Performance analysis of a-Si:H detectors deposited on CMOS chips

2004 ◽  
Vol 808 ◽  
Author(s):  
C. Miazza ◽  
S. Dunand ◽  
N. Wyrsch ◽  
A. Shah ◽  
N. Blanc ◽  
...  
Keyword(s):  
Dark Current ◽  
Cmos Technology ◽  
Silicon Detectors ◽  
Particle Detection ◽  
Glass Substrates ◽  
Density Values ◽  
Increased Sensitivity ◽  
Current Densities ◽  
Primary Focus ◽  
Possible Cause

ABSTRACTImage and particle sensors based on thin-film on CMOS technology are currently being developed at our laboratory. In this technology, amorphous silicon detectors are vertically integrated on top of dedicated CMOS chips. For both, vision and particle detection, this approach is expected to enhance the performances. In fact very high fill factors, increased sensitivity, and integration level, coupled with extremely low dark current density values can potentially be attained.A first optimization of the a-Si:H diodes (>1mm2) on glass substrates, with the primary focus on reducing dark current densities, gave Jdark values as low as 1 pA/cm2 (at -1 V for 1 m thick detectors). These detectors were then deposited on CMOS readout chips, but so far this step was unfortunately accompanied by an increase in Jdark to values over 10 nA/cm2.Here, the possible cause for such an increase in Jdark as well as possible “remedies” against this effect will be discussed; the principle cause is supposed to be the influence of chip topology. Possible solutions include surface treatments as well as the use of metal-i-p diode configuration. Results obtained so far with these methods are given.

Vertically Integrated Amorphous Silicon Particle Sensors

2004 ◽  
Vol 808 ◽  
Author(s):  
N. Wyrsch ◽  
C. Miazza ◽  
S. Dunand ◽  
A. Shah ◽  
D. Moraes ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Material Properties ◽  
Dark Current ◽  
Silicon Particle ◽  
Particle Beam ◽  
High Energy ◽  
Beta Particle ◽  
Particle Detection ◽  
Glass Substrates ◽  
Hydrogenated Amorphous

ABSTRACTVertically integrated particle sensors have been developed using thin-film on ASIC technology. Hydrogenated amorphous silicon n-i-p diodes have been optimized for particle detection. These devices were first deposited on glass substrates to optimize the material properties and the dark current of very thick diodes (with thickness up to 50 m). Corresponding diodes were later directly deposited on two types of CMOS readout chips. These vertically integrated particle sensors were tested in beta particle beam from 63Ni and 90Sr sources. Detection of single low- and high- energy beta particle was achieved.

Development of Vertically Integrated Imaging and Particle Sensors

2003 ◽  
Vol 762 ◽  
Author(s):  
N. Wyrsch ◽  
C. Miazza ◽  
S. Dunand ◽  
A. Shah ◽  
N. Blanc ◽  
...  
Keyword(s):  
Dark Current ◽  
Direct Detection ◽  
Reverse Bias Voltage ◽  
Particle Detection ◽  
Particle Detectors ◽  
Beta Particles ◽  
Glass Substrates ◽  
Cmos Imagers ◽  
Pulse Illumination ◽  
Hydrogenated Amorphous

AbstractIntegrated imaging and particle sensors have been developed using thin-film on ASIC technology. For this purpose, hydrogenated amorphous silicon diodes, in various configurations, have been optimized for imaging and direct particle detection. These devices were first deposited on glass substrates and later on CMOS readout chips. With an optimization of the material properties and of the diode, a dark current of 1 pA/cm2 could be achieved on p-i-n structures at reverse bias voltage of 1 V. CMOS imagers, incorporating these optimized diodes were then fabricated and characterized. Very thick diodes (with thicknesses up to 50 μm) were also optimized and deposited on glass and on CMOS readout chips. Particle detectors in TFA technology with 12 and 30 μm a-Si:H n-i-p diodes have been fabricated and characterized using light pulse illumination. Direct detection of single low-energy beta particles has been demonstrated.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

Controlling factors in localised corrosion morphologies observed for magnesium immersed in chloride containing electrolyte

