Model Equations of the Self-Consistent Surface-Potential MOS-Model HiSIM

Workshop on Compact Modeling Tutorial

Abstract

The drift-diffusion approximation based modeling for circuit simulation is becoming standard. Different from the conventional drift approximation, equations describing device characteristics are functions of surface potentials, which are obtained by solving the Poisson equation iteratively.

HiSIM (Hiroshima-university STARC IGFET Model) is the first commonly available MOSFET model, based on the complete drift-diffusion approximation. The iteration procedure became not critical in HiSIM due to the solving method developed.

This tutorial focuses on the concept of the drift-diffusion approximation and clarifies important equations used in HiSIM. Device physics applied for modeling 100nm-MOSFET technologies will be overviewed in an easily understandable way. All phenomena appear in advanced MOSFET are demonstrated to be modeled closely based on their physical origins, and thus resulting in a small number of model parameters.

Table of Contents

1. Introduction: correlation between device structure with impurity profile and device performance
2. Model Descriptions: derivation of equations based on the drift-diffusion approximation
3. Modeling Device Phenomena: origin of observed device phenomena and their modeling
4. RF Applications: carrier response under the high frequency operation and its modeling with noise
5. Parameter Extraction: concept of local optimization based on the drift-diffusion approximation