Patent ID: 8475593
Filing Date: 2013-07-02
Classification: C30B,Y10T

Abstract:
1. A crystal preparing method which produces a group III nitride crystal using a crystal preparing device, the crystal preparing device including a crucible holding a mixed molten metal containing alkali metal and group III metal, a reaction container having a container space which contacts the mixed molten metal and holding a molten alkali metal between the container space and an outside of the container, the molten alkali metal contacting the container space, and a piping disposed below the crucible and connected with the reaction container, the crystal preparing method comprising: a first step of placing the alkali metal and the group III metal into the crucible in an inert gas or nitrogen gas atmosphere; a second step of placing the alkali metal into the piping in the inert gas or nitrogen gas atmosphere; a third step of filling the container space of the reaction container with nitrogen gas; a fourth step of heating the crucible to a crystal growth temperature; a fifth step of heating the molten alkali metal at a specific temperature at which a vapor pressure of the alkali metal which evaporates from the molten alkali metal is substantially equal to a second vapor pressure of the alkali metal which evaporates from the mixed molten metal; and a sixth step of holding a temperature of the crucible to the crystal growth temperature, and holding a temperature of the molten alkali metal to the specific temperature for a predetermined time.