On The Role Of The Interface Charge In Non-Ideal Metal-Semiconductor Contacts

TL;DR

This paper investigates how interface charge influences non-ideal behaviors in metal-semiconductor contacts, linking microscopic defect properties to macroscopic electrical characteristics through a simplified theoretical model.

Contribution

It introduces a model connecting interface disorder and defect density to bias-dependent interface charge, explaining non-ideality in metal-semiconductor contacts.

Findings

Interface charge depends on disorder, defect density, and barrier pinning.

Model predictions match experimental data on ideality factor and capacitance.

Provides a microscopic understanding of non-ideality origins.

Abstract

The bias dependent interface charge is considered as the origin of the observed non-ideality in current-voltage and capacitance-voltage characteristics. Using the simplified model for the interface electronic structure based on defects interacting with the continuum of interface states, the microscopic origin of empirical parameters describing the bias dependent interface charge function is investigated. The results show that in non-ideal metal-semiconductor contacts the interface charge function depends on the interface disorder parameter, density of defects, barrier pinning parameter and the effective gap center. The theoretical predictions are tested against several sets of published experimental data on bias dependent ideality factor and excess capacitance in various metal-semicoductor systems.