Ternary alloy thin film of TiZrV for achieving extreme high vacuum environment

Ternary alloy films of elements Ti, Zr of IVB and V of VB show very surprising behavior in gettering and very helpful to achieve the extremely clean environment from residuals present inside a sealed system. For efficient gettering action, the superficial surface oxide which make the lm passive, need to reduce in lower oxides or in metallic state. In this paper a ternary alloy thin film of TiZrV has been prepared on SS substrate by co-sputtering of targets of Ti, Zr, V metal wires of purity 99.8% in Ar plasma. The cylindrical type DC-magnetron sputtering system has been used for preparation of the films. For studying the gettering properties of the film, it has been annealed in-situ at different temperatures under ultra high vacuum ambient and characterizes the film by XPS after each heating cycle. XPS results show that superficial surface oxides TiO₂, ZrO₂ and V₂O₅ of its constituents which were formed after the film exposed in atmosphere have been reduced to lower oxides of Ti, Zr and V and also in metallic after in-situ annealing. It has been also seen that carbide formed during the activation of the film remain on the surface. Using this film on big SS substrate, a getter vacuum pump has been developed and tested for creating Extreme High Vacuum of the level of 10^-12 mbar. The role of morphology of the film has been also studied. (author)