Title :
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
fDate :
3/1/1997 12:00:00 AM
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;
Journal_Title :
Electron Devices, IEEE Transactions on
