Planar split-gate SiC MOSFET with embedded channel diode

Abstract

The application discloses a planar separate gate SiC MOSFET with an embedded channel diode and belongs to the technical field of semiconductors. The SiC MOSFET structure is a separate gate structure, on the basis of a planar device structure, a source polycrystalline silicon structure is embedded and directly contacts with a source metal. The source polycrystalline silicon embedded on the basis of a traditional planar structure makes the JFET area of the device shorter and the on-resistance of the device larger. Therefore, in order to reduce the on-resistance of the device, the concentration of the JFET area under the gate is increased and the width is increased. When the device is turned on in the forward direction, the structure has four conductive channels compared with two conductive channels of a traditional device. The reverse on-voltage of the freewheeling diode is smaller than the reverse on-voltage of the body diode, the opening of the body diode is avoided, and the system loss is reduced. Meanwhile, the bipolar degradation effect existing in the traditional device is avoided, and the reliability of the device is improved.