Resonator-quantum well infrared photodetectors

Infrared Physics & Technology

et al. 2015

h i g h l i g h t sWe report on the performance of a 640 Â 512 resonant quantum well infrared photodetector (R-QWIP) focal plane array (FPA). We report on the conversion efficiency and quantum efficiency as a function of bias and temperature. We report on the dark current and Noise Equivalent Temperature Difference as a function of bias and temperature. a r t i c l e i n f o t r a c tIn this work, the performance of a 640 Â 512 long-wavelength resonant quantum well infrared photodetector (R-QWIP) focal plane array (FPA) was evaluated as a function of operating temperature, bias, and photon flux using an F/2.2 optic. From these FPA measurements an assessment of the dark current, noise, conversion efficiency and noise-equivalent temperature difference is provided herein. Histogram results are used to support a statistical interpretation of operability and non-uniformity across the R-QWIP FPA. In addition, single pixel devices fabricated from the same wafer lot enabled supplemental noise gain and spectral response measurements. The spectral response of this R-QWIP structure was confirmed to peak around 8.3 microns with a spectral bandwidth or approximately 1 micron (full-width half maximum) and the noise gain measurements were used to provide an estimation of the expected external quantum efficiency (conversion efficiency = quantum efficiency ⁄ gain).Published by Elsevier B.V.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Progress in resonator quantum well infrared photodetector (R-QWIP) focal plane arrays

DeCuir

Infrared Physics & Technology

et al. 2015

“…We applied it to design a new detector structure, which uses a resonator to increase the QE of the detectors. [8][9][10] We call the detector resonator-QWIP or R-QWIP. The R-QWIP structure uses the active pixel volume as a resonator to store the incident light until the light is absorbed.…”

Section: Introductionmentioning

confidence: 99%

Design and fabrication of resonator-quantum well infrared photodetector for SF6 gas sensor application

J. Micro/Nanolith. MEMS MOEMS

DeCuir

et al. 2017

Abstract. The infrared absorption of SF 6 gas is narrowband and peaks at 10.6 μm. This narrowband absorption posts a stringent requirement on the corresponding sensors as they need to collect enough signal from this limited spectral bandwidth to maintain a high sensitivity. Resonator-quantum well infrared photodetectors (R-QWIPs) are the next generation of QWIP detectors that use resonances to increase the quantum efficiency for more efficient signal collection. Since the resonant approach is applicable to narrowband as well as broadband, it is particularly suitable for this application. We designed and fabricated R-QWIPs for SF 6 gas detection. To achieve the expected performance, the detector geometry must be produced according to precise specifications. In particular, the height of the diffractive elements and the thickness of the active resonator must be uniform, and accurately realized to within 0.05 μm. Additionally, the substrates of the detectors must be completely removed to prevent the escape of unabsorbed light in the detectors. To achieve these specifications, two optimized inductively coupled plasma etching processes were developed. Due to submicron detector feature sizes and overlay tolerance, we used an advanced semiconductor material lithography stepper instead of a contact mask aligner to pattern wafers. Using these etching techniques and tool, we have fabricated focal plane arrays with 30-μm pixel pitch and 320 × 256 format. The initial test revealed promising results. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

“…This long integration time has prevented their applications in high speed imaging [1,2]. Recently, we have established a three-dimensional finite element electromagnetic (EM) model to calculate QE quantitatively [3][4][5][6]. This theoretical tool allows us to design new optical coupling structures to achieve a larger QE.…”

Section: Introductionmentioning

confidence: 99%

Advanced inductively coupled plasma etching processes for fabrication of resonator-quantum well infrared photodetector

Infrared Physics & Technology

Jhabvala

et al. 2015

Self Cite

Jhabvala, C. A.; Waczynski, A.; and Olver, K., "Advanced inductively coupled plasma etching processes for fabrication of resonator-quantum well infrared photodetector" (2015). t r a c tResonator-quantum well infrared photodetectors (R-QWIPs) are the next generation of QWIP detectors that use resonances to increase the quantum efficiency (QE). To achieve the expected performance, the detector geometry must be produced in precise specification. In particular, the height of the diffractive elements (DE) and the thickness of the active resonator must be uniformly and accurately realized to within 0.05 lm accuracy and the substrates of the detectors have to be removed totally. To achieve these specifications, two optimized inductively coupled plasma (ICP) etching processes are developed. Using these etching techniques, we have fabricated a number of R-QWIP test detectors and FPAs with the required dimensions and completely removed the substrates of the test detectors and FPAs. Their QE spectra were tested to be in close agreement with the theoretical predictions. The operability and spectral non-uniformity of the FPA is about 99.57% and 3% respectively.Published by Elsevier B.V.