Thermal resistance of interfaces in AlN-diamond thin film composites

The effective thermal conductivity of single and multilayer AlN/diamond composite films deposited on silicon substrate with a planar interface is determined experimentally. As a result of the small thickness and the good crystalline quality of the AlN and diamond films, the contribution to the effective thermal resistivity from the films remained very small and enabled the evaluation of the thermal barrier resistance associated with the interfaces. The interfacial thermal resistance of AlN/Si, diamond/Si, and AlN/diamond interfaces was evaluated from the experimental measurements of the effective thermal conductivity of the layered structures. The results show that amorphous regions formed along the interfaces are responsible for high thermal resistance in the layered structures. Modeling of the interfacial thermal resistance has been carried out to explain the effective thermal conductivity of the single and multilayer AlN/diamond composite films in terms of the microstructure of the interfaces. (C) 2002 American Institute of Physics.