Method of manufacturing Group III nitride crystals, method of manufacturing semiconductor substrate, Group III nitride crystals, semiconductor substrate, and electronic device

A method of manufacturing Group III nitride crystals, comprising:

• (i) forming a semiconductor layer that includes crystal-nucleus generation regions at its surface and is made of a semiconductor, the semiconductor being expressed by a composition formula of AluGavIn1-u-vN (where 0≦u≦1, 0≦v≦1, and u+v≦1);
• and
• (ii) growing Group III nitride crystals on the semiconductor layer by bringing the crystal-nucleus generation regions of the semiconductor layer into contact with a melt in an atmosphere including nitrogen, the melt containing nitrogen, at least one Group III element selected from the group consisting of gallium, aluminum, and indium, and at least one of alkali metal and alkaline-earth metal;
• wherein the crystal-nucleus generation regions have a carrier concentration of 1×1017 cm−3 or lower.

A method of manufacturing Group III nitride crystals, comprising:

• (i-1) forming an undercoating layer made of a semiconductor that is expressed by a composition formula of AlsGatIn1-s-tN (where 0≦s≦1, 0≦t≦1, and s+t≦1);
• (i-2) exposing a surface of the undercoating layer to the air;
• (i-3) forming a semiconductor layer on the undercoating layer by growing a semiconductor that is expressed by a composition formula of AluGavIn1-u-vN (where 0≦u≦1, 0≦v≦1, and u+v≦1) and includes crystal-nucleus generation regions at its surface;
• and
• (ii) growing Group III nitride crystals on the semiconductor layer by bringing the crystal-nucleus generation regions of the semiconductor layer into contact with a melt in an atmosphere including nitrogen, the melt containing nitrogen, at least one Group III element selected from the group consisting of gallium, aluminum, and indium, and at least one of alkali metal and alkaline-earth metal;
• wherein the crystal-nucleus generation regions are at least one of pits and hillocks.

A method of manufacturing Group III nitride crystals, comprising:

• (i-a) forming a semiconductor layer made of a semiconductor that is expressed by a composition formula of AluGavIn1-u-vN (where 0≦u≦1, 0≦v≦1, and u+v≦1);
• (i-b) forming crystal-nucleus generation regions by processing a surface of the semiconductor layer by at least one of scribing and dicing to form grooves on the surface of the semiconductor layer;
• and
• (ii) growing Group III nitride crystals on the semiconductor layer by bringing the crystal-nucleus generation regions of the semiconductor layer into contact with a melt in an atmosphere including nitrogen, the melt containing nitrogen, at least one Group III element selected from the group consisting of gallium, aluminum, and indium, and at least one of alkali metal and alkaline-earth metal.

A method of manufacturing Group III nitride crystals, comprising:

• (i-a) forming a semiconductor layer made of a semiconductor that is expressed by a composition formula of AluGavIn1-u-vN (where 0≦u≦1, 0≦v≦1, and u+v≦1);
• (i-b) forming the crystal-nucleus generation regions by roughening a surface of the semiconductor layer by etching;
• and
• (ii) growing Group III nitride crystals on the semiconductor layer by bringing the crystal-nucleus generation regions of the semiconductor layer into contact with a melt in an atmosphere including nitrogen, the melt containing nitrogen, at least one Group III element selected from the group consisting of gallium, aluminum, and indium, and at least one of alkali metal and alkaline-earth metal.