101 research outputs found
Testbeam and Laboratory Characterization of CMS 3D Pixel Sensors
The pixel detector is the innermost tracking device in CMS, reconstructing
interaction vertices and charged particle trajectories. The sensors located in
the innermost layers of the pixel detector must be upgraded for the ten-fold
increase in luminosity expected with the High- Luminosity LHC (HL-LHC) phase.
As a possible replacement for planar sensors, 3D silicon technology is under
consideration due to its good performance after high radiation fluence. In this
paper, we report on pre- and post- irradiation measurements for CMS 3D pixel
sensors with different electrode configurations. The effects of irradiation on
electrical properties, charge collection efficiency, and position resolution of
3D sensors are discussed. Measurements of various test structures for
monitoring the fabrication process and studying the bulk and surface
properties, such as MOS capacitors, planar and gate-controlled diodes are also
presented.Comment: 14 page
Radiation hard 3D silicon pixel sensors for use in the ATLAS detector at the HL-LHC
The High Luminosity LHC (HL-LHC) upgrade requires the planned Inner Tracker (ITk) of the ATLAS detector to tolerate extremely high radiation doses. Specifically, the innermost parts of the pixel system will have to withstand radiation fluences above 1 Ă— 1016 neqcm-2. Novel 3D silicon pixel sensors offer a superior radiation tolerance compared to conventional planar pixel sensors, and are thus excellent candidates for the innermost parts of the ITk. This paper presents studies of 3D pixel sensors with pixel size 50 Ă— 50 ÎĽm2 mounted on the RD53A prototype readout chip. Following a description of the design and fabrication steps, Test Beam results are presented for unirradiated as well as heavily irradiated sensors. For particles passing at perpendicular incidence, it is shown that average efficiencies above 96% are reached for sensors exposed to fluences of 1 Ă— 1016 neqcm-2 when biased to 80 V.publishedVersio
Characterization of proton irradiated 3D-DDTC pixel sensor prototypes fabricated at FBK
In this paper we discuss results relevant to 3D Double-Side Double Type
Column (3D-DDTC) pixel sensors fabricated at FBK (Trento, Italy) and oriented
to the ATLAS upgrade. Some assemblies of these sensors featuring different
columnar electrode configurations (2, 3, or 4 columns per pixel) and coupled to
the ATLAS FEI3 read-out chip were irradiated up to large proton fluences and
tested in laboratory with radioactive sources. In spite of the non optimized
columnar electrode overlap, sensors exhibit reasonably good charge collection
properties up to an irradiation fluence of 2 x 10**15 neq/cm2, while requiring
bias voltages in the order of 100 V. Sensor operation is further investigated
by means of TCAD simulations which can effectively explain the basic mechanisms
responsible for charge loss after irradiation.Comment: Preprint submitted to Nuclear Instruments and Methods A, 11 pages, 13
fig
Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip
The ATLAS Collaboration will upgrade its semiconductor pixel tracking
detector with a new Insertable B-layer (IBL) between the existing pixel
detector and the vacuum pipe of the Large Hadron Collider. The extreme
operating conditions at this location have necessitated the development of new
radiation hard pixel sensor technologies and a new front-end readout chip,
called the FE-I4. Planar pixel sensors and 3D pixel sensors have been
investigated to equip this new pixel layer, and prototype modules using the
FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN
SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test
results are presented, including charge collection efficiency, tracking
efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS
Preliminary results of 3D-DDTC pixel detectors for the ATLAS upgrade
Presented at: 9th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors - RD09. Florence, Italy, 30 September - 2 October 20093D Silicon sensors fabricated at FBK-irst with the Double-side Double Type Column (DDTC) approach and columnar electrodes only partially etched through p-type substrates were tested in laboratory and in a 1.35 Tesla magnetic field with a 180GeV pion beam at CERN SPS. The substrate thickness of the sensors is about 200μm, and different column depths are available, with overlaps between junction columns (etched from the front side) and ohmic columns (etched from the back side) in the range from 110μm to 150μm. The devices under test were bump bonded to the ATLAS Pixel readout chip (FEI3) at SELEX SI (Rome, Italy). We report leakage current and noise measurements, results of functional tests with Am241 γ-ray sources, charge collection tests with Sr90 β-source and an overview of preliminary results from the CERN beam test.publishedVersio
Preliminary results of 3D-DDTC pixel detectors for the ATLAS upgrade
3D Silicon sensors fabricated at FBK-irst with the Double-side Double Type
Column (DDTC) approach and columnar electrodes only partially etched through
p-type substrates were tested in laboratory and in a 1.35 Tesla magnetic field
with a 180GeV pion beam at CERN SPS. The substrate thickness of the sensors is
about 200um, and different column depths are available, with overlaps between
junction columns (etched from the front side) and ohmic columns (etched from
the back side) in the range from 110um to 150um. The devices under test were
bump bonded to the ATLAS Pixel readout chip (FEI3) at SELEX SI (Rome, Italy).
We report leakage current and noise measurements, results of functional tests
with Am241 gamma-ray sources, charge collection tests with Sr90 beta-source and
an overview of preliminary results from the CERN beam test.Comment: 8 pages, 8 figures, presented at RD09 - 9th International Conference
on Large Scale Applications and Radiation Hardness of Semiconductor
Detectors, 30 September - 2 October 2009, Florence, Ital
R&D Paths of Pixel Detectors for Vertex Tracking and Radiation Imaging
This report reviews current trends in the R&D of semiconductor pixellated
sensors for vertex tracking and radiation imaging. It identifies requirements
of future HEP experiments at colliders, needed technological breakthroughs and
highlights the relation to radiation detection and imaging applications in
other fields of science.Comment: 17 pages, 2 figures, submitted to the European Strategy Preparatory
Grou
Simulations of 3D detectors
3D detectors, in which the n and p electrodes are columns etched through the silicon substrates, have proven high radiation tolerance and thus are one of the most suitable candidates for harsh radiation environments, such as vertex detectors. Being the process much more complicated than the planar one, over the years, several simplified 3D families have been studied and fabricated. In this context, TCAD simulations are an excellent tool to predict the behaviour and performance of new detector concepts. In this paper we give an overview of this simulation activity mainly focussing on the 3D FBK technology. We show that it is possible to reproduce
also unexpected phenomena, such as the observed charge multiplication in highly irradiated devices
Development of Active and Slim Edge Terminations for 3D and Planar Detectors
We report novel solutions for the edge termination in silicon detectors. In the framework of a project aimed at the optimization of 3D detectors with active edge, we have developed both active edges using a single sided process with support wafer, and slim edges using a double sided process without support wafer. TCAD simulations and experimental tests have been carried out to validate and compare the proposed approaches.
While active edges can provide a better sensitivity up to a few microns from the physical edge, slim edges can simplify the fabrication technology while limiting the dead area at the edge to about 50 ÎĽm. The main design and technological issues are reported in this paper, along with selected results from TCAD simulations and electro-optical tests performed on these devices
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