Development of innovative silicon radiation detectors

Abstract

Silicon radiation detectors fabricated at the IMB-CNM (CSIC) Clean Room facilities using the most innovative techniques in detector technology are presented in this thesis. TCAD simulation comprises an important part in this work as becomes an essential tool to achieve exhaustive performance information of modelled detectors prior their fabrication and subsequent electrical characterization. Radiation tolerance is also investigated in this work using TCAD simulations through the potential and electric field distributions, leakage current and capacitance characteristics and the response of the detectors to the pass of different particles for charge collection efficiencies. Silicon detectors investigated in this thesis were developed for specific projects but also for applications in experiments which can benefit from their improved characteristics, as described in Chapter 1. Double-sided double type columns 3D (3D-DDTC) detectors have been developed under the NEWATLASPIXEL project in the framework of the CERN RD50 collaboration for the ATLAS Inner Detector upgrades and the introduction of a new pixel layer called Insertable B-Layer. The radiation tolerance of slim-edge (“edgeless”) detectors, whose current terminating structure reduces the insensitive area of detectors to 50 μm, for close-to-beam experiments like the TOTEM experiment at HL-LHC, have been simulated under the EU TOSTER project. Ultra-thin 3D detectors, which combine 3D detector technology and thin membrane fabrication process, are also studied in this work. They provide an alternative to the present Neutral Particle Analyzers at the International Thermonuclear Experimental Reactor (ITER) in the ions detection for plasma diagnosis, and they are also being used in neutron detection experiments after being covered with any layer containing 10B whose high capture cross-section of thermal neutrons allows their detection through the emitted alpha. Finally, active-edge detectors have been studied for applications in X-ray beam positioning, X-ray sensors for beamstops and detectors with pad, microstrip and Medipix2 designs for research purposes.