TRASPORTO DI CALORE ATTRAVERSO UN’INTERFACCIA: UN PROBLEMA CLASSICO RIVISITATO IN CHIAVE MODERNA

I describe a set of computational experiments using molecular dynamics simulations, showing that the interface between two solid materials can be described as an autonomous thermodynamical system. By making use of the Gibbs description for such an interface, I discuss a robust nonequilibrium thermodynamics theoretical framework providing information about its corresponding thermal boundary resistance. In particular, I show that the termal resistance of a junction between two pure solid materials can be regarded as an interface property, depending solely on the interface temperature.

Evaluation of the Impact of Al Atoms on SiO2/ SiC Interface Property by Using 4H-SiC n+-Channel Junctionless MOSFET

To investigate the impact of Al atoms on channel mobility at SiO2/SiC interface, we fabricated the junctionless metal-oxide-semiconductor field-effect transistors (MOSFETs), in which thin n+-SiC epitaxial layers with and without Al+ ion implantation were used as a channel, and compared their electrical characteristics. The effective mobility (meff) of n+-channel junctionless MOSFET without Al doping was estimated to be 14.9 cm2/Vs, which is higher than inversion-mode MOSFET fabricated with the same gate oxidation condition (3.1 cm2/Vs). The meff values of the MOSFETs with low Al doping concentration (5´1017 and 1´1018 cm-3) were almost the same as that of Al-free MOSFET, and the device with the highest Al doping (5´1018 cm-3) exhibited slight mobility degradation of about 15% compared to the other devices. Hall mobility in thick n+ layer with the highest Al doping was also slightly degraded, suggesting that Al atoms in the channel are not the major cause of degraded SiO2/SiC interface property.