Patent ID: 7999346

Claim:
A semiconductor device, comprising a silicon carbide semiconductor substrate having a silicon surface and a carbon surface, an ohmic metal layer joined to the carbon surface of the silicon carbide semiconductor substrate in an ohmic contact, the ohmic metal layer being composed of molybdenum or an alloy of molybdenum and at least one metal material selected from the group consisting of titanium, chromium, manganese, zirconium, tantalum, and tungsten, a Schottky metal layer joined to the silicon surface of the silicon carbide semiconductor substrate in a Schottky contact, and a first multi-layer structure including the Schottky metal layer and a first metal layer formed on a surface of the Schottky metal layer, the Schottky metal layer composed of molybdenum, and the first metal layer composed of any one of aluminum, an aluminum-silicon alloy, and an aluminum-silicon-copper alloy, wherein carrier concentration of a first semiconductor layer on a side of the carbon surface of the silicon carbide semiconductor substrate is higher than concentration of a second semiconductor layer on a side of the silicon surface of the silicon carbide semiconductor substrate.