Low-Temperature Annealing of Electron, Neutron, and Proton Irradiation Effects on SiC Radiation Detectors

Silicon carbide (SiC) is a wide bandgap semiconductor with outstanding properties that make it especially appropriate for radiation monitoring in radiation harsh environments and for elevated temperature operation. In this work, radiation effects in electron-, neutron-, and proton-irradiated 4H-SiC p-n junction diodes are investigated by means of electrical characterization, including current–voltage characteristics measured at different temperatures ranging from −50 °C to +200°C. Moreover, the stability of the radiation-induced effects is evaluated through a series of low-temperature treatments (up to 400 °C). Interestingly for applications, partial recovery of diode rectification functionality is observed for electron-irradiated devices. Furthermore, partial recuperation of detectors’ charge collection efficiency (CCE) is registered on either electron-, neutron-, or proton-irradiated devices. Remarkably, it is observed that the limited conduction registered for highly irradiated SiC detectors allows their operation in forward bias conditions. In fact, while providing some lower CCE, they show better energy resolution than in conventional reverse bias operation. Advantages of using SiC devices in alpha particle detection in harsh environments, as well as simplification of current Si experiments, can be envisaged

Electron, Neutron, and Proton Irradiation Effects on SiC Radiation Detectors

Owing to their low dark current, high transparency, high thermal conductivity, and potential radiation hardness, there is a special interest in silicon carbide (SiC) devices for radiation monitoring in radiation harsh environments and with elevated temperatures and, especially, for the plasma diagnostic systems in future nuclear fusion reactors. In this work, four-quadrant p-n junction diodes produced on epitaxial 4H-SiC substrates are studied. The impact of electron, neutron, and proton irradiations (up to fluences of 1 × 10 16 electrons (e)/cm 2 , 2 × 10 15 neutrons (n)/cm 2 , and 2.5 × 10 15 protons (p)/cm 2 , respectively) on the electrical characteristics is studied by means of current-voltage (I-V) and capacitance-voltage (C-V) techniques. Regardless of the particle type and applied fluences, the results show similar low reverse currents for irradiated SiC devices, which are at least about four orders of magnitude lower than comparable Si devices. The effects of irradiation on interquadrant resistance and charge build-up in the interquadrant isolation are assessed. Furthermore, device performance as a radiation detector is investigated upon exposure to a collimated 239 Pu- 241 Am- 244 Cm trialpha source. The performance at room temperature is preserved even for the highest irradiation fluences, despite the fact that the rectification character in electrical characteristics is lost. From the results, advantages of using SiC devices in alpha particle detection in harsh environments can be envisaged.This work was supported in part by the Spanish Ministry of Science, Innovation and Universities through the Nuclear and Particle Physics Program under Project FIS-FPN-RTI2018-094906-B-C22 (MCIU/FEDER UE), in part by the European Union’s Horizon 2020 Research and Innovation Program under Grant 654168 (AIDA-2020), in part by a collaborative research project at Nuclear Professional School, School of Engineering, The University of Tokyo, under Grant 20016, in part by The Japan Society for the Promotion of Science KAKNHI under Grant JP19K05337, and in part by MINECO through the use of the Spanish ICTS Network MICRONANOFABS. The work of Gemma Rius was supported by the Spanish Ministry of Science and Innovation through Ayudas Ramón y Cajal 2016 under Reference RYC-2016-21412.Peer reviewe