Evaluation of thermal resistance at the silicon/diamond interface through infrared photothermal radiometry

Besides knowledge of thermal conductivities, information about the interfacial thermal resistances existing in layered systems such as power electronic packages is of primary importance. Indeed, thermal boundary resistances have a critical influence on the heat transfer process occurring between the layers. In this study, modulated infrared photothermal radiometry was employed to measure the thermal response of diamond films deposited on silicon substrates through laser-assisted combustion synthesis. The thermal resistance normal to the diamond/silicon interface was then estimated from the measurement of the phase and the amplitude of the thermal response. Preliminary results show that the layered diamond/Si system exhibits an interfacial thermal resistance of about 4×10^-8 K.W^-1. The technique developed in this study enables a precise evaluation of the thermal resistance at the diamond/silicon interface and is promising for various thermal management applications of diamond thin-films in optics, electronics, or mechanics.