9μm Cutoff 128×128 AlGaAs/GaAs Quantum Well Infrared Photodetector Focal Plane Arrays

We design and fabricate a 128×128 AlGaAs/GaAs quantum well infrared photodetector focal plane array (FPA).The device is achieved by metal organic chemical vapor deposition and GaAs integrated circuit processing technology.A test structure of the photodetector with a mesa size of 300μm×300μm is also made in order to obtain the device parameters.The measured dark current density at 77K is 1.5E-3A/cm2 with a bias voltage of 2V.The peak of the responsivity spectrum is at 8.4μm,with a cutoff wavelength of 9μm.The blackbody detectivity is shown to be 3.95E8 (cm·Hz1/2) /W.The final FPA is flip-chip bonded on a CMOS read-out integrated circuit.The infrared thermal images of some targets at room temperature background are successfully demonstrated at 80K operating temperature with a ratio of dead pixels of less than 1%.