A5023245748- CCD and CMOS Imaging Sensors
- Particle Detector Development and Performance
- Infrared Target Detection Methodologies
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Advanced Semiconductor Detectors and Materials
- Semiconductor materials and devices
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Advanced Optical Sensing Technologies
- Thin-Film Transistor Technologies
- Ultrasonics and Acoustic Wave Propagation
- Advancements in Semiconductor Devices and Circuit Design
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Integrated Circuits and Semiconductor Failure Analysis
- Photocathodes and Microchannel Plates
- Silicon and Solar Cell Technologies
- Image Processing Techniques and Applications
- Geophysical Methods and Applications
- Radiation Effects in Electronics
- Silicon Carbide Semiconductor Technologies
- Medical Imaging Techniques and Applications
Lawrence Berkeley National Laboratory
2016-2025
Goddard Space Flight Center
2016
Fermi National Accelerator Laboratory
2010-2012
University of Colorado Colorado Springs
2012
Argonne National Laboratory
2010
Cerro Tololo Inter-American Observatory
2008
The Ohio State University
2008
United States Department of Energy
2005
Cornell University
1956-2003
Stockholm University
2003
The Dark Energy Camera is a new imager with 22 diameter field of view mounted at the prime focus Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. camera was designed and constructed by Survey Collaboration meets or exceeds stringent requirements for wide-field supernova surveys which collaboration uses it. consists five-element optical corrector, seven filters, shutter 60 cm aperture, charge-coupled device (CCD) focal plane 250 μm thick fully depleted CCDs cooled inside...
The breakdown of thin oxides (7.9-32 nm) subjected to high-field current injection is investigated in this study. physical mechanism found be localized field enhancement at the cathode interface due hole trapping. source trapping believed impact ionization SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> . A quantitative model for oxide based on and presented shown agree well with experimental <tex...
We have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (CCD) to achieve an unprecedented noise level 0.068 e^{-} rms/pixel. This is the first time that discrete subelectron has been achieved reproducible over millions pixels on stable, large-area detector. enables contemporaneous, discrete, and quantized measurement charge pixels, irrespective whether they contain zero electrons or thousands...
We present the first results from a dark matter search using six Skipper-CCDs in SENSEI detector operating at SNOLAB. employ bias-mitigation technique of hiding approximately 46% our total data and aggressively mask images to remove backgrounds. Given exposure after masking 100.72 gram-days well-performing sensors, we observe 55 two-electron events, 4 three-electron no events containing 4-10 electrons. The are consistent with pileup one-electron events. Among 2 appear pixels that likely...
Charge-coupled devices (CCDs) have been fabricated on high-resistivity, n-type silicon. The resistivity, the order of 10 000 /spl Omega//spl middot/cm, allows for depletion depths several hundred micrometers. Fully depleted, back-illuminated operation is achieved by application a bias voltage to an ohmic contact wafer back side consisting thin in situ doped polycrystalline silicon layer capped indium tin oxide and dioxide. This good short-wavelength response, while relatively large depleted...
It is known that when an n-channel metal-oxide-semiconductor field-effect transistor biased with a high positive gate voltage, hole current appears in the substrate cathode. Recent experiments indicate holes are generated within oxide. We show this generation mechanism linked to oxide time-dependent breakdown. When fluence reaches certain critical value, breakdown occurs. This agreement hole-trapping-induced model. For very thin oxides rate can become so low dominated by tunneling of...
A novel readout architecture that uses multiple nondestructive floating-gate amplifiers (FGAs) to achieve subelectron noise in a thick, fully depleted silicon detector is presented. This multiple-amplifier sensing charge-coupled device (MAS-CCD) can perform independent charge measurements with each amplifier; then be combined further reduce the noise. allows getting operation less time compared single-nondestructive-amplifier CCDs. The performance of this demonstrated, emphasizing ability...
We present results from data acquired by the SENSEI experiment at SNOLAB after a major upgrade in May 2023, which includes deploying 16 new sensors and replacing copper trays that house CCDs with light-tight design. observe single-electron event rate of $(1.39 \pm 0.11) \times 10^{-5}$ e$^-$/pix/day, corresponding to $(39.8 3.1)$ e$^-$/gram/day. This is an order-of-magnitude improvement compared previous lowest silicon detector for any photon near-infrared-ultraviolet range. use these obtain...
A silicon microstrip vertex detector has been constructed and installed in the Collider Detector at Fermilab. The device designed to operate a hadron collider. It began collecting data May of 1992 functioned within specification. Technical details are presented on all aspects system its performance.
It is shown that after holes are injected and trapped in silicon dioxide (SiO2), subsequent electron injection will generate neutral traps. The density of traps generated about 30% the holes. proposed created by energy released through recombination electrons holes, this mechanism electron-trap generation during high-field oxide stressing. Similar field thickness dependencies rate hole further support model. This model can reconcile main evidence for electron-trapping breakdown with...
