III nitride crystal substrate and light-emitting device

摘要

Toward making available III nitride crystal substrates advantageously employed in light-emitting devices, and light-emitting devices incorporating the substrates, a III nitride crystal substrate has a major face whose surface area is not less than 10 cm2 and is characterized by: edge dislocations in the crystal being concentrated along propagation lines forming an angle of some 0° to 5° with a given {0001} plane of the crystal; screw dislocations in the crystal being concentrated along propagation lines forming an angle of some 45° to 60° with the given {0001} plane; and in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density being between 1×104 cm−2 to 3×106 cm−2 inclusive, and the ratio of screw-dislocation density to the total dislocation density being 0.5 or greater.

主权项

1. A Group-III nitride crystal substrate having a major face whose surface area is not less than 10 cm2, the III-nitride crystal substrate characterized by:
edge dislocations in the crystal being concentrated along propagation lines forming an angle of some 0° to 5° with a given {0001} plane of the crystal; screw dislocations in the crystal being concentrated along propagation lines forming an angle of some 45° to 60° with the given {0001} plane; and in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density being between 1×104 cm−2 and 3×106 cm−2 inclusive, and the ratio of screw-dislocation density to the total dislocation density being 0.5 or greater.