The invention discloses a
fast recovery diode semiconductor device and a preparation method thereof, and the device comprises a substrate, a plurality of upper grooves which are formed through downward
etching from the upper surface of the substrate, and a plurality of lower grooves which are formed through upward
etching from the lower surface of the substrate. The inner side wall of the upper groove and the upper surface area connected between the upper grooves are doped to form a first doped layer, the inner side wall of the lower groove and the lower surface area connected between the lower grooves are doped to form a second doped layer, the upper grooves are filled with
metal to form first electrodes, and the lower grooves are filled with
metal to form second electrodes. Compared with a traditional FRD device, the area
utilization rate can be improved on the premise that the
chip size is guaranteed, and the FRD device has more advantages in electrical parameters such as conduction
voltage drop under the same size; the cost of the
chip is effectively reduced, and the promotion of national
electrification is facilitated; meanwhile, according to the structure, the junction edge position uses the surface of the
silicon substrate to enable the junction edge position to be approximate to a planar junction, the complexity of
terminal design is greatly reduced, and the
chip size is further optimized.