Ferroelectric IR bolometers - from ceramic hybrid arrays to direct thin film integration

Abstract

Abstract Bolometer elements in large arrays, at a pitch from 100 down to 40μm, offer uncooled and simple operation in thermal imaging applications. A hybrid array technology, exploiting the pyroelectric property of ferroelectric ceramic materials in the bolometer elements, has produced a range of successful linear and 2-D arrays. High merit for the ceramic has been coupled to fabrication technologies including solder bump bonding of the elements to the multiplexer IC. However, other designs will compete for low costs in the large arrays required for civil applications. In particular, direct deposition of thin film ferroelectric material onto suitable thermal microstructures on the silicon readout IC, could provide substantial reductions in costs and improved performance. This integration will require processes compatible with the silicon IC. Already, lead based perovskite films are showing considerable potential. The successful technology will form the basis for a rapid growth of commercial IR imaging and...