Patent ID: 9677192
Date: 2017-06-13
CPC Classifications: C30B

Claim:
1. A group 13 nitride crystal substrate produced by growing a group 13 nitride crystal on a seed-crystal substrate in a melt containing a group 13 metal and an Na flux in the presence of a nitrogen-containing gas, wherein a content of inclusions in the group 13 nitride crystal grown in a region of the seed-crystal substrate except for a circumferential portion of the seed-crystal substrate, the region having an area fraction of 70% relative to an entire the seed-crystal substrate, is 5% or less, wherein the inclusions at least contain the flux, wherein the content of inclusions is an area fraction of a black portion of a binarized image obtained by binarizing a photograph of a polished surface of the substrate, the group 13 nitride crystal substrate having as dislocation density of 10