As far as cooled staring arrays are concerned, InfraRed (IR) detectors with a 320x256 format are produced at mass production level since the end of the nineties but the request for miniaturization and affordability is more and more important for IR systems. To answer these requirements, SOFRADIR has taken its HgCdTe (Mercury Cadmium Telluride/ MCT) material and process as well as its hybridization technology to the next even more advanced level of sophistication and is now offering large format detectors with graduated levels of performances regarding pitch size and cryogenics.
For Mid Wave (MW) applications a TV (640x480 or 640x512) format MCT with 15 μm pixel pitch is offered allowing the integration of highly miniaturized cryogenics including the use of quarter Watts micro-coolers and dedicated to compact systems or to the upgrade of existing systems using TV/4 (320x240) format. This new 15 μm pitch MCT TV format exhibits a very small size cryogenics in order to fit the system requirements of miniaturization and cost reduction.
For Long Wave (LW) applications, 288x4 TDI scanning arrays are offered with compact cryogenics and take advantage of the use of the same advanced cryogenics developments.
Finally, as far as long wave staring arrays are concerned a 25 μm pitch 384x288 HgCdTe detector has been developed allowing the use of 0.5W micro cooler with miniaturized cryogenics.
The characteristics and performances of these new IR detectors are presented in this paper.
Infrared systems require today high resolution detectors, in miniaturized configurations, and with cost reduction. To answer these requirements, SOFRADIR has taken its HgCdTe (Mercury Cadmium Telluride/ MCT) material and process as well as its hybridization technology to the next even more advanced level of sophistication, and is now offering large format detectors with graduated levels of performances regarding pitch size and cryogenics. For large format LW detectors, Sofradir takes advantage of the Thales Research Technology (TRT) Quantum Well Infrared Photodetector (QWIP) process working at up to 75K to offer a very compact large array QWIP IDDCA. For Mid Wave applications, the SCORPIO 15 μm pixel pitch TV format (640×512) HgCdTe detector is released, for operation above 100K, allowing the use of 0.3W microcooler with miniaturized cryogenics, either for new compact systems or for the direct upgrade of existing 30µm pitch TV/4 format systems. This new 15μm pitch HgCdTe TV format exhibits high performances in optimized very small size cryogenics in order to achieve a cost effective production level. Doing so, this detector will become the most affordable large format at production level in the coming years.
For Long Wave applications two new detectors are launched: the HgCdTe approach for high frame rate applications with a medium format detector (25μm pitch 384×288), and the large format (640×512 20μm) QWIP approach for high resolution imagery applications. These LW detectors are offered with microcoolers and miniaturized cryogenics. The performances of these new IR detectors are presented in this paper as well as the development trends for even higher resolution IR detectors at Sofradir.
SOFRADIR has moved to large quantity production for 2.5 generation IR detectors (320x256 format) since 2001. The move from 2nd generation to 2.5-generation IR detectors, mainly for MWIR applications, has been successfully achieved at SOFRADIR thanks to improvements of the technologies fully dedicated to performance improvements as well as production capacity increase for staring arrays. Then, in order to prepare future military and industrial needs, SOFRADIR has been working in close relationship with CEA-LETI/LIR on third generation development based on HgCdTe materials. This effective approach has been one of the keys to success in preparing third generation IR detectors. Three main areas are investigated for the third generation IR detectors: large IRFPA manufacturing following a cost effective approach, development of new IR detector structures and design of new silicon readout circuits. Developments in progress are presented regarding these main areas.