Sputter deposition of thin films on different substrate materials analyzed by means of modulated IR radiometry

Modulated IR radiometry, which is usually applied to sputter-deposited thin films and coatings, to determine the thermal transport properties of the thin films, is applied in this work to analyze the effects of different substrate materials and the effects of the interface coating-substrate on the resulting multi-layer system. For this purpose, a small number of ZrN films of different thickness were deposited on different substrate materials (stainless steel, Si, and glass) and were analyzed with the help of modulated IR radiometry, using heating modulation frequencies in the range from 1Hz to 100kHz, allowing depth-resolved thermal measurement from the sub-micron range to the millimeter range. The effects of pre-treatment of the substrates and of the interface between thin films and substrate were also analyzed. Compositional and structural properties of the thin films were obtained by RBS, XRD, and SEM. Preliminary results on the effects of substrates of limited thickness and three-dimensional heat transport, at the transition from coatings of good thermal transport properties to substrates of low thermal transport properties, are reported. A biasing effect related to the deposition process was also identified.