Patent ID: 11942517
Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A method of manufacturing a silicon carbide semiconductor device, the method comprising:
preparing a silicon carbide epitaxial substrate including a silicon carbide single crystal substrate and a silicon carbide epitaxial layer, the silicon carbide epitaxial layer being provided on the silicon carbide single crystal substrate, the silicon carbide epitaxial layer having impurity ions capable of imparting a first conductivity type;
forming a trench in the silicon carbide epitaxial layer, the trench having a first side surface and a second side surface opposite to the first side surface;
forming a second region by obliquely implanting, into the first side surface, impurity ions capable of imparting a second conductivity type; and
forming a fourth region by obliquely implanting, into the second side surface, the impurity ions capable of imparting the second conductivity type, wherein
the silicon carbide epitaxial layer includes a first superjunction portion and a second superjunction portion, the first superjunction portion having a first region and the second region, the first region having the first conductivity type, the first region being in contact with the second region, the second superjunction portion having a third region and the fourth region, the third region having the first conductivity type, the third region being in contact with the fourth region, and
a bottom surface of the trench is located between the silicon carbide single crystal substrate and each of the second region and the fourth region in a direction perpendicular to a boundary surface between the silicon carbide single crystal substrate and the silicon carbide epitaxial layer,
the method further comprising filling the trench with an insulator.