Defect Profiling of Oxide-Semiconductor Interfaces Using Low-Energy Muons

TL;DR

This study demonstrates the use of low-energy muon spin rotation (LEμSR) to analyze and distinguish defect profiles and structural changes at oxide-semiconductor interfaces with nanometer depth resolution.

Contribution

It introduces a novel application of LEμSR for depth-resolved defect profiling at oxide-semiconductor interfaces, specifically for Si and SiC, with comparative analysis of different oxide growth methods.

Findings

LEμSR can distinguish oxide and semiconductor layers at nanometer scale.

Oxidation causes measurable structural changes at interfaces.

Different oxide growth methods influence defect formation.

Abstract

Muon spin rotation with low-energy muons (LE{\mu}SR) is a powerful nuclear method where electrical and magnetic properties of surface-near regions and thin films can be studied on a length scale of $\approx$\SI{200}{\nano\meter}. In this work, we show the potential of utilizing low-energy muons for a depth-resolved characterization of oxide-semiconductor interfaces, i.e. for silicon (Si) and silicon carbide (4H-SiC). Silicon dioxide (SiO$_2$) grown by plasma-enhanced chemical vapor deposition (PECVD) and by thermal oxidation of the SiO$_2$-semiconductor interface are compared with respect to interface and defect formation. The nanometer depth resolution of {\mu}allows for a clear distinction between the oxide and semiconductor layers, while also quantifying the extension of structural changes caused by the oxidation of both Si and SiC.