Method for manufacturing group-III nitride semiconductor crystal substrate

A method for manufacturing a group III nitride semiconductor crystal substrate, the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×107 cm−3 in a crystal near the principal surface over an entire in-lane region thereof, and
• wherein a c-plane of the seed crystal substrate has inside the crystal a warpage that is concave surface-shaped toward the principal surface.

A method for manufacturing a group III nitride semiconductor crystal substrate the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×1017 cm−3 in a crystal near the principal surface over an entire in-plane region thereof, and
• wherein a growth surface includes a flat c-plane in the liquid phase growth method.

A method for manufacturing a group III nitride semiconductor crystal substrate, the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid chase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has a atomic oxygen concentration of not more than 1×107 cm−3 in a crystal near the principal surface over an entire in-plane region thereof, and
• wherein an incorporated oxygen concentration in the crystal varies depending on a plane orientation of a crystal growth interface.

A method for manufacturing a group III nitride semiconductor crystal substrate the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×1017 cm−3 in a crystal near the principal surface over an entire in-region thereof, and
• wherein the atomic oxygen concentration is within a range from 3×1016 cm−3 to 5×1016 cm−3.

A method for manufacturing a group III nitride semiconductor crystal substrate, the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor vase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×1017 cm−3 in a crystal near the principal surface over an entire in-plane region thereof, and
• wherein the near the principal surface includes a region within 20 μm in depth from the principal surface.

A method for manufacturing group III nitride semiconductor crystal substrate, the method comprising:

• providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by vapor has growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×1017 cm−3 in a crystal near the principal surface over an entire in-plane region thereof, and
• wherein a dislocation density in the group III nitride single crystal grown by the vapor phase growth method is not more than 1×107 cm−2.

A method for manufacturing a group III nitride semiconductor crystal substrate, the method comprising:

• providing, as a seed crystal substrate a group III nitride single crystal grown by a liquid phase growth method;
• and
• homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate,
• wherein the principal surface of the seed crystal substrate includes a +c-plane,
• wherein an entirety of a surface of the seed crystal substrate has an atomic oxygen concentration of not more than 1×1017 cm−3 in a crystal near the principal surface over an entire in-plane region thereof, and
• wherein the seed crystal substrate is free of a region of an N-polar face with reversed polarity partially emerged on a Ga-polar face of the principal surface.