Method and device for feeding arsenic dopant into a silicon crystal growing apparatus

A method for feeding arsenic dopant to a silicon melt in a silicon crystal growing apparatus having a crystal growing chamber comprising the steps of:

• placing granular solid arsenic dopant in a vessel attached to a feed tube, the feed tube comprising a fixed tube and a movable tube in concentric arrangement;
• lowering the moveable tube toward the silicon melt with an actuator connected to the moveable tube to selectively position the moveable tube at the upper surface of the silicon melt;
• and
• releasing the dopant from the vessel to allow dopant to travel down the feed tube and into the melt at the upper surface of the melt.

A method for feeding arsenic dopant to a silicon melt in a silicon crystal growing apparatus having a crystal growing chamber, comprising the steps of:

• placing granular solid arsenic dopant in a vessel attached to a feed tube comprising a fixed tube and a moveable quartz tube having an angled tip, the fixed tube and moveable quartz tube being in concentric arrangement;
• lowering the moveable tube toward the silicon melt with an actuator connected to the moveable tube to selectively position the moveable tube at an upper surface of the silicon melt;
• releasing the dopant from the vessel to allow the dopant to travel down the feed tube to a catch located in the moveable tube for catching the dopant material when it is released from the vessel;
• and
• introducing argon gas into the feed tube below the vessel causing sublimation of the dopant resulting in dopant laden argon exiting the angled tip of the moveable quartz tube at the upper surface of the silicon melt.

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 attached to the vessel comprising a fixed tube and a movable tube concentrically arranged with the fixed tube;
• and
• a catch located within the moveable tube for catching the dopant material when it is released from the vessel.