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Germanium CCDs for large-format SWIR and x-ray imaging

May 25, 2017
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Journal Article
Author:
Christopher W. Leitz
…
Published in:
J. Instrum., Vol. 12, No. 5, May 2017, C05014.
Topic:
photonics
R&D area:
R&D group:

Summary

Germanium exhibits high sensitivity to short-wave infrared (SWIR) and X-ray radiation, making it an interesting candidate for imaging applications in these bands. Recent advances in germanium processing allow for high-quality charge-coupled devices (CCDs) to be realized in this material. In this article, we discuss our evaluation of germanium as an absorber material for CCDs via fabrication and analysis of discrete devices such as diodes, metal-insulator-semiconductor capacitors, and buried-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). We then describe fabrication of our first imaging device on germanium, a 32 x 1 x 8.1 um linear shift register. Based on this work, we find that germanium is a promising material for CCDs imaging in the SWIR and X-ray bands.
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Summary

Germanium exhibits high sensitivity to short-wave infrared (SWIR) and X-ray radiation, making it an interesting candidate for imaging applications in these bands. Recent advances in germanium processing allow for high-quality charge-coupled devices (CCDs) to be realized in this material. In this article, we discuss our evaluation of germanium as an...

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Germanium CCDs for large-format SWIR and x-ray imaging

The TESS camera: modeling and measurements with deep depletion devices

July 29, 2016
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Conference Paper
Author:
Deborah F. Woods
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Published in:
Proc. SPIE 9904, Space Telescopes and Instrumentation 2016: Optical, Infrared, and Millimeter Wave, 29 July 2016, 99042C.
Topic:
optics
R&D area:
R&D group:

Summary

The Transiting Exoplanet Survey Satellite, a NASA Explorer-class mission in development, will discover planets around nearby stars, most notably Earth-like planets with potential for follow up characterization. The all-sky survey requires a suite of four wide field-of-view cameras with sensitivity across a broad spectrum. Deep depletion CCDs with a silicon layer of 100 um thickness serve as the camera detectors, providing enhanced performance in the red wavelengths for sensitivity to cooler stars. The performance of the camera is critical for the mission objectives, with both the optical system and the CCD detectors contributing to the realized image quality. Expectations for image quality are studied using a combination of optical ray tracing in Zemax and simulations in Matlab to account for the interaction of the incoming photons with the 100 um silicon layer. The simulations include a probabilistic model to determine the depth of travel in the silicon before the photons are converted to photo-electrons, and a Monte Carlo approach to charge diffusion. The charge diffusion model varies with the remaining depth for the photo-electron to traverse and the strength of the intermediate electric field. The simulations are compared with laboratory measurements acquired by an engineering unit camera with the TESS optical design and deep depletion CCDs. In this paper we describe the performance simulations and the corresponding measurements taken with the engineering unit camera, and discuss where the models agree well in predicted trends and where there are differences compared to observations.
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Summary

The Transiting Exoplanet Survey Satellite, a NASA Explorer-class mission in development, will discover planets around nearby stars, most notably Earth-like planets with potential for follow up characterization. The all-sky survey requires a suite of four wide field-of-view cameras with sensitivity across a broad spectrum. Deep depletion CCDs with a silicon...

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The TESS camera: modeling and measurements with deep depletion devices

Development of CCDs for REXIS on OSIRIS-REx

July 24, 2014
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Conference Paper
Author:
Kevin K. Ryu
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Published in:
SPIE, Vol. 9144, Space Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray, 22 June 2014, 91444O.
Topic:
optics
R&D area:
R&D group:

Summary

The Regolith x-ray Imaging Spectrometer (REXIS) is a coded-aperture soft x-ray imaging instrument on the OSIRIS-REx spacecraft to be launched in 2016. The spacecraft will fly to and orbit the near-Earth asteroid Bennu, while REXIS maps the elemental distribution on the asteroid using x-ray fluorescence. The detector consists of a 2x2 array of back-illuminated 1kX1k frame transfer CCDs with a flight heritage to Suzaku and Chandra. The back surface has a thing p+-doped layer deposited by molecular-beam epitaxy (MBE) for maximum quantum efficiency and energy resolution at low x-ray energies. The CCDs also feature an integrated optical-blocking filter (OBF) to suppress visible and near-infrared light. The OBF is an aluminum film deposited directly on the CCD back surface and is mechanically more robust and less absorptive of x-rays than the conventional free-standing aluminum-coated polymer films. The CCDs have charge transfer inefficiencies of less than 10^-6, and dark current of le-/pixel/second at the REXIS operating temperature of -60 degrees C. The resulting spectral resolution is 115 eV at 2 KeV. The extinction ratio of the filter is ~10^12 at 625 nm.
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Summary

The Regolith x-ray Imaging Spectrometer (REXIS) is a coded-aperture soft x-ray imaging instrument on the OSIRIS-REx spacecraft to be launched in 2016. The spacecraft will fly to and orbit the near-Earth asteroid Bennu, while REXIS maps the elemental distribution on the asteroid using x-ray fluorescence. The detector consists of a...

