LWIR 128X128 GAAS ALGAAS MULTIPLE QUANTUM-WELL HYBRID FOCAL PLANE ARRAY

This paper describes the fabrication and performance of a new type of hybrid focal plane array (FPA). The hybrid consists of a 128 x 128 GaAs/AlGaAs superlattice multiple quantum well detector array with peak response at 7.7-mu-m mated to a high-performance CMOS readout with direct injection input. The quantum well infrared photodetector (QWIP) array was fabricated by MBE. Optical gratings were excluded to facilitate evaluation of the basic detector technology. This FPA-level assessment was prompted by the numerous discrete detector investigations previously reported demonstrating the feasibility of infrared detection using optically excited intersubband transitions in GaAs quantum wells in the GaAs/AlGaAs material system. Progress with discrete GaAs quantum well detector has been rapid in the last few years in reducing dark currents and increasing responsivity. Reported here are the first FPA results. The mean D* at 78 K was 5.76 x 10(9) cm-square-root Hz/W. Total FPA 1/f noise was negligible, as corroborated by imagery having minimum resolvable temperature (MRT) of 30 mK at 0.07 cycles/mrad. No gain nonuniformity correction was used in the imaging demonstration.