QmagiQ - Technology, QWIP FPA

We currently offer standard 1-Color LWIR QWIP FPAs in formats upto 640x512.
Our near-term and long-term product development are as follows.

Near-Term Roadmap (In Development)

Bookmark this page to check our progress periodically.

Click here to see our prior history in 2-Color. The drawings/pictures will look familiar to some. There is a good reason for this. QmagiQ engineers first developed and demonstrated this technology in 1997 while at Lockheed-Martin. The results have been widely disseminated and presented in the years since. It is a measure of our expertise that no other group in the world has successfully pulled off a similar development yet. If you are looking for 2-Color, you have come to the right place - the original team that first made it all happen.

QDIPs theoretically offer higher sensitivity and higher operating temperature than QWIPs, at comparable or lower cost. The subject of intense academic research and a promising path to tenure (as evidenced by the volume of technical publications in the last 10 years), QDIPs have sadly yet to live up to their promise. As device experts, we are applying a variety of design/process tricks to make QDIPs a commercial reality. Our goal is to make a QDIP FPA operating at/near room temperature.

Long-Term Roadmap

Some chemical/biological agents have characteristic spectral signatures in the infrared. Our goal is to make chips that detect light with hyperfine spectral resolution, each chip covering a broad IR spectral band. These next-gen FPAs will not just "see" - they will "recognize" targets. They will essentially be spectrometers on chips.

Why indeed. In a nutshell, cost and performance. If you want a high-performance large (320x256 and larger) 2D LWIR FPA in this lifetime at reasonable cost, QWIP technology is the only way to go. Sure, MCT technology is only two years away, and has been for the last 20 years. But if you want results, not promises, and have products to deliver with limited budgets, you cannot afford to not look at QWIPs. It will save you time and money, and deliver performance. Guaranteed.

Technology Overview

Developed in the mid-1980s in several university and industrial labs, QWIP technology arose from the confluence of bandgap engineering afforded by compound-semiconductor heterostructures, and ultra-high-vacuum epitaxy techniques such as molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD).

Unlike photovoltaic (PV) or photoconductive (PC) detectors that rely on interband (valence band to conduction band) absorption in semiconductors, QWIPs rely on intersubband absorption of light between quantized energy states in quantum wells within the conduction/valence band.

Such square quantum wells usually consist of GaAs layers sandwiched between AlGaAs barriers: the GaAs layer thickness determines the well width, the Al% in the barrier AlGaAs controls the well depth. By adjusting these two parameters, quantum wells can be created having two bound states with an energy separation that can be controlled to be anywhere from ~ 3 µm to ~ 20 µm. The wells are doped to provide electrons in the ground state which resides near the well bottom. Incoming photons with the right energy pop/excite these electrons to the excited state that is designed to be near the well top, from where they are swept out by an applied voltage. QWIPs thus have a sharp spectral response, dictated by the sharpness of the quantized states. A QWIP is the simplest and most striking manifestation of quantum mechanics - the classic "particle-in-a-box" problem in any QM textbook.

The cost and performance advantages of QWIP technology arise from the maturity of GaAs/AlGaAs growth and process technology. For example, QmagiQ FPAs are fabricated on wafers upto 6-inches in diameter and use the latest and best growth and process tools. This automated production guarantees the best sensitivity, uniformity, and reproducibility.

Vertical sidewalls (RIE)
Precise control of small patterns (RIE)
Narrow trenches between pixels
High fill-factor (> 87% in 320x256 FPA)
High-yield wafer-level process
3-inch and 6-inch automated wafer handling

Mature MBE/MOCVD growth process
Multi-wafer growth reactors (upto 15 3-inch wafers per growth run)
Quality control procedures in place
High uniformity
Superior wafer-to-wafer reproducibility
Excellent lot-to-lot reproducibility
Material cost is low and continues to drop as volume increases
Maximum GaAs wafer size = 6-inches

320x256x1 format (XxYxSpectral-band)
Pitch = 30 µm
LWIR (peak wavelength at ~ 8.6 µm)
Fill-factor > 87%
Operability >> 99.5%
Non-uniformity < 3% uncorrected
NETD < 20 mK (@ 60K, f/2, 100 Hz)
QE = 15%, CE = 5%
Operating Temperature = 65 - 77K
In production

Pixels isolated electrically & optically
3 bumps per pixel
Vertical sidewalls
Small vias
> 80% fill-factor top color
> 85% fill-factor bottom color
Architecture Advantages
   Narrow QWIP spectral response ideal for multi-color applications
   No optical filter required
   No signal-processing required
   Spatially-registered images
   Simultaneous integration
   Wide range of spectral band combinations possible
   Single-chip solution dramatically lowers size, power, and cost of multi-band imaging

Peak wavelength as low as 4.0 µm achievable in QWIP
Shorter wavelength detection achieved with integrated pin diode



