PbTiO/sub 3/ thin films for pyroelectric detection

Due to its high pyroelectric coefficient, low permittivity and relatively low piezoelectric coefficients, lead titanate is an important candidate for use in pyroelectric detectors. Sol-gel processing of lead titanate thin films, in combination with micro-machining of silicon substrates, is being used for the development of low-cost infra-red detectors with properties equivalent to existing "bulk" or single crystal devices. Here we report on some aspects of the sol-gel chemistry, the optimisation of the pyroelectric figure of merit and the fabrication and characterisation of an infra-red detector, consisting of two pyroelectric elements on a micro-machined SiO/sub 2/-Si/sub 3/N/sub 4/ membrane.