Method for manufacturing group 13 nitride crystal and group 13 nitride crystal

A method for manufacturing a group 13 nitride crystal, comprising:

• arranging a seed crystal in a mixed melt containing an alkali metal and a group 13 element, retained in a reaction vessel,
• the seed crystal being a group 13 nitride seed crystal manufactured by vapor phase epitaxy and having an off-angle 1.5° or more and 2° or less with respect to a principal plane of the seed crystal, and
• a member made of alumina, whose purity is higher than 99.9% and whose Si concentration is lower than 100 ppm, being arranged in the reaction vessel and in contact with the mixed melt;
• and
• growing an interface layer on the principal plane of the seed crystal;
• and
• supplying a nitrogen-containing gas into the mixed melt and growing a group 13 nitride crystal on the interface layer, which was grown on the seed crystal,
• a pressure of the nitrogen-containing gas in growing the group 13 nitride crystal being set higher than a pressure of the nitrogen-containing gas in elevating a temperature in the reaction vessel to a crystal growth temperature of the group 13 nitride crystal, and
• the interface layer having a photoluminescence emission peak whose wavelength is longer than a wavelength of a photoluminescence emission peak of the grown group 13 nitride crystal.