The invention relates to a SiC groove type
JFET device structure and a preparation method thereof. The SiC groove type
JFET device structure comprises a drain metallization layer, a SiC N + substrate layer, a first N type drift region, a source groove structure, a second N type drift region, a P-well region, an N + source region, a P + gate region, an isolation
dielectric layer, a gate metallization layer and a source metallization layer. The source trench structure is arranged in the first N-type drift region, the upper surface of the source trench structure is in contact with the P-well region and the source metallization layer, and an
oxide layer and a
polycrystalline silicon layer are sequentially filled in a trench, so that the upper surface of the trench structure is flush with the upper surface of the first N-type drift region. By introducing the trench structure connected with the source
electrode in the drift region, the transverse
electric field distribution condition in the device can be optimized, the peak
electric field is reduced, the conduction capability of the device is further improved under the condition of ensuring that the original
breakdown voltage is not changed, the performance of the SiC
JFET is greatly improved, and the
conduction loss during working is reduced.