The influence of deposition parameters on Ti/Pt film growth by confocal sputtering and the temperature dependent resistance behavior using SiOx and Al2O3 substrates

Abstract

Abstract This paper presents the influence of sputtering power and pressure on microstructural growth and morphology of Ti/Pt films and their electrical properties for possible applications in thin film thermal electrical devices. For these applications a high temperature coefficient of resistance near to that of the bulk material is aspired to. Films deposited by a confocal sputtering arrangement showed at a high Ar pressure of 8 Pa columnar growth and a rough surface, contrary to films produced at 0.5 Pa. An increase in pressure and a decrease in power resulted in a higher electrical conductivity and in a higher temperature coefficient of resistance (TCR). This electrical behavior correlates to the film's micro-structure. Furthermore, the influence of two different substrate materials such as thermally oxidized Si and Al 2 O 3 ceramics on the electrical properties of the films and on the resulting crystalline film growing is presented. Ti/Pt films deposited on oxidized (1 0 0)-orientated Si showed a textured film growth with a preferred Pt(1 1 1) peak contrary to the deposition on Al 2 O 3 substrates. Films deposited on Al 2 O 3 substrates also have a preferred (1 1 1) peak, but a polycrystalline structure. On the basis of these structural and crystalline investigations we want to discuss the resistivity and TCR behavior after the annealing processes.