Patent attributes
In silicon single crystal growth by the Czochralski method using a quartz crucible, a silicon single crystals with a uniform distribution of oxygen concentration can be produced in high yield without being affected by changes of crystal diameter and initial amount of melt feedstock. The oxygen concentration is adjusted by estimating oxygen concentration during growth on the basis of a relationship among three parameters: crucible rotation rate (Ω), crucible temperature (T), and the ratio (β) of contact area of molten silicon with the inner wall of the crucible and with atmospheric gas, and by associating the temperature (T) with the ratio (β) by the function 1/β×Exp(−E/T) where E is the dissolution energy (E) of quartz into molten silicon to control at least one of the rotation rate (Ω) and temperature (T) to conform the estimated oxygen concentration to a target concentration.
