Patent ID: 8324704
Filing Date: 2012-12-04
Classification: H01L

Abstract:
1. A silicon carbide semiconductor device with a Schottky barrier diode, the silicon carbide semiconductor device comprising: a first conductivity type silicon carbide substrate having a first surface and a second surface opposite to the first surface; a first conductivity type silicon carbide drift layer on the first surface of the substrate, the drift layer having an impurity concentration less than an impurity concentration of the substrate; a Schottky electrode on the drift layer, the Schottky electrode forming a Schottky contact with a surface of the drift layer in a cell region of the drift layer; and an ohmic electrode on the second surface of the substrate, wherein the Schottky electrode includes an oxide layer that is in direct contact with the surface of the drift layer and made of an oxide of a first metal, the first metal is molybdenum, titanium, nickel, or an alloy of at least two of these elements, the Schottky electrode further includes a metal layer on the oxide layer and an electrode layer on the metal layer, the metal layer is made of a second metal, the second metal is the same as the first metal, the Schottky electrode further includes a cap layer located between the metal layer and the electrode layer, and the cap layer is made of a fourth metal having a higher resistance to oxidation than the second metal.