p-on-n HgCdTe Infrared Focal-Plane Arrays: From Short-Wave to Very-Long-Wave Infrared

This paper reports on recent developments made at the DEFIR joint laboratory on fabrication of planar p-on-n arsenic (As)-ion-implanted HgCdTe photodiodes. Our infrared focal-plane arrays (IRFPAs) cover a wide spectral range, from the short-wave infrared (SWIR) to the very-long-wave infrared (VLWIR). Our planar p-on-n technology is a classical one based on ion implantation followed by diffusion and activation. The p-type doping is obtained by As implantation, and n-type indium (In) doping is achieved during the epilayer growth. Our p-on-n IRFPAs show state-of-the-art performance from the SWIR to VLWIR spectral range. Mid-wave infrared (MWIR) and long-wave infrared (LWIR) FPAs have been designed with a television (TV) format and 15 mu m pixel pitch. Preliminary results of high-operating-temperature detectors obtained in the MWIR (lambda (c) = 5.3 mu m at 80 K) have shown highly promising electrooptical performance above 130 K. For space applications, imagers dedicated to low-flux detection have first been produced as TV/4 focal-plane arrays, with 15 mu m pitch in the SWIR range (2 mu m). Finally, TV/4 arrays with 30 mu m pixel pitch have been manufactured for the VLWIR range. The measured dark current fits the "Rule 07," with homogeneous imagers.