Utilization of Ion Accelerators for Studying and Modelling of Radiation Induced Defects in Semiconductors and Insulators (F11016)
The main scope of the CRP is to further enhance the present understanding of radiation effects of electronic materials created by accelerator-based irradiation and measurements combined with theoretical modelling and simulation.
In order to help the interpretation and prediction of the experimental data, a new software, called IST (IBIC Simulation Tool) was developed in order to develop semiconductor electronic devices with improved radiation hardness. The software is based on direct atomistic simulation of radiation process using Monte Carlo simulation and it allows interfacing with external electrostatic models, ionization and vacancy density profiles to calculate real-time total and time-resolved charge collection efficiency (CCE) pulses, statistical profiles, spectra. The IST also provides a model for the carriers' lifetime degradation in irradiated devices, describing the linear decrease in CCE in low damage regime and providing a quantitative description of the radiation hardness parameter.
The originality of the software lies that it is the very first software to calculate charge collection efficiency profiles in semiconductor electronic devices and, in particular, nuclear detectors.
Left: Ion Beam Induced Charge collection maps by showing the results of area selective ion beam irradiations of Si pin diodes with 2 MeV H+ ions at different fluences. Right: Ion Beam Induced Charge collection spectrum as simulated from the whole area.
13 research institutions have participated actively in this project from 12 Member States: Australia, Croatia, Germany, Finland, India, Italy, Japan, Malaysia, Singapore, Spain, United Kingdom, United States.
The IST code was developed by Mr Jacopo Forneris who is a young scientist at University of Torino, Italy. Mr Forneris partly worked on the code as an Intern at the IAEA Physics Section. The CRP participants provided the experimental data to test and validate the code. The results are also available in an international scientific publication as Forneris et al.: A Monte Carlo software for the 1-dimensional simulation of IBIC experiments, Nuclear Instruments and Methods in Physics Research B 332 (2014) 257–260 Mr Forneris was awarded with the Elsevier "Young Researcher for Best Manuscript" prize in 2014 for this publication. A tutorial on the theory of Ion Beam Induce Charge technique and the corresponding Monte Carlo simulation including target preparation, pre- and post-process of simulation data specialized for ion irradiation was also developed by Mr Forneris.
Both the tutorial and the IST software are available for free of charge through the IAEA Accelerator Knowledge Portal (http://nucleus.iaea.org/sites/accelerators/knowledgerepository/Code/Forms/AllItems.aspx)