Fast Wafer-Scale Characterization Techniques for CZT

This program will develop a turnkey system capable of rapidly producing high-resolution maps of transmittance, energy gap, composition, lattice constant, second-phases and residual strain fields in a variety of substrates critical to Ballistic Missile Defense. The characterization tool developed under this program will address the needs of the fabricators of infrared detectors and focal plane arrays, by providing a means for rapid screening of substrates prior to fabrication of these devices. This capability promises to reduce the finished cost by removing substrates with sub-optimal properties prior to the costly detector fabrication process. The commercial system created by this program will also aid crystal growers by providing feedback on the quality of wafer production. The ability to measure the uniformity of composition along with the size and density of second-phases is invaluable for assessing the effects of process changes, and for improving furnace design and control by revealing the shape of the growth interface. The design is applicable to a variety of substrates for long-wave infrared sensors such as cadmium zinc telluride and gallium antimonide, and has the potential to substantially reduce production costs and to improve performance of these devices.