The invention discloses a multifunctional protection device and a manufacturing process thereof, belonging to the technical field of protection devices. A
silicon dioxide layer is grown on a P-type single-
crystal silicon wafer, a
boron ion implantation window is photoetched on the front side of the P-type single-
crystal silicon wafer, a light
boron layer is doped on the front side of the P-type single-
crystal silicon
wafer by
ion implantation, and the light
boron layer is redistributed by high-temperature
diffusion, a light
phosphorus implantation window is photoetched on the front and back sides of the P-type single-crystal silicon wafer, a
phosphorus layer is
ion implanted on the front and back sides of the P-type single-crystal silicon wafer, and the
phosphorus layer is redistributed by high-temperature
diffusion, a concentrated
boron diffusion zone window is photoetched on the front side of the P-type single-crystal silicon wafer, concentrated
boron diffusion is performed on the front side, concentrated phosphorus layer
diffusion windows are photoetched on the front and back sides of the P-type single-crystal silicon wafer, concentrated phosphorus layer diffusion is performed on both sides, a groove
etching window is photoetched on the front side of the P-type single-crystal silicon wafer,
silicon etching is performed to form an inner groove mesa structure, and metallization treatment is performed on the front and back sides of the P-type single-crystal silicon wafer to construct a
metal layer.