15 research outputs found
Characterization of Thin Pixel Sensor Modules Interconnected with SLID Technology Irradiated to a Fluence of 2\,n/cm
A new module concept for future ATLAS pixel detector upgrades is presented,
where thin n-in-p silicon sensors are connected to the front-end chip
exploiting the novel Solid Liquid Interdiffusion technique (SLID) and the
signals are read out via Inter Chip Vias (ICV) etched through the front-end.
This should serve as a proof of principle for future four-side buttable pixel
assemblies for the ATLAS upgrades, without the cantilever presently needed in
the chip for the wire bonding.
The SLID interconnection, developed by the Fraunhofer EMFT, is a possible
alternative to the standard bump-bonding. It is characterized by a very thin
eutectic Cu-Sn alloy and allows for stacking of different layers of chips on
top of the first one, without destroying the pre-existing bonds. This paves the
way for vertical integration technologies.
Results of the characterization of the first pixel modules interconnected
through SLID as well as of one sample irradiated to \,\neqcm{}
are discussed.
Additionally, the etching of ICV into the front-end wafers was started. ICVs
will be used to route the signals vertically through the front-end chip, to
newly created pads on the backside. In the EMFT approach the chip wafer is
thinned to (50--60)\,m.Comment: Proceedings to PSD
Production and Characterisation of SLID Interconnected n-in-p Pixel Modules with 75 Micrometer Thin Silicon Sensors
The performance of pixel modules built from 75 micrometer thin silicon
sensors and ATLAS read-out chips employing the Solid Liquid InterDiffusion
(SLID) interconnection technology is presented. This technology, developed by
the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It
allows for stacking of different interconnected chip and sensor layers without
destroying the already formed bonds. In combination with Inter-Chip-Vias (ICVs)
this paves the way for vertical integration. Both technologies are combined in
a pixel module concept which is the basis for the modules discussed in this
paper.
Mechanical and electrical parameters of pixel modules employing both SLID
interconnections and sensors of 75 micrometer thickness are covered. The
mechanical features discussed include the interconnection efficiency, alignment
precision and mechanical strength. The electrical properties comprise the
leakage currents, tuning characteristics, charge collection, cluster sizes and
hit efficiencies. Targeting at a usage at the high luminosity upgrade of the
LHC accelerator called HL-LHC, the results were obtained before and after
irradiation up to fluences of
(1 MeV neutrons).Comment: 16 pages, 22 figure
Recent Results of the ATLAS Upgrade Planar Pixel Sensors R&D Project
To cope with the higher occupancy and radiation damage at the HL-LHC also the
LHC experiments will be upgraded. The ATLAS Planar Pixel Sensor R&D Project
(PPS) is an international collaboration of 17 institutions and more than 80
scientists, exploring the feasibility of employing planar pixel sensors for
this scenario.
Depending on the radius, different pixel concepts are investigated using
laboratory and beam test measurements. At small radii the extreme radiation
environment and strong space constraints are addressed with very thin pixel
sensors active thickness in the range of (75-150) mum, and the development of
slim as well as active edges. At larger radii the main challenge is the cost
reduction to allow for instrumenting the large area of (7-10) m^2. To reach
this goal the pixel productions are being transferred to 6 inch production
lines and more cost-efficient and industrialised interconnection techniques are
investigated. Additionally, the n-in-p technology is employed, which requires
less production steps since it relies on a single-sided process.
