Research On Radiation Hardening Technology Of 600V LDMOS

600V LDMOS is widely used in various power conversion integrated circuits,such as switching power supply circuits,half-bridge drive circuits,high-voltage gate drive circuits,etc.In aerospace and other radiation environments,LDMOS is used as the core component of electronic equipment.It is very sensitive to radiation.Generally speaking,space radiation will produce two failure mechanisms:Single-Event-Effect(SEE)and Total-Ionizing-Dose Effect(TID).This paper uses Sentaurus TCAD software to designed 600 V LDMOS device,and simulates the radiation response of the device to SEE and TID.Using the simulated data,the basic physical mechanism of SEE and TID of the LDMOS device was analyzed,and corresponding hardening technology were made for SEE and TID on the device.For SEE,from different incident positions,different angles,and different depths of incidence,the simulation and analysis of SEE were carried out.The simulation found that SEE that caused the failure of LDMOS devices was mainly single event burnout(SEB).In view of this problem,a study on the burn-out mechanism was carried out,and it was found that the high-density electron-hole pairs generated on the single-particle trajectory caused the parasitic BJT to burn out in an amplified state and the impact ionization resulted in avalanche breakdown at the drain/N drift region.Aiming at the problem that BJT is in the amplified state,optimizing the concentration and position of the P buried layer without increasing the threshold voltage makes the base resistance of the BJT decrease and it is more difficult to be in the amplified state,which ultimately increases the device burnout threshold by 76.64%.For the problem of avalanche breakdown,the introduction of local SOI in the middle of the drift region increases the burnout threshold by 20.3%without reducing the withstand voltage of the device below600 V.For TID,the total dose effect of 600V LDMOS is more obvious than that of deep submicron CMOS devices,mainly due to the relatively thick oxide layer of LDMOS devices,and the trapped charges and interface states of the oxide layer generated by radiation induction will be more obvious.Threshold voltage V_T drifts,changes in electrical characteristics such as G_m drop and breakdown voltage BV drop,simulation and analysis of TID on withstand voltage,threshold voltage,leakage current,through the analysis of the simulation results,proposed a dual The gate LDMOS structure reduces the threshold voltage drift caused by the total dose.The simulation results show that the dual gate device maintain the conventional device transfer?output?switching and other electrical characteristics.Under 1Mrad(SiO₂)dose radiation,the threshold voltage of the conventional structure device The drift is 105.8%,while the threshold voltage drift proposed new dual-gate structure is only 10.2%.