Super-junction MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) with soft reverse recovery characteristic

Abstract

The invention belongs to the technical field of power semiconductors, and particularly relates to a super-junction MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) with a soft reverse recovery characteristic. According to the device, the high-concentration P-type buffer layer is introduced into the super-junction structure of the voltage-resistant region, the length of a body diode drift region is prolonged by the introduced P-type buffer layer, so that the distribution of carriers in the drift region is closer to a drain electrode, the extraction of the carriers in the drift region is slowed down, and meanwhile, the highly-doped P-type buffer layer is not completely depleted when the device is withstand voltage, so that carriers in the highly-doped P-type buffer layer can be slowly extracted during reverse conduction, the drop rate di / dt of reverse recovery current is reduced, and the reverse recovery characteristic is improved. The super-junction MOSFET with the soft reverse recovery characteristic has the beneficial effects that di / dt and dv / dt during reverse recovery are optimized, so that the reverse recovery characteristic of the super junction MOSFET is improved.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, in particular to a super junction MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET for short) with soft reverse recovery characteristics. Background technique [0002] When super-junction MOSFETs are used in driving motor application circuits such as full bridges, their body diodes play a role in freewheeling. When the body diode conducts, a large number of hole carriers are stored in the drift region. In the process of switching the body diode from the conduction state to the withstand voltage state, the carriers stored in the body need to be discharged to form a large reverse current. Since the drift region of the super-junction MOSFET is completely exhausted at a lower voltage, the carriers in the drift region are discharged, so the di / dt and dv / dt of the body diode of the super-junction MOSFET are extremely large during reverse recovery, and the reverse recovery...

AI Technical Summary

Problems solved by technology

High di / dt and high dv / dt will lead to serious electromagnetic interference noise, coupled with the influence of parasitic inductance in the system, high di / dt will lead to high voltage overshoot, which will adversely affect the application system

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