Nitride semiconductor multilayer structure, light emitting element, light source apparatus, and method for producing nitride semiconductor multilayer structure

A nitride semiconductor multilayer structure comprising:

• a first nitride semiconductor layer;
• a second nitride semiconductor layer;
• and
• a third nitride semiconductor layer formed between the first nitride semiconductor layer and the second nitride semiconductor layer,
• wherein the third nitride semiconductor layer includes a first region and a second region that surrounds the first region in a same plane, and
• the second region has a largest band gap, among the first nitride semiconductor layer, the second nitride semiconductor layer, the first region, and the second region.

A method for producing a nitride semiconductor multilayer structure, the method comprising:

• forming a first nitride semiconductor layer, a second nitride semiconductor layer, and a third nitride semiconductor layer on a substrate, the third nitride semiconductor layer being formed between the first nitride semiconductor layer and the second nitride semiconductor layer and including at least an indium and a nitrogen;
• and
• performing heat treatment so as to reduce an indium content of a part of the third nitride semiconductor and form, in the third nitride semiconductor layer, a first region and a second region that surrounds the first region in a same plane, the first region including at least the indium and a nitrogen and allowing an electric current to flow through the first region between the first nitride semiconductor layer and the second, nitride semiconductor layer, and the second region including at least the nitrogen and preventing the electric current from flowing through the second region,
• wherein the indium content of the second region is greater than or equal to zero and lower than the indium content of the first region.