Observations of very fast electron traps at SiC/high-κ dielectric interfaces

Very fast interface traps have recently been suggested to be the main cause behind poor channel-carrier mobility in SiC metal–oxide–semiconductor field effect transistors. It has been hypothesized that the NI traps are defects located inside the SiO2 dielectric with energy levels close to the SiC co...

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Bibliographic Details
Main Authors: Arnar M. Vidarsson, Axel R. Persson, Jr-Tai Chen, Daniel Haasmann, Jawad Ul Hassan, Sima Dimitrijev, Niklas Rorsman, Vanya Darakchieva, Einar Ö. Sveinbjörnsson
Format: Article
Language:English
Published: AIP Publishing LLC 2023-11-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/5.0160287
Description
Summary:Very fast interface traps have recently been suggested to be the main cause behind poor channel-carrier mobility in SiC metal–oxide–semiconductor field effect transistors. It has been hypothesized that the NI traps are defects located inside the SiO2 dielectric with energy levels close to the SiC conduction band edge and the observed conductance spectroscopy signal is a result of electron tunneling to and from these defects. Using aluminum nitride and aluminum oxide as gate dielectrics instead of SiO2, we detect NI traps at these SiC/dielectric interfaces as well. A detailed investigation of the NI trap density and behavior as a function of temperature is presented and discussed. Advanced scanning transmission electron microscopy in combination with electron energy loss spectroscopy reveals no SiO2 at the interfaces. This strongly suggests that the NI traps are related to the surface region of the SiC rather than being a property of the gate dielectric.
ISSN:2166-532X