Patent ID: 7863682

Claim:
A semiconductor device having a junction barrier Schottky diode comprising: a SiC substrate having a first conductive type and including first and second surfaces; a drift layer having the first conductive type, disposed on the first surface of the substrate, made of SiC, and having an impurity concentration, which is lower than that of the substrate; an insulation film disposed on the drift layer and having an opening in a cell region; a Schottky barrier diode having a Schottky electrode and an ohmic electrode, wherein the Schottky electrode is disposed in the cell region and contacts the drift layer through the opening of the insulation film with Schottky contact, and wherein the ohmic electrode is disposed on the second surface of the substrate; a terminal structure having a RESURF layer and disposed on an outer periphery of the cell region, wherein the RESURF layer has a second conductive type, surrounds the cell region, and is disposed in a surface portion of the drift layer; and a plurality of second conductive type layers, each of which is disposed in another surface portion of the drift layer on an inner side of the RESURF layer, contacts the Schottky electrode, wherein the second conductive type layers are separated from each other by a predetermined distance, wherein: the plurality of second conductive type layers and the drift layer provide a PN diode; the Schottky electrode includes a first Schottky electrode and a second Schottky electrode; the first Schottky electrode contacts each of the second conductive type layers with ohmic contact; the second Schottky electrode contacts the drift layer with the Schottky contact, the plurality of second conductive type layers includes a center portion and a plurality of ring portions; the center portion is disposed at a center of the cell region; each of the ring portions surrounds the center portion and has a point symmetry around the center portion; the plurality of ring portions includes an utmost outer ring portion, which is disposed on an utmost outer side of the ring portions; the plurality of ring portions includes a plurality of middle ring portions, which is disposed between the utmost outer ring portion and the center portion; each ring portion has a cross section taken along a radial direction; and the cross sections of the middle ring portions have a line symmetry with respect to the center of the cell region.