Patent ID: 7520932

Claim:
A method of analyzing carbon concentration in crystalline silicon, said method comprising the steps of: providing a zoned and annealed silicon core extracted from a polycrystalline silicon composition with the zoned and annealed silicon core having a columnar shape and including a single crystalline silicon region and a freeze-out melt region with the freeze-out melt region disposed adjacent to the single crystalline silicon region and with the regions spaced along a length of the columnar shape; removing a section from the zoned and annealed silicon core perpendicular to the length of the columnar shape; determining carbon concentration of the section; optionally, determining a weight of the section; optionally, determining a weight of the single crystalline silicon region; optionally, determining carbon concentration of the single crystalline silicon region based on the carbon concentration of the section, the weight of the section, the weight of the single crystalline silicon region, and an effective segregation coefficient; optionally, determining carbon concentration of the polycrystalline silicon composition based on the carbon concentration of the single crystalline silicon region; wherein the step of removing the section is further defined as removing the section from the freeze-out melt region with the entire freeze-out melt region in the section to enable determination of carbon concentration in the crystalline silicon with a sensitivity at less than or equal to 10 parts per billion atomic.