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Development of CCDs for REXIS on OSIRIS-REx

New CCD imagers for adaptive optics wavefront sensors

June 22, 2014
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Conference Paper
Author:
Daniel R. Schuette
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Published in:
SPIE, Vol. 9148, Adaptive Optics Systems IV, 22 June 2014, 91485O.
Topic:
optics
R&D area:
R&D group:

Summary

We report on two recently developed charge-coupled devices (CCDs) for adaptive optics wavefront sensing, both designed to provide exceptional sensitivity (low noise and high quantum efficiency) in high-frame-rate low-latency readout applications. The first imager, the CCID75, is a back-illuminated 16-port 160x160 pixel CCD that has been demonstrated to operate at frame rates above 1,300 fps with noise of
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Summary

We report on two recently developed charge-coupled devices (CCDs) for adaptive optics wavefront sensing, both designed to provide exceptional sensitivity (low noise and high quantum efficiency) in high-frame-rate low-latency readout applications. The first imager, the CCID75, is a back-illuminated 16-port 160x160 pixel CCD that has been demonstrated to operate at...

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New CCD imagers for adaptive optics wavefront sensors

Orthogonal transfer arrays for wide-field adaptive imaging

June 7, 2007
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Conference Paper
Author:
Barry E. Burke
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Published in:
Proc. 2007 Int. Image Sensor Workshop, 7-10 June 2007.
Topic:
optics
R&D area:
R&D group:

Summary

The orthogonal transfer array (OTA) is a novel charge-coupled device (CCD) imager based on the orthogonal-transfer CCD (OTCCD). The OTCCD, in turn, is a device capable of charge transfer in all directions and has been developed for adaptive imaging in ground-based astronomy. By using a bright guide star as a beacon, the OTCCD can correct for wavefront tilt due to atmospheric effects as well as compensation for telescope shake, which in turn enhances the resolution and SNR. However, for wide field-of-view imaging the atmospheric wavefront distortions decorrelate over distances more than a few 10's of arcmin and hence an array of independently driven OTCCDs is required. To resolve this issue we developed the OTA, which consists of a two-dimensional array of OTCCDs combined with addressing and control logic to enable independent clocking of each OTCCD. This device enables spatially varying electronic tip-tilt correction and was developed for the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) program at the University of Hawaii Institute for Astronomy (UH/IfA)
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Summary

The orthogonal transfer array (OTA) is a novel charge-coupled device (CCD) imager based on the orthogonal-transfer CCD (OTCCD). The OTCCD, in turn, is a device capable of charge transfer in all directions and has been developed for adaptive imaging in ground-based astronomy. By using a bright guide star as a...

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Orthogonal transfer arrays for wide-field adaptive imaging

The orthogonal-transfer array: a new CCD architecture for astronomy

June 21, 2004
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Conference Paper
Author:
Barry E. Burke
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Published in:
SPIE Vol. 5499, Optical and Infrared Detectors for Astronomy, 21 June 2004, pp. 185-192.
Topic:
optics
R&D area:
R&D group:

Summary

The orthogonal-transfer array (OTA) is a new CCD architecture designed to provide wide-field tip-tilt correction of astronomical images. The device consists of an 8..8 array of small (~500x500 pixels) orthogonal-transfer CCDs (OTCCD) with independent addressing and readout of each OTCCD. This approach enables an optimum tip-tilt correction to be applied independently to each OTCCD across the focal plane. The first design of this device has been carried out at MIT Lincoln Laboratory in support of the Pan-STARRS program with a collaborative parallel effort at Semiconductor Technology Associates (STA) for the WIYN Observatory. The two versions of this device are functionally compatible and share a common pinout and package. The first wafer lots are complete at Lincoln and at Dalsa and are undergoing wafer probing.
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Summary

The orthogonal-transfer array (OTA) is a new CCD architecture designed to provide wide-field tip-tilt correction of astronomical images. The device consists of an 8..8 array of small (~500x500 pixels) orthogonal-transfer CCDs (OTCCD) with independent addressing and readout of each OTCCD. This approach enables an optimum tip-tilt correction to be applied...

