MWIR InAsSb Barrier Detector Data and Analysis

摘要

Mid-wavelength infrared (MWIR) InAsSb alloy barrier detectors grown on GaAs substrates were characterized as a function of temperature to evaluate their performance. Detector arrays were fabricated in a 1024 × 1024 format on an 18 urn pitch. A fanout was utilized to directly acquire data from a set of selected detectors without an intervening read out integrating circuit (ROIC). The detectors have a cutoff wavelength equal to ～ 4.9 μm at 150 K. The peak internal quantum efficiency (QE) required a reverse bias voltage of 1 V. The detectors were diffusion-limited at the bias required to attain peak QE. Multiple 18 μm × 18 μm detectors were tied together in parallel by connecting the indium bump of each detector to a single large metal pad on the fanout. The dark current density at -1 V bias for a set of 64 × 64 and 6×6 array of detectors, each of which were tied together in parallel was ～ 10~(-3) A/cm~2 at 200 K and 5 × 10~(-6) A/cm~2 at 150 K. The 4096 (64 × 64) and 36 (6 × 6) detectors, both have similar J_(dark) vs V_d characteristics, demonstrating high operability and uniformity of the detectors in the array. The external QE measured using a narrow band filter centered at ～ 4 μm had values in the 65 - 70 % range. Since the detectors were illuminated through a GaAs substrate which has a reflectance of 29%, the internal QE is greater than 90 %. A 1024 × 1024 ROIC on an 18 μm pitch was also designed and fabricated to interface with the barrier detectors. QE at 150 K for a 1024 × 1024 detector array hybridized to a ROIC matched the QE measured on detectors that were measured directly through a fanout chip. Median D at 150 K under aflux of 1.07× 10~(15)ph/(cm~2/s was 1.0× 10~(11) cm Hz~(1/2)/W.