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

Abstract

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.

Synchronously wired infrared antennas for resonant single-quantum-well photodetection up to room temperature

“…QWIPs made of other materials (e.g., InGaAs/InP) 40 have shown similar or higher responsivity and detectivity; SWAs can be combined with these materials as well. Through these optimizations, less toxic SWA-enhanced QWIPs would replace the widely used but toxic HgCdTe detectors 26 in some spectroscopic applications [15][16][17][18] . As Palaferri et al demonstrated 12 , gigahertz-frequency detection would be another promising application that only antenna-enhanced QWIPs can realize.…”

“…In this Article, we not only clarify the physical foundations underlying the SWAs, but also present their application to mid-infrared photodetectors incorporating only a single quantum well (QW). Practical responsivity without polarization dependence at a predetermined wavelength in the fingerprint region, extending up to room temperature, is promising for spectroscopic applications [15][16][17][18] and free-space data transfer 12 . However, applications are not limited to detectors; SWAs offer greater design freedom as a fundamental platform for optoelectronic metadevices [19][20][21] .…”

The influence of different angles of grating on the performance of quantum well infrared photodetectors

“…However, the quantum efficiency of quantum well detectors has always been a difficult problem to overcome. In order to solve this problem, many teams have conducted corresponding research work [1][2][3][4][5][6][7] . Among them, the Arnaud Berurier team has conducted research on 11-14um wide spectral detectors [8] .…”