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The orthogonal-transfer array: a new CCD architecture for astronomy

Broadband (200-1000 nm) back-illuminated ccd imagers

June 16, 2002
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Conference Paper
Author:
Barry E. Burke
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Published in:
Scientific Detectors Workshop 2002, 16-22 June 2002.p. 41-50.
Topic:
optics
R&D area:
R&D group:

Summary

Improved and stable blue/UV quantum efficiency has been demonstrated on 2Kx4K imagers using molecular-beam epitaxy to create a thin doped layer on the back surface. Quantum efficiency data on thick (40-50 pm) imagers with single and dual-layer anti-reflection coatings is presented that demonstrates high and broadband response. Measurements of the optical point-spread response show the devices to be fully depleted with good response across a broad spectrum, but interesting features appear in the near-IR as a result of deeply penetrating light being scattered off the surface structure of the CCD.
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Summary

Improved and stable blue/UV quantum efficiency has been demonstrated on 2Kx4K imagers using molecular-beam epitaxy to create a thin doped layer on the back surface. Quantum efficiency data on thick (40-50 pm) imagers with single and dual-layer anti-reflection coatings is presented that demonstrates high and broadband response. Measurements of the...

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Broadband (200-1000 nm) back-illuminated ccd imagers

Silicon-on-insulator-based single-chip image sensors: low-voltage scientific imaging

January 1, 2002
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Conference Paper
Author:
Vyshnavi Suntharalingam
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Published in:
Experimental Astronomy, Vol. 14, No. 2, 2002, pp. 91-98.
Topic:
sensors
R&D area:
R&D group:

Summary

A low-voltage (
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Summary

A low-voltage (

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Silicon-on-insulator-based single-chip image sensors: low-voltage scientific imaging

Monolithic 3.3V CCD/SOI-CMOS Imager Technology

December 10, 2000
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Conference Paper
Author:
Vyshnavi Suntharalingam
…
Published in:
IEEE Int. Eelctron Devices Mtg., 10-13 December 2000, pp. 30.3.1-30.3.4.
Topic:
semiconductor (CMOS)
R&D area:
R&D group:

Summary

We have developed a merged CCD/SOI-CMOS technology that enables the fabrication of monolithic, low-power imaging systems on a chip. The CCD's, fabricated in the bulk handle wafer, have charge-transfer inefficiencies of about 1x10(-5) and well capacities of more than 100,000 electrons with 3.3-V clocks and 8x8um pixels. Fully depleted 0.35pm SOI-CMOS ring oscillators have stage delay of 48ps at 3.3V. We demonstrate for the first time an integrated image sensor with charge-domain A/D conversion and on-chip clocking.
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Summary

We have developed a merged CCD/SOI-CMOS technology that enables the fabrication of monolithic, low-power imaging systems on a chip. The CCD's, fabricated in the bulk handle wafer, have charge-transfer inefficiencies of about 1x10(-5) and well capacities of more than 100,000 electrons with 3.3-V clocks and 8x8um pixels. Fully depleted 0.35pm...

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Monolithic 3.3V CCD/SOI-CMOS Imager Technology

SOI wafer selection for CCD/SOI-CMOS technology [Abstract]

October 2, 2000
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Conference Paper
Author:
Vyshnavi Suntharalingam
…
Published in:
2000 IEEE Int. SOI Conf. Proc., 2-5 October 2000, pp. 136-137.
Topic:
semiconductor (CMOS)
R&D area:
R&D group:

Summary

We have developed a process that monolithically integrates fully depleted SOI CMOS (FDSOI) with high-performance CCD image sensors. This integrated technology that enables charged-coupled devices (CCD's) to be in close proximity to, yet isolated from, FDSOI circuits. This approach exploits both the advantages of FDSOI (fast, low-power CMOS with potentially enhanced radiation performance) and those of CCD's (high quantum efftciency, low noise, and architectural flexibility). This 3.3 V, 0.3 mu m CCD/FDSOI-CMOS technology thus enables fabrication of low-power, compact imaging systems. Material requirements for CCD imagers are perhaps the most stringent of any device and require special attention to the quality of the bulk or handle wafer. We report here characterization of various SOI handle wafers for use in fabrication of bulk imaging devices.
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Summary

We have developed a process that monolithically integrates fully depleted SOI CMOS (FDSOI) with high-performance CCD image sensors. This integrated technology that enables charged-coupled devices (CCD's) to be in close proximity to, yet isolated from, FDSOI circuits. This approach exploits both the advantages of FDSOI (fast, low-power CMOS with potentially...

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SOI wafer selection for CCD/SOI-CMOS technology [Abstract]
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