Overview of the radiation simulation session at the workshop 23-24 April on Radiation Effects at the LHC experiments and Impact on Operation and Performance. For more details see:
Comprehensive overview of results of measurements with Silicon Detectors with gain.
(UFSD).
Time resolution,signal-to-noise, bias voltage as a function of irradiation levels with neutrons and protons will be shown for sensors with thickness from 35um to 60um, some with substitution of Boron by Gallium and infusion of Carbon.
We present a High-Voltage vertical JFET, conceived as a candidate for the High-Voltage Multiplexing switch in the ATLAS upgrade of the silicon microstrip Inner Tracker (ITk). Both n-type and p-type HV-JFETs have been successfully fabricated in the silicon processing facility of Brookhaven National Lab. Probe station measurements of un-irradiated devices show low leakage currents and high...
Thin LGAD detectors from CNM were irradiated with neutrons to 6e14 and 3e15 cm-2 and annealed in steps up to 10000 min at 60C. After each annealing step charge collection and leakage currents were measured to determine gain, break-down performance and evolution of leakage currents. It was found that apart from leakage current which decreases with annealing in accordance with expectations the...
We will present the last technological developments at CNM on LGAD detectors for ATLAS HGTD and CMS ETL. In this sense, we will summarize the actual status of the new AIDA2020 fabrication run to integrate thin LGADs in 4-inches, 35 and 50 microns thick, silicon on silicon wafers, showing a description of the integrated structures in the mask set and a summary of the fabrication process. In...
OVERMOS is a MAPS detector test structure fabricated using high resistivity substrate in 180nm CMOS process provided by TowerJazz.It consists of several arrays of 40 x 40 um2 and 40 x 400 um2 pixels which also feature in-pixel CA and full analogue read out.
A number of these device have been irradiated with neutrons and are currently being tested to investigate radiation damage effects....
Where we present TCAD simulations results on the brand new ILGAD device, in two flavours, 300 um and 50 um thickness. Radiation effects in signal formation an particularly in the risign time are considered.
For the high-luminosity phase of the Large Hadron Collider (HL-LHC), at the
expected position of the innermost pixel detector layer of the CMS and ATLAS
experiments, the estimated equivalent neutron fluence after 3000 fb$^{-1}$
is 2$\cdot$10$^{16}$ n$_{eq}$/cm$^2$, and the IEL (Ionizing Energy Loss) dose
in the SiO$_2$ is 12 MGy. The optimisation of the pixel sensors and the
understanding...
Overview of the sensor simulation session at the workshop 23-24 April on Radiation Effects at the LHC experiments and Impact on Operation and Performance
The High Voltage-Monolithic Active Pixels Sensors (HV-MAPS) detector technology is a promising candidate for particle physics experiments. While standard hybrid sensors require bump-bonding or gluing to assemble the sensor and the readout electronics together, fully monolithic HV-MAPS allow integrating these parts onto one single chip, which makes them more cost-efficient especially for...
Two sets of passive CMOS detectors were studied: thinned with processed and metalized backplane and not thinned without backplane processing with substrate biased through the implant on top of the device. Detectors were irradiated with neutrons in reactor in Ljubljana. Collected charge was measured with electrons from Sr-90 source using an external amplifier. Depletion depth and charge...
With the upcoming HL-LHC upgrade, there is ongoing investigations on the viability of HV-CMOS sensors for the upgrade of the ATLAS pixel detector. The HV-CMOS technology is showing great promise, however, a drawback in the standard process is the use of low resistivity silicon (10 - 20 Ωcm) wafers, as this commonly only provides a rather small depletion region before breakdown voltage is...
This contribution will describe the developments foreseen for the characterization of the RD50 MPW1 HV-CMOS monolithic pixel sensors implemented in the LFoundry 150 nm technology in the framework of the RD50 collaboration. A custom board to accommodate the RD50 MPW1 device under test is being designed. This board will be fully compatible with the CaR (Control and Readout) interface board used...
