For the special usage, the effort of developing AlN single crystals has been very hot in the world. The AlNbaseUV LEDs are used on the field of sterilization, purification, curing and analyzing, which can advance human’s livingand medical processes etc.. AlN single crystals were grown by the PVT (Physical vapor transport) method. On the growingprocess, carbon crucibles with three different types such as normal size, taller than normal and wider than normal wereused for comparison. The processing temperature was in the range of 1900~2100oC and ambient pressure was 200~1 Torr.
When the taller crucible was used, the sublimation mass was greater than normal dimension one but the best condition ofgrowth changes widely. However the wider one gave much sublimation mass and growing condition was more stable thannormal dimension. On limited growing furnace system, the changes of crucible dimension of PVT method provide thechange of best condition for growth rate, as-grown crystal quality and growth condition stability.