Energy deposition simulation and structure design of SiC X-ray detector

• 1、School of Microelectronics, Dalian University of Technology, Dalian 116620

Abstract：Silicon carbide (SiC) is a wide bandgap semiconductor material with excellent characteristics such as large displacement threshold energy, high breakdown electric field, fast electron saturation drift speed and high thermal conductivity, which is suitable for the preparation of high temperature and radiation resistant X-ray detectors. In this paper, Monte Carlo simulation software (Geant4) simulated the energy deposition of X-rays by 104 μm thickness silicon carbide. Firstly, the permeability of X-ray photons emitted by 55Fe, 241Am and 109Cd in silicon carbide was studied, and it was found that the X-ray photons emitted by 55Fe and 241Am were completely absorbed in silicon carbide, while the X-rays emitted by 109Cd were basically not significantly absorbed. Secondly, based on the X-rays (~5.9keV) emitted by 55Fe, the effects of aluminum and phosphorus doping on X-ray energy deposition in 4H-SiC were studied, and it was found that the medium concentration doping in silicon carbide did not have a significant effect on X-ray energy deposition. Finally, through data analysis, it is found that the 5.9keV X-rays released by the 55Fe ray source mainly deposit energy in silicon carbide through the photoelectric effect.A silicon carbide X-ray detector based on PiN structure was designed using 4H-SiC materials, and electrical parameters were simulated using Silvaco. The detector operates at 1050 V, has a sensitive area of 100 μm, and a forward opening voltage of 6 V, reaching a current of 10 mA at 25 V.

Keywords： Microelectronics and solid-state electronics；4H-SiC；X-ray detection