InGaAs/InGaP quantum dots and nanopillar structures for infrared focal plane array applications

InGaAs/InGaP quantum-dots have been grown by low-pressure metalorganic chemical vapor deposition technique on GaAs substrate. The important growth parameters, such as growth temperature, V/III ratio, etc, have been optimized. A 10-stack quantum-dot infrared photodetector based on these InGaAs dots showed a detectivity of 3.6x10(10)cmHz(1/2)/W at 95K. The peak photoresponse was 4.7 mum with a cutoff at 5.2 mum. A 256x256 rniddle-wavelength infrared focal plane array based on our quantum-dot detectors was fabricated via dry etching technique. The detector array was bonded to a silicon readout integrated circuit via flip chip bonding with indium bumps. A noise equivalent temperature difference of 509 mK was achieved for this array at 120K. With the goal of improving array uniformity, exploratory work into nanopillar structure IR detectors was also performed. Experimental methods and characterization results are presented here.