Method for manufacturing silicon carbide semiconductor device and silicon carbide semiconductor device

A silicon carbide semiconductor device comprising:

• a silicon carbide layer including an n-type region having an n conductivity type and a p-type region having a p conductivity type;
• an electrode layer formed on the n-type region and the p-type region as being in contact with the n-type region and the p-type region;
• and
• a coating layer formed on the electrode layer,
• the electrode layer containing titanium, aluminum, silicon, and oxygen, and
• aluminum and oxygen being present at an interface between the electrode layer and the coating layer, wherein
• an atom concentration of carbon at an interface between the silicon carbide layer and the electrode layer is not higher than 10%.

A silicon carbide semiconductor device comprising:

• a silicon carbide layer including an n-type region having an n conductivity type and a p-type region having a p conductivity type;
• an electrode layer formed on the n-type region and the p-type region as being in contact with the n-type region and the p-type region;
• and
• a coating layer formed on the electrode layer,
• the electrode layer containing titanium, aluminum, silicon, and oxygen, and
• aluminum and oxygen being present at an interface between the electrode layer and the coating layer, wherein
• an atom concentration of aluminum in inside of the electrode layer is lower than an atom concentration of aluminum at the interface between the electrode layer and the coating layer,
• an atom concentration of oxygen in inside of the electrode layer is lower than an atom concentration of oxygen at the interface between the electrode layer and the coating layer,
• the coating layer is a barrier metal layer or a metal interconnection layer,
• an average value of a thickness of the electrode layer is not smaller than 50 nm and not greater than 500 nm,
• relation of (Tmax−Tmin)/Tave≤1.0 is satisfied, where Tmax represents a maximum value of the thickness of the electrode layer, Tmin represents a minimum value of the thickness of the electrode layer, and Tave represents the average value,
• an atom concentration of carbon at an interface between the silicon carbide layer and the electrode layer is not higher than 10%, and
• an average value of an atom concentration of carbon in inside of the electrode layer is not higher than 10%.