Low dark current and high fill factor are two crucial characteristics for the realization of the InAs/GaSb superlattice (SL)
technology as third generation focal plane arrays (FPAs). Recent development proved high performance results for the
complementary barrier infrared detector (CBIRD) design, and a high-quality etch technique is required to minimize
surface leakage currents. We report on a n-CBIRD with 10.3 μm cutoff, exhibiting a responsivity of 1.7 A/W and dark
current density of 1×10-5 A/cm2 at 77K under 0.2 V bias, without AR coating and without passivation. Results from four
different mesa isolation techniques are compared on single element diodes: chemical wet etch using
C4H6O6:H3PO4:H2O2:H2O, BCl3/Ar inductively coupled plasma (ICP), CH4/H2/Ar ICP, and CH4/H2/BCl3/Cl2/Ar ICP.
The CH4/H2/BCl3/Cl2/Ar etched structures yielded more than 2.5 times improvement in dark current density and nearvertical
sidewalls. Using this etching technique, we then implement a 1k x 1k p-CBIRD array with 11.5 μm cutoff and
peak responsivity of 3 A/W. Operating at T = 80K, the array yielded a 81% fill factor with 98% operability and
performance results of 21% quantum efficiency, 53 mK NE▵T, and NEI of 6.9×1013 photons/sec-cm2.