A Novel 4H-SiC Pinched Barrier Rectifier

In this paper, design, fabrication and experimental analysis of a novel 4H-SiC pinched barrier rectifier (PBR) are presented. The operation mechanism of the pinched barrier is analyzed by numerical simulation and energy band diagrams. PN junction depth (X-j) and spacing (S) parameters in the diode structure are carefully designed to achieve a prototype optimal structure, and both forward and reverse characteristics are compared with those of JBS diodes by experimental results. It is demonstrated that, only by simply adjusting the PN junction depth and spacing parameters, the pinched barrier diode can obtain relatively optimal performance close to that of JBS diodes. The addition of channel doping concentration (N-ch) consideration for the structure design can achieve further improvements and superior performances than JBS diodes. In comparison with the optimum JBS diode design (S=1.2 mu m), for an on-set voltage control of 0.8V, PBR diode with optimum design sets of S and Nch can achieve a wider trade-off window (S <= 0.8 mu m) between the device forward and reverse performances. Furthermore, PBR diode can achieve superior performance with lower forward voltage drop (1.3V) than JBS diode (1.6V) for the same reverse blocking capability (similar to 1600V). The performance limit of PBR diode is also explored in this paper. For a minimum limit on-set voltage control of 0.6V, a lowest voltage drop of 1.1V as well as a wide design window can be achieved.