The partnership between RVS, Seek Thermal and Freescale Semiconductor continues on the path to bring the latest technology and innovation to both military and commercial customers. The partnership has matured the 17μm pixel for volume production on the Thermal Weapon Sight (TWS) program in efforts to bring advanced production capability to produce a low cost, high performance product. The partnership has developed the 12μm pixel and has demonstrated performance across a family of detector sizes ranging from formats as small as 206 x 156 to full high definition formats. Detector pixel sensitivities have been achieved using the RVS double level advanced pixel structure. Transition of the packaging of microbolometers from a traditional die level package to a wafer level package (WLP) in a high volume commercial environment is complete. Innovations in wafer fabrication techniques have been incorporated into this product line to assist in the high yield required for volume production. The WLP seal yield is currently > 95%. Simulated package vacuum lives >> 20 years have been demonstrated through accelerated life testing where the package has been shown to have no degradation after 2,500 hours at 150°C. Additionally the rugged assembly has shown no degradation after mechanical shock and vibration and thermal shock testing. The transition to production effort was successfully completed in 2014 and the WLP design has been integrated into multiple new production products including the TWS and the innovative Seek Thermal commercial product that interfaces directly to an iPhone or android device.

At the 2010 meeting of the Defense and Security Symposia Raytheon reported on the status of their efforts to establish a high rate uncooled detector manufacturing capability. At that time we had just finished the transition of the 640 x 480, 25 mu m product to our 200 mm wafer fab line at Freescale semiconductor and established an automated packaging and test capability.Over the past year we have continued to build on that foundation. In this paper we will report on this year's progress in completing the transition of our 25 mu m product line to Freescale semiconductor. Included will be the 320 x 240 product transition and a summary of SPC and defectivity data from one year's production.Looking beyond 25 mu m, we are well along in our transition of the 17 mu m product line to Freescale, with test results being available for the 640 x 480. Additionally, we will report on progress / status of the Tailwind program, which is developing a 2048 x 1536, 17 mu m uncooled sensor. Data to be reported includes the establishment of subfield stitching at a high rate commercial fab and the development of the detector package and electronics.With 17 mu m transitioned to production, Raytheon has started work on the HD LWIR program, which is laying the foundation for the next generation of uncooled detectors by further shrinking the pixel to <17 mu m. With the HD LWIR program just beginning, we will review our development strategy and program plan.

RVS has made a significant breakthrough in the development of an athermal (TECless) 640 x 480 uncooled sensor with a unit cell size of 17 μm x 17 μm, and performance approaching that of the 25μm arrays. The sensor design contains a highly productized FPA and is designed to achieve excellent sensitivity (low NETD and low spatial noise) with good dynamic range. The improved performance is achieved through bolometer structure improvements, innovative ROIC design, and flexible, low power electronics architecture. We will show updated performance and imagery on these sensors, which is currently being measured at <50mK, f/1, 30 Hz. Pixel operability is greater than 99 % on most FPAs, and uncorrected responsivity nonuniformity is less than 3% (sigma/mean). The combination of reduced FPA pixel size and improved effective thermal sensitivity enhances performance by providing smaller, lighter-weight systems via reduced optics size. Or, alternatively, increased range via enhanced pixel resolution without increasing mass (maintaining optical size). We will also show the advancements made in our uncooled common architecture electronics in terms of reduced power and size for man-portable and missile applications.

RVS has made a significant breakthrough in the development of a 640 x 512 uncooled array with a unit cell size of 17 μm x 17 μm, and performance approaching that of the 25μm arrays. The successful development of this array is the first step in achieving mega-pixel formats. This FPA is designed to ultimately achieve performance of (<50mK, f/1, 30 Hz) with an 8 msec time constant. The SB-400 is a highly productized ROIC and is designed to achieve very good sensitivity (low NETD and low spatial noise) and good dynamic range. The improved performance is through bolometer structure improvements and an innovative ROIC design. It also has a simple and flexible electrical interface which allows external electronics to be small, lightweight, low-cost, and low-power. Almost all adjustments can be made through the serial interface; hence there is no need for external adjustable (DAC) circuitry. The improved power supply rejection helps maintain highly stable detector and strip resistor bias voltages which helps reduce spatial noise and image artifacts. The combination of reduced FPA pixel size and improved effective thermal sensitivity enhances weapon sight performance by providing smaller, lighter-weight sights via reduced optics size or increased range via enhanced pixel resolution without increasing mass or increased range via improved NETD (lower f/#) without increasing mass. We will also provide an update on the enhanced performance and yield producibility of our NVESD ManTech 640 x 480 25μm arrays. We will also show the improvement in our uncooled common architecture electronics in terms of reduced power and size for helmet and rifle mounted sensors and a variety of missile applications.

