Impact of the Stress on the Sub-Micron N-Metal Oxide Semiconductor Field Effect Transistor Characteristics

R Marrakh,A Bouhdada

doi:10.1155/2001/18731

Abstract

In this paper, we present a drain current model for stressed short-channel MOSFET's. Stress conditions are chosen so that the interface states generated by hot-carriers are dominant. The defects generated during stress time are simulated by a spatio-temporal gaussian distribution. The parasitic source and drain resistances are included. We also investigate the impact of the interface charge density, generated during stress, on the transconductance. Simulation results show a significant degradation of the drain current versus stress time.

Highlights

The degradation of the NMOS transistors caused by hot carrier injection in the oxide and at the Si-SiO2 interface constitutes a potential limit to device scaling
In this work we devote our effort to develop a drain current model in relation with the defect density generated by the hot-carrier-injection during stress time
Simulation results allow us to deduce the impact of the stress time on the I-V characteristic and on the transconductance

Summary

INTRODUCTION

The degradation of the NMOS transistors caused by hot carrier injection in the oxide and at the Si-SiO2 interface constitutes a potential limit to device scaling. The transistor miniaturization entails the presence of higher electric fields that provide enough energy to the channel electrons which may generate electron-hole pairs through impact ionization These electrons and holes contribute to the gate and substrate current [1,2,3,4,5] and they may create damage in the oxide or in the interface near the drain junction [6,7,8]. In this work we devote our effort to develop a drain current model in relation with the defect density generated by the hot-carrier-injection during stress time. This defect density is modeled by a spatio-temporal distribution. Simulation results allow us to deduce the impact of the stress time on the I-V characteristic and on the transconductance

DRAIN CURRENT MODELING

III.1. Impact on los- Vos Characteristic

CONCLUSION