Utilization of Ion Accelerators for Studying and Modelling of Radiation Induced Defects in Semiconductors and Insulators

The CRP results provided the very first protocol and the only one is available so far to evaluate the radiation hardness of semiconductor materials and devices under any kind of MeV ion, which is important to all research communities involving the use of these ions, such as in ion beam analysis, ion beam modification of materials, radiation effects in insulators. The experimental and theoretical approach can be used by all laboratories to provide data independent of the experimental setup concerning radiation hardness.

The new results will improve the ability of the ion beam accelerator community to characterize the response of semiconductors detectors to cumulative irradiation of all forms, and to better predict their life-time.

IBIC technique has proven to be a very powerful tool for the functional characterization of semiconductor devices; it has been extensively applied and optimised by expert groups (ANSTO, RBI, SANDIA, NUS), adopted for the first time at CNA and used for the first time at UniLe to map the CCE efficiency of diamond diodes.

New experimental techniques and set-ups have been installed and used for material characterization: notably Transient Current Technique (TCT) at UniDe and UniS, Alpha Particle and Heavy Ion Charge Transient (APQTS and HIQTS, respectively) at JAEA, a new high resolution IBIC system at NUS.

Enhanced skills in device simulations have been acquired at UniDe by using SILVACO simulation software to model the electronic features of the Si diodes under study and at SANDIA with ATLAS TCAD software to model the IBIC processes.
The transport modelling developed during the CRP has been exploited by UniTo and NUS for the interpretation of experiments aimed to fabricate micro- and nano- structures in porous silicon.
A new deterministic single ion implanter has been designed at UniLe mainly devoted to the controlled creation of NV centers in diamond. Noteworthy, a new high resolution IBIC technique based on ion tracks in mica foils has been investigated, which can lead to a spot size below 100 nm.. This is a breakthrough for non-developed countries in order to setup a cheap ion nanobeam for different types of experiments with high reliability.

All the participants agreed that the most important benefit from this CRP is the expanded network of collaborating researchers and institutions. The reinforcement of already existing collaborations and the activation of new ones (among them, the new collaboration among MNA, UniHe, UniS, CNA, JAEA, RBI and ANSTO on ion/electron/neutron/ion irradiated SiC diodes or between UniDe and NUS for diode fabrication and educational activities), has led to a generally improvement of the expertise and the capabilities of the CRP participants.

The achievement of the main CRP objectives, the dissemination of new experimental techniques and theoretical model have contributed to improve the competiveness of CRP members in applications for national and international grants, as demonstrated for example by grants to JAEA, in collaboration with RBI, from the Japan Society for the Promotion of Science for the development of diamond detectors, to MNA for the Semiconductor Nuclear Radiation Detector Laboratory from the Malaysian Nuclear Agency and to CNA to study the feasibility of Fast-Ion Loss Detector for ITER based on SiC diodes.