RVS has made a significant breakthrough in the development of a 640 x 512 uncooled array with a unit cell size of 17 pm x 17 mu m, and performance approaching that of the 25 mu m arrays. The successful development of this array is the first step in achieving mega-pixel formats. This FPA is designed to ultimately achieve performance of (< 50mK, f/1, 30 Hz) with an 8 msec time constant. The SB-400 is a highly productized ROIC and is designed to achieve very good sensitivity (low NETD and low spatial noise) and good dynamic range. The improved performance is through bolometer structure improvements and an innovative ROIC design. It also has a simple and flexible electrical interface which allows external electronics to be small, lightweight, low-cost, and low-power. Almost all adjustments can be made through the serial interface; hence there is no need for external adjustable (DAC) circuitry. The improved power supply rejection helps maintain highly stable detector and strip resistor bias voltages which helps reduce spatial noise and image artifacts.The combination of reduced FPA pixel size and improved effective thermal sensitivity enhances weapon sight performance by providing smaller, lighter-weight sights via reduced optics size or increased range via enhanced pixel resolution without increasing mass or increased range via improved NETD (lower f/#) without increasing mass. We will also provide an update on the enhanced performance and yield producibility of our NVESD ManTech 640 x 480 25 mu m arrays.We will also show the improvement in our uncooled common architecture electronics in terms of reduced power and size for helmet and rifle mounted sensors and a variety of missile applications.

RVS has made a significant breakthrough in the development of a 640 × 512 array with a unit cell size of 20μm × 20 μm and performance equivalent to that of the 25μm arrays. The successful development of this array is the first step in achieving mega-pixel formats. This FPA is designed to ultimately achieve performance near the temperature fluctuation limited NETD (<20mK, f/1, 30 Hz). The SB-300 is a highly productized readout and is designed to achieve very good sensitivity (low NETD and low spatial noise) and good dynamic range. The improved performance is through bolometer structure improvements and an innovative ROIC design. It also has a simple and flexible electrical interface which allows external electronics to be small, light, low-cost, and low-power. Almost all adjustments can be made through the serial interface; hence there is no need for external adjustable (DAC) circuitry. The improved power supply rejection helps maintain highly stable detector and strip resistor bias voltages which helps reduce spatial noise and image artifacts. We will show updated performance and imagery on these arrays, which is currently being measured at <30mK, f/1,555 30 Hz. Pixel operability is greater than 99.5% on most FPAs, where the uncorrected responsivity nonuniformity is less than 4% (sigma/mean), and time constant for these arrays was measured at <8msec. We will report detailed FPA performance results including responsivity, noise, uniformity and pixel operability. We also plan to present video imagery from the most recent FPAs. The reduction in pixel size offers several potential benefits for IR systems. For a given system resolution (IFOV) requirement, the 20 μm pixel will allow an optical volume that is 50 % the size of a 25 μm based system! We will also provide an update on the enhanced performance and yield producibility of our NVESD ManTech 640 × 480 25 μm arrays, and also show data on 25 μm arrays that have been designed for faster time constants (5 ms), while maintaining high performance. We will also show the improvement in our uncooled 320 × 240 and 640 × 480 sensor electronics in terms of reduced power and size for helmet and rifle mounted sensors.

