Data reduction in 3 omega method for thin-film thermal conductivity determination

The 3 omega method has been proven to be very useful for determining the th ermal conductivity of thin films and their substrates. Several simplificati ons are often used in determining the thermal conductivity of the films bas ed on the experimentally measured 3 omega signal. These simplifications, ho wever, have limited range of applicability. In this work, we present a deta iled analysis and mathematical modeling of the 3 omega method applied for d ifferent experimental conditions. Effects considered include the finite sub strate thickness, anisotropic nature of the film and substrate thermal cond uctivity, the film-substrate thermal property contrasts, the effect of heat capacitance of the heater, and the effect of thermal boundary resistance. Several experimental results are analyzed using the models presented. This work shows that the 3 omega method can be extended to a wide range of sampl e conditions, with anisotropic conductivities in both the substrate and the film, and with small film-substrate conductivity contrast. (C) 2001 Americ an Institute of Physics.