Abstract
The ammonothermal method, which uses supercritical ammonia fluid instead of supercritical water in the cases of hydrothermal growths of quarts and ZnO, is one of the promising techniques for a mass-production of GaN wafers. Especially, recently, bulk GaN crystal growth by the ammonothermal method is reported from several research laboratories. The expectation for practical use of it becomes higher. In this report, element technologies of the ammonothermal method, development situation in the world and recent results of Tohoku University are introduced.