Millimeter-wave (mmw) imagers offer advantages for numerous applications, including: all weather reconnaissance, search and rescue, law enforcement, and security screening for homeland defense. The use of bolometer-based imagers for mmw provides potential advantages of low power, small size, weight, and cost. In addition, bolometer-based imagers provide the unique capability of detection over an enormous spectral range, i.e., from mmw through the sub-mmw (from 100 GHz through greater than 1 THz). We report on high-resolution materials transmission measurements as well as advances in mmw imager architectures that seek to exploit improved imager sensitivity and resolution enabled by operation at sub-mmw and THz frequencies

RVS is producing high-quality microbolometer FPAs with 25 μm pixels. We have developed formats in both 320 x 240 and 640 x 480 array formats. These FPAs have demonstrated sensitivities that are comparable to microbolometer FPAs with 50 μm pixels with the best measured NETD value for these FPAs now <25mK with an f/1 aperture and operating at 30 Hz frame rates. Pixel operability is greater than 99.9% on most FPAs, and uncorrected responsivity nonuniformity is less than 3% (sigma/mean). These 25 μm microbolometer detectors also have a relatively fast thermal time constant of approximately 10 msec. These arrays have produced excellent image quality, and are currently fielded in a variety of systems. We will report on our latest performance data and IR captive flight test imagery. We will also show data on 25μm arrays that have been designed for faster time constants (5 msec), while maintaining high performance. RVS is also developing a 320 x 240 50μm mid-wave responding FPA. We will review the MWIR sensitivity improvements with this array and provide IR imagery. RVS is developing a 640 x 480 25μm uncooled FPA for a countermine detection application using a two-band assembly designed to be sensitive in both the Restrahlen and Thermal spectral bands. We will provide IR image data on these arrays. RVS has made a significant breakthrough in the development of a 640 x 512 array with a unit cell size of 20 μm x 20 μm, and performance approaching that of the 25μm arrays. The successful development of this array is the first step in achieving mega-pixel formats. This FPA is designed to ultimately achieve performance near the temperature fluxuation limited NETD (<20mK, f/1, 30 Hz). We will show updated performance and imagery on these arrays, which is currently being measured at <45mK, f/1, 30 Hz.

Raytheon is producing high-quality 320 x 240 microbolometer FPAs with 25 mum pitch pixels. The 320 x 240 FPAs have a sensitivity that is comparable to microbolometer FPAs with 50 mum pixels. Typical NETD values for these FPAs are <50mK with an f/1 aperture and operating at 30 Hz frame rates. Pixel operability is greater than 99.9% on most FPAs, and uncorrected responsivity nonuniformity is less than 4% (sigma/mean). These 25 mum microbolometer detectors also have a relatively fast thermal time constant of approximately 10 msec. These arrays have produced excellent image quality, and are currently fielded in a variety of demonstration systems.The pixel size reduction facilitates a significant FPA cost reduction since the number of die printed on a wafer can be increased, and also has enabled the development of a large-format 640 x 480 FPA array.Raytheon is producing these arrays with excellent sensitivity and typical NETD values of <50mK with an f/1 aperture and operating at 30 Hz frame rates. These arrays have excellent operability and image quality. Several dual FOV prototype 640 x 480 systems have been delivered under the LCMS and UAV programs.RVS has developed a flexible uncooled front end (UFE) electronics that will serve as the basis for the camera engine systems using 320 x 240 arrays. RVS has developed a 640 x 480 Common Uncooled Engine (CUE) which is intended for small pixel, high performance applications. The CUE is the ideal cornerstone for ground and airborne systems, multi-mode sensor, weapon sight or seeker architectures, and commercial surveillance.

