Structure to provide effective channel-stop in termination areas for trenched power transistors

Abstract

The present invention discloses a trenched DMOS device supported on a substrate of a first conductivity type including a core cell area which includes at least a trenched DMOS cell having a gate disposed in a trench and a drain region disposed in the substrate, the substrate further includes a termination area which includes at least a channel-stop trench. The trenched DMOS cell includes a source region of the first conductivity type extending from the top surface of the substrate adjacent to the trenches in the substrate. The trenched DMOS cell further includes a body region of a second conductivity type of opposite polarity from the first conductivity type, the body region extends from the top surface surrounding the source region adjacent the trenches in the substrate. The trenched DMOS device further includes an insulating layer lining the trenches and a conductive material filling the trenches. The channel stop trench in the termination area with the conductive material filled therein is in electrical contact with the drain region via a metal contact formed thereon wherein the channel stop trench filled with the conductive material is surrounded by and insulated from the substrate by the insulating layer lining the channel stop trench whereby a channel stop is formed therein.

Dependencies are inferred from the claim text.