Crystal growing systems and crucibles for enhancing heat transfer to a melt

Abstract

A system for growing an ingot from a melt includes an outer crucible, an inner crucible, and a weir. The outer crucible includes a first sidewall and a first base. The first sidewall and the first base define an outer cavity for containing the melt. The inner crucible is located within the outer cavity, and has a central longitudinal axis. The inner crucible includes a second sidewall and a second base having an opening therein.

What is claimed is: 
     
         1 . A system for growing an ingot from a melt, the system comprising:
 an outer crucible defining an outer cavity for containing the melt;   an inner crucible located within the outer cavity, the inner crucible having a central longitudinal axis, the inner crucible including a second sidewall and a second base extending radially inward from the second sidewall and having an opening therein, the opening in the second base, the second crucible, and the outer crucible concentric with the central longitudinal axis; and   a first, annular weir separating the outer crucible from the inner crucible, the first weir separate from the inner crucible and the outer crucible.   
     
     
         2 . The system of  claim 1 , wherein the opening has a first diameter, the first weir has a second diameter, the second sidewall has a third diameter, the third diameter being greater than the first and second diameters. 
     
     
         3 . The system of  claim 1 , wherein the opening is defined by an annular rim tapered with respect to the central longitudinal axis, the rim being substantially aligned with the first weir. 
     
     
         4 . The system of  claim 1 , wherein the first weir has a plurality of first weir passageways extending therethrough to permit the melt to flow between an outer melt zone and an inner melt zone. 
     
     
         5 . The system of  claim 4 , further comprising a second, annular weir positioned radially outward from the first weir and supporting the inner crucible along the second base, the second weir having a plurality of second weir passageways extending therethrough. 
     
     
         6 . The system of  claim 5 , wherein the first weir passageways and the second weir passageways are diametrically opposed from one another to provide a circuitous path for the melt. 
     
     
         7 . The system of  claim 1 , further comprising a shaft for supporting the inner and outer crucibles, and a heater disposed radially outward from the shaft. 
     
     
         8 . The system of  claim 1 , further comprising a heater disposed below the first base of the outer crucible and radially inward from the first sidewall of the outer crucible. 
     
     
         9 . A system for growing an ingot from a melt, the system comprising:
 an outer crucible defining an outer cavity for containing the melt;   an inner crucible located within the outer cavity, the inner crucible including a second sidewall and a second base extending radially inward from the second sidewall and having an opening therein, the opening having a first cross-sectional area;   a first, annular weir separating the outer crucible from the inner crucible, the first weir having a second cross-sectional area, wherein a ratio between the first cross-sectional area and the second cross-sectional is at least about 0.25, the first weir being separate from the inner crucible and the outer crucible; and   a heat reflector disposed on top of the inner and outer crucibles, the heat reflector configured to prevent a flow of gas from the outer crucible to the inner crucible.   
     
     
         10 . The system of  claim 9 , wherein the second sidewall and the second base define an inner cavity, the opening in the second base sized to facilitate heat transfer from the outer cavity to the inner cavity. 
     
     
         11 . The system of  claim 9 , wherein the opening has a first diameter, the first weir has a second diameter, and the ratio between the first diameter and the second diameter is at least about 0.5. 
     
     
         12 . The system of  claim 11 , wherein the first weir has a first weir passageway extending therethrough to permit the melt to flow between an outer melt zone and an inner melt zone. 
     
     
         13 . The system of  claim 12 , further comprising a second, annular weir positioned radially outward from the first weir, the second weir having a second weir passageway extending therethrough. 
     
     
         14 . The system of  claim 13 , wherein the first weir passageway and the second weir passageway are diametrically opposed from one another to provide a circuitous path for the melt. 
     
     
         15 . The system of  claim 11 , further comprising a shaft for supporting the inner and outer crucibles, and a heater disposed radially outward from the shaft. 
     
     
         16 . A system for growing an ingot from a melt, the system comprising:
 an outer crucible;   an inner crucible located within the outer crucible, the inner crucible including a second sidewall and a second base extending radially inward from the second sidewall and having an opening therein, the opening has a first diameter and the second sidewall has a third diameter;   a first, annular weir separate from the inner crucible and the outer crucible, the first weir has a second diameter less than the third diameter and greater than the first diameter; and   a second, annular weir separate from the inner crucible and the outer crucible and having a fourth diameter less than the third diameter and greater than the second diameter, at least one of the first weir or second weir separating the outer crucible from the inner crucible.   
     
     
         17 . The system of  claim 16  further comprising a third, annular weir separate from the inner crucible and the outer crucible and having a fifth diameter less than the third diameter and greater than the third diameter. 
     
     
         18 . The system of  claim 17 , wherein the inner crucible has a central longitudinal axis, and the opening in the second base, the inner crucible, the outer crucible, the first weir, the second weir, and the third weir are concentric with the central longitudinal axis. 
     
     
         19 . The system of  claim 16 , wherein the ratio between the first diameter and the second diameter is at least about 0.5. 
     
     
         20 . The system of  claim 17 , wherein the first weir has a first weir passageway extending therethrough, the second weir has a second weir passageway extending therethrough, the third weir has a third weir passageway extending therethrough, at least two of the first weir passageway, the second weir passageway, and the third weir passageway being diametrically opposed from one another.