Design of a small pitch (7.5µm) MWIR HgCdTe array operating at high temperature (130K) with high imaging performances

Event: SPIE Defense + Commercial Sensing, 2022, Orlando, Florida, United StatesInternational audienceSWAPc (Size, Weight And Power-cost) is a strong trend in IR imaging systems. It requires focal planearrays with smaller pixels, operating at high temperatures. For MW systems, the full spectral band (upto 5µm) shows a strong advantage over the blue band (4.1µm) as it maximizes the number of incomingphotons from a room temperature scene. Few years ago, LETI and Lynred have been developing7.5µm pitch MCT arrays in MW full band. The first version of this technology was based on n/p diodesoperating at 110K maximum temperature. Switching to p/n using extrinsic doping allows today animportant gain in dark current, enabling operating temperature up to 130K or even higher. This paperwill describe our latest results in the design and fabrication of such HOT small pitch arrays, startingwith test chip arrays, followed by the full the characterization of 1280x1024 7.5µm pitch arrays. Firstorder figure of merit (dark current, QE…) are of course considered, but second order figure of meritwill also be discussed such as noise tails