Design and simulation of 4H-SiC low gain avalanche diode

Abstract

In the applications of nuclear and high-energy physics, Silicon Low Gain Avalanche Diodes (Si LGAD) as particle detectors have been shown to perform well in time resolution. Compared with silicon, 4H Silicon Carbide (4H-SiC) has a wider band gap, better radiation resistance, higher saturated carrier velocity and lower temperature sensitivity. Therefore, 4H-SiC LGAD is suitable for the detection of Minimum Ionization Particles (MIPs) under extreme radiation and temperature. However, due to the complexity of SiC device design and production, high performance SiC LGAD devices have not yet been produced. In this work, we use TCAD tools to design and simulate two n-type 4H-SiC LGAD structures with different electric field profiles, I/V and C/V characteristics and gain efficiencies. Through the analysis of simulation results, the LGAD with a triangle electric field profile in the gain layer has a higher gain efficiency, while the design with a trapezoid electric field profile is less affected by the gain layer thickness and more stable at high temperature. Subsequently, we will develop a set of SiC production processes under the guidance of this work.