Thermal characterization of tungsten thin films by pulsed photothermal radiometry

Thermal conductivity and thermal interface resistance of tungsten thin films were investigated by means of pulsed photothermal radiometry. The experimental system based on a nanosecond pulsed laser and a high-speed IR photodetector is presented. Calibration of the IR defector is described. The thermal properties of the samples are identified by comparison with an analytical solution of the heat transfer equation for layered samples already presented in the literature. The experimental system enables investigation of micron and submicron thick metallic films. The investigated films were deposited by magnetron sputtering on iron substrates using two different deposition conditions. The measured thermal conductivity values ranged from 40 to 62 W.m(-1).K-1 and thermal contact resistances from 0.05 to 1.1 10(-8) m(2).K.W-1.