Patent ID: 7922817

Claim:
A feed assembly for feeding a dopant to a silicon melt in a crystal growing apparatus comprising: a vessel for holding and releasing a dopant solid material; an elongate feed tube operatively connected to the vessel, said feed tube comprising a fixed tube and a movable tube concentrically arranged with the fixed tube; and an actuator connected to said moveable tube for moving the moveable tube relative to the fixed tube for advancing the moveable tube toward an upper surface of the silicon melt in the apparatus and retracting the moveable tube away from the upper surface of the silicon melt to selectively position the moveable tube for introducing the dopant material released from the vessel to the silicon melt when the feed assembly is mounted on the crystal growing apparatus, the actuator comprising a linear translator attached to the moveable tube, the linear translator comprising a magnet fixed to the moveable tube and a slide magnetically coupled with and adjacent the magnet, the magnet and moveable tube being configured to move in response to movement of the slide.