Dr. William Tennant Profile

Dr. William Tennant

CEO at Tennant Electro Optics Consulting, Inc.

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Author

Publications (27)

Proceedings Article | 23 April 2020 Presentation

Thermal imaging quantum detectors, past, present, and (possible) future: HgCdTe vs competitors (Conference Presentation)

William Tennant

Proceedings Volume 11407, 114070U (2020) https://doi.org/10.1117/12.2561054

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Proceedings Article | 17 June 2016 Paper

Analysis of the auger recombination rate in P+N−n−N−N HgCdTe detectors for hOT applications

J. Schuster, W. Tennant, E. Bellotti, P. Wijewarnasuriya

Proceedings Volume 9819, 98191F (2016) https://doi.org/10.1117/12.2224383

KEYWORDS: Infrared detectors, Long wavelength infrared, Mercury cadmium telluride, Cadmium, Sensors, Electrons, Diffusion, Doping, Heterojunctions, Instrument modeling

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Infrared (IR) photon detectors must be cryogenically cooled to provide the highest possible performance, usually to temperatures at or below ~ 150K. Such low operating temperatures (T_op) impose very stringent requirements on cryogenic coolers. As such, there is a constant push in the industry to engineer new detector architectures that operate at higher temperatures, so called higher operating temperature (HOT) detectors. The ultimate goal for HOT detectors is room temperature operation. While this is not currently possibly for photon detectors, significant increases in T_op are nonetheless beneficial in terms of reduced size, weight, power and cost (SWAP-C). The most common HgCdTe IR detector architecture is the P⁺n heterostructure photodiode (where a capital letter indicates a wide band gap relative to the active layer or “AL”). A variant of this architecture, the P⁺N−n−N−N heterostructure photodiode, should have a near identical photo-response to the P+n heterostructure, but with significantly lower dark diffusion current. The P⁺N−n−N−N heterostructure utilizes a very low doped AL, surrounded on both sides by wide-gap layers. The low doping in the AL, allows the AL to be fully depleted, which drastically reduces the Auger recombination rate in that layer. Minimizing the Auger recombination rate reduces the intrinsic dark diffusion current, thereby increasing Top. Note when we use the term “recombination rate” for photodiodes, we are actually referring to the net generation and recombination of minority carriers (and corresponding dark currents) by the Auger process. For these benefits to be realized, these devices must be intrinsically limited and well passivated. The focus of this proceeding is on studying the fundamental physics of the intrinsic dark currents in ideal P⁺N−n−N−N heterostructures, namely Auger recombination. Due to the complexity of these devices, specifically the presence of multiple heterojunctions, numerical device modeling techniques must be utilized to predict and understand the device operation, as analytical models do not exist for heterojunction devices.

Proceedings Article | 25 September 2012 Paper

4Kx4K format 10-micron pixel pitch H4RG-10 hybrid CMOS silicon visible focal plane array for space astronomy

Yibin Bai, William Tennant, Selmer Anglin, Andre Wong, Mark Farris, Min Xu, Eric Holland, Donald Cooper, Joseph Hosack, Kenneth Ho, Thomas Sprafke, Robert Kopp, Brian Starr, Richard Blank, James Beletic, Gerard Luppino

Proceedings Volume 8453, 84530M (2012) https://doi.org/10.1117/12.926748

KEYWORDS: Staring arrays, Readout integrated circuits, Astronomy, Sensors, Silicon, Quantum efficiency, Detector arrays, Capacitance, Cadmium sulfide, Silicon carbide

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SPIE Journal Paper | 1 June 2011

Analysis and performance of type-II superlattice infrared detectors

Igor Vurgaftman, Chadwick Canedy, Eric Jackson, Jill Nolde, Chaffra Affouda, Edward Aifer, Jerry Meyer, Andrew Hood, Allan Evans, William Tennant

OE, Vol. 50, Issue 06, 061007, (June 2011) https://doi.org/10.1117/12.10.1117/1.3578926

KEYWORDS: Photodiodes, Quantum efficiency, Superlattices, Mercury cadmium telluride, Doping, Infrared detectors, Long wavelength infrared, Sensors, Heterojunctions, Electrons

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Proceedings Article | 4 May 2010 Paper

LWIR high performance focal plane arrays Based on type-II strained layer superlattice (SLS) materials

