Method of manufacturing silicon single crystal, silicon single crystal, and wafer
AssigneeSiltronic AG
InventorsKatsuhiko Nakai, Masamichi Ohkubo
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Abstract
P-type silicon single crystals from which wafers having high resistivity, good radial uniformity of resistivity and less variation in resistivity can be obtained, are manufactured by the Czochralski method from an initial silicon melt in which boron and phosphorus are present, the boron concentration is not higher than 4E14 atoms/cm3 and the ratio of the phosphorus concentration to the boron concentration is not lower than 0.42 and not higher than 0.50.
Claims11
-10. (canceled)
A method for manufacturing a silicon single crystal, comprising growing a p-type silicon single crystal by the Czochralski method from an initial silicon melt in which boron is present in a concentration not higher than 4E14 atoms/cm3, phosphorus is contained in the initial silicon melt, and the ratio of phosphorus concentration to boron concentration is not lower than 0.42 and not higher than 0.50.
A p-type silicon single crystal grown by the Czochralski method from an initial silicon melt to which boron and phosphorus were added, having a resistivity along a central crystal growth axis not lower than 50 Ω·cm and a rate of change in resistivity along said central crystal growth axis not higher than 10%, measured in a constant diameter section of the p-type silicon single crystal up to a point where 80% of the single crystal has been solidified from the silicon melt.
Dependencies are inferred from the claim text.