Junction barrier Schottky diode and preparation method thereof

The embodiment of the invention provides a junction barrier Schottky diode and a preparation method thereof. The preparation method comprises the steps that a substrate with an epitaxial layer on the surface is provided, the substrate is N-type heavily doped, and the epitaxial layer is N-type lightly doped; forming a P-type doped first region in the epitaxial layer; a P-type heavily-doped second region is formed in the first region, the doping concentration of P-type ions in the second region is larger than that of P-type ions in the first region, and the size of the second region is smaller than that of the first region in the thickness direction perpendicular to the substrate; the surface, far away from the substrate, of the second region is rougher than the surface, far away from the substrate, of the epitaxial layer and the surface, far away from the substrate, of the first region; and forming a metal layer on one side, far away from the substrate, of the epitaxial layer, wherein the metal layer and the e