Trench MOS device having a termination structure with multiple field-relaxation trenches for high voltage applications
First Claim
1. A termination structure for a semiconductor device, said termination structure comprising:
- a semiconductor substrate having an active region and a termination region;
a plurality of trench cells located only in the termination region and extending from a boundary of the active region toward an edge of the semiconductor substrate;
a termination trench formed in the termination region on a side of the plurality of trench cells remote from the active region;
a conductive spacer located adjacent a sidewall of the termination trench nearest the plurality of trench cells;
a first oxide layer formed in the termination trench and contacting a sidewall of the conductive spacer;
a first conductive layer formed on a backside surface of the semiconductor substrate;
a second conductive layer formed atop the active region and the termination region wherein the plurality of trench cells are filled with a conductive material up to a top surface of a plurality of mesas;
wherein the second conductive layer extends from the active area as a continuous layer and completely covering the plurality of trench cells and at least a portion of the termination trench such that the second conductive layer, the conductive spacer and a field plate formed in the termination region are electrically coupled to one another.
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Accused Products
Abstract
A termination structure for a semiconductor device includes a semiconductor substrate having an active region and a termination region. Two or more trench cells are located in the termination region and extend from a boundary of the active region toward an edge of the semiconductor substrate. A termination trench is formed in the termination region on a side of the trench cells remote from the active region. A conductive spacer is located adjacent to a sidewall of the termination trench nearest the trench cells. A first oxide layer is formed in the termination trench and contacts a sidewall of the conductive spacer. A first conductive layer is formed on a backside surface of the semiconductor substrate. A second conductive layer is formed atop the active region and the termination region.
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Citations
18 Claims
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1. A termination structure for a semiconductor device, said termination structure comprising:
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a semiconductor substrate having an active region and a termination region; a plurality of trench cells located only in the termination region and extending from a boundary of the active region toward an edge of the semiconductor substrate; a termination trench formed in the termination region on a side of the plurality of trench cells remote from the active region; a conductive spacer located adjacent a sidewall of the termination trench nearest the plurality of trench cells; a first oxide layer formed in the termination trench and contacting a sidewall of the conductive spacer; a first conductive layer formed on a backside surface of the semiconductor substrate; a second conductive layer formed atop the active region and the termination region wherein the plurality of trench cells are filled with a conductive material up to a top surface of a plurality of mesas; wherein the second conductive layer extends from the active area as a continuous layer and completely covering the plurality of trench cells and at least a portion of the termination trench such that the second conductive layer, the conductive spacer and a field plate formed in the termination region are electrically coupled to one another. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A semiconductor device, comprising:
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a semiconductor substrate having at least one trench MOS device located in an active region of the semiconductor substrate; a plurality of trench cells only located in a termination region of the semiconductor substrate adjacent to the active region of the semiconductor substrate, the plurality of trench cells extending from a boundary between the active and termination regions toward an edge of the semiconductor substrate; a termination trench formed in the termination region on a side of the plurality of trench cells remote from the active region; a first oxide layer lining the plurality of trench cells and the termination trench; a conductive spacer located adjacent a sidewall of the termination trench nearest the plurality of trench cells; a second oxide layer formed in the termination trench and contacting a sidewall of the conductive spacer; a first conductive layer formed on a backside surface of the semiconductor substrate; and a second conductive layer located atop the active region and the termination region, a portion of the second conductive layer located in the termination region defining a field plate. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of forming a semiconductor device, comprising:
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forming at least one trench MOS device located in an active region of a semiconductor substrate, forming a plurality of trench cells located in a termination region of the semiconductor substrate adjacent to the active region of the semiconductor substrate, the plurality of trench cells extending from a boundary between the active and termination regions toward an edge of the semiconductor substrate, forming a termination trench in the termination region of the semiconductor substrate on a side of the plurality of trench cells remote from the active region, forming a conductive spacer located adjacent a sidewall of the termination trench nearest the plurality of trench cells, forming a first oxide layer in the termination trench which contacts a sidewall of the conductive spacer, forming a first conductive layer on a backside surface of the semiconductor substrate, forming a second conductive layer located atop the active region; and forming a first conductive layer on a backside surface of the semiconductor substrate, wherein the plurality of trench cells are filled with a conductive material up to a top surface of a plurality of mesas, wherein the second conductive layer extends from the active area as a continuous layer and completely covering the plurality of trench cells and at least a portion of the termination trench such that the second conductive layer, the conductive spacer and a field plate formed in the termination region are electrically coupled to one another. - View Dependent Claims (18)
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Specification