Simulation And Exprimental Investigation Of High Voltage 4H-SiC Power Rectifiers

The third generation semiconductor materials which is represented by SiC are able to work under high pressure and high temperature environment because of their excellent physical properties, and greatly improve the efficiency of energy conversion. They play an important role not only in the field of traditional industries, but also in the application of solar energy, wind energy, hybrid vehicles, and other areas of the new energy.High-voltage silicon carbide power rectifier with excellent DC characteristics and switching characteristics is especially suitable for use in the field of high-voltage power electronic application. 4H-SiC PiN power rectifier has high reverse breakdown voltage and minimum reverse leak current. 4H-SiC JBS power rectifier with a kind unique structure has PiN-like high breakdown voltage and SBD-like low on resistance, and is one of the most common devices of the 4H-SiC power rectifiers. Based on the basic theory of semiconductor device physics, 4H-SiC PiN and 4H-SiC JBS power rectifier is investigated using the device simulation software Silvaco-Atlas.Through theoretical analysis and simulation, the 4H-SiC PiN and 4H-SiC JBS cell structure parameters are determined. The two kinds of devices characteristic of conduction, temperature and transient are analyzed in theory and studiedon the basis of numerical simulation. Field Plate(FP), Field Limiting Ring(FLR) and a variety of Junction Termination Extension(JTE) technology are investigated through simulation. A space modulated JTE(SM-JTE) is investigated through computer simulation, which requires lower dose precision of ion implantation. The SM area can modulate the dose of JTE and prevent devices from pre-breakdown. The termination efficiency of SM-JTE is higher than single-zone JTE.Some ideal termination structures in the simulation are selected to conduct experiments. The experiments show that the 4H-SiC PiN power rectifier with JTE structure reaches the reverse breakdown voltage of 3000 V and has forward voltage drop of 3.4V. The breakdown voltage of 4H-SiC JBS power rectifier with FLR structure can reach up to 5000 V, and the Ron is as low as 6.3 mΩ·cm2.