Vertical gallium nitride Schottky diode

摘要

A vertical conduction nitride-based Schottky diode is formed using an insulating substrate which was lifted off after the diode device is encapsulated on the front side with a wafer level molding compound. The wafer level molding compound provides structural support on the front side of the diode device to allow the insulating substrate to be lifted off so that a conductive layer can be formed on the backside of the diode device as the cathode electrode. A vertical conduction nitride-based Schottky diode is thus realized. In another embodiment, a protection circuit for a vertical GaN Schottky diode employs a silicon-based vertical PN junction diode connected in parallel to the GaN Schottky diode to divert reverse bias avalanche current.

主权项

1. A method for forming a vertical conduction nitride-based Schottky diode, comprising:
providing an insulating substrate; forming a nitride-based semiconductor body of a first conductivity type on the insulating substrate; forming a first metal layer on a front side of the nitride-based semiconductor body to form a Schottky junction, the first metal layer forming an anode electrode of the Schottky diode; forming a second metal layer on the first metal layer; forming a solder ball on the second metal layer; forming a wafer level molding layer 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; separating the insulating substrate from the semiconductor body to expose a backside of the nitride-based semiconductor body; and forming a third metal layer on an exposed 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, 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.