Fabrication of 12 μm pixel-pitch 1280 × 1024 extended short wavelength infrared focal plane array using heterojunction type-II superlattice-based photodetectors

Arash Dehzangi, Abbas Haddadi, Romain Chevallier, Yiyun Zhang, Manijeh Razeghi*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

We present an intial demonstration of a 1280 × 1024 extended short-wavelength infrared focal plane array (FPA) imager with 12 μm pixel-pitch based on type-II InAs/AlSb/GaSb superlattice heterojunction photodetectors, with a novel bandstructure-engineered photo-generated carrier extractor as the window layer in the hetero structure to efficiently extract the photo-generated carriers. This heterostructure with a larger bandgap top window/contact layer leads to the device having lower dark current density compared to conventional pn junction devices. The large format FPA was fabricated with 12 μm pixel-pitch using a developed fabrication process. Test pixels fabricated separately exhibit 100% cut-off wavelengths of ∼2.22, ∼2.34 μm, and ∼2.45 μm at 150, 200 K, and 300 K. The test devices achieve saturated quantum efficiency values under zero bias of 54.3% and 68.4% at 150 and 300 K, under back-side illumination and without any anti-reflection coating. At 150 K, these photodetectors exhibit dark current density of 1.63 × 10 -7 A cm -2 under -20 mV applied bias providing a specific detectivity of 1.01 × 10 11 cm • Hz 1/2 /W at 1.9 μm.

Original languageEnglish (US)
Article number03LT01
JournalSemiconductor Science and Technology
Volume34
Issue number3
DOIs
StatePublished - Feb 4 2019

Keywords

  • extended short-wavelength infrared
  • focal plan arrays
  • small pixel pitch
  • type II superlattice

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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