Method of producing silicon single crystal
AssigneesOsaka Titanium Co., Ltd., Kyushu Electronic Metal Co., Ltd.
InventorsKaoru Kuramochi, Makoto Ito, Kiichiro Kitaura
Life of this patent
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Abstract
A method of producing a silicon single crystal, in which a cylindrical partition is immersed in a molten pure silicon liquid or molten silicon liquid containing a Sb dopant within a crucible and the molten liquid inside the partition is pulled up from the crucible to produce the silicon single crystal, wherein an interval between a lower end of the partition and a crucible bottom is changed to control an oxygen concentration in the pulling-up silicon single crystal. The interval is reduced in the case where the oxygen concentration in the pulling-up silicon single crystal is to be increased while the interval is increased in the case where the oxygen concentration is to be reduced.
Claims18
A method of producing a silicon single crystal, comprising the steps of:
- pulling up a silicon single crystal from a molten silicon liquid in a crucible, the silicon single crystal being pulled up at a position located inside a cylindrical partition immersed in the molten silicon liquid, the partition being immovably fixed relative to the crucible so as to provide a set interval through which molten silicon flows from outside to inside the partition, the interval extending between a lower end of said partition and a bottom of said crucible;
- and
- adjusting the interval at a set distance prior to the pulling-up step so as to control an oxygen concentration in the silicon single crystal pulled-up from the melt.
A method of producing a silicon single crystal, comprising the steps of:
- pulling up a silicon single crystal from a molten silicon liquid containing antimony as a dopant in a crucible, the silicon single crystal being pulled up at a position located inside a cylindrical partition immersed in the molten silicon liquid, the partition having a thickness of 5 to 20 mm and being immovably fixed relative to the crucible so as to provide a set interval through which molten silicon flows from outside to inside the partition, the interval extending between a lower end of said partition and a bottom of said crucible;
- adjusting the interval at a set distance prior to the pulling-up step so as to control an oxygen concentration in the silicon single crystal pulled up from the melt;
- and
- controlling a rate of evaporation of Sb.sub.2 O.sub.3 by adjusting the temperature of the molten liquid inside the partition, whereby the silicon single crystal has an oxygen concentration of greater than 15.times.10.sup.17 atoms/cm.sup.3.
Dependencies are inferred from the claim text.