The Static Characteristics Of4H-SiC Junction Barrier Schottky Diodes

With its superior performance, silicon carbide (SiC) has become an ideal semiconductormaterial for the production of high-frequency, anti-radiation, high temperature, and low powerconsumption and high power electronic devices. Junction barrier Schottky diode (JBS) is acombination of the Schottky diode with its fast switching characteristic of and the PiN diodewith its high voltage and low leakage current characteristics. As an excellent performancematerial, SiC combining the advantages of the JBS structure is the current power diodedevelopment trend in the field of high-frequency power application and has broad applicationprospects in the high power systems, aerospace power systems, nuclear detections andcommunication systems.In this paper, the design of the high-voltage4H-SiC JBS device structure and theinvestigation of the performance simulation technology are carried out in the two-dimensionaldevice simulation software ATLAS. In order to reduce the reverse leakage current andimprove the reverse voltage capability of the device, the forward characteristics and reverseblocking characteristics of the4H-SiC junction barrier Schottky diode are studied with the useof the structure parameter optimization and the active region optimization to improve the driftregion electric field distribution to improve reverse voltage capability and reduce the leakagecurrent of the device without sacrificing the forward voltage drop.Since the Schottky barrier reduction effect in the high electric field strength limits thedevelopment of the device in high-voltage direction, it has become a key point to for devicedesign to improve the electric field distribution of the drift region to reduce the Schottkybarrier lowering effect. This paper studies the two bottom of the trench with oxide spacerjunction barrier Schottky diode (TSOB-JBS) and TSOB active region generates a layer ofoxide spacer structure to optimize the electric field distribution in the drift region (OI-TSOB-JBS), through the theoretical calculation of the design and simulation, the optimized theOI-TSOB structure has superior reverse blocking characteristics than that of the TSOBstructure. Next, the junction barrier Schottky diode (PIMP-JBS PTBP-JBS) with its dopingconcentration in the active region having gradient distribution of P-gradient is investigated.Through maintaining the structure parameters of the PIMP and PTBP same with the ordinaryJBS structure and reducing the device process complexity, the breakdown voltage of the JBS structure exceeds1.6kV by improving the depth and concentration of the P-gradient, while thebreakdown voltage of the ordinary JBS structure is only885V and the reverse leakage currenthas also been greatly reduced. In addition, the TSOB-JBS, OI-TSOB-JBS, PIMP-JBSPTBP-JBS four structures are designed with the feasibility process.