Authors:
Sandro Rao
1
;
Elisa D. Mallemace
1
;
G. Cocorullo
2
;
L. Dehimi
3
;
4
and
Francesco G. Della Corte
1
Affiliations:
1
Department of Information Engineering Infrastructures and Sustainable Energy (DIIES), Università Mediterranea, 89122, Reggio Calabria, Italy
;
2
Dipartimento di Ingegneria Informatica, Modellistica, Elettronica e Sistemistica (DIMES), Università della Calabria, 87036, Rende, Cosenza, Italy
;
3
Faculty of Material Science, University of Batna, 05000 Batna, Algeria
;
4
Laboratory of Metallic and Semi-conducting Materials (LMSM), University of Biskra, BP 145, 07000 Biskra, Algeria
Keyword(s):
Optically-Controlled SiC Power MOSFET, Temperature Monitoring, Integrated-Fabry-Perot Cavity, Junction Temperature.
Abstract:
The temperature-dependent optical properties of silicon carbide (SiC), such as refractive index and reflectivity, have been used for a direct monitoring of the junction temperature of a power MOSFET. In particular, the optical response of a 4H-SiC MOSFET-integrated Fabry-Perot cavity to temperature changes has been investigated through parametric optical simulations at the wavelength of 450 nm. The reflected optical power exhibited oscillatory patterns caused by the multiple beam interference for which the MOSFET epilayer, between the gate-oxide and the doped 4H-SiC substrate, acts as a Fabry-Perot etalon. These results were used to calculate the refractive index change and, therefore, the optical phase shift of ∆φ= π/2 corresponding to a temperature variation that can be considered as a warning for the device “health”. In practical applications, the periodic monitoring of the optic spectrum at the interferometric structure output gives an essential information about the device opera
ting temperature condition that, for high power operations, may lead to device damages or system failure.
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