2015 ◽  
Vol 180 ◽  
pp. 313-330 ◽  
Author(s):  
Geraint Williams ◽  
Nick Birbilis ◽  
H. Neil McMurray
Keyword(s):  
Current Density ◽  
Radial Growth ◽  
Cathodic Current Density ◽  
Nacl Solution ◽  
High Concentration ◽  
Cathodic Current ◽  
Density Distributions ◽  
Filiform Corrosion ◽  
Density Values ◽  
Current Densities

The early stages of localised corrosion affecting magnesium (Mg) surfaces when immersed in aqueous sodium chloride (NaCl) solutions involves the propagation of dark regions, within which both anodic metal dissolution and cathodic hydrogen evolution occur. For nominally “pure” Mg, these dark areas can either take the form of discs which expand radially with time, or filiform-like tracks which lengthen with time. For Mg surfaces which display disc-form corrosion features in concentrated NaCl electrolyte, a transition to filiform corrosion (FFC) is observed as the concentration is decreased, indicating ohmic constraints on radial propagation. A similar effect is observed when Mg specimens of different iron impurity are immersed in a fixed, high concentration NaCl solution, where disc-form corrosion is observed on samples having ≥280 ppm Fe, but FFC predominates at ≤80 ppm Fe. An in situ scanning vibrating electrode technique (SVET) is used to determine current density distributions within the propagating corrosion features. Cathodic current density values of between −100 and −150 A m−2 measured in central areas of disc-like features are sufficient to sustain the radial growth of a local anode at the perimeter of the discs. However, for high purity Mg specimens (≤80 ppm Fe), cathodic current densities of −10 A m−2 or less are measured over FFC affected regions, indicating that linear propagation arises when there is insufficient cathodic current produced on the corroded surface to sustain radial growth. The results are consistent with surface control of localised corrosion propagation in concentrated electrolyte, but ohmic control in dilute, lower conductivity NaCl solution.

scholarly journals Image Sensors Based on Thin-film on CMOS Technology: Additional Leakage Currents due to Vertical Integration of the a-Si:H Diodes

2006 ◽  
Vol 910 ◽  
Author(s):  
Clement Miazza ◽  
N. Wyrsch ◽  
G. Choong ◽  
S. Dunand ◽  
C. Ballif ◽  
...  
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Vertical Integration ◽  
Dark Current ◽  
Cmos Technology ◽  
Image Sensors ◽  
Dark Current Density ◽  
Leakage Currents ◽  
Planar Configuration ◽  
Cmos Chip

AbstractImage sensors based on thin-film on CMOS technology (TFC) have been developed. In this approach, amorphous silicon (a-Si:H) detectors are vertically integrated on top of a CMOS readout chip so as to form monolithic image sensors. In order to reduce as far as possible the dark current density (Jdark) of the TFC sensors, we have focused on analyzing and understanding the behavior of Jdark in this type of detectors. Edge effects along the periphery and at the corners of the pixel, due to the non planar configuration of the vertically integrated photodiodes, are found to be responsible for an increase of the dark current. A new and adapted solution for the minimization of Jdark is proposed, which combines the use of a metal-i-p a-Si:H diode configuration with a deposition on top of an unpassivated CMOS chip. Values of Jdark as low as 12 pA/cm2 at a reverse polarization of V = -1 V are measured on such TFC sensors.

Semiconductor detectors

2020 ◽  
pp. 255-372
Author(s):  
Hermann Kolanoski ◽  
Norbert Wermes
Keyword(s):  
Particle Physics ◽  
Nuclear Physics ◽  
Gamma Ray ◽  
Semiconductor Detectors ◽  
Silicon Detectors ◽  
Particle Detection ◽  
Semiconductor Physics ◽  
Pixel Detectors ◽  
Drift Chambers ◽  
Electronic Measurement

Already since the early 1960s semiconductor detectors have been employed in nuclear physics, in particular for gamma ray energy measurement. This chapter concentrates on position sensitive semiconductor detectors which have been developed in particle physics since the 1980s and which feature position resolutions in the range of 50–100 μ‎m by structuring the electrodes, thus reaching the best position resolutions of electronic detectors. For the first time this made the electronic measurement of secondary vertices and therewith the lifetime of heavy fermions possible. The chapter first conveys the basics of semiconductor physics, of semiconductor and metal-semiconductor junctions used in electronics and detector applications as well as particle detection with semiconductor detectors. It follows the description of different detector types, like strip and pixel detectors, silicon drift chambers and charged-coupled devices. New developments are addressed in the sections on ‘Monolithic pixel detectors’ and on ‘Precision timing with silicon detectors’. In the last sections detector deterioration by radiation damage is described and an overview of other semiconductor detector materials but silicon is given.

