This article describes new imaging capabilities and technologies developed for infrared focal plane arrays (FPAs) at SCD. One of the new technologies is the patterning of the back surface of the FPA, whose front surface is bonded to a silicon readout integrated circuit (ROIC). Another is the hybridization of a spectral filter to the same back surface. <p> </p>Increased image resolution has been achieved by using an opaque mask on the backside of the FPA with small central apertures. The reduced fill factor of the sensor leads to lower crosstalk between neighboring pixels and a higher Nyquist frequency. A highly detailed multi-mega pixel image is obtained when the sensor is micro-scanned relative to the imaging optics. <p> </p>Spectral filtering was achieved by hybridization of a designated filter to the backside of the FPA. The filter was glued to the FPA with high accuracy achieving single pixel resolution. System implementation of these SWIR sensor cameras has been demonstrated at imec and is reported in this paper. <p> </p>First results are reported for a continuously varying monolithic filter deposited onto the FPA, which has a high spectral dispersion. We report electro-optical measurements on several different sensors and describe some of their key parameters.
In recent years SCD has developed InGaAs/InP technology for Short-Wave Infrared (SWIR) imaging. The first product, Cardinal 640, has a 640×512 (VGA) format at 15μm pitch, and more than two thousand units have already been delivered to customers. Recently we have also introduced Cardinal 1280 which is an SXGA array with 10μm pitch aimed for long-range high end platforms . One of the big challenges facing the SWIR technology is its proliferation to widespread low cost and low SWaP applications, specifically Low Light Level (LLL) and Image Intensifier (II) replacements. In order to achieve this goal we have invested and combined efforts in several design and development directions: 1. Optimization of the InGaAs pixel array, reducing the dark current below 2fA at 20° C in order to save TEC cooling power under harsh light and environmental conditions. 2. Design of a new "Low Noise" ROIC targeting 15e noise floor and improved active imaging capabilities 3. Design of compact, low SWaP and low cost packages. In this context we have developed 2 types of packages: a non-hermetic package with thermo-electric cooler (TEC) and a hermetic TEC-Less ceramic package. 4. Development of efficient TEC-Less algorithms for optimal imaging at both day-light and low light level conditions. The result of these combined efforts is a compact low SWaP detector that provides equivalent performance to Gen III image intensifier under starlight conditions. In this paper we will present results from lab and field experiments that will support this claim.
In recent years SCD has developed InGaAs/InP technology for Short-Wave Infrared (SWIR) imaging. The first
product, Cardinal 640, has a 640x512 (VGA) format at 15μm pitch, and more than a thousand units have already
We now present Cardinal 1280, having the smallest pitch available today (10μm), with a 1280x1024 (SXGA)
format. Cardinal 1280 addresses both long-range daylight imaging, and passive or active imaging in Low Light
Level (LLL) conditions.
The Readout Integrated Circuit supports snapshot imaging at 13 bit resolution with a frame rate of 160Hz at full
format, or a frame rate of 640Hz with 2x2 binning. It also has a Low Noise Imaging (LNIM) mode with 35ereadout
noise with internal Correlated Double Sampling (CDS). An asynchronous Laser Pulse Detection (ALPD)
mode is implemented with 2x2 binning in parallel to SWIR imaging (with 10 μm resolution). The new 10 μm
pixel is sensitive down to the visible (VIS) spectrum, with a typical dark current of ~ 0.5fA at 280K, and a
quantum efficiency >80% at 1550nm.
The Focal Plane Array is integrated into a ruggedized, high vacuum integrity, metallic package, with a Thermo-
Electric Cooler (TEC) for optimized performance, and a high grade Sapphire window. In this paper we will
present the architecture and preliminary measurement results.
Advanced electro-optical systems are designed towards a more compact, low power, and low cost solution with respect to traditional systems. Integration of several components or functionalities, such as infrared imager, laser designator, laser range finder (LRF), into one multi-function detector serves this trend. SNIR Read-Out Integrated Circuit (ROIC) incorporates this high level of signal processing and with relatively low power consumption. In this paper we present measurement results from a Focal Plane Array (FPA) where the SNIR ROIC is Flip-Chip bonded to a 15µm pitch VGA InGaAs detector array. The FPA is integrated into a metallic vacuum sealed package. We present InGaAs arrays with dark current density below 1.5 nA/cm<sup>2</sup> at 280K (typically 1fA), Quantum Efficiency higher than 80% at 1550 nm and operability better than 99.5%. The metallic package is integrated with a low power proximity electronics which delivers Camera Link output. The overall power dissipation is less than 1W, not including Thermal-Electric Cooling (TEC), which is required in some applications. The various active and passive operation modes of this detector will be reviewed. Specifically, we concentrate on the "high gain" mode with low readout noise for Low Light Level imaging application. Another promising feature is the Asynchronous Laser Pulse Detection (ALPD) with remarkably low detection thresholds.
