Patent ID: 7604696
Filing Date: 2009-10-20
Classification: C30B

Abstract:
1. A method of making a solar grade silicon wafer, said method comprising the steps of: providing a ceramic solar grade wafer mold that has a porosity that is greater than zero; providing a mixture that includes a suspending medium, a suspended binding agent, and a suspended pore-occluding agent; treating said ceramic solar grade wafer mold with said mixture to produce a ceramic solar grade wafer mold having a reduced porosity; providing a slurry including a liquid that essentially prevents the oxidation of silicon powder and a silicon powder that is essentially free of oxides; introducing said slurry into said ceramic solar grade wafer mold having a reduced porosity; precipitating said silicon powder from said slurry to form a preform of said solar grade silicon wafer; and crystallizing said preform to make said solar grade silicon wafer.