Low-Cost Uncooled Infrared Detector Arrays in Standard CMOS

摘要: This paper reports the development of a low-cost 128 x uncooled infrared focal plane array (FPA) based on suspended and thermally isolated CMOS p+-active/n-well diodes. The FPA is fabricated using standard 0.35 μm process followed by simple post-CMOS bulk micromachining that does not require any critical lithography or complicated deposition steps; therefore, cost almost equal to chip. fabrication steps include an RIE etching reach silicon anisotropic obtain pixels. During etching, metal layers are used as masking layers, narrow openings such 2 can be defined between support arms. approach allows achieving small pixel size 40 with fill factor 44%. scanned at 30 fps monolithically integrated multi-channel parallel readout circuitry which composed low-noise differential transconductance amplifiers, switched capacitor (SC) integrators, sample-and-hold circuits, various other circuit blocks for reducing effects variations in detector voltage operating temperature. has temperature coefficient -2 mV/K, thermal conductance value 1.8 10-7 W/K, time constant 36 msec, providing measured DC responsivity (R) 4970 V/W under continuous bias. Measured noise 0.69 μV 8 kHz bandwidth scanning rate, resulting detectivity (D*) 9.7 108 cm√HzW. Contribution 1/f component found negligible due single crystal nature n-well its low bias levels. 0.76 μV, expected NETD 1 K when f=1 optics. decreased below 350 mK decreasing electrical help increased number channels optimizing steps. uniformity very good mature technology. uncorrected non-uniformity pixels after 0.2% deviation only 1.5 mV, improved structure compensate drops along routing resistances array. Non-uniformity sensitivity less than 3% mean -2.05 mV/K 61 μV/K, respectively. voltages 2.3 relaxing requirements stabilization. Considering performance steps, proposed method cost-effective fabricate large format arrays imaging applications.