SiC semiconductor device with offset in trench bottom
First Claim
1. A semiconductor device, comprising:
- a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom;
a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric;
a body region of a first conductivity type adjoining the first sidewall; and
a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom,wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom, which adjoins the first sidewall, and a second section of the trench bottom, which adjoins the second sidewall, are offset to one another by a vertical offset so that the second section of the trench bottom which adjoins the second sidewall is arranged deeper in the SiC semiconductor body than the first section of the trench bottom which adjoins the first sidewall,wherein a second section of a bottom of the gate electrode which adjoins the second section of the trench bottom is arranged deeper in the SiC semiconductor body along the vertical direction than a first section of the bottom of the gate electrode which adjoins the first section of the trench bottom.
1 Assignment
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Accused Products
Abstract
A semiconductor device includes a trench extending from a first surface into a SiC semiconductor body. The trench has a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom. A gate electrode is arranged in the trench and is electrically insulated from the SiC semiconductor body by a trench dielectric. A body region of a first conductivity type adjoins the first sidewall. A shielding structure of the first conductivity type adjoins at least a portion of the second sidewall and the trench bottom. A first section of the trench bottom and a second section of the trench bottom are offset to one another by a vertical offset along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface.
9 Citations
24 Claims
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1. A semiconductor device, comprising:
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a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom; a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric; a body region of a first conductivity type adjoining the first sidewall; and a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom, wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom, which adjoins the first sidewall, and a second section of the trench bottom, which adjoins the second sidewall, are offset to one another by a vertical offset so that the second section of the trench bottom which adjoins the second sidewall is arranged deeper in the SiC semiconductor body than the first section of the trench bottom which adjoins the first sidewall, wherein a second section of a bottom of the gate electrode which adjoins the second section of the trench bottom is arranged deeper in the SiC semiconductor body along the vertical direction than a first section of the bottom of the gate electrode which adjoins the first section of the trench bottom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of manufacturing a semiconductor device, the method comprising:
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forming a first trench extending from a first surface into a SiC semiconductor body; forming a shielding structure of a first conductivity type in the SiC semiconductor body by introducing dopants of a first conductivity type through a bottom of the first trench into the SiC semiconductor body; forming a second trench extending from the first surface into the SiC semiconductor body; and forming a gate electrode in the second trench, wherein the second trench extends deeper into the SiC semiconductor body than the first trench, wherein the first trench and the second trench laterally merge one another so as to set a second section of a trench bottom of the second trench deeper in the SiC semiconductor body than a first section of the trench bottom of the second trench, and so that a second section of a bottom of the gate electrode is arranged deeper in the SiC semiconductor body along the vertical direction than a first section of the bottom of the gate electrode. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A semiconductor device, comprising:
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a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom; a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric; a body region of a first conductivity type adjoining the first sidewall; and a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom, wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom and a second section of the trench bottom are offset to one another by a vertical offset, wherein the shielding structure includes a shielding region of the first conductivity type and a connection region of the first conductivity type, the connection region being arranged between the shielding region and the first surface, wherein a doping concentration profile of the shielding region has a peak along the vertical direction that is located deeper in the SiC semiconductor body than the trench bottom.
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21. A semiconductor device, comprising:
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a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom; a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric; a body region of a first conductivity type adjoining the first sidewall; a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom; and a source region of a second conductivity type between the body region and the first surface, wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom and a second section of the trench bottom are offset to one another by a vertical offset, wherein a first portion of the source region is arranged between the first sidewall of the trench and a second portion of the source region, wherein a bottom of the second portion of the source region is arranged deeper in the SiC semiconductor body along the vertical direction than a bottom of the first portion. - View Dependent Claims (22)
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23. A semiconductor device, comprising:
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a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom; a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric; a body region of a first conductivity type adjoining the first sidewall; a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom; a current spread zone of a second conductivity type; and a drift zone of the second conductivity type, wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom and a second section of the trench bottom are offset to one another by a vertical offset, wherein the current spread zone is arranged between the body region and the drift zone, wherein the current spread zone adjoins the body region and the shielding structure, wherein an average net doping concentration of the current spread zone is greater than an average net doping concentration of the drift zone.
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24. A semiconductor device, comprising:
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a trench extending from a first surface into a SiC semiconductor body, the trench having a first sidewall, a second sidewall opposite to the first sidewall, and a trench bottom, wherein a sidewall plane of the first sidewall is formed by a main crystal plane of the SiC semiconductor body, and wherein the second sidewall is tilted with respect to the main crystal plane; a gate electrode arranged in the trench and electrically insulated from the SiC semiconductor body by a gate dielectric; a body region of a first conductivity type adjoining the first sidewall; a shielding structure of the first conductivity type adjoining at least a portion of the second sidewall and the trench bottom; and a source region of a second conductivity type formed exclusively along the first sidewall, wherein along a vertical direction extending from the first surface to a second surface of the SiC semiconductor body opposite to the first surface, a first section of the trench bottom and a second section of the trench bottom are offset to one another by a vertical offset.
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Specification