Sputtered thin films of CuBr for ammonia microsensors: morphology, composition and ageing

Sensitive and selective ammonia sensors were realised by sputter depositing a CuBr film on copper interdigitated electrodes. The effect of the self bias voltage on the composition and morphology of the films was analysed. Films deposited with a self bias voltage above 400 V are well adapted to sensor application since they show a large specific area. Ageing of the films is related to copper diffusion from the electrodes into an originally sub-stoichiometric Cu1−xBr film.