Various tantalum (Ta)-doped vanadium oxide (VO x :Ta) films with various Ta doping contents were deposited on the Si substrates as the sensitive layer of the floating-type microbolometers using a magnetron radio frequency (RF) co-sputtering system. The vanadium (V) target and the tantalum pentoxide (Ta 2 O 5 ) target were used to deposit the VO x :Ta films. To improve the microbolometer responsivity by effectively reducing the thermal loss from the Si substrates, the floating-type microbolometers were fabricated using bulk micromachining technique. From the X-ray photoelectron spectroscopy (XPS) spectra, except the V 2 O 5 and V 6 O 13 , the lower oxygen state of VO x films, such as VO 2 and V 2 O 3 , were also obtained by doping Ta into the VO x films. Consequently, compared with the VO 2 microbolometers, the VO x :Ta microbolometers could operate at a higher operating temperature range. The temperature coefficient of resistance (TCR) and the resistivity of the VO x :Ta (Ta content of 7.63%) films measured by four point probe measurement in heating system were -3.47%/K and 9.32 Ω-cm, respectively. The Ta-doped VO x microbolometer revealed a higher responsivity of 341 kV/W compared with 106 kV/W of the undoped VO x microbolometer.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films