Electron surface scattering kernel for a plasma facing a semiconductor

TL;DR

This paper develops a new electron surface scattering kernel based on invariant embedding, accounting for microphysics at the interface, and demonstrates its effectiveness for modeling plasma interactions with semiconductors like silicon and germanium.

Contribution

It introduces a novel scheme for constructing an electron surface scattering kernel that incorporates interface microphysics within a randium-jellium model, applicable to various materials.

Findings

Emission yields match experimental data well.

Kernel effectively models electron backscattering at semiconductor interfaces.

Applicable to dielectrics and metals.

Abstract

Employing the invariant embedding principle for the electron backscattering function, we present a scheme for constructing an electron surface scattering kernel to be used in the boundary condition for the electron Boltzmann equation of a plasma facing a semiconducting solid. The scheme takes the solid's microphysics responsible for electron emission and backscattering from the interface within a randium-jellium model into account and is applicable to dielectrics and metals as well. As an illustration, we consider silicon and germanium, describing the interface potential by a Schottky barrier and including impact ionization across the energy gap as well as scattering on phonons and ion cores. The emission yields deduced from the kernel agree well enough with measured data to support its use in the electron boundary condition of a plasma facing silicon or germanium.