Patent ID: 8994140
Filing Date: 2015-03-31
Classification: H01L

Abstract:
1. A vertical conduction nitride-based Schottky diode, comprising: a nitride-based semiconductor body of a first conductivity type; a first metal layer formed on a front side of the nitride-based semiconductor body forming a Schottky junction therewith, the first metal layer forming an anode electrode of the Schottky diode; a second metal layer formed on the first metal layer; a third metal layer formed on a backside of the nitride-based semiconductor body, the third metal layer forming an ohmic contact with the semiconductor body and forming a cathode electrode of the Schottky diode; a termination structure formed at an edge of the first metal layer, the termination structure being configured to reduce electric field crowding at the edge of the anode electrode, wherein the termination structure comprises a guard ring comprising a nitride-based epitaxial layer of a second conductivity type, opposite the first conductivity type, formed on the front side of the nitride-based semiconductor body at the edge of the first metal layer, the nitride-based epitaxial layer having a step recess where the part of the epitaxial layer having a thinner thickness is disposed towards the Schottky junction of the Schottky diode; and a dielectric field plate formed on a top surface of the nitride-based epitaxial layer, the dielectric field plate extending up to the step recess of the nitride-based epitaxial layer; a solder ball formed on the second metal layer; and a wafer level molding layer formed on the front side of the nitride-based semiconductor body, the wafer level molding layer encapsulating the second metal layer and at least part of the solder ball, wherein the Schottky diode has a vertical current path from the solder ball, through the anode electrode and the Schottky junction to the cathode electrode.