The invention discloses a
silicon carbide Trench MOS device and a manufacturing method thereof, and belongs to the technical field of power semiconductors. The method includes: a layer of a polysilicon region distributed in a pi shape is additionally arranged under a
trench gate structure of a conventional device, the polysilicon region and an epitaxial layer form a Si / SiC
heterojunction, and a
diode is integrated in the device. Compared with a parasitic
silicon carbide diode which directly employs a
silicon carbide Trench MOS, according to the
silicon carbide Trench MOS device and the manufacturing method thereof, the junction
voltage drop of the device
diode during application is substantially reduced, and the switch-on characteristic of the device is improved through large
junction area of the
heterojunction; moreover, the gate-drain
capacitance and the ratio of the gate-drain
capacitance to the gate-source
capacitance of the device are reduced, and the performance and the reliability of the device MOS during application are enhanced; besides, the
silicon carbide Trench MOS device and the manufacturing method thereof are also advantageous in that the
reverse recovery time is short, the
reverse recovery charges are less, and advantages including low reverse leakage, high
breakdown voltage, and good temperature stabilization performance of the conventional
silicon carbide Trench MOS device are maintained. In conclusion, according to the silicon carbide Trench MOS device and the manufacturing method thereof, the prospect is wide in circuits such as inversion circuits and
chopper circuits etc.