A Schottky diode comprises: a substrate; a first semiconductor layer located on the substrate; a second semiconductor layer located on the first semiconductor layer, two-dimensional electron gas being formed at an interface between the first semiconductor layer and the second semiconductor layer; a cathode located on the second semiconductor layer and forming an ohmic contact with the second semiconductor layer; a first passivation dielectric layer located on the second semiconductor layer; a field plate groove formed in the first passivation dielectric layer; and an anode covering the field plate groove and a portion of the first passivation dielectric layer.