Method of making symmetrical blocking high voltage breakdown semiconductor device

Abstract

A symmetrical blocking high breakdown voltage semiconductor device in which the lower junction termination is brought to the upper surface is fabricated by diffusing first and second regions of a first conductivity type into an upper surface of an epitaxial layer of a second conductivity type disposed on a substrate, and forming a groove having sloped sidewalls in the upper surface such that the groove extends through the second diffused region, the epitaxial layer and into the substrate. A thin layer of impurities of the first conductivity type is implanted into the sidewalls, and the impurities are electrically activated to form a low resistivity path that connects the substrate to the second diffused region. Subsequently, the semiconductor device may be separated from the wafer by cutting the wafer at the groove. The manufacturing process enables substantially complete fabrication of a plurality of devices while still in wafer form, thereby avoiding the inconvenience of processing individual dice.

Dependencies are inferred from the claim text.