firstpage

441

Lastpage

447

Abstract

A new analytic threshold-voltage model for a MOSFET device with localized interface charges is presented. Dividing the damaged MOSFET device into three zones, the surface potential is obtained by solving the two-dimensional (2-D) Poisson´s equation. Calculating the minimum surface potential, the analytic threshold-voltage model is derived. It is verified that the model accurately predicts the threshold voltage for both fresh and damaged devices. Moreover, the Drain-Induced Barrier Lowering (DIBL) and substrate bias effects are included in this model. It is shown that the screening effects due to built-in potential and drain bias dominate the impact of the localized interface charge on the threshold voltage. Calculation results show that the extension, position and density of localized interface charge are the main issues influencing the threshold voltage of a damaged MOSFET device. Simulation results using a 2-D device simulator are used to verify the validity of this model, and quite good agreement is obtained for various cases

Keywords

MOSFET; hot carriers; interface states; semiconductor device models; surface potential; 2-D device simulator; MOSFET; SUMMOS; built-in potential; damaged MOSFET device; drain bias; drain-induced barrier lowering; hot carrier effects; interface trap density; localized interface charge; screening effects; simulation results; substrate bias effects; surface potential; threshold-voltage model; two-dimensional Poisson equation; Charge carrier processes; Degradation; Electron traps; Hot carrier effects; Hot carriers; MOSFET circuits; Poisson equations; Substrates; Threshold voltage; Two dimensional displays;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.556154

Filename

556154