A. Hood, A. Evans, A. Ikhlassi, G. Sullivan, E. Piquette, D. Lee, W. Tennant, I. Vurgaftman, C. Canedy, E. Jackson, J. Nolde, C. Yi, E. Aifer

Proceedings Volume 7660, 76601M (2010) https://doi.org/10.1117/12.850976

KEYWORDS: Staring arrays, Long wavelength infrared, Mercury cadmium telluride, Sensors, Etching, Quantum efficiency, Gallium antimonide, Semiconducting wafers, Superlattices, Laser sintering

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Proceedings Article | 7 May 2009 Paper

MEMS-based tunable filters for compact IR spectral imaging

William Gunning, Stefan Lauxtermann, Hakan Durmas, Min Xu, Philip Stupar, Robert Borwick, Donald Cooper, Paul Kobrin, Miikka Kangas, Jeffrey DeNatale, William Tennant

Proceedings Volume 7298, 72982I (2009) https://doi.org/10.1117/12.819017

KEYWORDS: Staring arrays, Microelectromechanical systems, Long wavelength infrared, Optical filters, Mirrors, Fabry–Perot interferometers, Sensors, Silicon, Capacitance, Tunable filters

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Proceedings Article | 7 May 2009 Paper

HgCdTe at Teledyne

W. Tennant, J. Arias, J. Bajaj

Proceedings Volume 7298, 72982V (2009) https://doi.org/10.1117/12.821350

KEYWORDS: Mid-IR, Short wave infrared radiation, Liquid phase epitaxy, Mercury cadmium telluride, Sensors, Silicon, Doping, Diodes, Metalorganic chemical vapor deposition, Semiconducting wafers

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Proceedings Article | 22 July 2008 Paper

Teledyne Imaging Sensors: infrared imaging technologies for astronomy and civil space

James Beletic, Richard Blank, David Gulbransen, Donald Lee, Markus Loose, Eric Piquette, Thomas Sprafke, William Tennant, Majid Zandian, Joseph Zino

Proceedings Volume 7021, 70210H (2008) https://doi.org/10.1117/12.790382

KEYWORDS: Staring arrays, Readout integrated circuits, Infrared sensors, Infrared imaging, Astronomy, Mercury cadmium telluride, Optical sensors, Sensors, Electrons, Quantum efficiency

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Proceedings Article | 10 October 2003 Paper

High-resolution extended NIR camera

Scott Cabelli, Jianmei Pan, Steven Bernd, William Tennant, John Blackwell, S. Bhargava, John Pasko, Eric Piquette, Dennis Edwall

Proceedings Volume 5074, (2003) https://doi.org/10.1117/12.488517

KEYWORDS: Staring arrays, Infrared cameras, Near infrared, Optical filters, Electronics, Mercury cadmium telluride, Cameras, Sensors, Interfaces, Head

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Proceedings Article | 19 September 2001 Paper

Adaptive ladar receiver for multispectral imaging

Kenneth Johnson, Mohan Vaidyanathan, Song Xue, William Tennant, Lester Kozlowski, Gary Hughes, Duane Smith

Proceedings Volume 4377, (2001) https://doi.org/10.1117/12.440097

KEYWORDS: Staring arrays, Readout integrated circuits, Signal to noise ratio, Indium gallium arsenide, Mercury cadmium telluride, LIDAR, Sensors, Receivers, Imaging devices, Detector arrays

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Proceedings Article | 15 December 2000 Paper

Progress toward high-performance infrared imaging systems-on-a-chip

Lester Kozlowski, Kadri Vural, William Tennant, William Kleinhans, Isoris Gergis

Proceedings Volume 4130, (2000) https://doi.org/10.1117/12.409863

KEYWORDS: Staring arrays, Infrared imaging, Imaging systems, Sensors, Video, Amplifiers, Infrared radiation, Charge-coupled devices, CMOS technology, System on a chip

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Proceedings Article | 26 July 1999 Paper

HgCdTe detectors and FPAs for remote sensing applications

Arvind D'Souza, Larry Dawson, Dan Berger, Stewart Clark, Priyalal Wijewarnasuriya, Jagmohan Bajaj, Jose Arias, William Tennant, Lester Kozlowski, Kadri Vural

Proceedings Volume 3698, (1999) https://doi.org/10.1117/12.354499

KEYWORDS: Staring arrays, Readout integrated circuits, Long wavelength infrared, Mid-IR, Short wave infrared radiation, Mercury cadmium telluride, Custom fabrication, Sensors, Remote sensing, Detector arrays

