Silicon carbide substrate, and method for producing the substrate, and semiconductor device utilizing the substrate

A silicon carbide substrate comprising a silicon carbide crystal grown by supplying silicon atoms and carbon atoms on a surface of a silicon carbide substrate, characterized in that:

• said surface of said silicon carbide substrate on which said silicon carbide crystal is to be grown is an off-cut surface inclined 0.05° to 10° with respect to one of the faces selected from a {0001} face of a hexagonal silicon carbide crystal and a {111} face of a cubic silicon carbide crystal, and
• an amount of silicon atoms to be supplied and an amount of carbon atoms to be supplied are so controlled that said amount of silicon atoms is in excess of said amount of carbon atoms.

A silicon carbide substrate comprising a silicon carbide crystal grown by supplying silicon atoms and carbon atoms on a surface of a silicon carbide substrate, characterized in that:

• said silicon carbide crystal has a different crystal system from a crystal system of said silicon carbide substrate on which said silicon carbide crystal is to be grown, and said silicon carbide crystal is grown in a predetermined selective region in said silicon carbide substrate.

A silicon carbide substrate comprising a silicon carbide crystal grown utilizing a step-flow growth by supplying silicon atoms and carbon atoms on a surface of a silicon carbide substrate, characterized in that:

• said silicon carbide crystal is one of the crystals selected from a hexagonal silicon carbide crystal and a cubic silicon carbide crystal, and
• said surface of said silicon carbide substrate has one of the step edges selected from a step edge of a [11{overscore (2)}0] direction of a hexagonal silicon carbide crystal and a step edge of a [110] direction of a cubic silicon carbide crystal.

A silicon carbide substrate comprising a silicon carbide crystal grown utilizing a step-flow growth by supplying silicon atoms and carbon atoms on a surface of a silicon carbide substrate, characterized in that:

• said silicon carbide crystal is one of the crystals selected from a hexagonal silicon carbide crystal and a cubic silicon carbide crystal,
• said surface of said silicon carbide substrate on which said silicon carbide crystal is to be grown is one of the off-cut surfaces selected from an off-cut surface inclined towards approximately a <1{overscore (1)}00> direction with respect to a {0001} face of a hexagonal silicon carbide crystal and an off-cut surface inclined towards approximately a <112> direction with respect to a {111} face of a cubic silicon carbide crystal, and
• a surface roughness of said silicon carbide crystal is 10 nm or lower.

A silicon carbide substrate comprising a first silicon carbide crystal and a second silicon carbide crystals each being a single phase and having a crystal system different from each other, wherein;

• said substrate has a structure comprising at least two layers of said first silicon carbide crystal and at least one layer of said second silicon carbide crystal, said at least one layer of second silicon carbide crystal being sandwiched between said at least two layers of first silicon carbide crystal;
• and
• each of said layers is stacked with an abrupt interface therebetween.

A semiconductor device comprising a silicon carbide substrate in which a first silicon carbide crystal and a second silicon carbide crystal are stacked with an abrupt interface therebetween, said first silicon carbide crystal and a second silicon carbide crystal each having a different crystal system from each other and being a single phase.