A speed-optimized, low-noise APD with 0.18 μm CMOS technology for the VLC applications

2020 ◽  
Vol 34 (29) ◽  
pp. 2050321
Author(s):  
Wei Wang ◽  
Hong-An Zeng ◽  
Fang Wang ◽  
Guanyu Wang ◽  
Yingtao Xie ◽  
...  
Keyword(s):  
Dark Current ◽  
Complementary Metal Oxide Semiconductor ◽  
Visible Light Communication ◽  
Cmos Technology ◽  
Low Noise ◽  
Oxide Semiconductor ◽  
Excess Noise ◽  
Avalanche Breakdown ◽  
Cmos Process ◽  
Noise Characteristics

A new avalanche photodiode device applied to a visible light communication (VLC) system is designed using a standard 0.18 [Formula: see text]m complementary metal oxide semiconductor process. Compared to regular CMOS APD devices, the proposed device adds a [Formula: see text]-well layer above the deep [Formula: see text]-well/[Formula: see text]-substrate structure, and an [Formula: see text]/[Formula: see text] layer is deposited upon it. The [Formula: see text]/[Formula: see text] layer acts as an avalanche breakdown layer of the device, and an STI structure is used to prevent the edge break prematurely. The simulation results shows that the avalanche breakdown voltage is as low as 9.9 V, dark current is below [Formula: see text] A under −9.5 V bias voltage, and the 3 dB bandwidth is of 5.9 GHz. It is due to the use of the 0.18 [Formula: see text]m CMOS process-specific STI protection ring and short-circuits the connection of the deep [Formula: see text]-well/[Formula: see text]-substrate, and the dark current is reduced to be lower than two orders of magnitude compared to regular CMOS APD. Gain and noise characteristics are accurately calculated from Hayat dead-space model applied to this CMOS APD. So, this device’s gain and excess noise factor are 20 and 2.5, respectively.

Different cap-barrier design for MOCVD grown HOT HgCdTe barrier detectors

2015 ◽  
Vol 23 (2) ◽  
Author(s):  
M. Kopytko ◽  
A. Kębłowski ◽  
W. Gawron ◽  
P. Madejczyk
Keyword(s):  
High Temperatures ◽  
Dark Current ◽  
Structural Unit ◽  
Vapour Deposition ◽  
Contact Layer ◽  
Wide Bandgap ◽  
Bottom Contact ◽  
Current Densities ◽  
Barrier Detectors ◽  
P Type

AbstractThe performance of HgCdTe barrier detectors with cut-off wavelengths up to 3.6 μm fabricated using metaloorganic chemi- cal vapour deposition operated at high temperatures is presented. The detectors’ architecture consists of four layers: cap contact, wide bandgap barrier, absorber and bottom contact layer. The structures were fabricated both with n- and p-type absorbing layers. In the paper, different design of cap-barrier structural unit (n-BThe devices with a p-type cap contact exhibit very low dark current densities in the range of (2÷3)×10

Utilization of in vivo alkylated metabolites as a possible cause of increased sensitivity of tumor cells to alkylating agents

1975 ◽  
Vol 2 (2) ◽  
pp. 151-157 ◽  
Author(s):  
M. I. Lerman ◽  
O. Yu. Abakumova ◽  
N. G. Kutcenko ◽  
I. S. Sokolova ◽  
L. B. Gorbacheva ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Alkylating Agents ◽  
Increased Sensitivity ◽  
Possible Cause

Thin-film silicon detectors for particle detection

2004 ◽  
Vol 1 (5) ◽  
pp. 1284-1291 ◽  
Author(s):  
N. Wyrsch ◽  
S. Dunand ◽  
C. Miazza ◽  
A. Shah ◽  
G. Anelli ◽  
...  
Keyword(s):  
Thin Film ◽  
Silicon Detectors ◽  
Particle Detection ◽  
Thin Film Silicon
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