15 research outputs found
Test-beam Performance Results of the FASTPIX Sub-Nanosecond CMOS Pixel Sensor Demonstrator
Within the ATTRACT FASTPIX project, a monolithic pixel sensor demonstrator
chip has been developed in a modified 180 nm CMOS imaging process technology,
targeting sub-nanosecond timing precision for single ionising particles. It
features a small collection electrode design on a 25 micrometers-thick
epitaxial layer and contains 32 mini matrices of 68 hexagonal pixels each, with
pixel pitches ranging from 8.66 to 20 micrometers. Four pixels are transmitting
an analog output signal and 64 are transmitting binary hit information. Various
design variations are explored, aiming at accelerating the charge collection
and making the timing of the charge collection more uniform over the pixel
area. Signal treatment of the analog waveforms, as well as reconstruction of
digital position, time and charge information, is carried out off-chip. This
contribution introduces the design of the sensor and readout system and
presents performance results for various pixel designs achieved in recent test
beam measurements with external tracking and timing reference detectors. A time
resolution below 150 ps is obtained at full efficiency for all pixel pitches.Comment: 14 pages, 15 figures, submitted to NIMA (special issue for ULITIMA
2023 conference
Transient Monte Carlo Simulations for the Optimisation and Characterisation of Monolithic Silicon Sensors
An ever-increasing demand for high-performance silicon sensors requires
complex sensor designs that are challenging to simulate and model. The
combination of electrostatic finite element simulations with a transient Monte
Carlo approach provides simultaneous access to precise sensor modelling and
high statistics. The high simulation statistics enable the inclusion of Landau
fluctuations and production of secondary particles, which offers a realistic
simulation scenario. The transient simulation approach is an important tool to
achieve an accurate time-resolved description of the sensor, which is crucial
in the face of novel detector prototypes with increasingly precise timing
capabilities. The simulated time resolution as a function of operating
parameters as well as the full transient pulse can be monitored and assessed,
which offers a new perspective on the optimisation and characterisation of
silicon sensors.
In this paper, a combination of electrostatic finite-element simulations
using 3D TCAD and transient Monte Carlo simulations with the Allpix Squared
framework are presented for a monolithic CMOS pixel sensor with a small
collection diode, that is characterised by a highly inhomogeneous, complex
electric field. The results are compared to transient 3D TCAD simulations that
offer a precise simulation of the transient behaviour but long computation
times. Additionally, the simulations are benchmarked against test-beam data and
good agreement is found for the performance parameters over a wide range of
different operation conditions
Developing a Monolithic Silicon Sensor in a 65 nm CMOS Imaging Technology for Future Lepton Collider Vertex Detectors
Monolithic CMOS sensors in a 65 nm imaging technology are being investigated
by the CERN EP Strategic R&D Programme on Technologies for Future Experiments
for an application in particle physics. The appeal of monolithic detectors lies
in the fact that both sensor volume and readout electronics are integrated in
the same silicon wafer, providing a reduction in production effort, costs and
scattering material. The Tangerine Project WP1 at DESY participates in the
Strategic R&D Programme and is focused on the development of a monolithic
active pixel sensor with a time and spatial resolution compatible with the
requirements for a future lepton collider vertex detector. By fulfilling these
requirements, the Tangerine detector is suitable as well to be used as
telescope planes for the DESY-II Test Beam facility. The project comprises all
aspects of sensor development, from the electronics engineering and the sensor
design using simulations, to laboratory and test beam investigations of
prototypes. Generic TCAD Device and Monte-Carlo simulations are used to
establish an understanding of the technology and provide important insight into
performance parameters of the sensor. Testing prototypes in laboratory and test
beam facilities allows for the characterization of their response to different
conditions. By combining results from all these studies it is possible to
optimize the sensor layout. This contribution presents results from generic
TCAD and Monte-Carlo simulations, and measurements performed with test chips of
the first sensor submission.Comment: 7 pages, 8 figures, submitted to IEEE Xplore as conference record for
2022 IEEE NSS/MIC/RTS
Digital Pixel Test Structures implemented in a 65 nm CMOS process
The ALICE ITS3 (Inner Tracking System 3) upgrade project and the CERN EP R&D
on monolithic pixel sensors are investigating the feasibility of the Tower
Partners Semiconductor Co. 65 nm process for use in the next generation of
vertex detectors. The ITS3 aims to employ wafer-scale Monolithic Active Pixel
Sensors thinned down to 20 to 40 um and bent to form truly cylindrical half
barrels. Among the first critical steps towards the realisation of this
detector is to validate the sensor technology through extensive
characterisation both in the laboratory and with in-beam measurements. The
Digital Pixel Test Structure (DPTS) is one of the prototypes produced in the
first sensor submission in this technology and has undergone a systematic
measurement campaign whose details are presented in this article.