	Near-Term Roadmap \| Long-Term Roadmap \| QWIP Technology \| Technology Charts We currently offer standard 1-Color LWIR QWIP FPAs in formats upto 640x512. Our near-term and long-term product development are as follows. Near-Term Roadmap (In Development) Bookmark this page to check our progress periodically. 2-Color mid-format 320x256 MWIR/LWIR QWIP FPA featuring - Pixel-registered imaging - Simultaneous integration - Other dual-band combinations possible - NIR/LWIR, LWIR/LWIR, MWIR/MWIR, etc Click here to see our prior history in 2-Color. The drawings/pictures will look familiar to some. There is a good reason for this. QmagiQ engineers first developed and demonstrated this technology in 1997 while at Lockheed-Martin. The results have been widely disseminated and presented in the years since. It is a measure of our expertise that no other group in the world has successfully pulled off a similar development yet. If you are looking for 2-Color, you have come to the right place - the original team that first made it all happen. 1-Color very-large-format 1Kx1K LWIR QWIP FPA - for those who will settle for no less than a million infrared pixels 1-Color LWIR Quantum Dot Infrared Photodetector (QDIP) FPA QDIPs theoretically offer higher sensitivity and higher operating temperature than QWIPs, at comparable or lower cost. The subject of intense academic research and a promising path to tenure (as evidenced by the volume of technical publications in the last 10 years), QDIPs have sadly yet to live up to their promise. As device experts, we are applying a variety of design/process tricks to make QDIPs a commercial reality. Our goal is to make a QDIP FPA operating at/near room temperature. Long-Term Roadmap Terahertz imaging arrays for use in security screening - safer alternative to Xrays Hyperspectral infrared arrays - with potential applications in chemical and biological threat sensing Some chemical/biological agents have characteristic spectral signatures in the infrared. Our goal is to make chips that detect light with hyperfine spectral resolution, each chip covering a broad IR spectral band. These next-gen FPAs will not just "see" - they will "recognize" targets. They will essentially be spectrometers on chips. Heterodyne QWIP arrays for Infrared LIDAR - arrays that will both image and provide range/velocity information about the target Back to the top Why indeed. In a nutshell, cost and performance. If you want a high-performance large (320x256 and larger) 2D LWIR FPA in this lifetime at reasonable cost, QWIP technology is the only way to go. Sure, MCT technology is only two years away, and has been for the last 20 years. But if you want results, not promises, and have products to deliver with limited budgets, you cannot afford to not look at QWIPs. It will save you time and money, and deliver performance. Guaranteed. Technology Overview Developed in the mid-1980s in several university and industrial labs, QWIP technology arose from the confluence of bandgap engineering afforded by compound-semiconductor heterostructures, and ultra-high-vacuum epitaxy techniques such as molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). Unlike photovoltaic (PV) or photoconductive (PC) detectors that rely on interband (valence band to conduction band) absorption in semiconductors, QWIPs rely on intersubband absorption of light between quantized energy states in quantum wells within the conduction/valence band. Such square quantum wells usually consist of GaAs layers sandwiched between AlGaAs barriers: the GaAs layer thickness determines the well width, the Al% in the barrier AlGaAs controls the well depth. By adjusting these two parameters, quantum wells can be created having two bound states with an energy separation that can be controlled to be anywhere from ~ 3 µm to ~ 20 µm. The wells are doped to provide electrons in the ground state which resides near the well bottom. Incoming photons with the right energy pop/excite these electrons to the excited state that is designed to be near the well top, from where they are swept out by an applied voltage. QWIPs thus have a sharp spectral response, dictated by the sharpness of the quantized states. A QWIP is the simplest and most striking manifestation of quantum mechanics - the classic "particle-in-a-box" problem in any QM textbook. The cost and performance advantages of QWIP technology arise from the maturity of GaAs/AlGaAs growth and process technology. For example, QmagiQ FPAs are fabricated on wafers upto 6-inches in diameter and use the latest and best growth and process tools. This automated production guarantees the best sensitivity, uniformity, and reproducibility. Back to the top The physics, technology, and advantages of QWIPs are captured in the following snapshot charts. Vertical sidewalls (RIE) Precise control of small patterns (RIE) Narrow trenches between pixels High fill-factor (> 87% in 320x256 FPA) High-yield wafer-level process 3-inch and 6-inch automated wafer handling Mature MBE/MOCVD growth process Multi-wafer growth reactors (upto 15 3-inch wafers per growth run) Quality control procedures in place High uniformity Superior wafer-to-wafer reproducibility Excellent lot-to-lot reproducibility Material cost is low and continues to drop as volume increases Maximum GaAs wafer size = 6-inches 320x256x1 format (XxYxSpectral-band) Pitch = 30 µm LWIR (peak wavelength at ~ 8.6 µm) Fill-factor > 87% Operability >> 99.5% Non-uniformity < 3% uncorrected NETD < 20 mK (@ 60K, f/2, 100 Hz) QE = 15%, CE = 5% Operating Temperature = 65 - 77K In production Pixels isolated electrically & optically 3 bumps per pixel Vertical sidewalls Small vias > 80% fill-factor top color > 85% fill-factor bottom color Architecture Advantages Narrow QWIP spectral response ideal for multi-color applications No optical filter required No signal-processing required Spatially-registered images Simultaneous integration Wide range of spectral band combinations possible Single-chip solution dramatically lowers size, power, and cost of multi-band imaging Peak wavelength as low as 4.0 µm achievable in QWIP Shorter wavelength detection achieved with integrated pin diode Back to the top