Linear bolometer array using a high TCR VO_x-Au film

Abstract

We present a design for a low-noise bolometer linear array based on the temperature-dependent conductivity of a VO xAu film. Typical thin film bolometers must compromise between low resistivity to limit Johnson noise and high temperature coefficient of resistivity (TCR) to maximize responsivity. Our vanadium oxide is alloyed with a small concentration of gold by co-sputtering, which gives very low resistivity and very high TCR simultaneously. The film is fabricated on an air bridge device having high thermal conductivity and small thermal time constant optimized for 30 to 60 Hz frame rates. The linear array functions as a low-power profile sensor with a modulated bias. For 1 V bias, we predict responsivity exceeding 1200 V/W. Johnson noise dominates with predicted NEP values as low as 1.0 x 10 -11 W/Hz 1/2 . Preliminary device testing shows film resistivity below 2.5 Ω-cm with TCR exceeding -2.0%. Preliminary measurements of NEP and D* are reported.

Wide Dynamic Range, Angle-Sensing, Long-Wave Infrared Detector Using Nano-Antenna Arrays

“…The performance of this device can be enhanced by employing more complicated fabrication techniques. For example, one can use higher TCR bolometers 35,36 , lower loss substrates 37,38 , or thermally isolate the microbolometers from the substrate 39,40 . Additionally, rather than using a bolometer, other detectors such as MIM diodes 8,9 can be used.…”

Enhanced performance of VOx-based bolometer using patterned gold black absorber

“…[10]. Some changes to feature size and material thickness were made to enhance performance, increase structural stability, and improve the production yield.…”

“…8,9 Meanwhile, Plasmonics, Inc. has developed high-performance room-temperature air-bridge bolometers based on VO x -Au thin films. 10 In this paper, we report successful integration of patterned gold black onto such a bolometer array, which resulted in a substantial improvement in detector performance.…”

“…Devices are typically optimized for mid-wave IR (MWIR, 3-5 µm wavelength) or long-wave IR (LWIR, [8][9][10][11][12] µm wavelength) by Fabry-Perot 1,2 and other resonant structures, [3][4][5] whose peak absorbance and bandwidth depend on resonator Q and hence on fabrication tolerances. In contrast, gold black is a well-known absorber with very high absorption over a broad spectral range, 6 and which is easily deposited using an ordinary thermal evaporator.…”

Análise comparativa das propriedades elétricas de camadas e multicamadas de VOx depositadas por pulverização catódica para aplicação em bolômetros

“…De acordo com os dados apresentados na Tabela 2, verificou-se que os valores de Rs e TCR de todas as multicamadas estavam bem próximos, ou seja, dentro de faixas estreitas que vão de 5,6 a 17,0 kΩ/quad e de 1,70 a 2,36 %/K, respectivamente, valores comumente encontrados em camadas de VO X para emprego em dispositivos do tipo bolômetro [2,13,14]. A relação entre o TCR das amostras de multicamadas e suas respectivas resistências de folha pode ser observada na…”