The increasing demand for short wave infrared (SWIR) imaging technology for soldier-based and unmanned
platforms requires camera systems where size, weight and power consumption are minimized without loss of
performance. Goodrich, Sensors Unlimited Inc. reports on the development of a novel focal plane (FPA) array for
DARPA's MISI (Micro-Sensors for Imaging) Program. This large format (1280 x 1024) array is optimized for
day/night imaging in the wavelength region from 0.4 μm to 1.7 μm and consists of an InGaAs detector bump bonded to a
capacitance transimpedance amplifier (CTIA)-based readout integrated circuit (ROIC) on a compact 15 μm pixel pitch.
Two selectable integration capacitors provide for high dynamic range with low (< 50 electrons) noise, and expanded onchip
ROIC functionality includes analog-to-digital conversion and temperature sensing. The combination of high
quality, low dark current InGaAs with temperature-parameterized non-uniformity correction allows operation at ambient
temperatures while eliminating the need for thermoelectric cooling. The resulting lightweight, low power
implementation is suitable for man-portable and UAV-mounted applications.
There are few choices when identifying detector materials for use in the SWIR wavelength band. We have exploited the
direct-bandgap InGaAs material system to achieve superior room temperature (293°K) dark current. We have
demonstrated sensitivity from 400nm through 2.6um with this material system and thus provide the opportunity to sense
not only the visible, but also the J-band (1.25um), H-band (1.65um) and K-band (2.2um) windows. This paper discusses
the advantages of our hybridized CMOS-InGaAs material system versus other potential SWIR material systems.
The monolithic planar InGaAs detector array enables 100% fill factor and thus, high external quantum efficiency. We
have achieved room-temperature pixel dark current of 2.8fA and shot noise of 110 electrons per pixel per second. Low
dark current at +300K allows uncooled packaging options, affording the system designer dramatic reductions in size,
weight (cameras <28grams), and power (<2.5W). Commercially available InGaAs pin arrays have shown diode lifetime
mean time between failures (MTBF) of 10<sup>11</sup>hours for planar InGaAs detectors<sup>1</sup>, far exceeding telecom-grade reliability
requirements. The use of a hybrid CMOS-InGaAs system allows best of breed materials to be used and permits efficient, cost-effective,
volume integration. Moreover, we will discuss how the InGaAsP material system is compatible with CMOS monolithic
integration. Taken together, these advantages, we believe, make InGaAs the obvious choice for all future SWIR