Effect of high temperature annealing on resistivity and temperature coefficient of resistance of sputtered platinum thin films of SiO2/Pt/SiOx interfaces

Abstract The influence of high temperature annealing up to 800∘C on electrical resistivity and temperature coefficient of resistance of magnetron sputtered platinum films were investigated experimentally and theoretically. Highly adherent platinum films were manufactured on silicon oxide interfaces without using additional adhesion layers like titanium or tantalum. Such platinum films can be extremely useful for the fabrication of microelectromechanical sensors. X-ray diffraction studies exhibit grain sizes in the range of 39 nm for the as-deposited case to 162 nm after annealing at 800 ∘C. Thereby film resistivity values decrease from 16.8 ± 0.4 µΩ cm to 12.7 ± 0.2 µΩ cm and temperature coefficient of resistance values increase from 2180 ppm/K to 2810 ppm/K. A good accordance to the model of Mayadas and Shatzkes for resistivity as well as Tellier and Tosser for temperature coefficient of resistance could be found. The reflection coefficient for electrons at grain boundaries is extracted for both models.