SILICON CARBIDE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF SILICON CARBIDE SEMICONDUCTOR DEVICE

摘要

In a silicon carbide semiconductor device, a trench penetrates a source region and a first gate region and reaches a drift layer. On an inner wall of the trench, a channel layer of a first conductivity-type is formed by epitaxial growth. On the channel layer, a second gate region of a second conductivity-type is formed. A first depressed portion is formed at an end portion of the trench to a position deeper than a thickness of the source region so as to remove the source region at the end portion of the trench. A corner portion of the first depressed portion is covered by a second conductivity-type layer.

主权项

1. A silicon carbide semiconductor device comprising a JFET, the JFET including:
a semiconductor substrate including a first conductivity-type substrate made of silicon carbide, a drift layer of a first conductivity-type formed on the first conductivity-type substrate by epitaxial growth, a first gate region of a second conductivity-type formed on the drift layer by epitaxial growth, and a source region of the first conductivity-type formed on the first gate region by epitaxial growth or ion implantation; a trench penetrating the source region and the first gate region and reaching the drift layer, the trench having a strip shape whose longitudinal direction is set in one direction; a channel layer of the first conductivity-type formed on an inner wall of the trench by epitaxial growth; a second gate region of the second conductivity-type formed on the channel layer; a first depressed portion formed at an end portion of the trench, the first depressed portion formed to a position deeper than a thickness of the source region so as to remove the source region from the end portion of the trench; and a second conductivity-type layer covering a corner portion at a boundary between a bottom surface and a side surface of the first depressed portion.