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

Autor: Arnar M. Vidarsson, Axel R. Persson, Jr-Tai Chen, Daniel Haasmann, Jawad Ul Hassan, Sima Dimitrijev, Niklas Rorsman, Vanya Darakchieva, Einar Ö. Sveinbjörnsson
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: APL Materials, Vol 11, Iss 11, Pp 111121-111121-7 (2023)
Druh dokumentu: article
ISSN: 2166-532X
DOI: 10.1063/5.0160287
Popis: 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.
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