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US 2008/0258152 A1Published application
SiC semiconductor device having outer periphery structure
AssigneeDenso Corporation
InventorsTakeo Yamamoto, Eiichi Okuno
Life of this patent
Estimating the term…
Abstract
A SiC semiconductor device includes: a SiC substrate; a SiC drift layer on the substrate having an impurity concentration lower than the substrate; a semiconductor element in a cell region of the drift layer; an outer periphery structure including a RESURF layer in a surface portion of the drift layer and surrounding the cell region; and an electric field relaxation layer in another surface portion of the drift layer so that the electric field relaxation layer is separated from the RESURF layer. The electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region. The electric field relaxation layer has a ring shape.
Claims17
A SiC semiconductor device comprising:
- a substrate made of SiC and having a first conductive type, wherein the substrate includes a first surface and a second surface;
- a drift layer disposed on the first surface of the substrate, wherein the drift layer is made of SiC and has the first conductive type, and the drift layer has an impurity concentration lower than that of the substrate;
- a semiconductor element disposed in a cell region of the drift layer;
- an outer periphery structure disposed on an outer periphery of the cell region, wherein the outer periphery structure includes a RESURF layer having a second conductive type, and the RESURF layer is disposed in a surface portion of the drift layer and surrounds the cell region;
- and
- an electric field relaxation layer having the second conductive type, wherein the electric field relaxation layer is disposed in another surface portion of the drift layer so that the electric field relaxation layer is separated from the RESURF layer, the electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region, and the electric field relaxation layer has a ring shape.
3 more elements
A SiC semiconductor device comprising:
- a substrate made of SiC and having a first conductive type, wherein the substrate includes a first surface and a second surface;
- a drift layer disposed on the first surface of the substrate, wherein the drift layer is made of SiC and has the first conductive type, and the drift layer has an impurity concentration lower than that of the substrate;
- a semiconductor element disposed in a cell region of the drift layer;
- an outer periphery structure disposed on an outer periphery of the cell region, wherein the outer periphery structure includes a RESURF layer having a second conductive type, and the RESURF layer is disposed in a surface portion of the drift layer and surrounds the cell region;
- and
- an electric field relaxation layer having the second conductive type, wherein the electric field relaxation layer is disposed in another surface portion of the drift layer, the electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region, the electric field relaxation layer has a tapered shape so that a depth of the electric field relaxation layer becomes shallower with going toward a center of the cell region, and the electric field relaxation layer has a ring shape.
3 more elements
A SiC semiconductor device comprising:
- a substrate made of SiC and having a first conductive type, wherein the substrate includes a first surface and a second surface;
- a drift layer disposed on the first surface of the substrate, wherein the drift layer is made of SiC and has the first conductive type, and the drift layer has an impurity concentration lower than that of the substrate;
- a semiconductor element disposed in a cell region of the drift layer;
- an outer periphery structure disposed on an outer periphery of the cell region, wherein the outer periphery structure includes a RESURF layer having a second conductive type, and the RESURF layer is disposed in a surface portion of the drift layer and surrounds the cell region;
- and
- an electric field relaxation layer having the second conductive type, wherein the electric field relaxation layer is disposed in another surface portion of the drift layer, the electric field relaxation layer is disposed on an inside of the RESURF layer so that the electric field relaxation layer is disposed in the cell region, the electric field relaxation layer has an impurity concentration, which becomes smaller with going deeper and with going toward a center of the cell region, and the electric field relaxation layer has a ring shape.
3 more elements
Dependencies are inferred from the claim text.