Patent ID: 6236099
Filing Date: 2001-05-22
Classification: H01L

Abstract:
A termination structure for a gated MOS device having an active area; said active area consisting of a plurality of spaced trenches in a common silicon die of one of the conductivity types, each of said trenches containing a respective MOS gate structure; the exterior trenches in said active area having a relatively high electric field at their bottom outer corners; said termination structure comprising a plurality of concentric ring-shaped trenches surrounding said active area and being spaced between said active area and the peripheral edge of said die; each of said plurality of ring-shaped trenches having a diffusion extending from its walls and bottom which is of a conductivity type opposite to said one of the conductivity types; each of said plurality of ring-shaped trenches having a conductive polysilicon plug of a conductivity of said conductivity type opposite to one of the conductivity types; said active area having a common source contact; said plurality of ring-shaped trenches being out of direct contact with said common source contact and comprising floating rings.