Semiconductor device and method for manufacturing same

A semiconductor device comprising:

• a substrate;
• a first silicon carbide layer formed on the substrate and made of silicon carbide containing an impurity of a first conductivity type;
• a second silicon carbide layer formed on the first silicon carbide layer and made of silicon carbide;
• and
• at least one electrode comprising a metal,
• wherein the second silicon carbide layer consists of at least one first semiconductor layer and at least two second semiconductor layers,
• the first semiconductor layer and the second semiconductor layers are alternately stacked,
• the first semiconductor layer is composed of a compound semiconductor and serves as a region through which carriers flow,
• the second semiconductor layers are composed of a compound semiconductor and contain an impurity of the first conductivity type for carriers at a higher concentration than the first semiconductor layer and are thinner than the first semiconductor layer, and
• a metal that is the constituent material of the electrode diffuses into the second silicon carbide layer from the top side to directly contact at least each of the second semiconductor layers.