IBIC analysis of SiC detectors developed for fusion applications

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 177; p. 109100
• Main Authors: Jiménez-Ramos, M.C., López, J. García, Osuna, A. García, Rodríguez-Ramos, M., Barroso, A. Villalpando, Muñoz, M. García, Andrade, E., Pellegrini, G., Ugobono, S. Otero, Godignon, P., Rafí, J.M., Rius, G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2020; Elsevier BV
• Subjects: Alpha particles; Alpha rays; Charge collection efficiency; Charge efficiency; Detectors; Diagnostic systems; Energy resolution; Fluence; Fusion reactors; Ion beam induced charge; Ion beams; Irradiation; Minority carrier lifetime; Nuclear fusion; Nuclear fusion reactors; Nuclear reactors; Radiation damage; SiC detectors; Silicon carbide; Charge collection efficiency; SiC detectors; Ion beam induced charge; Minority carrier lifetime; Radiation damage
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2020.109100

In this work, we consider a 4H-SiC detector as a plasma diagnostic system for the detection of fusion-born alpha particles in future nuclear fusion reactors. A nuclear microprobe was used to locally irradiate micrometer-sized regions of the detector with 3.5 MeV He ions to fluences from 5 × 109 to 5 × 1011 cm-2. Ion Beam Induced Charge (IBIC) microscopy was employed to study its degradation in Charge Collection Efficiency (CCE) and energy resolution after irradiation. At high reverse-bias voltages, both parameters remain practically unaffected for fluences up to 1 × 1011 cm-2, while a significant deterioration of the spectroscopic performance was observed above 3 × 1011 cm-2. A theoretical drift-diffusion model, in combination with Shockley-Read-Hall recombination statistics, was used to obtain the holes lifetime from the fitting of the experimental CCE values measured at different reverse voltages. Holes lifetime was found to strongly decrease with increasing particle fluence, changing from 57 ns in pristine detectors to 0.2 ns after irradiation with a fluence of 1 × 1011 cm-2. •Radiation hardness of SiC diodes is studied for the detection of 3.5 MeV He ions.•The CCE and energy resolution are not degraded for fluences up to 1 × 1011 cm-2.•Degradation of the spectrometric properties is observed at fluences ≥ 3 × 1011 cm2.•Minority carrier lifetime strongly deteriorate with increasing particle fluence.