Study On Radiation Cumulative Damage Effect Of SiC Schottky Diodes And Field Effect Transistor

Silicon carbide(SiC),as the third-generation wide bandgap semiconductor material,has excellent physicochemical properties and is the core of the development of highpower,high-frequency,high-temperature,and strong radiation resistance technologies.During the service of the device in orbit,it may be affected by the radiation of charged particles in space,resulting in the degradation of the electrical performance of the device,which will affect the reliability of the spacecraft in orbit.Therefore,it is important to research the radiation damage effects on silicon carbide devices.This article takes silicon carbide Schottky diode(SBD)and metal oxide semiconductor field effect transistor(MOSFET)as the research objects.Based on a series of high-energy electron,?-ray and heavy ion irradiation experiments,the semiconductor device performance parameter tester is used to test the electricity.The change law of performance,combined with TCAD and SRIM software to simulate the radiation effects of the two devices,combined with the experimental results,to explore the influence factors and damage mechanism of the electrical performance degradation of silicon carbide devices under irradiation.By comparing and analyzing the degradation of the electrical properties of 4H-SiC MOSFET and SBD devices under the irradiation of 1MeV high-energy electrons,?-rays and 20 MeV Si,the damage mechanism of the devices was analyzed.Hydrogen immersion was used to study the effect of hydrogen on the radiation effect of 4H-SiC MOSFET.In the ?-ray irradiation experiment,it was found that hydrogen element can inhibit the change of the threshold voltage of the MOSFET with a bias gate voltage of +20V.The two SiC devices often have the effect of an external electric field in the working state.In this paper,a bias voltage is applied during the irradiation of the device according to the electrical parameters of the device to explore the radiation effect of the device under the bias voltage.The gate bias of the MOSFET promotes the change in the threshold voltage of high-energy electrons and gamma rays.The defect distribution of 20 MeV Si ions incident on the SBD was calculated using SRIM software.The calculation results show that the incident depth of 20 MeV Si ions in the SiC SBD is located in the epitaxial layer of the device,and the displacement damage caused by the incident ions is concentrated at the end of the range.By comparing the effects of ionization and displacement damage accumulation on electrical properties,the damage mechanism of Si ions to SiC was analyzed.