Patent ID: 8303924
Filing Date: 2012-11-06
Classification: C30B,Y10T

Abstract:
1. A method for producing a bulk AlN single crystal, the method which comprises: providing an outer growing crucible and an inner growing crucible inside said outer growing crucible, and a crucible lid for the inner and outer growing crucibles, with a gap formed between the inner growing crucible and the crucible lid, the outer growing crucible having a crucible bottom opposite from the crucible lid, and the inner growing crucible having a lateral crucible inner wall and a crystal growth region; placing a monocrystalline AlN seed crystal having a central longitudinal mid-axis in the crystal growth region of the growing crucible; growing the bulk AlN single crystal in a growth direction oriented substantially parallel to the lateral crucible inner wall and parallel to the longitudinal mid-axis by deposition on the AlN seed crystal; maintaining a free space between both AlN crystals and the lateral crucible inner wall; allowing some of the AlN growth gas phase generated inside the crystal growth region for growing the bulk AlN single crystal to escape through the gap between the inner growing crucible and the crucible lid, and depositing on the crucible bottom of the outer growing crucible; and setting up a radial temperature profile inside the crystal growth region, perpendicularly to the growth direction, the radial temperature profile having a central temperature in a region of the longitudinal mid-axis at most 5 K higher than an edge temperature on an edge of the AlN seed crystal or the growing bulk AlN single crystal.