Morphological study on non-seeded grown AlN single crystals

The growth of AlN single crystals of large size and good quality is of prime importance for UV LEDs and power devices applications. However, the crystals having the size of more than 1 inch and high quality have not been reported in the world. In the PVT growth of AlN, the crystal morphology of as grown were important because the preferred orientation of growth of it was evaluated for growth rate increase. In the present study, the AlN single crystals grown by PVT process were evaluated by the side of the growth morphology. Optical microscopic characterization was carried out to observe the shape of the crystals and the growth facets. Furthermore the growth habit of it were discussed by observation of the surface of AlN crystals.