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New silicon 3-D-microdetectors have been developed to perform microdosimetry measurements for applications in hadron therapy. In this work, the charge collection efficiency (CCE) of an improved second generation of microdetectors having two different thicknesses (10 and 20 $\mu \text{m}$) and a diameter of 25 $\mu \text{m}$ has been studied by means of the ion beam induced charge (IBIC) technique. New methods to study the active volume and the CCE of microdosimeters are proposed and verified here. The results show that, for this new generation of microdetectors, the CCE is 100% for radial distances up to 10.2 $\mu \text{m}$ from the center of the device, and it rapidly decays between 10.2 $\mu \text{m}$ and the detector edge. The characterization of the CCE conducted here will allow us to completely explain the energy spectra obtained during the microdosimetry studies performed in clinical centers. [ABSTRACT FROM AUTHOR]

An ultra-thin 3-D detector (U3DTHIN) with a 10-\mum-thick active region has been proposed to apply for microdosimetry in heavy ion therapy where the ion beam incidence is normal to the detector. The advantage of the detector is that the detector substrate below the silicon-on-insulator layer has been etched away. Extremely small columnar 3-D electrodes allow the detector to be fully depleted at very low biases with a minimum dead region due to their size. In this paper, a charge collection study of the U3DTHIN detector carried out using an ion beam-induced charge collection (IBICC) technique is presented. The IBICC study utilized a microbeam of 5.5 MeV He^2 + and 20 MeV^12C ions focused to approximately 1-\mum diameter. Full charge collection was observed from a bias as low as -10 V. A comparison of the detector response when irradiated from the front and rear side is also presented. [ABSTRACT FROM PUBLISHER]

The planned upgrade to the CERN Large Hadron Collider (LHC), the Super-LHC (sLHC) will increase its luminosity by a factor of ten. This necessitates the development of silicon tracking detectors that are significantly more radiation resistant than the ones employed at the LHC. Currently, new detector technologies are being developed to cope with the increased levels of radiation damage at the sLHC. A possible radiation hard option for silicon short strip devices (SSD) in the inner layers of sLHC trackers are 3-D detectors with rows of columnar electrodes processed into the bulk material. These are joined together to form strips. While the excellent radiation hardness of this design has been proven before in lab experiments, a 3-D SSD prototype has now been investigated for the first time in a beam test with pions of a nominal energy of 180 GeV. The use of analog LHC-speed electronics, a beam telescope and time-resolved measurements allowed for detailed studies of the signal behavior on the hit strip and its neighboring strips. Charge collection and efficiency were as well measured with respect to time and point of incidence of the beam particles on the detector. The results of these measurements are presented in this paper. [ABSTRACT FROM AUTHOR]

Abstract: Silicon detectors in 3D technology are a candidate for applications in environments requiring an extreme radiation hardness, as in the innermost layers of the detectors at the proposed High-Luminosity LHC. In 3D detectors, the electrodes are made of columns etched into the silicon perpendicular to the surface. This leads to higher electric fields, a smaller depletion voltage and a reduced trapping probability of the charge carriers compared to standard planar detectors. In this article, the signal and the noise of irradiated n-in-p and p-in-n 3D silicon strip detectors are compared. The devices under test have been irradiated up to a fluence of 2×1016 1MeV neutron equivalent particles per square centimetre , which corresponds to the fluence expected for the inner pixel detector layers at the High-Luminosity LHC. A relative charge collection efficiency of approximately 70% was obtained even after the highest irradiation fluence with both detector types. The influence of different temperatures on the signal and the noise is investigated and results of annealing measurements are reported. [Copyright &y& Elsevier]

Abstract: 3D silicon sensors, where plasma micromachining is used to etch deep narrow apertures in the silicon substrate to form electrodes of PIN junctions, were successfully manufactured in facilities in Europe and USA. In 2011 the technology underwent a qualification process to establish its maturity for a medium scale production for the construction of a pixel layer for vertex detection, the Insertable B-Layer (IBL) at the CERN-LHC ATLAS experiment. The IBL collaboration, following that recommendation from the review panel, decided to complete the production of planar and 3D sensors and endorsed the proposal to build enough modules for a mixed IBL sensor scenario where 25% of 3D modules populate the forward and backward part of each stave. The production of planar sensors will also allow coverage of 100% of the IBL, in case that option was required. This paper will describe the processing strategy which allowed successful 3D sensor production, some of the Quality Assurance (QA) tests performed during the pre-production phase and the production yield to date. [Copyright &y& Elsevier]

Abstract: 3D silicon sensors, where electrodes penetrate the silicon substrate fully or partially, have successfully been fabricated in different processing facilities in Europe and USA. The key to 3D fabrication is the use of plasma micro-machining to etch narrow deep vertical openings allowing dopants to be diffused in and form electrodes of pin junctions. Similar openings can be used at the sensor''s edge to reduce the perimeter''s dead volume to as low as ∼4μm. Since 2009 four industrial partners of the 3D ATLAS R&D Collaboration started a joint effort aimed at one common design and compatible processing strategy for the production of 3D sensors for the LHC Upgrade and in particular for the ATLAS pixel Insertable B-Layer (IBL). In this project, aimed for installation in 2013, a new layer will be inserted as close as 3.4cm from the proton beams inside the existing pixel layers of the ATLAS experiment. The detector proximity to the interaction point will therefore require new radiation hard technologies for both sensors and front end electronics. The latter, called FE-I4, is processed at IBM and is the biggest front end of this kind ever designed with a surface of ∼4cm2. The performance of 3D devices from several wafers was evaluated before and after bump-bonding. Key design aspects, device fabrication plans and quality assurance tests during the 3D sensors prototyping phase are discussed in this paper. [Copyright &y& Elsevier]