In-situ electrical characterization of co-evaporated Zr–Ti, Zr–V and Zr–Co thin getter films during thermal activation

Abstract

Sheet resistance of transition metal-based getter films was recorded during 1 h 15 min of activation at 250 °C by in situ 4-probes measurement under vacuum. Co-evaporated alloys of Zr–Ti, Zr–V and Zr–Co with different compositions were studied. Results show that resistivity and temperature coefficient of resistance (TCR) are linked and follow the Mooij rule. A gradual disorder in the structure was deduced from the less disordered—pure metals then Zr–Ti then Zr–V—to the highest, i.e. Zr–Co. A specific study of Zr–Ti showed that the grain size directly impacts TCR and resistivity of as-deposited film, and oxygen content after activation at 250 °C. For Zr–V and Zr–Co, the amorphous structure has to be taken into account and it has been shown that too much disorder in the structure is detrimental for sorption ability. The most oxidized films no longer follow the Mooij rule after annealing.