Speaker
Description
4H silicon carbide (4H-SiC) is a wide-bandgap semiconductor with compelling properties for radiation-hard particle detectors, including high breakdown fields, excellent thermal stability, and low leakage currents even after irradiation. These characteristics make it a promising candidate for next-generation detectors in extreme environments like future hadron colliders, medical ion accelerators, and fusion reactors. However, the microscopic evolution of radiation damage in 4H-SiC remains poorly understood: inconsistencies of defect parameters in the literature limit the reliability of device simulations needed to design optimized detectors.
To address this, we present a comprehensive, comparative irradiation study of 4H-SiC PIN diodes. Diodes were irradiated with 24 GeV protons (5e12 to 5e15 p/cm²) and neutrons (1e13 to 1e18 neq/cm²) and characterized before and after irradiation via current–voltage (IV), capacitance–voltage (CV), and UV-laser-based charge collection efficiency (CCE) measurements in forward and reverse bias.
Our results confirm the established picture in the high-fluence regime characterized by negligible increases in leakage current level, a loss of rectification, and voltage-independent capacitance. Crucially, the low-fluence regime reveals a complex transition driven by competing defect-mediated mechanisms, shifting from generation-dominated leakage to carrier removal and compensation, bridging the gap between the pristine and the trap-dominated regime. The results also provide well-resolved, quantitative observables for the verification of defect models. They inform TCAD simulation models currently under development, designed to capture the physics of radiation-induced defects in 4H-SiC PIN structures and aiming to establish a basis for simulation-driven detector optimisation.