Electronic device of vertical MOS type with termination trenches having variable depth
First Claim
1. An electronic device, comprising:
- a chip of semiconductor material having a main surface and a substrate region of said semiconductor material with a first type of conductivity extending from the main surface;
at least one vertical MOS transistor, formed in an active area of the chip, the transistor including;
at least one body region in the semiconductor material with a second conductivity type extending from the main surface in the substrate region;
one or more cells, each cell having;
a source region in the semiconductor material of the first conductivity type extending from the main surface in the body region;
a gate trench;
a gate region of electrically conductive material in the gate trench extending from the main surface in the body region and in the substrate region; and
an insulating gate layer electrically insulating the gate region from said semiconductor material; and
a termination structure including;
a plurality of termination rings surrounding at least a part of the active area on the main surface, each termination ring including;
at least one termination trench extending from the main surface in the chip;
at least one floating element of electrically insulating material in the at least one termination trench; and
at least one bottom region of said semiconductor material of the second conductivity type extending from at least a deepest portion of a surface of the termination trench in the chip, wherein the termination trenches each have a depth from the main surface decreasing moving away from the active area; and
an edge ring in the substrate region, the edge ring having the second conductivity type, the termination rings extending into the edge ring, the edge ring extending from the main surface in the substrate region to a depth greater than a depth of at least one of the plurality of termination rings.
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Accused Products
Abstract
An electronic device is integrated on a chip of semiconductor material having a main surface and a substrate region with a first type of conductivity. The electronic device has a vertical MOS transistor, formed in an active area having a body region with a second conductivity type. A set of one or more cells each one having a source region of the first conductivity, a gate region of electrically conductive material in a gate trench extending from the main surface in the body region and in the substrate region, and an insulating gate layer, and a termination structure with a plurality of termination rings surrounding at least part of the active area on the main surface, each termination ring having a floating element of electrically insulating material in the termination trench extending from the main surface in the chip and at least one bottom region of said semiconductor material of the second conductivity type extending from at least one deepest portion of a surface of the termination trench in the chip; the termination trenches have a depth from the main surface decreasing moving away from the active area.
15 Citations
28 Claims
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1. An electronic device, comprising:
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a chip of semiconductor material having a main surface and a substrate region of said semiconductor material with a first type of conductivity extending from the main surface; at least one vertical MOS transistor, formed in an active area of the chip, the transistor including; at least one body region in the semiconductor material with a second conductivity type extending from the main surface in the substrate region; one or more cells, each cell having; a source region in the semiconductor material of the first conductivity type extending from the main surface in the body region; a gate trench; a gate region of electrically conductive material in the gate trench extending from the main surface in the body region and in the substrate region; and an insulating gate layer electrically insulating the gate region from said semiconductor material; and a termination structure including; a plurality of termination rings surrounding at least a part of the active area on the main surface, each termination ring including; at least one termination trench extending from the main surface in the chip; at least one floating element of electrically insulating material in the at least one termination trench; and at least one bottom region of said semiconductor material of the second conductivity type extending from at least a deepest portion of a surface of the termination trench in the chip, wherein the termination trenches each have a depth from the main surface decreasing moving away from the active area; and an edge ring in the substrate region, the edge ring having the second conductivity type, the termination rings extending into the edge ring, the edge ring extending from the main surface in the substrate region to a depth greater than a depth of at least one of the plurality of termination rings. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21)
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10. A device, comprising:
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a substrate having an outermost edge; a transistor region in the substrate; a termination structure formed in the substrate between the transistor region and the outermost edge, the termination structure including; a plurality of insulating floating elements; a plurality of termination trenches extending into the substrate, each trench including one of the plurality of insulating floating elements, each trench having a depth, the depth of each respective trench decreasing as the respective trench is further from the transistor region and closer to the outermost edge; a protective layer on the substrate and on the plurality of termination trenches; and a field oxide layer formed on the protective layer positioned between the termination structure and the outermost edge. - View Dependent Claims (11, 12, 13, 14, 15)
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22. A device, comprising:
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a semiconductor substrate having an active area and a termination structure area around the active area; a transistor in the active area, the transistor including at least one cell having a source region; a plurality of termination trenches in the termination structure area, each termination trench having a different depth, each termination trench including; a floating element of electrically insulating material; and a doped bottom region that is separated from a surface of the substrate by the floating element; a protective layer on the substrate that covers the plurality of termination trenches, the protective layer including a plurality of openings that expose the surface of the substrate, at least one of the plurality of openings is between two of the plurality of termination trenches; and a conductive layer coupled to the source region, the conductive layer formed on the protective layer and in the plurality of openings. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification