Termination design by metal strapping guard ring trenches shorted to a body region to shrink termination area

摘要

This invention discloses a semiconductor power device formed in a semiconductor substrate of a first conductivity type comprises an active cell area and a termination area surrounding the active cell area and disposed near edges of the semiconductor substrate. The termination area includes a plurality of trenches filled with a conductivity material forming a shield electrode and insulated by a dielectric layer along trench sidewalls and trench bottom surface wherein the trenches extending vertically through a body region of a second conductivity type near a top surface of the semiconductor substrate and further extending through a surface shield region of the first conductivity type. A dopant region of the second conductivity type disposed below the surface shield region extending across and surrounding a trench bottom portion of the trenches. At least a metal connector disposed above the top surface of the semiconductor substrates electrically connecting to the shield electrode of at least two trenches and shorted to the body region.

主权项

1. A semiconductor power device formed in a semiconductor substrate of a first conductivity type comprises an active cell area and a termination area surrounding the active cell area and disposed near edges of the semiconductor substrate wherein:
the termination area includes first termination zone adjacent to the active cell area having a plurality of trenches filled with a conductivity material forming a shield electrode and insulated by a dielectric layer along trench sidewalls and a trench bottom surface wherein the trenches extending vertically through a body region of a second conductivity type, opposite the first conductivity type, near a top surface of the semiconductor substrate and further extending through a surface shield region of the first conductivity type wherein the surface shield region of the first conductivity type is an N type doped region doped with an arsenic dopant and a voltage blocking layer of the first conductivity type below the surface shield region is doped with a phosphorous dopant; a first termination zone buried dopant region of the second conductivity type disposed at the bottom of the plurality of trenches; and a metal connector disposed above the top surface of the semiconductor substrate wherein the shield electrode of at least two adjacent trenches are electrically connected together by the metal connector and are shorted to the body region in between the two connected adjacent trenches thus generating electric dead zones in the surface shield region between adjacent shorted trenches.