Patent ID: 9611564
Date: 2017-04-04
CPC Classifications: C30B

Claim:
1. A method for growing nitride bulk single crystal, characterized by comprising the following steps: A. arranging a crystal pre-growth chamber, a crystal growth chamber and a valve located between the abovementioned two chambers, placing a seed crystal in the crystal growth chamber, and switching off the valve between the abovementioned two chambers; B. introducing raw materials in the crystal pre-growth chamber; when the raw materials are dissolved to meet the stable oversaturation conditions required by the growth, switching on the valve between the crystal pre-growth chamber and the crystal growth chamber; and C. entering the raw material solution in the stable oversaturation state into the crystal growth chamber and starting crystal growth; wherein the flow process of the raw material solution in the stable oversaturation state comprises: in the crystal growth process, regulating the pressure difference between the crystal pre-growth chamber and the crystal growth chamber, thereby regulating the liquid level difference between the two chambers so as to adjust the surface of the seed crystal to the liquid level difference Δh, restricting the distance Δh from the melt liquidus surface in the crystal growth chamber to the upper surface of the seed crystal meet with the diffusion free path of N ions at the growth conditions; after the crystal growth is completed, regulating the pressure difference between the crystal pre-growth chamber and the crystal growth chamber to force the raw material solution in the crystal growth to flow back to the crystal pre-growth chamber; and so, when the liquid level of the raw material solution is lower than the upper surface of the bulk single crystal material, the contact between the surface of the nitride bulk single crystal and the raw material solution is terminated.