Test for the mitigation of the Single Event Upset for ASIC in 130 nm technology

The Micro Vertex Detector (MVD) is the innermost sensitive layer of the PANDA experiment at the new Facility for Antiproton and Ion Research (Fair). The MVD will be composed of two kind of sensors: hybrid pixels and double sided strips. The front end electronics of the MVD will be placed at a few centimetres from the interaction point, where high radiation levels are expected. Therefore the ASIC have to be designed with radiation tolerant techniques, both in terms of Total Ionizing Dose (TID) and Single Event Upset (SEU). The TID issue has been addressed using a sub micron technology as the CMOS 130 nm, which has proven an intrinsic good tolerance to radiation damage. On the other hand these technologies are very sensitive to SEU, due to the reduced size of the active devices. Therefore SEU mitigation techniques have to be applied at circuit level, in order to prevent data corruption and failure of the control logic. Various architectures and techniques are proposed in literature, which essentially show a trade off between protection level and area penalty. Some of these techniques have been implemented in the prototypes for the readout of MVD pixel sensors, based on space constraints. The prototypes have been then tested at the Legnaro INFN facility with ions of various species, in order to asses the effective capability of SEU mitigation. The obtained results have shown some limitation in the implementation of these techniques, which will serve as a guideline for the design of the final ASIC

Influence of Halo Implantations on the Total Ionizing Dose Response of 28-nm pMOSFETs Irradiated to Ultrahigh Doses

In this paper, the total ionizing dose (TID) response of a commercial 28-nm high-k CMOS technology at ultrahigh doses is measured and discussed. The degradation of pMOSFETs depends not only on the channel width but also on the channel length. Short-channel pMOSFETs exhibit a higher TID tolerance compared to long ones. We attributed this effect to the presence of the halo implantations. For short-channel lengths, the drain halo can overlap the source one, increasing the average bulk doping along the channel. The higher bulk doping attenuates the radiation-induced degradation, improving the TID tolerance of short-channel transistors. The results are finally compared and discussed through technology computer-aided design simulations

Introducing the CTA concept

The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project

Monolithic active pixel sensor development for the upgrade of the ALICE inner tracking system

ALICE plans an upgrade of its Inner Tracking System for 2018. The development of a monolithic active pixel sensor for this upgrade is described. The TowerJazz 180 nm CMOS imaging sensor process has been chosen as it is possible to use full CMOS in the pixel due to the offering of a deep pwell and also to use different starting materials. The ALPIDE development is an alternative to approaches based on a rolling shutter architecture, and aims to reduce power consumption and integration time by an order of magnitude below the ALICE specifications, which would be quite beneficial in terms of material budget and background. The approach is based on an in-pixel binary front-end combined with a hit-driven architecture. Several prototypes have already been designed, submitted for fabrication and some of them tested with X-ray sources and particles in a beam. Analog power consumption has been limited by optimizing the Q/C of the sensor using Explorer chips. Promising but preliminary first results have also been obtained with a prototype ALPIDE. Radiation tolerance up to the ALICE requirements has also been verified

Neutron production targets for a new Single Event Effects facility at the 70 MeV Cyclotron of LNL-INFN

A high-current (500 μA) variable energy (35-70 MeV) proton cyclotron is under construction at the INFN LNL for the SPES project and will be commissioned in 2014. This opens up the prospect of a high flux neutron irradiation facility in Italy that could perform various research activities, in particular studies of Single Event Effects (SEE) induced in microelectronic devices and systems by atmospheric neutrons at sea level. In this paper we first review neutron-induced SEE, describe neutron testing facilities and briefly illustrate the project at LNL. We then describe two types of high power production targets under design to produce neutrons with a continuous atmospheric-like differential energy spectra in the energy range accessible to the accelerator. One target is a high power W-based thick target that will completely stop the 70 MeV protons. Another target, under preliminary study, is based on a multi-material target made, in this case, of two different materials, light (Be) and a heavy material such as Ta or Pb

Technical design report for the upgrade of the ALICE inner tracking system

ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) based on monolithic CMOS pixel detectors. The primary focus of the ITS upgrade is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP. With respect to the current detector, the new Inner Tracking System will significantly enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30×30 μm2. This document, submitted to the LHCC (LHC experiments Committee) in September 2013, presents the design goals, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector and physics performance

Bias Dependence of Total Ionizing Dose Effects on 28-nm Bulk MOSFETs

This paper investigates the effects of total ionizing dose up to 1 Grad on 28-nm bulk MOSFETs under different bias conditions during irradiation. The aim is to assess the potential use of this commercial bulk CMOS technology in the future high-luminosity Large Hadron Collider at CERN that will require highly improved radiation-tolerant tracking systems

Total dose effects on deep-submicron SOI technology for Monolithic Pixel Sensor development

We developed and characterized Monolithic pixel detectors in deep-submicron Fully Depleted (FD) Silicon On Insulator (SOI) technology. This paper presents the first studies of total dose effects from ionizing radiation performed on single transistor test structures. This work shows how the substrate bias condition during irradiation heavily affects the resulting radiation damage

Characterisation of a Thin Fully Depleted SOI Pixel Sensor with High Momentum Charged Particles

This paper presents the results of the characterisation of a thin, fully depleted pixel sensor manufactured in SOI technology on high-resistivity substrate with high momentum charged particles. The sensor is thinned to 70 $\mu$m and a thin phosphor layer contact is implanted on the back-plane. Its response is compared to that of thick sensors of same design in terms of signal and noise, detection efficiency and single point resolution based on data collected with 300 GeV pions at the CERN SPS. We observe that the charge collected and the signal-to-noise ratio scale according to the estimated thickness of the sensitive volume and the efficiency and single point resolution of the thinned chip are comparable to those measured for the thick sensors.Comment: 8 pages, 3 figures, submitted to Nucl. Instr. and Meth., section