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US 2013/0047670 A1Published application
Purification of a Metalloid by Consumable Electrode Vacuum Arc Remelt Process
AssigneeConsarc Corporation
InventorRaymond J. ROBERTS
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Abstract
A metalloid such as silicon in the form of a preheated solid electrode is purified by a CEVAR purification process by producing an ingot with controlled heating and cool down after the preheated electrode is melted in a CEVAR furnace system using a short CEVAR open-bottomed crucible.
Claims14
A method of producing a silicon ingot from a silicon electrode in a CEVAR purification process performed in a short CEVAR open-bottomed crucible disposed in a CEVAR furnace, the method comprising:
- heating the silicon electrode to a temperature below the melting point of the silicon electrode prior to initiation of the CEVAR purification process to form a preheated silicon electrode having a CEVAR process resistivity;
- melting the preheated silicon electrode by the CEVAR purification process for formation of a silicon ingot at an elevated temperature at the open bottom of the short CEVAR opened-bottomed crucible;
- passing the silicon ingot at the elevated temperature through a heating system adjacent to the short CEVAR open-bottomed crucible;
- and
- regulating the heating system to provide a temperature-controlled thermal environment for the silicon ingot at the elevated temperature as the silicon ingot exits the open-bottomed crucible to cool the silicon ingot without cracking
2 more elements
A CEVAR furnace system for producing a purified silicon ingot from a silicon electrode, the CEVAR furnace system comprising:
- a silicon electrode heating apparatus for preheating the silicon electrode to form a preheated silicon electrode;
- a gas-tight CEVAR furnace chamber;
- a short CEVAR open-bottomed crucible for containment of an arc zone from a CEVAR purification process melting the preheated silicon electrode, the short CEVAR open-bottomed crucible disposed in the gas-tight CEVAR furnace chamber;
- a preheated silicon electrode drive system for lowering the preheated silicon electrode within the short CEVAR open-bottomed crucible as the lower end of the preheated silicon electrode melts in the CEVAR purification process;
- an ingot heating apparatus disposed adjacent to the open bottom of the short CEVAR open-bottomed crucible through which the silicon ingot formed in the CEVAR purification process passes;
- an ingot heating controller for controlling the ingot heating apparatus to provide a temperature-controlled thermal environment for the silicon ingot passing through the ingot heating apparatus;
- and
- an ingot withdrawal drive system for alternatively withdrawing the silicon ingot from the short CEVAR open-bottomed crucible at a vertical growth rate of the silicon ingot during steady state of the CEVAR purification process or raising the short CEVAR open-bottomed crucible, the silicon electrode and the ingot heating apparatus at the vertical growth rate of the silicon ingot during steady state of the CEVAR purification process.
5 more elements
Dependencies are inferred from the claim text.