Study On Total Ionizing Dose And Single Event Effect Of SiC DT-MOSFET Device

With social development and energy transformation,low-carbon environmental protection and sustainable development have become a social consensus.In this context,the application of SiC MOSFET devices can make electronic systems more miniaturized and lightweight,and are gradually becoming mainstream devices in modern power conversion systems.Among them,SiC double trench MOSFET(DT-MOSFET)device has lower onresistance and smaller chip size,and has become a new research hotspot.Due to its excellent electrical performance,SiC DT-MOSFET devices will be gradually applied to spacecraft and space power stations in the future.SiC DT-MOSFET devices are facing radiation damage in space applications,which affects the stability of the system.At present,on the one hand,the radiation effects of SiC DT-MOSFET devices at home and abroad are few,lack of corresponding simulation research and test data,it is still in the early stage;On the other hand,the influence of total ionizing dose on internal microscopic parameters of devices is rarely studied,and the trigger mechanism of single event burnout(SEB)is unclear.Therefore,the total ionizing dose and single event effect of SiC DT-MOSFET devices are studied in this paper to provide data support for its space application.The main research contents of this paper are:(1)Study on the total ionizing dose of SiC DT-MOSFET devices.In this paper,the total ionizing dose experiment of the device is carried out by using the electron irradiation source.it is found that the electron irradiation will reduce the threshold voltage of the device,but the effect of annealing at room temperature is very weak.The corresponding simulation work is carried out on the optimized device model by using TCAD software.The simulation results show that the decrease of the device threshold voltage caused by the total ionizing dose is mainly due to the ionization effect caused by irradiation,which makes the P-body region of the device form different degrees of inversion layer and expand gradually with the increase of gate voltage,which leads to the decrease of device threshold voltage.(2)Study on single event effect of SiC DT-MOSFET devices.The results show that the single event effect sensitive position of the device is located on the right side of the N+source region close to the gate trench;The SEB of the device is mainly caused by the positive feedback large current of the parasitic BJT and the avalanche multiplication effect in the high electric field area;It is also found that the N-type buffer layer can reduce the SEB sensitivity of the device.In addition,the law and reason of the influence of different LET and temperature on the SEB threshold voltage of the device are also studied.(3)Synergistic study of total ionizing dose and single event effect of SiC DT-MOSFET devices.The results show that the oxide trap charge induced by the total ionizing dose will increase the sensitivity of the device to the single event effect;However,with the increase of LET or temperature,the influence of the total ionizing dose on the single event effect of the device becomes weaker.