Hybrid CdZnTe, CdTe, GaAs, selenium and PbI2 pixel detector arrays with 50×50μm2 pixel sizes that convert X-rays directly into charge signals are under development at NOVA for application to digital mammography. These detectors have superior X-ray quantum efficiency compared to either emulsion-based film, phosphor-based detectors or other low-Z, solid-state detectors such as silicon. During this work, CdZnTe and CdTe pixel detectors gave the best results. The other detectors are at very early stages of development and need significant improvement. Among other detectors, selenium is showing the highest potential. The preliminary results show that single crystal CdZnTe detectors yield better results in Detective Quantum Efficiency (DQE) as well as in images obtained from phantoms, compared to the polycrystalline CdZnTe detectors. This is due to the non-uniformities in the polycrystaline CdZnTe that degrade the charge transport properties. In this paper, preliminary results from thin (0.15 to 0.2mm) CdZnTe and CdTe detectors will be presented in terms of MTF, DQE and phantom images. Because of the charge-coupling limitation of the readout Application Specific Integrated Circuit (ASIC) that was originally designed for Si detectors, the detector is biased to collect holes from the input. This charge collection mode limits the CdZnTe detector performance. Their DQE measurements yield 25% and 65% for the polycrystal and single-crystal CdZnTe detectors, respectively. Polycrystal CdTe test detectors were also hybridized to the same type charge readout chip. Since CdTe has much longer hole-propagation lengths compared to CdZnTe, it shows better performance in the hole-collecting mode. However, it suffers from polarization. Excellent images were also obtained from the CdTe detectors. Future work to redesign the readout ASIC and thus improve the detector performance will be discussed. These detectors can also be used for other medical radiography with increased thickness and also for industrial imaging such as non-destructive evaluation and non-destructive inspection.

Hybrid CdZnTe and CdTe pixel detector arrays that convert X-rays directly into charge signals are under development at Nova for applications to digital mammography. CdZnTe and CdTe have superior X-ray conversion efficiency compared to either emulsion based film, phosphor-based detectors or other low-Z, solid-state detectors such as silicon. In this paper, latest results from thin (0.15 to 0.2 mm) CdZnTe and CdTe detectors will be presented in terms of MTF, DQE and phantom images. Single crystal CdZnTe detectors yield better results in DQE as well as phantom images, compared to the poly-crystal CdZnTe detectors. This is due to the non-uniformities in the poly-crystal that degrade the charge transport properties. Because of the charge-coupling limitation of the readout ASIC that was originally designed for Si detectors, the detector is biased to collect holes from the front side. This charge collection mode limits the CdZnTe detector performance. Their DQE measurements yield 25% and 65% for the poly-crystal and single-crystal CdZnTe detectors respectively. Poly-crystal CdTe test detectors were also hybridized to the same type charge readout chip. Since CdTe has much longer hole-propagation lengths compared to CdZnTe, it shows better performance in the hole-collecting mode. However, severe polarization effect degrades performance of the present device. Excellent images were also obtained from the CdTe detectors. Future work to redesign the readout ASIC and thus improve the detector performance is discussed. Applications to industrial imaging such as Non-Destructive Evaluation (NDE) and Non-Destructive Inspection (NDI) are also discussed.

A new high-resolution detector has been developed for use in a slot-scanned digital mammography system. The detector is a hybrid device that consists of a CCD operating in time-delay integration mode that is bonded to a 150-microm-thick CdZnTe photoconductor array. The CCD was designed with a detector element pitch of 50 microm. Two devices were evaluated with differing crystalline quality. Incomplete charge collection was a source of reduction in DQE. This occurs in both devices due to characteristically low mobility-lifetime products for CdZnTe, with the greatest losses demonstrated by the multicrystalline sample. The mobility-lifetime products for the multicrystalline device were found to be 2.4 x 10(-4) and 4.0 x 10(-7) cm2/V for electrons and holes, respectively. The device constructed with higher quality single crystal CdZnTe demonstrated mobility-lifetime products of 1.0 x 10(-4) and 4.4 x 10(-6) cm2/V for electrons and holes. The MTF and DQE for the device were measured at several exposures and results were compared to predictions from a linear systems model of signal and noise propagation. The MTF at a spatial frequency of 10 mm(-1) exceeded 0.18 and 0.56 along the scan and slot directions, respectively. Scanning motion and CCD design limited the resolution along the scan direction. For an x-ray beam from a tungsten target tube with 40 microm molybdenum filtration operated at 26 kV, the single crystal device demonstrated a DQE(0) of 0.70 +/- 0.02 at 7.1 x 10(-6) C/kg (27 mR) exposure to the detector, despite its relatively poor charge collection efficiency.