Long range sights and targeting systems require a combination of high spatial resolution, low temporal NETD, and wide
field of view. For practical electro-optical systems it is hard to support these constraints simultaneously. Moreover,
achieving these needs with the relatively low-cost Uncooled μ-Bolometer technology is a major challenge in the design
and implementation of both the bolometer pixel and the Readout Integrated Circuit (ROIC).
In this work we present measured results from a new, large format (1024×768) detector array, with 17μm pitch. This
detector meets the demands of a typical armored vehicle sight with its high resolution and large format, together with
low NETD of better than 35mK (at F/1, 30Hz). We estimate a Recognition Range for a NATO target of better than 4 km
at all relevant atmospheric conditions, which is better than standard 2nd generation scanning array cooled detector. A
new design of the detector package enables improved stability of the Non-Uniformity Correction (NUC) to
environmental temperature drifts.
Short wavelength Infra Red (SWIR) imaging has gained considerable interest in recent years. The main applications
among others are: active imaging and LADAR, enhanced vision systems, low light level imaging and security
In this paper we will describe SCD's considerable efforts in this spectral region, addressing several platforms:
1. Extension of the mature InSb MWIR product line operating at 80K (cut-off wavelength of 5.4μm).
2. Extension of our new XB<sub>n</sub><i>n</i> InAsSb "bariode" technology operating at 150K (cut-off of 4.1μm).
3. Development of InGaAs detectors for room temperature operation (cut-off of 1.7μm)
4. Development of a SNIR ROIC with a low noise imaging mode and unique laser-pulse detection modes.
In the first section we will present our latest achievements for the cooled detectors where the SWIR region is combined
with MWIR response. Preliminary results for the NIR-VIS region are presented where advanced substrate removal
techniques are implemented on flip-chip hybridized focal plane arrays.
In the second part we will demonstrate our VGA, 15μm pitch, InGaAs arrays with dark current density below 1.5nA/cm<sup>2</sup>
at 280K. The InGaAs array is hybridized to the SNIR ROIC, thus offering the capability of low SWaP systems with
laser-pulse detection modes.
A new generation of high-performance uncooled detector arrays, with 17 and 25 μm pitch, improved sensitivity, and
extended spectral response were developed recently by SCD. This development brings the uncooled infrared technology
very close to the performance of traditional second generation cooled LWIR detectors, and enables a new range of
applications. We demonstrate the use of our Very High Sensitivity (VHS) 25 μm pitch detector with F/2.4, for long
range observation systems. We also present the new Wide-Band (WB) detector, where the detector absorption is tuned to
both the MWIR and LWIR bands, which is optimal for use in some applications such as situation awareness.
Furthermore, in this work we present our 17 μm pitch new family of detectors with different array formats (QVGA,
VGA and XGA). These detectors are targeting a wide range of applications, from medium-performance with low Size,
Weight and Power (SWaP) applications, up to high-performance imaging applications.
Over the last decade SCD has established a state of the art VO<sub>x</sub> μ-Bolometer product line. Due to its overall advantages
this technology is penetrating a large range of systems. In addition to a large variety of detectors, SCD has also recently
introduced modular video engines with an open architecture.
In this paper we will describe the versatile applications supported by the products based on 17μm pitch: Low SWaP
short range systems, mid range systems based on VGA arrays and high-end systems that will utilize the XGA format.
These latter systems have the potential to compete with cooled 2<sup>nd</sup> Gen scanning LWIR arrays, as will be demonstrated
by TRM3 system level calculations.
Last year we have introduced the development program of SCD's 17μm pitch VGA VO<sub>x</sub> μ-Bolometer detector <sup>(1)</sup>. Due
to the overall size, weight and power advantages the 17μm pitch is currently being considered for the next generation
systems such as thermal weapon sights (TWS), driver vision enhancers (DVE) and digitally fused goggles (DENVG).
In the first part of this paper we will discuss in detail the performance of this detector. Specifically, we will elaborate on
the radiometric results, ROIC performance and operability. Detailed measurements for a wide temperature range will be
presented as well.
In the second part, we will describe some new capabilities and features that are enabled by the advanced 0.18um VLSI
technology. These features will be embedded in new products that are currently under development.
In this paper SCD's 17μm pitch large format VOx μ-Bolometer detector is introduced. In the first part the radiometric
performance and the challenges involved in achieving the desired pixel sensitivity are discussed. We elaborate on the
progress towards the performance design goal (< 50mK@F/1, 60Hz) utilizing various test structures and technology
demonstration platforms. The combination of reduced pixel size and high-end thermal sensitivity can provide smaller
light weight systems.
In the second part the ROIC architecture options will be presented in depth. New capabilities and features are enabled
by the advanced 0.18um VLSI technology. Explicitly, we address the contribution in terms of system flexibility,
simplification and reduced power dissipation. Some vital tasks, such as coarse non-uniformity correction, are done
internally thus facilitating the user interface.