The results confirm the goals of detection efficiency and non-ionising and
ionising radiation hardness up to the expected levels for ALICE ITS3 and also
demonstrate operation at +20 C and a detection efficiency of 99% for a DPTS
irradiated with a dose of 1 MeV ncm.
Furthermore, spatial, timing and energy resolutions were measured at various
settings and irradiation levels.Comment: Updated threshold calibration method. Implemented colorblind friendly
color palette in all figures. Updated reference
Performance of the FASTPIX Sub-Nanosecond CMOS Pixel Sensor Demonstrator
Within the ATTRACT FASTPIX project, a monolithic pixel sensor demonstrator chip has been developed in a modified 180 nm CMOS imaging process, targeting sub-nanosecond timing measurements for single ionizing particles. It features a small collection electrode design on a 25 micron thick epitaxial layer and contains 32 mini matrices of 68 hexagonal pixels each, with pixel pitches ranging from 8.66 to 20 micron. Four pixels are transmitting an analog output signal and 64 are transmitting binary hit information. Various design variations are explored, aiming at accelerating the charge collection and making the timing of the charge collection more uniform over the pixel area. Signal treatment of the analog waveforms, as well as reconstruction of time and charge information, is carried out off-chip. This contribution introduces the design of the sensor and readout system and presents the first performance results for 10 ÎŒm and 20 ÎŒm pixel pitch achieved in measurements with particle beams
Development of novel single-die hybridisation processes for small-pitch pixel detectors
Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, especially for small-scale applications, such interconnect technologies need to be suitable for the assembly of single dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25 ”m and 55 ”m are presented in this contribution â an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing using support wafers, as well as a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The fine-pitch bump-bonding process is qualified with hybrid assemblies from a recent bonding campaign at Frauenhofer IZM. Individual CLICpix2 ASICs with 25 ”m pixel pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50 ”m to 130 ”m. The device characterisation was conducted in the laboratory as well as during a beam test campaign at the CERN SPS beam-line, demonstrating an interconnect yield of about 99.7%.Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, especially for small-scale applications, such interconnect technologies need to be suitable for the assembly of single dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25 ”m and 55 ”m are presented in this contribution â an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing using support wafers, as well as a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The fine-pitch bump-bonding process is qualified with hybrid assemblies from a recent bonding campaign at Frauenhofer IZM. Individual CLICpix2 ASICs with 25 ”m pixel pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50 ”m to 130 ”m. The device characterisation was conducted in the laboratory as well as during a beam test campaign at the CERN SPS beam-line, demonstrating an interconnect yield of about 99.7%. The ACF interconnect technology replaces the solder bumps by conductive micro-particles embedded in an epoxy film. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACF using a flip-chip device bonder. The required pixel pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) plating process. This newly developed ACF hybridisation process is first qualified with the Timepix3 ASICs and sensors with 55 ”m pixel pitch. The technology can be also used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the two interconnect processes and presents preliminary hybridisation results with CLICpix2 and Timepix3 sensors and ASICs.Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, especially for small-scale applications, such interconnect technologies need to be suitable for the assembly of single dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25um and 55um are presented in this contribution -- an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing using support wafers, as well as a newly developed in-house single-die interconnection process based on ACF. The fine-pitch bump-bonding process is qualified with hybrid assemblies from a recent bonding campaign at Frauenhofer IZM. Individual CLICpix2 ASICs with 25um pixel pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50um to 130um. The device characterisation was conducted in the laboratory as well as during a beam test campaign at the CERN SPS beam-line, demonstrating an interconnect yield of about 99.7%. The ACF interconnect technology replaces the solder bumps by conductive micro-particles embedded in an epoxy film. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACF using a flip-chip device bonder. The required pixel pad topology is achieved with an in-house ENIG plating process. This newly developed ACF hybridisation process is first qualified with the Timepix3 ASICs and sensors with 55um pixel pitch. The technology can be also used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques
Comparison of different sensor thicknesses and substrate materials for themonolithic small collection-electrode technology demonstrator CLICTD
