Patent ID: 8721786
Filing Date: 2014-05-13
Classification: C30B,Y10T

Abstract:
1. A Czochralski (“CZ”) crystal growth furnace comprising: a base; a heater capable of generating a generally annular shaped heating zone, coupled to the base; a pedestal moveable relative to the heating zone; a crucible within the heating zone and coupled to the pedestal, capable of retaining a volume of molten crystal growth material forming a melt line oriented in a designated position within the heating zone; a seed growth rod retractable from the crucible, for forming a crystal boule thereon proximal the melt line from the molten crystal growth material, the melt line lowering within the crucible as the boule grows and is retracted; a gantry coupling the pedestal and the seed growth rod in a fixed orientation relative to each other wherein the crucible is located between the seed growth rod and the pedestal and wherein movement of the gantry causes the seed growth rod and pedestal to move in tandem; a gantry motion driver coupled to the gantry and the base for moving the gantry; a boule weight sensor for sensing boule weight; and a gantry controller coupled to the boule weight sensor and the gantry motion driver, for causing movement of the gantry and thus pedestal movement relative to the heater based at least in part on sensed boule weight, so that the melt line maintains the designated position during boule growth.