Two-dimensional currents at semiconductor surfaces as resonances within the classical current equation

TL;DR

This paper investigates the logarithmic voltage profiles observed on semiconductor surfaces with two-dimensional currents, analyzing their origins and conditions within a simple accumulation and inversion layer model, and exploring their occurrence in three-dimensional samples.

Contribution

It provides a theoretical analysis of the logarithmic voltage profile phenomenon, highlighting conditions for its appearance and the influence of surface conductivity parameters.

Findings

Logarithmic voltage drops can occur in three-dimensional samples.

Surface conductivity at large distances depends on few key parameters.

The phenomenon varies between accumulation and inversion layers.

Abstract

Logarithmic voltage profile characteristic to two-dimensional current flows has been reported for several semiconductor surfaces. We analyse this phenomenon within a simple model of accumulation and inversion layers. Prompted by numerical analysis of several conductivity profiles we point out how the logarithmic voltage drop may appear in the case of three-dimensional samples. It may or may not be observed both for the accumulation and the inversion layers. Further, the numerical data suggest that the surface conductivity at large distances is governed by very few parameters.