The Large Hadron Collider (LHC) at CERN has the highest energy and luminosity in the world. Radiation hardness is then a critical requirement for the inner tracker design. The inner tracker is important for identifying heavy quarks using high spatial precision detectors. Silicon detectors are now the primary technology for this application. 3D silicon sensors use a novel technology with penetrating electrodes and have excellent radiation hardness by design. It overcomes the signal loss with a low operation voltage by reducing the collection length compared to the current planar technology used in the ATLAS pixel detector. The ATLAS insertable B-layer (IBL) is an upgrade to improve tracking resolution of the inner tracker and will be installed in 2013. It will be composed of 75% planar sensors and 25% 3D sensors in the large-η region. It is important to simulate the IBL tracking performance and to have a valid model for 3D sensors. This thesis investigated the experimental data for heavily irradiated planar strip sensors and 3D sensors to develop a device simulator, in which impact ionisation has to be included. The modelling has found that the radiation induced effective doping concentration has two linear regimes with a smaller growth rate at high fluences. This shows the possibility to operate silicon sensors with a higher irradiation level. The signal efficiency of each pixel is the basis to simulate the whole IBL response. A model and a code were developed to calculate the induced signal from electron-hole pairs generated by the traversing charge particles. This results in a 2D efficiency map used as an input of the 3D digitiser for the Geant4 simulation. This map was adopted by the IBL software team for the whole tracker simulation and has been validated by the test beam data.

The objective of this thesis is to introduce an alternative temperature sensor in CMOS technology with small area, low power consumption, and high resolution that can be easily interfaced. A novel temperature sensor utilizing the interface–trap charge pumping phenomenon and the temperature sensitivity of generation current is proposed. This thesis presents the design and characterization of the proposed temperature sensor fabricated in 0.18µm CMOS technology. The prototype sensor is characterized for the temperature range of 27oC–120oC. It has frequency output and exhibits linear transfer characteristics, high sensitivity, and high resolution. This temperature sensor is proposed for microprocessor thermal management applications.

After ten years of massive success, the Large Hadron Collider (LHC) at CERN is going for an upgrade to the next phase, The High Luminosity Large Hadron Collider (HL-LHC) which is planned to start its operation in 2029. This is expected to have a fine boost to its performance, with an instantaneous luminosity of 5.0×1034 cm-2s -1 (ultimate value 7.5×1034 cm-2s -1 ) with 200 average interactions per bunch crossing which will increase the fluences up to more than 1016 neq/ cm2 , resulting in high radiation damage in ATLAS detector. To withstand this situation, it was proposed to make the innermost layer with 3D silicon sensors, which will have radiation tolerance up to 2×1016 neq/cm2 with a Total Ionization Dose of 9.9 MGy. Two-pixel geometries have been selected for 3D sensors, 50 × 50 μm2 for Endcap (ring), which will be produced by FBK (Italy) and SINTEF (Norway), and 25 × 100 μm2 for Barrel (stave), will be produced by CNM (Spain). A discussion is made in this thesis about the production of FBK on both geometries, as they have made a breakthrough with their Stepper lithography process. The yield improved, specifically for the geometry 25 × 100 μm2 with two electrode readouts, which was problematic in the mask aligner approach. Their sensors were characterized electrically at waferlevel as well as after integration with RD53a readout chip (RoC) on single-chip cards (SCC) and were verified against Innermost Tracker criteria. The SCCs were sent for irradiation up to 1×1016 neq/cm2 and were tested under electron test beam, and a hit efficiency of 97% was presented. Some more SCCs have been sent to Los Alamos for irradiating them up to 1.5×1016 neq/cm2 fluence. As the 3D sensors will be mounted as Triplets, a discussion is also made on their assembly and QA/QC process. A reception testing and electrical testing setup both at room temperature and the cold temperature was made and discussed, with results from some early RD53a RoC-based triplets. The pre-production sensors are already evaluated, and soon they will be available bump-bonded with ITkPixV1 RoC for further testing.

Le projet PLUME développe des échelles ultra-légères inspirées par le cahier des charges du détecteur de vertex pour le futur e+e- International Linear Collider (ILC). Nos travaux montrent que, pour une énergie de 350 GeV et une luminosité de 250 fb-1, l’ILC donnera accès à des états finals comme Hνν. Les modules PLUME exploitent le concept d’échelles double-face recouvertes de capteurs CMOS afin d’atteindre un budget de matière de 0,35 % en longueurs de radiation. Les tests effectués ont montré que les performances électriques des 12 capteurs intégrés sur ces échelles ne sont pas dégradées. La surface des échelles présente des déformations, mais nous avons mis au point un algorithme spécifique qui permet de corriger leurs effets lors du traitement des données. Finalement, une mesure de la longueur de radiation d’un prototype moins avancé a été réalisée avec un faisceau test au DESY. La valeur obtenue de 0,47±0,02 % en longueurs de radiation correspond au budget attendu. / The PLUME project develops ultra-light pixelated layers with specifications driven by the design of a vertex detector at the future e+e- International Linear Collider (ILC). The ILC will give access to final states like Hνν, as this work demonstrates for centre-of-mass energy 350GeV and a luminosity of 250 fb-1. PLUME devices exploit the concept of double-sided ladder spaved with thinned CMOS pixel sensors in order to reach a material budget of 0.35 % of radiation length. The present study validated that simultaneous operation of the 12 CMOS sensors integrated on such light ladders do not impact their electrical behaviour. Surface deformations were observed but a specific algorithm during the off- line analysis was proposed and successfully tested to preserve the native sensor spatial resolution. Finally, a measurement of the material budget of a less advanced ladder prototype has been performedat DESY test beam and yield 0.47±0.02 % of radiation length, matching the expected value.