Recent accomplishments obtained within the PPS are presented. The performance
in terms of charge collection and efficiency, obtained with radioactive sources
in the laboratory and at beam tests, is presented for devices built from
sensors of different vendors connected to either the present ATLAS chip FE-I3
or the new Insertable B-Layer chip FE-I4. The devices, with a thickness varying
between 75 mum and 300 mum, were irradiated to several fluences up to 2e16
neq/cm. Finally, the different approaches followed inside the collaboration to
achieve slim or active edges are presented.Comment: Proceedings for the Pixel 2012, 7 pages, 6 figures, accepted by NIM
Achievements of the ATLAS Upgrade Planar Pixel Sensors R&D Project
To extend the physics reach of the LHC, accelerator upgrades are planned
which will increase the integrated luminosity to beyond 3000 fb^-1 and the
pile-up per bunch-crossing by a factor 5 to 10. To cope with the increased
occupancy and radiation damage, the ATLAS experiment plans to introduce an
all-silicon inner tracker with the HL-LHC upgrade. To investigate the
suitability of pixel sensors using the proven planar technology for the
upgraded tracker, the ATLAS Upgrade Planar Pixel Sensor R&D Project (PPS) was
established comprising 19 institutes and more than 80 scientists. Main areas of
research are the performance assessment of planar pixel sensors with different
designs and substrate thicknesses up to the HL-LHC fluence, the achievement of
slim or active edges to provide low geometric inefficiencies without the need
for shingling of modules and the exploration of possibilities for cost
reduction to enable the instrumentation of large areas. This paper gives an
overview of recent accomplishments and ongoing work of the R&D project
Heavily Irradiated N-in-p Thin Planar Pixel Sensors with and without Active Edges
We present the results of the characterization of silicon pixel modules
employing n-in-p planar sensors with an active thickness of 150
m, produced at MPP/HLL, and 100-200 m thin active
edge sensor devices, produced at VTT in Finland. These thin sensors are
designed as candidates for the ATLAS pixel detector upgrade to be operated at
the HL-LHC, as they ensure radiation hardness at high fluences. They are
interconnected to the ATLAS FE-I3 and FE-I4 read-out chips. Moreover, the
n-in-p technology only requires a single side processing and thereby it is a
cost-effective alternative to the n-in-n pixel technology presently employed in
the LHC experiments. High precision beam test measurements of the hit
efficiency have been performed on these devices both at the CERN SpS and at
DESY, Hamburg. We studied the behavior of these sensors at different bias
voltages and different beam incident angles up to the maximum one expected for
the new Insertable B-Layer of ATLAS and for HL-LHC detectors. Results obtained
with 150 m thin sensors, assembled with the new ATLAS FE-I4 chip
and irradiated up to a fluence of
410, show that they are
excellent candidates for larger radii of the silicon pixel tracker in the
upgrade of the ATLAS detector at HL-LHC. In addition, the active edge
technology of the VTT devices maximizes the active area of the sensor and
reduces the material budget to suit the requirements for the innermost layers.
The edge pixel performance of VTT modules has been investigated at beam test
experiments and the analysis after irradiation up to a fluence of
510 has been performed
using radioactive sources in the laboratory.Comment: Proceedings for iWoRiD 2013 conference, submitted to JINS
Low mass hybrid pixel detectors for the high luminosity LHC upgrade
Reducing material in silicon trackers is of major importance for a good overall detector performance, and poses severe challenges to the design of the tracking system. To match the low mass constraints for trackers in High Energy Physics experiments at high luminosity, dedicated technological developments are required. This dissertation presents three technologies to design low mass hybrid pixel detectors for the high luminosity upgrades of the LHC. The work targets specifically the reduction of the material from the detector services and modules, with novel powering schemes, flip chip and interconnection technologies. A serial powering scheme is prototyped, featuring a new regulator concept, a control and protection element, and AC-coupled data transmission. A modified flip chip technology is developed for thin, large area Front-End chips, and a via last Through Silicon Via process is demonstrated on existing pixel modules. These technologies, their developments, and the achievable material reduction are discussed using the upgrades of the ATLAS pixel detector as a case study
Topical Workshop on Electronics for Particle Physics
The purpose of the workshop was to present results and original concepts for electronics research and development relevant to particle physics experiments as well as accelerator and beam instrumentation at future facilities; to review the status of electronics for the LHC experiments; to identify and encourage common efforts for the development of electronics; and to promote information exchange and collaboration in the relevant engineering and physics communities