Simulation Analysis And Reinforcement For Single Event Effects Of Shielded Gate MOSFET

Shielded Gate Trench Metal-Oxide-Semiconductor Field Effect Transistor（SGT MOSFET）,has the characteristics of low specific on-resistance and low gate charge.Its application can effectively improve the system efficiency and power density,and it is very competitive in the field of medium and low voltage power devices.In the radiation environment such as aerospace,the application of SGT MOSFET will be affected by various radiation effects.However,the research on the Single Event Effect（SEE）of SGT MOSFET at home and abroad is still very rare.Therefore,this thesis explores the failure process of single event effects of SGT MOSFET through simulation.Based on the mechanism and influencing factors of single event effects,the idea and scheme of anti-radiation reinforcement are proposed and the feasibility of the reinforcement scheme is verified by simulation.The main work contents and achievements of this thesis are described as follows:Firstly,this thesis analyzes the radiation effects of SGT MOSFET devices,including Total Ionizing Dose（TID）and Single Event Effect（SEE）,and focuses on Single Event Burnout（SEB）and Single Event Gate Rupture（SEGR）causing permanent damage to the device.Based on the correlation theory of single event effect,the simulation methods for SEB and SEGR are determined.Next,SGT MOSFET cell modeling and single event effect simulations are performed by Sentaurus.Different incident positions are selected on the surface of SGT MOSFET device for single event radiation simulation,and the process of single event failure is analyzed.The sensitive incident position of single event effect in SGT MOSFET device is determined as N+source region.On this basis,the single event effects of SGT MOSFET and conventional Trench MOSFET are compared and the main factors affecting the single event effects of SGT MOSFET are investigated.Finally,based on the process and mechanism of single event radiation failure of devices,the idea and scheme of anti-radiation reinforcement for SGT MOSFET are proposed,and the feasibility of anti-radiation reinforcement scheme is verified by simulation.According to the sensitive region of single event failure in SGT MOSFET,a new structure TGD（Transition over Gradual Drift）-SGT MOSFET with lightly doped N-type transition layer and gradually doped drift region is proposed.Compared to SGT MOSFET with uniformly doped drift region,TGD-SGT MOSFET effectively improve the resistance to single event effects,the V_SEB is improved by 26.9%compared to the unreinforced device.