Small collection-electrode monolithic CMOS sensors profit from a high signal-to-noise ratio and a small power consumption, but have a limited active sensor volume due to the fabrication process based on thin high-resistivity epitaxial layers. In this paper, the active sensor depth is investigated in the monolithic small collection-electrode technology demonstrator CLICTD. Charged particle beams are used to study the charge-collection properties and the performance of devices with different thicknesses both for perpendicular and inclined particle incidence. In CMOS sensors with a high-resistivity Czochralski substrate, the depth of the sensitive volume is found to increase by a factor two in comparison with standard epitaxial material and leads to significant improvements in the hit-detection efficiency and the spatial and time resolution
Pixel detector hybridization and integration with anisotropic conductive adhesives
International audienceA reliable and cost-effective interconnect technology is required for the development of hybrid pixel detectors. The interconnect technology needs to be adapted for the pitch and die sizes of the respective applications. For small-scale applications and during the ASIC and sensor development phase, interconnect technologies must also be suitable for the assembly of single-dies typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D program and the AIDAinnova collaboration, innovative and scalable hybridization concepts are under development for pixel-detector applications in future colliders. This contribution presents recent results of a newly developed in-house single-die interconnection process based on Anisotropic Conductive Adhesives (ACA). The ACA interconnect technology replaces solder bumps with conductive micro-particles embedded in an epoxy layer applied as either film or paste. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACA using a flip-chip device bonder. A specific pixel-pad topology is required to enable the connection via micro-particles and create cavities into which excess epoxy can flow. This pixel-pad topology is achieved with an in-house Electroless Nickel Immersion Gold process that is also under development within the project. The ENIG and ACA processes are qualified with a variety of different ASICs, sensors, and dedicated test structures, with pad diameters ranging from 12 ÎŒm to 140 ÎŒm and pitches between 20 ÎŒm and 1.3 mm. The produced assemblies are characterized electrically, with radioactive-source exposures, and in tests with high-momentum particle beams. A focus is placed on recent optimization of the plating and interconnect processes, resulting in an improved plating uniformity and interconnect yield
Developing a Monolithic Silicon Sensor in a 65 nm CMOS Imaging Technology for Future Lepton Collider Vertex Detectors
Monolithic CMOS sensors in a 65 nm imaging technology are being investigated by the CERN EP Strategic R&D Programme on Technologies for Future Experiments for an application in particle physics. The appeal of monolithic detectors lies in the fact that both sensor volume and readout electronics are integrated in the same silicon wafer, providing a reduction in production effort, costs and scattering material. The Tangerine Project WP1 at DESY participates in the Strategic R&D Programme and is focused on the development of a monolithic active pixel sensor with a time and spatial resolution compatible with the requirements for a future lepton collider vertex detector. By fulfilling these requirements, the Tangerine detector is suitable as well to be used as telescope planes for the DESY-II Test Beam facility. The project comprises all aspects of sensor development, from the electronics engineering and the sensor design using simulations, to laboratory and test beam investigations of prototypes. Generic TCAD Device and Monte-Carlo simulations are used to establish an understanding of the technology and provide important insight into performance parameters of the sensor. Testing prototypes in laboratory and test beam facilities allows for the characterization of their response to different conditions. By combining results from all these studies it is possible to optimize the sensor layout. This contribution presents results from generic TCAD and Monte-Carlo simulations, and measurements performed with test chips of the first sensor submission
Developing a Monolithic Silicon Sensor in a 65 nm CMOS Imaging Technology for Future Lepton Collider Vertex Detectors
Monolithic CMOS sensors in a 65 nm imaging technology are being investigated by the CERN EP Strategic R&D Programme on Technologies for Future Experiments for an application in particle physics. The appeal of monolithic detectors lies in the fact that both sensor volume and readout electronics are integrated in the same silicon wafer, providing a reduction in production effort, costs and scattering material. The Tangerine Project WP1 at DESY participates in the Strategic R&D Programme and is focused on the development of a monolithic active pixel sensor with a time and spatial resolution compatible with the requirements for a future lepton collider vertex detector. By fulfilling these requirements, the Tangerine detector is suitable as well to be used as telescope planes for the DESY-II Test Beam facility. The project comprises all aspects of sensor development, from the electronics engineering and the sensor design using simulations, to laboratory and test beam investigations of prototypes. Generic TCAD Device and Monte-Carlo simulations are used to establish an understanding of the technology and provide important insight into performance parameters of the sensor. Testing prototypes in laboratory and test beam facilities allows for the characterization of their response to different conditions. By combining results from all these studies it is possible to optimize the sensor layout. This contribution presents results from generic TCAD and Monte-Carlo simulations, and measurements performed with test chips of the first sensor submission