Nanostructured vanadium oxide thin film with high TCR at room temperature for microbolometer

In order to obtain high quality of thermal sensitive material, VOx thin film of high temperature coefficient of resistance (TCR) of 6.5%/K at room temperature has been deposited by reactive ion beam sputtering and post annealing method. AFM and XRD measurements indicate that the VOx thin film with nanostructured crystalline is composed of VO2 and V2O3. The nanostructured VOx microbolometer has been designed and fabricated. The measurement of the film system with TiN absorbing layer indicates that it has about 92% infrared absorption in the range of 8–14 μm. The performance of this bolometer, comparing with that of bolometer with common VOx, has a better result. At 20 Hz frequency and 10 μA bias current, the bolometer with high TCR has reached detectivity of 1.0 × 109 cm Hz1/2/W. It also indicates that this nanostructured VOx thin film has not only a higher TCR but also a lower noise than common VOx thin film without annealing.

► VOx thin film of high temperature coefficient of resistance (TCR) of 6.5%/K at room temperature has been deposited by reactive ion beam sputtering and post annealing method.
► AFM and XRD measurements indicate that the VOx thin film with nanostructured crystalline is composed of VO2 and V2O3.
► The nanostructured VOx microbolometer has been designed and fabricated.
► The measurement of the film system with TiN absorbing layer indicates that it has about 92% infrared absorption in the range of 8–14 μm.
► The performance of this bolometer, comparing with that of bolometer with common VOx, has a better result due to its higher TCR and lower noise.