Semiconductor device and method for manufacturing same

摘要

This semiconductor device includes a silicon carbide layer of a first conductivity type having first and second principal surfaces and including an element region and a terminal region surrounding the element region on the first principal surface. The silicon carbide layer includes a first dopant layer of the first conductivity type contacting with the first principal surface and a second dopant layer of the first conductivity type located closer to the second principal surface than the first dopant layer is. The terminal region has, in its surface portion with a predetermined depth under the first principal surface, a terminal structure including respective portions of the first and second dopant layers and a ring region of a second conductivity type running through the first dopant layer to reach the second dopant layer. The dopant concentration of the first dopant layer is twice to five times as high as that of the second dopant layer 22. When viewed along a normal to the first principal surface, the first dopant layer is arranged to contact with the ring region both inside and outside of the region.

主权项

1. A semiconductor device comprising a silicon carbide layer of a first conductivity type, the silicon carbide layer having a first principal surface and a second principal surface and including an element region and a terminal region which surrounds the element region on the first principal surface,
wherein the silicon carbide layer includes: a first dopant layer of the first conductivity type which contacts with the first principal surface; a second dopant layer of the first conductivity type which is located closer to the second principal surface than the first dopant layer is; and a third dopant layer of the first conductivity type which is located between the first and second dopant layers and has a lower dopant concentration than the second dopant layer and, the terminal region has, in its surface portion with a predetermined depth as measured from the first principal surface, a terminal structure which includes a portion of the first dopant layer, a portion of the second dopant layer, and a ring region of a second conductivity type that runs through the first and third dopant layers to reach the second dopant layer, the dopant concentration of the first dopant layer is twice to five times as high as the dopant concentration of the second dopant layer, when viewed along a normal to the first principal surface, the first dopant layer is arranged to contact with the ring region both inside and outside of the region.