Correlation of temperature response and structure of annealed v O x thin films for IR detector applications

Chandrasekaran Venkatasubramanian, Orlando M. Cabarcos, David L. Allara, Mark William Horn, S Ashok

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The effects of thermal annealing on vanadium oxide (V O x) thin films prepared by pulsed-dc magnetron sputtering were studied to explore methods of improving the efficiency of uncooled IR imaging microbolometers, particularly with respect to maximizing the temperature coefficients of resistance (TCR) (typically ∼2%) while minimizing resistivity values (typically 0.05-5 cm). Since high TCR values are usually associated with high resistivities, the experiments were designed to find processing conditions that provide an optimal balance in these properties and to then determine the underlying structural correlations which would enable rational design of thin films for this specific application. V O x films of different compositions were deposited by pulsed-dc reactive sputtering from a vanadium target at different oxygen flow rates. The deposited films were further modified by annealing in inert (nitrogen) and oxidizing (oxygen) atmospheres at four different temperatures for 10, 20, or 30 min at a time. The resistivities of the as-deposited films ranged from 0.2 to 13 cm and the TCR values varied from -1.6% to -2.2%. Depending on the exact annealing conditions, several orders of magnitude change in resistance and significant variations in TCR were observed. Optimal results were obtained with annealing in a nitrogen atmosphere. Structural characterization by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and Raman spectroscopy indicated changes in the film crystallinity and phase for annealing conditions over 300 °C with the onset and extent of the changes dependent on which annealing atmosphere was used.

Original languageEnglish (US)
Pages (from-to)956-961
Number of pages6
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Volume27
Issue number4
DOIs
StatePublished - Jul 17 2009

Fingerprint

Infrared detectors
Annealing
Thin films
Vanadium
annealing
detectors
thin films
vanadium oxides
coefficients
atmospheres
Temperature
electrical resistivity
Oxide films
temperature
Nitrogen
Oxygen
nitrogen
Reactive sputtering
Infrared imaging
oxygen

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Cite this

Venkatasubramanian, Chandrasekaran ; Cabarcos, Orlando M. ; Allara, David L. ; Horn, Mark William ; Ashok, S. / Correlation of temperature response and structure of annealed v O x thin films for IR detector applications. In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films. 2009 ; Vol. 27, No. 4. pp. 956-961.
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Correlation of temperature response and structure of annealed v O x thin films for IR detector applications. / Venkatasubramanian, Chandrasekaran; Cabarcos, Orlando M.; Allara, David L.; Horn, Mark William; Ashok, S.

In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 27, No. 4, 17.07.2009, p. 956-961.

Research output: Contribution to journalArticle

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