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Proceedings Article | 21 December 1998 Paper

HgCdTe multispectral infrared FPAs for remote sensing applications

Arvind D'Souza, Larry Dawson, Dan Berger, Arvel Markum, Jagmohan Bajaj, William Tennant, Jose Arias, Lester Kozlowski, Kadri Vural, Priyalal Wijewarnasuriya

Proceedings Volume 3498, (1998) https://doi.org/10.1117/12.333630

KEYWORDS: Staring arrays, Readout integrated circuits, Infrared sensors, Infrared imaging, Mid-IR, Short wave infrared radiation, Mercury cadmium telluride, Sensors, Detector arrays, Infrared radiation

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Infrared (IR) remote sensing imaging applications require high-performance Focal Plane Arrays (FPAs) operating in all ranges of the IR spectrum. Short wavelength (SWIR; 1 to 3 micrometer), middle wavelength (MWIR; 3 to 5 micrometer), mid- long wavelength (MLWIR; 6 to 8 micrometer), long wavelength (LWIR; 8 to 14 micrometer), and very long wavelength (VLWIR; greater than 14 micrometer). These diverse spectral bands require high performance detectors and Read Out Integrated Circuits (ROICs) to perform the multi-spectral mission requirements. Significant progress in the design and fabrication of HgCdTe detector arrays and Read Out Integrated Circuits (ROICs) over the past few years has led to the demonstration of high resolution, low noise and large format reliable FPAs. Hybrid FPAs have been measured and their performance parameters are presented. Focal Plane Array D* performance values have been obtained for a multitude of spectral ranges and configurations that include; (1) (lambda) _c equals 1.8 micrometer, 12 X 256 arrays operating at 295 K with median D* approximately 1.4 X 10¹² cm Hz^1/2/W, (2) (lambda) _c equals 2.4 micrometer, 12 X 256 arrays operating at 250 K with median D* equals 1.6 X 10¹² cm Hz^1/2/W, detectors used are grown by MBE on lattice matched CdZnTe, (3) PACE-1 detectors with (lambda) _c equals 2.5 micrometer, 1024 X 1024 arrays operating at 115 K with peak D* of 2.3 X 10¹³ cm Hz^1/2/W at a background flux (phi) _b equals 1.2 X 10¹¹ ph/cm²- s, (4) MBE HgCdTe on Silicon MWIR detectors have been fabricated and the detector R_oA performance for (lambda) _co approximately 5.0 micrometer is in the 10⁶ to 10⁷ ohm-cm² range at 78 K. (5) MBE HgCdTe on CdZnTe detectors, ((lambda) _c equals 15.8 micrometer at 65 K), 128 X 128 array operating at 40 K with peak D* of 2.76 X 10¹¹ cm Hz^1/2/W at a background flux (phi) _b equals 8.0 X 10¹⁵ ph/cm²-s. High performance 640 X 480 arrays imaging in the MWIR band have been fabricated on CdZnTe and PACE-1 substrates. The performance of these and additional FPAs will be presented.

Proceedings Article | 31 December 1997 Paper

HgCdTe detectors for infrared remote sensing applications

Arvind D'Souza, Larry Dawson, Eric Anderson, Arvel Markum, William Tennant, Lucia Bubulac, Majid Zandian, John Pasko, William McLevige, Dennis Edwall, Jeffrey Derr, John Jandik

Proceedings Volume 3221, (1997) https://doi.org/10.1117/12.298105

KEYWORDS: Infrared detectors, Long wavelength infrared, Signal to noise ratio, Infrared sensors, Mercury cadmium telluride, Imaging systems, Sensors, Remote sensing, Infrared radiation, Temperature metrology

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Proceedings Article | 26 August 1997 Paper

Performance of HgCdTe, InGaAs and quantum well GaAs/AlGaAs staring infrared focal plane arrays

Lester Kozlowski, Kadri Vural, Jose Arias, William Tennant, Roger DeWames

Proceedings Volume 3182, (1997) https://doi.org/10.1117/12.280406

KEYWORDS: Staring arrays, Infrared detectors, Photovoltaics, Indium gallium arsenide, Quantum wells, Mercury cadmium telluride, Silicon, Detector arrays, Infrared radiation, Quantum well infrared photodetectors

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SPIE Journal Paper | 1 May 1997