Since its initial synthesis and investigation more than 40 years ago, the HgCdTe alloy semiconductor system has evolved into one of the primary infrared detector materials for high-performance infrared focal-plane arrays (FPA) designed to operate in the 3-5 mum and 8-12 mum spectral ranges of importance for thermal imaging systems. Over the course of the past decade, significant advances have been made in the development of thin-film epitaxial growth techniques, such as molecular-beam epitaxy (MBE), which have enabled the synthesis of IR detector device structures with complex doping and composition profiles. The central role played by in situ sensors for monitoring and control of the MBE growth process are reviewed. The development of MBE HgCdTe growth technology is discussed in three particular device applications: avalanche photodiodes for 1.55 mum photodetection, megapixel FPAs on Si substrates, and multispectral IR detectors.

Raytheon has recently been funded by DARPA to develop an FPA for single shot eyesafe ladar operation. The goal of the program is to develop new high speed imaging arrays to rapidly acquire high resolution, three dimensional images of tactical targets at ranges as long as 7 to 10 kilometers. This would provide precision strike, target identification from rapidly moving platforms, such as air-to-ground seekers, which would enhance counter-counter measure (CCM) performance and the ability to lock-on after launch. Also a goal is to demonstrate the acquisition of hidden, camouflaged and partially obscured targets. Raytheon's approach consists of using HgCdTe APD arrays which offer unique advantages for high performance eyesafe LADAR sensors. These include: eyesafe operation at room temperature, low excess noise, high gain to overcome thermal and preamp noise, GHz bandwidth and high packing density. The detector array will be coupled with a Readout Integrated Circuit, ROIC, that will capture all the information required for accurate range determination. The two components encompass a hybrid imaging array consisting of two IC circuit chips vertically integrated via an array of indium metal "bumps." The chip containing the APD detector array and the silicon signal processing readout chip are independently optimized to provide the highest possible performance for each function.

HgCdTe APDs and APD arrays offer unique advantages for high-performance eyesafe LADAR sensors. These include: operation at room temperature, low-excess noise, high gain, high-quantum efficiency at eyesafe wavelengths, GHz; bandwidth, and high-packing density. The utility of these benefits for systems are being demonstrated for both linear and area array sensors. Raytheon has fabricated 32 element linear APD arrays utilizing liquid phase epitaxy (LPE), and packaged and integrating these arrays with low-noise amplifiers. Typical better APDs configured as 50-micron square pixels and fabricated utilizing RIE, have demonstrated high fill factors (>80%), low crosstalk (<2%), excellent uniformity, low dark currents (<10nA), and noise equivalent power (NEP) from 1 - 2 nW. Two units have been delivered to NVESD, assembled with range extraction electronics, and integrated into the CELRAP laser radar system. Tests on these sensors in July and October 2000 have demonstrated excellent functionality, detection of I-cm wires, and range imaging. Work is presently underway under DARPA's 3-D imaging Sensor Program to extend this excellent performance to area arrays. High-density arrays have been fabricated using LPE and molecular beam epitaxy (MBE). HgCdTe APD arrays have been made in 5 x 5, 10 x 10 and larger formats. Initial data shows excellent typical better APD performance with unmultiplied dark current <10 nA; and NEP <2.0 nW at a gain of 10.

Digital mammography has demanding imaging requirements, including very high spatial resolution (50 mu m) and SNR. To make efficient use of the radiation dose, it is also desirable that the DQE of the image receptor is high. To achieve these requirements, a prototype CCD read-out has been designed, which is hybridized to a semiconductor array to form a direct conversion detector that can be employed in a slot-scanned digital x-ray imaging system. The image quality of the detectors in which the CCD is hybridized to either a silicon photodiode array or a CdZnTe photoconductor array has been measured. A 1 mm thick silicon device has shown a DQE(f) of 0.64 at 0 mm(-1) falling to 0.14 at 10 mm(-1) in the slot direction (20 keV). The CdZnTe hybrid device is very thin (150 mu m) and has a theoretical DQE in excess of 0.9 at 20 keV. The resolution of the CdZnTe device is excellent, with an experimental MTF that is limited only by the detector element size, and the TDI scanning technique. However, the experimental DQE is lower than predicted, believed to be due to crystal non-uniformity, and excessive carrier trapping. Future work will investigate the improvement in image quality obtainable by using a very high purity single-crystal CdZnTe device.