摘要 |
A large sized bulk crystal is produced which allows to cut out a practical size of crystal substrate. The gallium nitride crystal has features in which a length L of c-axis is 9 mm or more, a crystal diameter d of a cross section orthogonal to the c-axis is 100 µm, and a ratio L/d of the length L of the c-axis and the crystal diameter d of the cross section orthogonal to the c-axis is 7 or more. By enlarging this elongated needle-like crystal, a bulk crystal with a large volume can be produced, and a large sized bulk crystal can be produced which allows to cut out a practical size of crystal substrate. |