Micro-optic integration with focal plane arrays

M. Edward Motamedi, William Tennant, Haluk Sankur, Robert Melendes, Natalie Gluck, Sangtae Park, Jose Arias, Jagmohan Bajaj, John Pasko, William McLevige, Majid Zandian, Randolph Hall, Karla Steckbauer, Patti Richardson

OE, Vol. 36, Issue 05, (May 1997) https://doi.org/10.1117/12.10.1117/1.601347

KEYWORDS: Microlens, Photoresist materials, Sensors, Diodes, Microlens array, Micro optics, Diffraction, Thin films, Staring arrays, Quantum efficiency

Proceedings Article | 17 June 1996 Paper

SWIR staring FPA performance at room temperature

Lester Kozlowski, William Tennant, Majid Zandian, Jose Arias, John Pasko

Proceedings Volume 2746, (1996) https://doi.org/10.1117/12.243052

KEYWORDS: Staring arrays, Short wave infrared radiation, Indium gallium arsenide, Mercury cadmium telluride, Modulation, Sensors, Interfaces, Field effect transistors, Multiplexers, Airglow

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Proceedings Article | 8 March 1996 Paper

Fabrication of microlens arrays by reactive ion milling

Haluk Sankur, Randolph Hall, M. Edward Motamedi, William Gunning, William Tennant

Proceedings Volume 2687, (1996) https://doi.org/10.1117/12.234628

KEYWORDS: Microlens array, Etching, Argon, Ions, Silicon, Zinc, Oxygen, Photoresist materials, Microlens, Infrared materials

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Proceedings Article | 8 March 1996 Paper

FPAs and thin film binary optic microlens integration

M. Edward Motamedi, William Tennant, Robert Melendes, Natalie Gluck, Sangtae Park, Jose Arias, Jagmohan Bajaj, John Pasko, William McLevige, Majid Zandian, Randolph Hall, Karla Steckbauer, Patti Richardson, Donald Cooper

Proceedings Volume 2687, (1996) https://doi.org/10.1117/12.234638

KEYWORDS: Thin films, Diffraction, Microlens array, Lenses, Sensors, Quantum efficiency, Photoresist materials, Microlens, Diodes, Photomasks

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The relatively large detector size of conventional focal plane arrays often acts as a limiting source of noise currents and requires these devices to run at undesirably low temperatures. To reduce the detector size without reducing the detector's quantum efficiency, we have developed efficient on-focal plane collection optics consisting of arrays of thin film binary optic microlenses on the back surface of hybrid detector array structures. P/n polarity photodiodes of an unusual `planar-mesa' geometry were fabricated in epitaxial HgCdTe deposited by molecular beam epitaxy on the `front' side of a CdZnTe substrate. Diffractive (8 - 16 phase level) Ge microlenses were deposited on 48 micrometers centers in a registered fashion (using an IR mask aligner and appropriate marks on the front surface of the CdZnTe) on the back side of the substrate using a lifting process. The lifting process circumvents some of the process limitations of the more conventional chemical etching method to diffractive microlens processing, allowing them to approach more closely their theoretical efficiency limit of > 95%. Prior to microlens deposition, but after diode fabrication, the test structures were flip- chip bonded or `hybridized' using indium interconnections to metallic strip lines which had been photolithographically deposited on sapphire dice (a process equally compatible with a silicon integrated circuit readout). After hybridization, the CdZnTe was thinned to equal the focal length of the lenses in the CdZnTe material. Optical characterization has demonstrated that the microlenses combined with the detector mesas concentrate light sufficiently to increase the effective collection area. The optical size of the mesa detectors being larger than the theoretical diffraction limit of the microlenses precludes determining whether the lenses themselves produce the theoretical diffraction-limited gain, but they clearly decrease required detector area by at least 3 - 6X. To our knowledge, this is the first successful demonstration of IR detectors and binary optics microlens integration.