Following from work in the wider community, specific High Voltage-CMOS (HV-CMOS) developments within the RD50 collaboration have started with a small test prototype (RD50-MPW1) in the 150 nm HV-CMOS technology from LFoundry S.r.l. The prototype, manufactured using mid (500 Ω·cm) and high (1.9 kΩ·cm) resistivity substrates, integrates two fully monolithic matrices of pixels and test structures...
Overview of the sensor measurements session at the CERN workshop 23-24 April 2018 on Radiation Effects at the LHC experiments and Impact on Operation and Performance
The HL-LHC is expected to reach luminosities of up to 3000 fb−1; the upgrade of innermost tracking detectors of the ATLAS experiment foresees a decrease in pixel size in order to enhance the positional resolution. In this talk, the collected charge characterisation of different pixel size geometry will be presented. Following irradiation, sensors with 50μm×50μm pixel size show higher charge...
A study of Silicon strip 3D sensors of sizes 50 um x 50 um and 25 um x 100 um, fabricated at CNM using double-sided technology is shown. Sensors are wire-bonded to ALIBAVA read-out system. Results about charge collection of non irradiated sensors are presented, and also irradiated up to fluences of 1.7E16. The response of the sensors in both a test beam of 120 GeV protons and pions, and...
Front-side biasing is an alternative method to bias a silicon sensor. Instead of directly applying high voltage to the back-side, one can exploit the conductive properties of the edge region to bias a detector exclusively via top-side connections. This option can be beneficial for the detector design and might help to facilitate the assembly process of modules. The effective bias voltage is...
In previous studies we presented results on long term annealing studies in irradiated p-type sensors until charge multiplication occurred.
Recently we carried out a deeper investigation on the charge multiplication phenomena of the annealed sensor, in particular its instability. We will show how it depends on bias voltage cycling and (less) on temperature. One sensor irradiated with neutrons...
The FBK, Universities and INFN of Turin and Trento groups are proposing an R&D project to RD50 collaboration, aimed at developing a new detector structure named high-density Low Gain Avalanche Detectors (HD-LGAD). The novel structure consists in a thin LGAD sensor with segmented multiplication junction, featuring small pixels and a reduced inter-pixel border region.
Standard LGADs made on thin...
Nitrogen enrich material showed an improvement of some defects after irradiation. NitroStrip is an RD50 project that aims to compare nitrogen enriched silicon wafers with FZ, DOFZ and MCz material. This presentation will show CCE measurements and electrical characterization of NitroStrip samples irradiated at different fluences with 23MeV protons.
The current of initially p- and n-type bulk silicon pad diodes has been studied for low and high forward and reverse bias voltages at -30 °C. The diodes were irradiated to neutron equivalent fluences $\Phi_{eq}>10^{15}~\text{cm}^{-2}$ with GeV protons.
At low bias voltages, the current is ohmic. The neutral bulk of highly irradiated diodes has approximately zero net fixed space charge and...
When irradiated with fast particles, the radiation damage associated with the removal of charge carriers in n-type silicon (n-Si) is mainly due to the formation of vacancy-type defects (divacancy, A and E centers). In p-Si, an important role in the removal of charge carriers is related with interstitial defects. The appearance of silicon interstitial atoms induced by irradiation initiates a...
Acceptor removal has been studied on p-type silicon sensors irradiated with protons and neutrons up to 7E15 $n_{eq}/cm^2$. Two sets of diodes were used: thin epitaxial diodes with different resistivities (10, 50, 250 and 1000 Ohm cm) and high resistivity float zone diodes with different thicknesses (100, 150, 200 and 285 um).
CV and IV measurements were performed to extract the effective...
In this brief talk I will present the available data on Initial acceptor removal and propose a simple parameterization to explain the basic feature of the data.
Methods are developed for the application of forward biased p–i–n photodiodes to measurements of charged particle fluence beyond 10^15 1-MeV-neutron-equivalent/cm^2. An order of magnitude extension of the regime where forward voltage can be used to infer fluence is achieved for OSRAM BPW34F devices.
Silicon detectors were recently irradiated with reactor neutrons up to fluence of 3e17 n/cm2. The irradiated samples include detectors previously irradiated with 1.6E17 n/cm2 so these were exposed to total of 4.6E17 n/cm2. Measurements have just started and first results will be presented in this contribution.
