Toward sub-micron pixels for short-wave infrared imaging

Chang Mo Kang, Jacob Rabinowitz, Simone Bianconi, Lining Liu, Melville Ulmer, Hooman Mohseni*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The sensitivity of infrared (IR) imagers can be significantly improved by reducing the size of photodetectors down to the diffraction limit. Emerging low-dimensional material enable submicron photodetectors, which can be diffraction limited and lead to significant sensitivity improvement in the critical short-wave IR band. However, reaching this limit requires pixel sizes smaller than the metal bumps needed for hybridization to silicon readout chips. Such tiny fragile pixels are susceptible to damages due to the mechanical pressure applied during flip-chip bonding, degrading the number of functional camera pixels. Herein, we systematically characterize the influence of the detector size on the imager pixel yield. We then introduce strategies for improving the yield of sub-micron pixels from less than half of total pixels to more than 3/4 of them. While we used a top-down fabrication for our detectors, the developed method is also applicable to bottom-up fabrication methods to make highly sensitive IR cameras based on emerging low-dimensional material such as catalyst-assisted nanowires.

Original languageEnglish (US)
Article number025007
JournalSemiconductor Science and Technology
Issue number2
StatePublished - Feb 2023


  • diffraction limited pixel size
  • flip-chip bonding
  • hybridization
  • indium bumping
  • operability

ASJC Scopus subject areas

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


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