Effects of nitridation on SiC/SiO$_2$ structures studied by hard X-ray photoelectron spectroscopy

TL;DR

This study uses advanced X-ray spectroscopy to investigate how nitridation improves the chemical quality of SiC/SiO₂ interfaces, crucial for power electronics, revealing defect passivation mechanisms.

Contribution

It provides new insights into the chemical processes of nitridation at SiC/SiO₂ interfaces using combined laboratory and synchrotron HAXPES techniques.

Findings

Nitridation passivates interface defects in SiC/SiO₂ structures.

Hard X-ray photoelectron spectroscopy reveals chemical changes due to nitridation.

Study enhances understanding of nitridation's role in improving device interfaces.

Abstract

SiC is set to enable a new era in power electronics impacting a wide range of energy technologies, from electric vehicles to renewable energy. Its physical characteristics outperform silicon in many aspects, including band gap, breakdown field, and thermal conductivity. The main challenge for further development of SiC-based power semiconductor devices is the quality of the interface between SiC and its native dielectric SiO$_2$. High temperature nitridation processes can improve the interface quality and ultimately the device performance immensely, but the underlying chemical processes are still poorly understood. Here, we present an energy-dependent hard X-ray photoelectron spectroscopy (HAXPES) study probing non-destructively SiC and SiO$_2$ and their interface in device stacks treated in varying atmospheres. We successfully combine laboratory- and synchrotron-based HAXPES to provide unique insights into the chemistry of interface defects and their passivation through nitridation processes.