Thermal diffusivities of thin films measured by transient thermal gratings

Abstract

Transient thermal gratings have been utilized for investigating heat diffusion in thin films. The gratings were observed by either the displacement technique or by thermoreflectance. Both observation modes allow a quantitative determination of lateral diffusivities. Spatial resolution in the µm range can be obtained, even for films with large thermal diffusivities. Results of thermal diffusivity measurements are presented for thin Au-, Cr-, and Ni-films, sputtered onto the quartz substrates with different thicknesses between l00nm and 3µm.