Nitride semiconductor crystal producing method, nitride semiconductor epitaxial wafer, and nitride semiconductor freestanding substrate

A nitride semiconductor epitaxial wafer, comprising:

• a plate-like seed crystal substrate;
• and
• a nitride semiconductor crystal grown over the seed crystal substrate,
• wherein the nitride semiconductor crystal includes a nitride semiconductor crystal grown in a principal surface direction of the seed crystal substrate, but around an outer end of the nitride semiconductor crystal grown in the principal surface direction, there is included no nitride semiconductor crystal grown in a face direction tilted from the principal surface, and having a higher impurity concentration than the nitride semiconductor crystal grown in the principal surface direction, or
• even when there is included the nitride semiconductor crystal having the higher impurity concentration around the outer end, a growth thickness of the nitride semiconductor crystal having the higher impurity concentration around the outer end is less than one tenth of a growth thickness of the nitride semiconductor crystal grown in the principal surface direction.