Semiconductor Device and method of manufacturing the same

A method of manufacturing a semiconductor device, comprising:

• a film forming step for forming a metal layer on one surface of a silicon carbide semiconductor substrate;
• and
• a heat-treating step for subjecting the metal layer to a heat treatment in a temperature range of 300° C. to 500° C. after the film forming step, to form an ohmic junction between the metal layer and the one surface of the silicon carbide semiconductor substrate,
• the film forming step including the step of forming the metal layer brought into contact with the silicon carbide semiconductor substrate using a metal material whose silicate formation free energy and carbide formation free energy at the temperature of the silicon carbide semiconductor substrate in the heat-treating step respectively take negative values.

A method of manufacturing a semiconductor device using a silicon carbide semiconductor substrate in which carrier concentration of a first semiconductor layer on a side of its one surface is higher than carrier concentration of a second semiconductor layer on a side of the other surface, comprising:

• a first film forming step for forming a first metal layer brought into contact with the first semiconductor layer in the silicon carbide semiconductor substrate;
• a second film forming step for forming a second metal layer brought into contact with the second semiconductor layer in the silicon carbide semiconductor substrate and composed of the same metal material as that composing the first metal layer;
• and
• a heat-treating step for simultaneously heat-treating the first metal layer and the second metal layer at a predetermined temperature after the first film forming step and the second film forming step, to form an ohmic junction between the first metal layer and the first semiconductor layer as well as to form a Schottky junction between the second metal layer and the second semiconductor layer,
• the first and second film forming steps including the steps of respectively forming the first and second metal layers brought into contact with the silicon carbide semiconductor substrate using a metal material whose silicate formation free energy and carbide formation free energy at the temperature of the silicon carbide semiconductor substrate in the heat-treating step respectively take negative values.