Growth and crystallinity of shaped and multiple sapphire crystals by a micro-pulling-down method

We developed a growth technique of shape-controlled and multiple crystals by a micro-pulling-down (mu-PD) method using a developed special configuration crucible. A square tube-shaped sapphire crystal was grown with a molybdenum crucible with square tube die of 4 mm x 4 mm outer periphery and 2 mm x 2 mm inner periphery on the bottom. In contrast, six multiple square-shaped sapphire crystals were simultaneously grown by a molybdenum crucible with six circularly arranged square-shaped dies with a size of 2 x 2 mm(2) on the bottom. Growth of six multiple square-shaped sapphire crystals indicated a single phase alpha-Al2O3 a and almost same lattice parameters by X-ray diffraction measurement. Crystallinities of the six crystals were high in all positions of crystals comparable to the crystals grown by the Czochralski method. (C) 2010 Elsevier B.V. All rights reserved.