Patent ID: 8535442

Claim:
A crystal growth system, for growing a crystalline material, said crystal growth system comprising: a furnace system containing at least a high-temperature melting zone and a sub-high temperature crystal growth zone, wherein said sub-high temperature zone has a temperature growth gradient transition range including a liquidus/solidus temperature transition of said crystalline material; a melting crucible in said high-temperature melting zone containing a melted batch melt of said crystalline material; a crystal growth crucible in said sub-high temperature zone; a melt conduit extending from said melting crucible to said crystal growth crucible for a transferring said melted batch melt; control means for controlling a growth rate of said crystalline material in said crystal growth crucible; positioning means in said control means for moving at least said crystal growth crucible relative to said sub-high temperature zone to maintain said growth rate and said temperature growth gradient transition range relative to a growth of said crystalline material during a use of said system; and at least one of a thermal valve means in said control means for thermally controlling said transfer of said melted batch along said melt conduit and a fluid control means in said control means for fluidly controlling said transfer of said melted batch along said melt conduit, whereby said at least one of said thermal valve means and said fluid control means enables an improved composition control; wherein said thermal valve means further comprises at least one as transfer conduit in close association with said melt conduit along a thermal valve region thereon enabling a thermal transfer there between, and gas flow control means for regulating a rate of gas transfer through said gas transfer conduit at said thermal valve region relative to said growth rate controlled by said means for controlling said growth rate, wherein said rate of gas transfer being sufficient to cool said thermal valve region of said melt conduit and solidify said melted batch in said melt conduit thereby ending said transfer of said melt independently of a level of said melted batch melt of said crystalline material in said melting crucible.