Electrical and mechanical behaviour of improved platinum on ceramic bolometers

摘要

Bolometers using Au meanders on a mica substrate under irradiation suffered severe degradation before 0.01 dpa. Therefore this work was undertaken to examine alternative more radiation resistant bolometer versions. Basic prototypes from CIEMAT with sputtered Pt meander sensors on Al_2O_3 and A1N ceramic substrates were tested during electron and neutron irradiation at CIEMAT and SCK/CEN Mol. Results up to 0.01 dpa showed acceptable behaviour of both substrates and better radiation resistance response of Pt compared with Au. However the electrical connection between terminals and meander was identified as a weak point of the design. In addition the electrical response of the sputtered metal films was observed to degrade at high temperatures ( ＞ 900 ℃) as a consequence of the discontinuity of the thin metal film and the formation of Pt islands.rnHere we report on an improved prototype, with reduced meander area, enhanced Pt film quality and adhesion, and better electrical connections. The improved bonding and hence stability of the meander was obtained by sputtering and thermally evaporating a Pt sensor on to polished surfaces of A1N and Al_2O_3 substrates. The thermal stability of the sputtered Pt deposit has also been followed using ESEM during in situ sample heating. After vacuum annealing at 400 ℃, these new prototypes were electrically characterized.