Patent ID: 11929400
Assignee: FUJI ELECTRIC CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A silicon carbide semiconductor device, comprising:
a semiconductor substrate containing silicon carbide, the semiconductor substrate having a first main surface and a second main surface opposite to each other;
a first-conductivity-type region provided in the semiconductor substrate so as to have a surface thereof exposed at the first main surface of the semiconductor substrate;
a plurality of second-conductivity-type regions selectively provided in the first-conductivity-type region at the first main surface of the semiconductor substrate, each in contact with the first-conductivity-type region;
a plurality of second-conductivity-type high-concentration regions provided respectively in and contacting the plurality of second-conductivity-type regions, each of the second-conductivity-type high-concentration regions having an impurity concentration higher than an impurity concentration of each of the second-conductivity-type regions;
a plurality of recesses provided in the semiconductor substrate at the first main surface of the semiconductor substrate, respectively exposing, each at a bottom thereof, the plurality of the second-conductivity-type high-concentration regions;
a first electrode including a titanium film and a metal film containing aluminum that are sequentially stacked on the first main surface of the semiconductor substrate, the titanium film being in contact with the first-conductivity-type region and forming Schottky junctions with the first-conductivity-type region, the titanium film being in contact with the second-conductivity-type high-concentration regions respectively at the bottoms of the recesses to thereby form an ohmic contact with each of the second-conductivity-type high-concentration regions; and
a second electrode provided on the second main surface of the semiconductor substrate, wherein
each of the second-conductivity-type high-concentration regions has an impurity concentration distribution in which the impurity concentration thereof is at a peak concentration at the bottom of the recess exposing said each second-conductivity-type high-concentration region, and decreases gradually therefrom in a depth direction.