Claims
- 1. A silicon oxide exhaust method for guiding a carrier gas, supplied from the top of a pulling chamber for pulling up a monocrystal according to the Czochralski technique, to a surface of a melt of a material for forming a monocrystal and exhausting to the outside of said pulling chamber silicon oxide vaporized from the surface of the melt accommodated in a crucible,
- said silicon oxide exhaust method comprising
- defining by a carrier gas branching means a bottom gap between a circumference of the pulled monocrystal and the surface of said melt and defining a top gap between said crucible and a heat retaining tube provided at the outside of the same,
- defining a first flow path through which said carrier gas flows toward said bottom gap between said carrier gas branching means and pulled monocrystal,
- defining a second flow path comprised of a flow path of the carrier gas passing through said top gap and a flow path of said carrier gas passing from said first flow path through said bottom gap and then passing between the surface of said silicon melt and a flow controller,
- forming the bottom gap and the top gap so that the amount of the carrier gas flowing through said bottom gap becomes greater than the amount of the carrier gas flowing through said top gap, and
- exhausting said silicon oxide together with said carrier gas through said second flow path to the outside of the pulling chamber.
- 2. A silicon oxide exhaust method as set forth in claim 1, wherein
- said crucible is heated by a heating means arranged between said crucible and said heat retaining tube and a gap is formed between said heating means and said heat retaining tube,
- said gap is connected to said second flow path, and said silicon oxide is exhausted together with said carrier gas to the outside of said pulling chamber through said gap.
- 3. A silicon oxide exhaust method as set forth in claims 2, wherein a portion of said top gap is positioned to the inside of the top end of the crucible.
- 4. A silicon oxide exhaust method as set forth in claim 1, wherein
- a diameter of the carrier gas branching means near the surface of the melt solution is constricted and
- an area of the opening of the constricted diameter portion is 1.5 to 2.0 times the sectional area of the pulled monocrystal.
- 5. A silicon oxide exhaust method as set forth in claim 1, wherein a sectional area (Ru) of said top gap is 0.5 to 1.4 times the sectional area (Rd) of the bottom gap.
- 6. A monocrystal pulling method as set forth in claims 1, wherein a relative rotational speed of the crucible or the pulled monocrystal is controlled so as to control the concentration of oxygen included in said monocrystal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-12668 |
Jan 1993 |
JPX |
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Parent Case Info
This application is a divisional of copending application Ser. No. 08/187,551, filed on Jan. 28, 1994, now allowed, the entire contents of which are hereby incorporated by reference.
US Referenced Citations (13)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0191111 |
Aug 1986 |
EPX |
1100087 |
Apr 1989 |
JPX |
1100086 |
Apr 1989 |
JPX |
3275586 |
Dec 1991 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
187551 |
Jan 1994 |
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