In this paper we report on new developments associated with SCD VOx μ-Bolometer product line. Lately, we have
introduced the BIRD6401,2, which is a high-sensitivity (< 50 mK @ F/1, 60Hz) VGA format detector with 25 μm pitch.
In the first part we present new data extracted from extensive measurements. These measurements were conducted
under various environmental and power constraints, exhibiting superior temporal sensitivity, long-term stability and
In the second part we describe the system implications of special features that were embedded within the FPA.
Explicitly, we will address the benefits of some special features aimed at lowering the system power dissipation while
maintaining low temporal and spatial NETD.
Finally, in the last part we outline SCD's future roadmap and development directions. We will elaborate on our latest
progress towards improved pixel sensitivity (25mK@F/1), advanced 0.18um ROIC technology, and the combination of
the two towards smaller pitch (17 μm) arrays.
In this paper we report preliminary data of <i>BIRD640</i>, which is a high-sensitivity (50 mK @ F/1, 60Hz) VGA format
detector with 25 μm pitch. This high performance is achieved by utilizing an improved pixel design. The product is
architecturally compatible to <i>BIRD384</i> and contains SCD's proprietary unique features (e.g. "Power-Save", Ambient drift
The ROIC architecture follows the framework of the previous designs. It consists of an internal timing machine with a
single clock that facilitates the system interface. Extensive effort was invested in reducing the detector and system power
dissipation. The ROIC supports special "low power" modes, where considerable power is saved with only minor
With its superior temporal sensitivity, long-term stability and operational flexibility <i>BIRD640</i> serves as an ideal
candidate for high end and high resolution uncooled VGA systems, particularly hand-held applications.
SCD has established an uncooled detector product line based on the high-end VO<sub>x</sub> μ-bolometer technology. The first
PFA launched was <i>BIRD384</i>, a 384x288 (or 320x240) configurable format with 25μm pitch. Typical NETD values for
these FPAs are below 50mK with an F/1 aperture and 60 Hz frame rate.
The product exhibits superior image uniformity, stability and reduced power consumption, making it most suitable for a
broad range of "high-end" military and commercial applications.
In this paper we report on our progress in development of new products in accordance with SCD's uncooled products
1. A "sensitive" version of <i>BIRD384</i> with an improved NETD of ~ 30mK @ F/1, 60Hz frame rate. This
performance is achieved by optimizing concurrently the membrane structure, pixel architecture and ROIC
2. An improved version of <i>BIRD384</i> ROIC that supports 100/120Hz frame rate and high dynamic range ("Fire Man" option).
3. First data of the <i>BIRD640</i> - a 640x480 array with 25μm pitch and NETD ≤ 50mK @ F/1, 60Hz frame rate.
Last year SCD presented an un-cooled detector product line based on the high-end VO<sub>x</sub> microbolometer technology. The first PFA (<i>BIRD</i>384) launched was a 384x288 software configurable (to 320x240 or other) format with 25μm pitch<sup>1</sup>. NETD values for these FPAs are better then 50mK with an F/1 aperture and 60 Hz frame rate.
Since then SCD has concentrated in improving both spatial and temporal performance. In order to reduce the Residual
Non-Uniformity (RNU) and increase the time span between shutter operations, SCD has incorporated various features within the FPA and supporting algorithms<sup>2</sup>.
Improved temporal performance was achieved by optimizing concurrently the membrane structure and ROIC electronics. SCD has demonstrated temporal NETD of ~ 20mK @ F/1 at 30Hz on a 160x120 BIRD compatible array.
This figure of merit, accompanied by the superior stability and reduced power consumption, makes SCD's VOx based detectors suitable candidates for a broad range of "high-end" military and commercial applications.
SCD is unveiling the first member of its new uncooled product line based on the high-end VOx technology. The detector is software configurable to various format standards including 384x288, 320x240 and others with 25μm pitch. The NETD values for these FPAs are better then 50mK with F#/1 aperture and 60 Hz frame rate. These detectors also exhibit a relatively fast thermal time constant of approximately 10msec. In order to improve the system level "cost-performance" in terms of power consumption and weight, SCD has introduced special features within the FPA & package. Among them is a proprietary "Power Save" architecture, in which the die temperature can be stabilized to the ambient temperature or a close enough discrete value, covering the range between -40c and 70c. Thus, the TEC power consumption is considerably reduced with minimal performance degradation. An additional benefit is improved "mission readiness" which is of vital importance for various system applications. A major limitation of systems based on uncooled detectors is the poor resilience to the ambient temperature drift. This drift degrades the spatial non-uniformity. As a result, frequent corrections using an optical shutter are required, specifically during the camera stabilization period. In order to increase the time span between shutter operations, SCD has incorporated various real-time monitoring features within the FPA and supporting algorithms. These features reduce the spatial noise by an order of magnitude.