Proceedings Article | 16 October 1995 Paper

Experimental comparison of staring IR sensor technologies including PV HgCdTe, PV InGaAs, and quantum well GaAs/AlGaAs

Lester Kozlowski, Jose Arias, William Tennant

Proceedings Volume 2373, (1995) https://doi.org/10.1117/12.224980

KEYWORDS: Staring arrays, Long wavelength infrared, Infrared sensors, Mid-IR, Photovoltaics, Indium gallium arsenide, Quantum wells, Mercury cadmium telluride, Sensors, Quantum well infrared photodetectors

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Proceedings Article | 7 October 1994 Paper

MBE HgCdTe infrared focal plane array (IRFPA) flexible manufacturing

Jose Arias, Majid Zandian, John Pasko, Jagmohan Bajaj, Lester Kozlowski, William Tennant, Roger DeWames

Proceedings Volume 2274, (1994) https://doi.org/10.1117/12.189243

KEYWORDS: Staring arrays, Long wavelength infrared, Mercury cadmium telluride, Databases, Mercury, Manufacturing, Diodes, Heterojunctions, Arsenic, Information operations

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Proceedings Article | 13 July 1994 Paper

Molecular beam epitaxy (MBE) HgCdTe flexible growth technology for the manufacturing of infrared photovoltaic detectors

Jose Arias, John Pasko, Majid Zandian, Jagmohan Bajaj, Lester Kozlowski, Roger DeWames, William Tennant

Proceedings Volume 2228, (1994) https://doi.org/10.1117/12.179662

KEYWORDS: Infrared detectors, Long wavelength infrared, Photovoltaics, Mercury cadmium telluride, Manufacturing, Infrared radiation, Infrared photography, Photovoltaic detectors, Heterojunctions, Molecular beam epitaxy

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SPIE Journal Paper | 1 March 1994

Attainment of high sensitivity at elevated operating temperatures with staring hybrid HgCdTe-on-sapphire focal plane arrays

Lester Kozlowski, William McLevige, Scott Cabelli, A. Vanderwyck, Donald Cooper, Edward Blazejewski, Kadri Vural, William Tennant

OE, Vol. 33, Issue 03, (March 1994) https://doi.org/10.1117/12.10.1117/12.163405

KEYWORDS: Sensors, Staring arrays, Field effect transistors, Modulation, Mid-IR, Mercury cadmium telluride, Temperature metrology, Capacitance, Capacitors, Optical amplifiers

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SPIE Journal Paper | 1 January 1994

High-performance 5-μm 640 x 480 HgCdTe-on-sapphire focal plane arrays

Lester Kozlowski, Robert Bailey, Scott Cabelli, Donald Cooper, Isoris Gergis, Annie Chen, William McLevige, Gary Bostrup, Kadri Vural, William Tennant, Philip Howard

OE, Vol. 33, Issue 01, (January 1994) https://doi.org/10.1117/12.10.1117/12.151551

KEYWORDS: Sensors, Staring arrays, Mercury cadmium telluride, Quantum efficiency, Long wavelength infrared, Cameras, Mid-IR, Sapphire, Temperature metrology, Silicon

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Proceedings Article | 10 December 1992 Paper

640 x 480 PACE HgCdTe FPA

Lester Kozlowski, Robert Bailey, Scott Cabelli, Donald Cooper, Gail McComas, Kadri Vural, William Tennant

Proceedings Volume 1735, (1992) https://doi.org/10.1117/12.138620

KEYWORDS: Staring arrays, Infrared detectors, Long wavelength infrared, Mid-IR, Mercury cadmium telluride, Sensors, Quantum efficiency, Detector arrays, Sapphire, Temperature metrology

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Proceedings Article | 1 September 1992 Paper

128 x 128 PACE-I HgCdTe hybrid FPAs for thermoelectrically cooled applications

Lester Kozlowski, S. Johnston, William McLevige, A. Vanderwyck, Donald Cooper, Scott Cabelli, Edward Blazejewski, Kadri Vural, William Tennant

Proceedings Volume 1685, (1992) https://doi.org/10.1117/12.137796

KEYWORDS: Staring arrays, Infrared detectors, Mid-IR, Short wave infrared radiation, Mercury cadmium telluride, Sensors, Spectroscopy, Detector arrays, Field effect transistors, Temperature metrology

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Proceedings Article | 1 December 1991 Paper

Large staring IRFPAs of HgCdTe on alternative substrates

Lester Kozlowski, Robert Bailey, Donald Cooper, Kadri Vural, E. Gertner, William Tennant

Proceedings Volume 1540, (1991) https://doi.org/10.1117/12.48747

KEYWORDS: Staring arrays, Mid-IR, Mercury cadmium telluride, Sensors, Calibration, Quantum efficiency, Reliability, Detector arrays, Infrared technology, Temperature metrology

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Showing 5 of 27 publications

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