Pyroelectric thin film sensor arrays integrated on silicon

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Abstract
Sol-gel deposited Pb(Ti,Zr)O3 thin films have been used to integrate pyroelectric arrays on silicon. The arrays of 1×12 (element size of 600 × 1100 mm2) and 1×50 elements (element size of 140 × 1100 mm2) are fabricated by standard photolithography techniques on top of a SiO2/Si3N4 buffer layer which acts as a thermally insulating membrane after micromachining of the silicon. The devices have been characterized using a large aperture blackbody radiation source operating at 423 K. Its radiation is focussed by an infrared optics onto a single element and provides a power density of 67 W/m2. A voltage responsivity of 460 V/W at a chopping frequency of 1 Hz is achieved. The frequency dependencies of the obtained current and voltage responsitivities allow to deduce the thermal and electrical time constants which are compared to thermal finite element calculations and the electrical circuit model.