Epitaxial Thin-Film Pyroelectric Infrared Arrays

This Phase I project will develop certain innovations in silicon wafer micromachining, and pulsed-laser deposition, to fabricate arrays of pyroelectric detectors from epitaxial metal-oxide thin films. These pyroelectric materials will be ferroelectric metal-oxides and hence have very large electric polarizations. Epitaxial films ensure low dielectric noise, and allow photolithographic array patterning. They will function as sensitive and fast infrared detectors, without cooling, for applications over the 2 to 20-micron wavelength range, including thermal imaging. Both recent market demands for arrays of IR detectors (focal plane arrays), and the market's insistence on lowering costs to bring arrays into the range of commercial applications, are pulling hard for new technology development. AFR, Inc. brings extensive experience with epitaxial oxide-film fabrication and thermal infrared detector design and fabrication, including micromachining. The later will utilize silicon-on-insulator (SOI) wafer technology to make possible ultrathin and uniform silicon membranes. Epitaxial conducting-oxide electrodes are available for use with the epitaxial oxide ferroelectrics and silicon substrates. The proposed uncooled IR arrays will respond directly to demand that is building rapidly in the commercial markets, namely that for thermal imaging across the dual bands of the mid-IR. Applications for these sensor devices include: factories and manufacturing monitoring, community and security services, transportation systems, and energy and environmental surveying.