Study On Space Radiation Effect And Reinforcement Design Of SOI-LIGBT With High Power Density

Silicon-on-insulator lateral insulated-gate bipolar transistor(SOI-LIGBT)is the core power component that promotes the development of monolithic power integrated system chip.The use of SOI substrate can effectively improve the anti-space radiation ability of the device,which has attracted great attention from academia and industry.In order to improve the stability and reliability of SOI-LIGBT devices in radiation environment,it is of great significance to study the space radiation effect of SOI-LIGBT devices.The damage mechanism of SOI-LIGBT against total-dose-irradiation and the single-event-irradiation is revealed through simulation and experiment.By improving the device structure,the tradeoff between the anti radiation reliability and high power density is optimized,and the SOI-LIGBT device with high power density and radiation resistance is developed.In this paper,the single event irradiation effect of SOI-LIGBT device is studied by TCAD simulation,and the influence of different irradiation conditions on the electrical performance of the device and the failure mechanism under single event irradiation are analyzed.The study found that the channel area under the gate is the sensitive area of the device under single-event irradiation,and the pulse peak value and width of the single-event transient current would increase with the increase of linear energy transfer and collector voltage.Due to the existence of parasitic bipolar transistors,single event irradiation leads to device latch up,resulting in device failure.Aiming at the single event failure mechanism,two schemes are proposed,which reduce the top silicon thickness and change the P-body junction depth.Finally,a SOI-LIGBT device with a safe operating voltage of 200V(@LET=37Me V?cm²/mg)against single event irradiation is designed,which meets the design requirements.Furthermore,anti-total-dose radiation characteristics of the 600V SOI-LIGBT in detail by experiments and simulations,and the effect of total-dose radiation on the electrical characteristics and carrier transport of the device is revealed.It is found that the positive charge accumulates in the gate oxygen under total dose irradiation,which makes the threshold of the device drift negatively.The output current increases with the increase of irradiation dose at the same gate voltage.The degradation of threshold voltage will be aggravated by applying positive gate voltage during total dose irradiation.Under the same overdrive voltage,the collector current increases with the increase of total irradiation dose when V_CE is small,and decreases with the increase of total irradiation dose when V_CE is large.By optimizing the gate oxide growth process,the threshold voltage degradation during the total dose irradiation can be effectively suppressed.