| abstract |
Provided is a freestanding GaN crystal substrate that is electrically conductive and emits very little yellow light from all surfaces, and a method for manufacturing the same. The present freestanding GaN crystal substrate grown by HVPE, has a (0001) face, and a {10-11} face and/or a {11-22} face existing together as crystal growth surfaces excluding crystal side surfaces, wherein the (0001) face growth crystal region has a carbon concentration of no more than 5x10 16 at/cm 3 , a silicon concentration of at least 5 x 10 17 silicon at/cm 3 and no more than 2 x 10 18 at/cm 3 , and an oxygen concentration of no more than 1 x 10 17 at/cm 3 , and in a faceted crystal region with at least a {10-11} face and/or a {11-22} face as a growth face, carbon concentration is no more than 3 x 10 16 at/cm 3 , silicon concentration is no more than 5 x 10 17 at/cm 3 , and oxygen concentration is at least 5 x 10 17 at/cm 3 and no more than 5 x 10 18 at/cm 3 . |