Simulation Of Single Event Effect On SiC Double-Trench MOSFETS

SiC Double-Trench MOSFET（SiC DT-MOSFET）,as a typical power device,has a broad application prospect because of its structure optimization based on SiC planar gate and groove gate MOSFET.It may be widely used in accelerator facilities,nuclear technology application system and space application technology in the future.In various radiation environments,Single Event Effect（SEE）is one of the main factors causing damage to semiconductor devices.Therefore,it is of great significance to carry out SEE research on SiC DT-MOSFET devices.In a SiC power MOSFET,the most common features are Single Event Burnout（SEB）and Single Event Gate Rupture（SEGR）,These two sees can cause serious damage to SiC power MOSFET devices.In this work,the SEB effect and SEGR effect in SiC DT-MOSFET devices are simulated.The simulation tool Sentaurus TCAD software is used to explore the mechanism of the failure caused by the SEB effect and SEGR effect in SiC DT-MOSFET devices.The influence of related factors on SEB effect and SEGR effect of SiC DT-MOSFET devices was evaluated,and the regional sensitivity of SEB effect and SEGR effect of SiC DT-MOSFET was analyzed.Finally,the influence of neutron radiation on SEB effect and SEGR effect of SiC DT-MOSFET is investigated.According to the study on the failure mechanism of SiC DT-MOSFET devices caused by the SEE effect of heavy ion radiation,the SEB effect of SiC DT-MOSFET device is mainly related to the parasitic transistor conduction inside the device.The SEGR effect of SiC DT-MOSFET is mainly related to the accumulation of heavy ion excited holes at the corner of gate oxide groove.At the same time,the key influencing factors of SEB effect and SEGR effect on SiC DT-MOSFET devices irradiated by heavy ions are studied in this work.SEB effect is affected by linear energy transfer of heavy ions,drain-source voltage,incident depth and incident location of heavy ions.SEB effect will be enhanced gradually with the increase of LET and drain-source voltage.With the increase of the incidence depth of heavy ions,when it penetrates through the emitter,base and collector of the whole parasitic transistor,it can make the parasitic transistor easier to conduct,and the SEB effect is more likely to occur in SiC DT-MOSFET devices.SEGR effect is also affected by linear energy transfer of heavy ions,drain-source voltage,gate-source voltage,incident depth and incident location of heavy ions.With the increase of LET and drain-source voltage,the electric field strength of gate oxide layer is easier to reach the critical breakdown field strength.With the increase of positive gate-source voltage,the electric field intensity of grid oxide layer decreases gradually.However,with the increase of the negative gate-source voltage,the electric field intensity of the gate oxide layer tends to increase,and the SEGR effect is more likely to occur in the off state.SEGR effect is also affected by the incident depth of heavy ions.With the increase of the incident depth of heavy ions,the electric field intensity of gate oxide layer gradually increases.When the incident depth of heavy ions reaches the N-drift region,SEGR effect will occur in the device.The SEGR effect is mainly affected by the ion track in the N-drift region.Both the SEB effect and the SEGR effect are affected by the incident position.The location of the gate near the source pole is the most sensitive region to the single event effect of the SiC DT-MOSFET devices in this work,and the SEGR effect is more likely to occur than the SEB effect.In addition,the effects of neutron radiation on SEB and SEGR effects of SiC DT-MOSFET devices are investigated.The results show that the threshold voltage for SEGR effect(V_DS=273V)is much lower than the threshold voltage for SEB effect(V_DS=1221V)under the condition of 5e8 atmospheric neutrons irradiated SiC DT-MOSFET.Therefore,compared with SEB effect,SEGR effect of SiC DT-MOSFET device is more likely to occur under the condition of atmospheric neutron radiation.In conclusion,SEGR effect is more likely to occur in SiC DT-MOSFET devices operating in radiation environment.The single event effect study of SiC DT-MOSFET devices irradiated by heavy ions and neutrons respectively in this work provides data support for the experimental study of single event effect of SiC DT-MOSFET devices,and provides a basis for anti-irradiation reinforcement of SiC DT-MOSFET devices.