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Description
This contribution presents an overview of the investigation of radiation effects in 4H-SiC PN diodes and LGADs fabricated by onsemi, including both single-channel and segmented (strip and pixel) devices. The sensors were irradiated with protons, reactor neutrons, and 60Co gamma rays. Radiation-induced changes were assessed using current-voltage (IV) and capacitance-voltage (CV) measurements, complemented by two-photon absorption transient current technique (TPA-TCT) measurements employing a tightly focused femtosecond laser at the ELI ERIC research infrastructure.
The results reveal markedly different responses to the various types of irradiation. Proton irradiation primarily modifies the electrical properties of the epitaxial layer, whereas neutron irradiation strongly alters the effective space-charge concentration, resulting in a substantial expansion of the depletion region beyond the nominal epitaxial layer and deep into the substrate. In contrast, gamma irradiation predominantly influences the depletion characteristics through ionization-induced effects while producing only minor changes in the leakage current. Combined with detailed results from in-depth charge injection measurements using laser pulses, the findings provide new insights into the radiation response of 4H-SiC detectors and contribute to the optimization of detector designs for operation in extreme radiation environments.