Design Of 1200v SiC LDMOS Device

1200V Lateral Double-Diffused Metal Oxide Semiconductor(LDMOS)can be used in high-voltage motor drive,high-voltage AC-DC converter and other fields.Silicon carbide(SiC)has become an ideal material for power devices due to its excellent physical,chemical,and thermal characteristics.SiC LDMOS have the advantages of achieving high breakdown voltage,ultra low on-resistance,good thermal stability and small chip area.Therefore,it can replace silicon-based LDMOS in high voltage work area and has a very broad application prospect.However,domestic research on 1200V SiC LDMOS devices is still relatively limited,and further research is needed.Based on the Silvaco simulation platform,three 1200V SiC LDMOS devices are designed.First,the traditional 1200V SiC LDMOS device was optimized for design.The effects of concentration of Pbody region,length and concentration of drift region and length of gate field plate on the electrical characteristics of the device were studied.Then on this basis,the 1200V SiC LDMOS device with P-top layer was optimized for design.The effects of the length,position and concentration of P-top layer on the electrical characteristics of the device were studied.Subsequently,the 1200V SiC LDMOS device with STI structure was optimized for design.The effects of length,depth and position of STI on the electrical characteristics of the device were studied.Finally,the electrical performance,temperature characteristics and manufacturing process difficulty of these three device structures are analyzed separately.Simulation results show the optimal solution in this paper is SiC LDMOS device with P-top layer.The device has a threshold voltage of5V,an off-state breakdown voltage of 1395V,an on-state breakdown voltage of 1320V(Vgs=15V),a specific characteristic on-resistance of 6.55 m??cm²,an off-state leakage current of 1×10^-27A/?m,and a maximum lattice temperature under working conditions is 398K.All parameters meet the requirements of the design index.