SEMICONDUCTOR DEVICE
First Claim
1. A semiconductor device comprising:
- a semiconductor substrate of a first conductivity type, formed of a silicon carbide semiconductor;
an active region disposed on a front surface of the semiconductor substrate and through which a main current flows, the active region having a periphery; and
an edge termination structure surrounding a periphery of the active region, whereinthe edge termination structure includes;
a plurality of semiconductor regions of a second conductivity type, disposed concentrically surrounding the periphery of the active region, each semiconductor region having a lower impurity concentration the further the semiconductor region is from the periphery, andan intermediate region of the second conductivity type, disposed so as to mutually contact adjacent ones of the plurality of semiconductor regions, the intermediate region having an impurity concentration that is lower than that of the adjacent semiconductor region on a side closer to the periphery and an impurity concentration that is higher than that of the adjacent semiconductor region on a side further from the periphery,the intermediate region includes a first subregion of the second conductivity type and a second subregion of the second conductivity type, the second subregion having an impurity concentration that is lower than that of the first subregion, a plurality of the first and second subregions being alternately and repeatedly arranged concentrically surrounding the adjacent semiconductor region on the side closer to the periphery of the active region,the plurality of second subregions having a same width, andthe plurality of first subregions having respective widths that are narrower the farther from the periphery of the active region the first subregions are arranged.
1 Assignment
0 Petitions
Accused Products
Abstract
In an edge termination structure portion, first and second JTE regions are disposed concentrically surrounding an active region. Between the first and second JTE regions, a p-type electric field relaxation region is disposed that includes a first subregion and a second subregion alternately and repeatedly arranged concentrically surround a periphery of the first JTE region. An average impurity concentration of the electric field relaxation region is higher that the impurity concentration of the first JTE region adjacent on the inner side and lower than the impurity concentration of the second JTE region adjacent on the outer side. First subregions have widths that decrease the farther outward they are arranged. Second subregions have widths that are substantially the same independent of position. The first subregions and the first JTE region have equal impurity concentrations. The second subregions and the second JTE region have equal impurity concentrations.
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Citations
41 Claims
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1. A semiconductor device comprising:
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a semiconductor substrate of a first conductivity type, formed of a silicon carbide semiconductor; an active region disposed on a front surface of the semiconductor substrate and through which a main current flows, the active region having a periphery; and an edge termination structure surrounding a periphery of the active region, wherein the edge termination structure includes; a plurality of semiconductor regions of a second conductivity type, disposed concentrically surrounding the periphery of the active region, each semiconductor region having a lower impurity concentration the further the semiconductor region is from the periphery, and an intermediate region of the second conductivity type, disposed so as to mutually contact adjacent ones of the plurality of semiconductor regions, the intermediate region having an impurity concentration that is lower than that of the adjacent semiconductor region on a side closer to the periphery and an impurity concentration that is higher than that of the adjacent semiconductor region on a side further from the periphery, the intermediate region includes a first subregion of the second conductivity type and a second subregion of the second conductivity type, the second subregion having an impurity concentration that is lower than that of the first subregion, a plurality of the first and second subregions being alternately and repeatedly arranged concentrically surrounding the adjacent semiconductor region on the side closer to the periphery of the active region, the plurality of second subregions having a same width, and the plurality of first subregions having respective widths that are narrower the farther from the periphery of the active region the first subregions are arranged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 34, 35, 36, 37, 38, 39)
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13. A semiconductor device comprising:
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a semiconductor substrate of a first conductivity type, formed of a silicon carbide semiconductor; an active region disposed on a front surface of the semiconductor substrate and through which a main current flows, the active region having a periphery; and an edge termination structure surrounding the periphery of the active region, wherein the edge termination structure includes; a plurality of semiconductor regions disposed concentrically surrounding the periphery of the active region, the plurality of semiconductor regions having a lower impurity concentration the further each of the plurality of semiconductor regions is from the periphery of the active region, and an intermediate region of the second conductivity type, disposed so as to mutually contact adjacent ones of the plurality of semiconductor regions, the intermediate region having an impurity concentration that is lower than that of the adjacent semiconductor region on a side closer to the periphery of the active region and an impurity concentration that is higher than that of the semiconductor region adjacent on a side further from the periphery of the active region, the intermediate region is divided into a plurality of sections concentrically surrounding the adjacent semiconductor region on a side closer to the periphery of the active region, a plurality of first subregions of the second conductivity type and a plurality of second subregions of the second conductivity type, the second subregions having an impurity concentration that is lower than that of the first subregion, alternately and repeatedly arranged, are disposed concentrically in the sections from an inner side toward an outer side relative to the periphery of the active region, a microregion including adjacent ones of the first subregion and the second subregion having a same width in a same section of the sections and having a width that is narrower the farther outward a section is positioned in which the microregion is arranged. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 40)
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24. A semiconductor device comprising:
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a semiconductor substrate of a first conductivity type, formed of a silicon carbide semiconductor; an active region disposed on a front surface of the semiconductor substrate and through which main current flows, the active region having a periphery; and an edge termination structure surrounding a periphery of the active region, wherein the edge termination structure includes; a plurality of semiconductor regions disposed concentrically surrounding a periphery of the active region, the farther outward a semiconductor region thereamong is arranged, the lower an impurity concentration thereof is, and an intermediate region disposed so as to mutually contact adjacent ones of the plurality of semiconductor regions, the intermediate region having an impurity concentration that is lower than that of the adjacent semiconductor region on a side closer to the periphery of the active region and an impurity concentration that is higher than that of the adjacent semiconductor region on a side further from the active region, the intermediate region is divided into a plurality of sections concentrically surrounding the adjacent semiconductor region on a side closer to the periphery of the active region, a plurality of first subregions of the second conductivity type and a plurality of second subregions of the second conductivity type, the plurality of second subregions of the second conductivity type having an impurity concentration that is lower than that of the plurality of first subregions of the second conductivity type, alternately and repeatedly arranged, are disposed concentrically in the sections from an inner side toward an outer side relative to the periphery of the active region, each of the plurality of sections has an average impurity concentration determined based on widths of the plurality of first subregions and the plurality of second subregions arranged in the said section, where the average impurity concentration is lower the farther outward the said section is arranged relative to the periphery of the active region, and an average impurity concentration difference between all adjacent sections is equal. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 41)
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Specification