Vertically integrated pixel microbolometers for IR imaging using high resistivity VOX

A. Basantani Hitesh, Hang Beum Shin, Thomas Nelson Jackson, Mark William Horn

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

Uncooled IR bolometers form an integral part of thermal imaging cameras. Vanadium oxide material currently used for IR imaging has a resistivity between 0.1 and 1 ohm-cm and a temperature coefficient of resistance (TCR) between -1.4%K-1 to -2.4%K-1. Higher TCR materials are desired, however, such materials inevitably have higher resistivity and therefore higher electrical resistance in a lateral resistor configuration. A high resistance leads to an increase in the Johnson-Nyquist noise of the bias-induced current, thereby limiting the performance of bolometers using high resistivity material. In this work, we demonstrate high resistivity, high TCR VOx and propose the use of a vertically integrated resistor configuration an alternate pixel structure design with lower Johnson noise when compared with the conventional lateral pixel design. Biased Target Ion Beam Deposition was used to deposit high resistivity vanadium oxide thin-films (∼85 nm thick). Electrical characterization of lateral resistor structures showed resistivities ranging from 2 × 1033 ohm-cm to 2.1 × 104 ohm-cm, TCR varying from -2.6%K-1 to -5%K-1, Johnson noise (pixel resistance of 1.3Gω) of 4.7 to 6μV/Hz and 1/f noise (normalized Hooge's parameter (α/n)) of 5 × 10-21 to 5 × 1018 cm-3. In contrast, the through-film resistor structures showed significantly higher resistivities at 3 × 104 Ohm-cm to 1.55 × 105 Ohm-cm, TCR similar to lateral resistive structure between -2.6%K-1 to -5.1%K -1, immeasurably low Johnson noise (pixel resistance of 48Kω) and normalized Hooge's parameter ranging from to 5×10-21 to 1×1018 cm-3. These results indicate the possible use of through-film resistors as an alternative to the conventional lateral-resistor design currently used in uncooled imaging microbolometers.

Original languageEnglish (US)
Title of host publicationInfrared Technology and Applications XXXIX
DOIs
StatePublished - Sep 17 2013
Event39th Infrared Technology and Applications - Baltimore, MD, United States
Duration: Apr 29 2013May 3 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8704
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Other

Other39th Infrared Technology and Applications
CountryUnited States
CityBaltimore, MD
Period4/29/135/3/13

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Hitesh, A. B., Shin, H. B., Jackson, T. N., & Horn, M. W. (2013). Vertically integrated pixel microbolometers for IR imaging using high resistivity VOX. In Infrared Technology and Applications XXXIX [87041A] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8704). https://doi.org/10.1117/12.2016292