The influence of crucible and crystal rotation on the sapphire single crystal growth interface shape in a resistance heated Czochralski system

Sapphire single crystals growth by the Czochralski (CZ) method usually have a high dislocation density caused in large part by convexity of the crystal growth interface its thermal gradient. In order to address these issues, we focus on the influence of crucible and crystal rotation on the crystal growth interface shape and thermal gradient in a resistance heating CZ system. Compared to a configuration with no crystal or crucible rotation, rotating both the crystal and crucible in the same direction will result in lower thermal gradient variation with radial location, but a higher convexity. On other hand, rotating the crystal and crucible in opposite directions will result in both lower thermal gradient variation with radial location and a lower convexity.