Design and simulation of a novel 4H-SiC LGAD timing device

Purpose Silicon-based fast timing detectors have been widely used in high-energy physics,nuclear physics,space exploration and other fields in recent years.However,silicon detectors often require complex low-temperature systems when operating in irradiation environment,and their detection performance decreases with the increase in the irradiation dose.Compared with silicon,silicon carbide(SiC)has a wider band gap,higher atomic displacement energy,saturated electron drift velocity and thermal conductivity.Simultaneously,the low-gain avalanche detector avoids cross talk and high noise from high multiplication due to its moderate gain,and thus can maintain a high detector signal without increasing noise.Aim Thus,the 4H-SiC particle detector,especially the low-gain avalanche detector,has the potential to detect the minimal ionizing particles under extreme irradiation and high-temperature environments.Method In this work,the emphasis was placed on the design of a 4H-SiC low-gain avalanche detector(LGAD),especially the epitaxial structure and technical process which play main roles.In addition,a simulation tool—RASER(RAdiation SEmiconductoR)—was developed to simulate the performances including the electrical properties and time resolution of the 4H-SiC LGAD we proposed.Conclusion The working voltage and gain effectiveness of the LGAD were verified by the simulation of electrical performances.The time resolution of the LGAD is(35.0±0.2)ps under the electrical field of−800 V,which is better than that of the 4H-SiC PIN detector.