Properties Investigation And Simulation Analysis Of SiC Power Device

Silicon carbide (SiC) is an attractive wide-gap semiconductorwith high thermal conductivity, high electron saturation velocity andhigh critical electric field for high-power applications. In the field ofpower semiconductor device, SiC device is a great potentialcompetitor in the military and civilian applications of powerelectronics system. SiC power device is a research focus of powerdevice. We concentrate on following aspects:(a) Base on semiconductor theory and the Silivaco technologycomputer aided design software (TCAD), SiC-MOSFET andSi-IGBT power devices were designed, which breakdown voltageare1000V. In the software simulation, Both SiC-MOSFET andSi-IGBT devices were placed under the same external environmentto discuss the electrical substitution condition betweenSiC-MOSFET and Si-IGBT for SiC-MOSFET applications in theelectronics system. In this thesis, SiC-MOSFET (drift thickness5μm,device width10μm) can substitute Si-IGBT (drift thickness110μm,device width10μm) under8V voltage drop. The temperature distribution in the SiC-MOSFET is better than Si-IGBT.Under8V voltage drop, The turn-off energy loss ofSiC-MOSFET is Si-IGBT’s25%.(b) For SiC-MOSFET with high resistance in the high voltagecircuit, we further study thermal and electrical properties ofSiC-IGBT based on SiC-MOSFET. In the thesis, the SiC-IGBT with3500V break voltage was designed. In the research, we simulationthermal and electrical properties of SiC-LIGBT, SiC-DIGBT,SiC-UIGBT in the same physical parameters and analyze the bestapplication condition of different structure SiC-IGBT.(c) SiC-SBD has been commercialized in recent years. In thethesis, we proposal a novel structure SiC SBD and use the TCADsimulation software to simulation electrical properties of the novelstructure SiC SBD and the conventional structure SiC SBD. Wedesign the conventional structure SiC SBD with1800V breakdownvoltage and calculate breakdown voltage of different inclined planeangles of the novel structure SiC SBD. In the calculation results, the45°inclined plane angles novel structure SiC SBD have wonderfulperformance in breakdown voltage(increase15%) and leakage current.For the high resistance of novel structure, field rings were used in theSBD to overcome high resistance and optimize field distribution.