| Abstract [eng] |
In high energy physics experiments the semiconductor particle detectors of pin structure are commonly employed for tracking of the ionising particles. However, ionising radiation creates defects and consequently affects the parameters of particle detectors. Therefore, it is necessary to characterize irradiated detectors and search for the new approaches on how to suppress or control the degradation process. Measurements of current-voltage, capacitance-voltage characteristics as well as deep level transient spectroscopy, thermally stimulated currents spectroscopy are employed for the characterization of irradiated particle detectors. At high irradiation fluences when defects concentration exceeds that of dopants, a generation current increases and, thus, the above mentioned techniques can not be applied for the correct evaluation of defect parameters. In this work, models describing displacement currents in detectors due to redistribution of electric field determined by variations of external voltage or a moving charge in electric field are discussed. These models were applied for creation of the advanced techniques which allow evaluating of charge transport, trapping and recombination/generation parameters in heavily irradiated detectors after irradiation. These techniques were applied for the spectroscopy of deep levels associated with defects, for cross-sectional scans within layered junction structures as well as for examination of defects evolution during irradiation. In this work, the detail analysis of the results obtained during irradiation and on post-irradiated detectors is presented. High power and high switching speed rectifiers of pin structure are widely employed in electronic circuits. The switching speed of these devices can be manipulated by introducing recombination centres ascribed to Au or Pt doping or by employing radiation technologies. Introduction of recombination centres inevitably leads to the enhancement of forward voltage drop and leakage current, and, thus, to degradation of a device parameters. Therefore, the static and dynamic parameters can be optimized in a compromise way. In this work, study of the optimization of functional parameters of power pin diodes has been performed. The developed technologies, based on irradiations with protons of various energy and fluence, to create layers of the enhanced recombination containing various profiles within a base region of the device, are described in this thesis. |
