THERMAL DIFFUSIVITIES OF THIN-FILMS MEASURED BY TRANSIENT THERMAL GRATINGS

Transient thermal gratings have been utilized for investigating heat d iffusion in thin films. The gratings were observed by either the displ acement technique or by thermoreflectance. Both observation modes allo w a quantitative determination of lateral diffusivities. Spatial resol ution in the mu m range can be obtained, even for films with large the rmal diffusivities. Results of thermal diffusivitiy measurements are p resented for thin Au-, Cr-, and Ni-films, sputtered onto the quartz su bstrates with different thicknesses between 100nm and 3 mu m.