A quantitative physical breakdown model for thin SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is developed. The mechanism responsible fcor oxide has been reexamined and found to be hole trapping at localized areas. built on this understanding of the wearout mechanism. Using model, which considers electron injection, generation charge during electrical stresses their effects I-V characteristics, all commonly used reliability tests...
The field dependence of the hole generation rate, also known as impact ionization coefficient α, in thin SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> (< 20 nm) was characterized by measuring negative flat-band shift due to trapping. In thicker oxides, <tex xmlns:xlink="http://www.w3.org/1999/xlink">\alpha = \alpha_{0}e^{-H/E}</tex> where H 78 MV/cm for electric fields ranging from 7 14 MV/cm, which covers range onset significant...
The breakdown of thin oxides (7.9-32 nm) subjected to high-field current injection is investigated in this study. physical mechanism found be localized field enhancement at the cathode interface due hole trapping. source trapping believed impact ionization SiO/sub 2/. A quantitative model for oxide based on and presented shown agree well with experimental J - t time-to-breakdown, (t/sub BD/) results. We observe that log t/sub BD/ varies linearly 1/E rather than E as commonly assumed....
We use a science-grade skipper charge-coupled device (skipper CCD) operating in low-radiation background environment to develop semiempirical model that characterizes the origin of single-electron events CCDs. identify, separate, and quantify three independent contributions events, which were previously bundled together classified as ``dark counts'': dark current, amplifier light, spurious charge. measure depends on exposure,...
Electrical breakdown of thin (32-nm) SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> films subjected to constant-current stressing is studied. By studying the effects reversing polarity bias and thermal annealing on charge-to-breakdown it determined that electrical not caused by widely-cited accumulation trapped electrons. Rather buildup positive charges near cathode at localized areas. The are mobile ions but exhibit many...
The Dark Energy Survey Collaboration has completed construction of the Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted on Blanco 4-meter telescope at CTIO. DECam used to perform 5000 sq. deg. with 30% time over 5 year period. During remainder time, and after survey, available as community instrument. All components have been shipped Chile post-shipping checkout finished in Jan. 2012. Installation is progress. A summary lessons learned an update performance...
We present results from a 3.25 kg-day target exposure of two silicon charge-coupled devices (CCDs), each with 24 megapixels and skipper readout, deployed in the DAMIC setup at SNOLAB. With reduction pixel readout noise factor 10 relative to previous detector, we investigate excess population low-energy events CCD bulk previously observed above expected backgrounds. address dominant systematic uncertainty analysis through depth fiducialization designed reject surface backgrounds on CCDs. The...
Millicharged particles appear in several extensions of the standard model, but have not yet been detected. These hypothetical could be produced by an intense proton beam striking a fixed target. We use data collected 2020 SENSEI experiment MINOS cavern at Fermi National Accelerator Laboratory to search for ultrarelativistic millicharged collisions protons NuMI with graphite The absence any ionization events 3 6 electrons allow us place world-leading constraints on masses between 30 380 MeV....
In this study we investigate the effects of oxidation and post‐oxidation annealing temperatures on breakdown thin (≈25 nm) dielectrics. We report a correlation between amount charge injected during high‐field stressing necessary for breakdown, , rate positive trapping stressing. The can be explained by model which assumes that results from an enhancement electric field at injecting interface due to trapped charge. For greater than ≈900°C increases markedly as result decreases significantly....
The link between hole generation/trapping and oxide breakdown is demonstrated by correlating with the current generated in oxide. Both exhibit same thickness field dependences. Charge-to-breakdown (Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BD</inf> ), time-to-breakdown (t breakdown-field (E ) increase dramatically as reduced below 80 Å due to rate of generation, which modeled an average electron energy analysis....
This work presents a candidate sensor for future spectroscopic applications, such as Stage-5 Spectroscopic Survey Experiment or the Habitable Worlds Observatory. new type of CCD features multiple in-line amplifiers at its output stage allowing measurements same charge packet, either in each amplifier and/or different amplifiers. Recently, operation an 8-amplifier has been experimentally demonstrated, and 16-amplifier is presented this work. enables noise level approximately $1^e_{\rm rms}$...
Abstract We present characterization results and performance of a prototype Multiple-Amplifier Sensing (MAS) silicon charge-coupled device (CCD) sensor with 16 channels potentially suitable for faint object astronomical spectroscopy low-signal, photon-limited imaging. The MAS CCD is designed to reach sub-electron readout noise by repeatedly measuring charge through line amplifiers during the serial transfer shifts. Using synchronized electronics based on Dark Energy Spectroscopic Instrument...
We present the first results from a dark matter search using six Skipper-CCDs in SENSEI detector operating at SNOLAB. With an exposure of 534.9 gram-days well-performing sensors, we select events containing 2 to 10 electron-hole pairs. After aggressively masking images remove backgrounds, observe 55 two-electron events, 4 three-electron and no electrons. The are consistent with pileup one-electron events. Among appear pixels that likely impacted by defects, although not strongly enough...