LPE growth of AlN single crystal using cold crucible under atmospheric nitrogen gas pressure

We have grown AlN single crystal on 6H-SiC substrate using Al-Cu solution of 1500-1600 °C. Nitrogen is supplied from gas phase under atmospheric pressure and the cold crucible technique is applied. Thickness of AlN reached 40 μm with the growth rate of 10 μm/h. Rather high growth rate in solution method is due to the increase in the melt surface area, dynamic convection of the melt and high temperature gradient along the seeded axis, which are easily realized in cold crucible technique. TEM observation reveals that the dislocation density beyond 10μm from the interface decreases by a factor of 10 to the power of -1 or -2. The melt included in between the substrate and AlN epi-layer eases stress in epi-layer and reduces cracks.