Microstructure of vanadium oxide used in microbolometers

B. D. Gauntta, J. Lia, O. M. Cabarcosa, H. A. Basantania, C. Venkatasubramaniana, S. S.N. Bharadwajaa, N. J. Podrazaa, Thomas Nelson Jackson, D. L. Allaraa, S. Antrazib, Mark William Horn, E. C. Dickeyc

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

3 Scopus citations

Abstract

Reactive pulsed DC sputtering was used to grow a systematic series of films with resistivity ranging from 1 × 10-3 to 6.8 × 10 4 Ohm cm and TCR varying from 0 to -4% K-1. Throughout the parameter space studied a transition from amorphous to nano-crystalline growth was observed. Films in the resistivity range of interest for microbolometers contained a FCC VOx (0.8 < x < 1.3) phase. Altering the sputtering energetics via substrate biasing resulted in highlycolumnar, nano-twinned grains of FCC VOx, providing a microstructure reminiscent of ion beam sputtered bolometer material. Electron diffraction in the TEM confirmed the presence of a secondary, oxygen-rich amorphous phase. Micro- Raman spectroscopy, which was also found to be sensitive to the secondary amorphous phase, was used to probe the chemical composition and morphology of VOx thin films. Raman spectra from high resistivity amorphous films show a broad feature around ∼890 cm-1, while spectra from lower resistivity nano-crystalline films exhibit this same amorphous feature and a second broad feature at ∼320 cm-1. The resulting microstructure can be described as a nano-composite material composed of a low-resistivity crystalline phase embedded in a high-resistivity amorphous matrix. Our results suggest that both phases are required to achieve a high TCR, low resistivity material.

Original languageEnglish (US)
Title of host publicationInfrared Technology and Applications XXXVII
Volume8012
DOIs
StatePublished - Sep 26 2011
EventInfrared Technology and Applications XXXVII - Orlando, FL, United States
Duration: Apr 25 2011Apr 29 2011

Other

OtherInfrared Technology and Applications XXXVII
CountryUnited States
CityOrlando, FL
Period4/25/114/29/11

All Science Journal Classification (ASJC) codes

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

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    Gauntta, B. D., Lia, J., Cabarcosa, O. M., Basantania, H. A., Venkatasubramaniana, C., Bharadwajaa, S. S. N., Podrazaa, N. J., Jackson, T. N., Allaraa, D. L., Antrazib, S., Horn, M. W., & Dickeyc, E. C. (2011). Microstructure of vanadium oxide used in microbolometers. In Infrared Technology and Applications XXXVII (Vol. 8012). [1] https://doi.org/10.1117/12.884161