Study and characterisation of semiconductor radiation detectors using the IBIC technique

• Autores: Adrián García Osuna
• Directores de la Tesis: Francisco Javier García López (dir. tes.), M. C. Jiménez-Ramos (dir. tes.)
• Lectura: En la Universidad de Sevilla ( España ) en 2022
• Idioma: español
• Número de páginas: 186
• Enlaces
  • Tesis en acceso abierto en: Idus
• Resumen

  • The work carried out in this thesis focuses on the study of radiation detectors based on semiconductor materials by applying the technique known as Ion Beam Induced Current (or IBIC technique). Radiation and particle detectors in general are essential in practically any experiment or application in nuclear physics (high energy accelerators, nuclear reactors, medical applications, etc.) and, as experiments and applications grow in complexity and requirements, detectors must also constantly improve in performance and features to be able to meet their needs. It is therefore necessary not only to improve detector manufacturing technology, but also to improve the technology related to the various methods for the study and characterisation of new detectors (IBIC, EBIC, TCT, TPA, etc.). The technique used in this thesis, i.e., the IBIC technique, is a powerful and versatile tool that uses focused ion beams for the characterisation of semiconductor radiation detectors. In this thesis, the IBIC technique has been applied in the context of three different research projects, each with different motivations and objectives and, therefore, each detector has a completely different design to offer specific features. However, thanks to the IBIC technique, it is possible to study and characterise all of them and obtain information that would not be possible with other techniques, getting to understand and deepen the physical mechanisms underlying their operation. On the one hand, the IBIC technique was applied to a commercial silicon detector in order to study the formation and evolution of defects caused by radiation in this material. This work is part of an IAEA Coordinated Research Project and the results will provide experimental data to extend current defect dynamics simulation models beyond existing time limits. On the other hand, the IBIC technique was used to study and characterise innovative silicon carbide (SiC) detectors manufactured at the Instituto de Microelectrónica de Barcelona, which are designed to operate under extreme temperature and radiation conditions in general and in future fusion reactors in particular. These results will be used to study the optimal operating point and its application limits, validating its use for the required application. In addition, this technique allows further study of various physical phenomena occurring within the detector, such as the reduction of the charge carriers mean lifetime, or the reduction of the mean energy required to generate an electron-hole pair in SiC as a function of temperature. Finally, the IBIC technique and also the Time-Resolved IBIC (TRIBIC) technique were used to study the phenomenon of charge density-induced gain suppression in Low Gain Avalanche Detectors (LGADs) fabricated at the Instituto de Microelectrónica de Barcelona. These detectors are aimed to detect minimum ionising particles in the future High-Luminosity Large Hadron Collider (HL-LHC) at CERN. Our results will help to better understand the phenomenon of charge multiplication and the role of the ionization charge density in the gain value. This information is of vital importance in order to correctly interpret the data provided by future HL-LHC experiments.