CARBON ELECTRODE AND APPARATUS FOR MANUFACTURING POLYCRYSTALLINE SILICON ROD

• US 20120222619A1
• Filed: 10/22/2010
• Published: 09/06/2012
• Est. Priority Date: 11/26/2009
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Netsu, Shigeyoshi, Kurotani, Shinichi, Kume, Fumitaka, Oguro, Kyoji, Hirahara, Masaru
• Granted Patent: US 9,562,289 B2
• Time in Patent Office: Days
• US Class Current: 118/723.R
• CPC Class Codes: C01B 32/225 Expansion; Exfoliation
• CPC Class Codes: C01B 33/035 by decomposition or reduction of gaseous or vaporised silicon compounds in the presence of heated filaments of silicon, carbon or a refractory metal, e.g. tantalum or tungsten, or in the presence of heated silicon rods on which the formed silicon is deposited, a silicon rod being obtained, e.g. Siemens process
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/458 characterised by the method used for supporting substrates in the reaction chamber

Abstract

The upper electrode 31 has a hole 35 extending from an upper surface 33 to a lower surface 34, a bolt 36 is inserted from the upper surface 33 of the upper electrode 31 into the hole 35, and secured in a lower electrode 32 by a screw. A gap 51 between an inside of the hole 35 and a straight body portion of the bolt 36 allows the upper electrode 31 to slide in all directions in a placement surface (upper surface of the lower electrode 32 in contact with the lower surface 34 of the upper electrode 31 in FIG. 2) that is a contact surface with an upper surface of the lower electrode 32, thereby providing an effect of preventing occurrence of a crack or a break in a U rod that can be expanded and contracted in all directions during a vapor phase growth process.

Claims

1. A carbon electrode comprising:

a lower electrode secured on a metal electrode that is an external electrode for electrifying a silicon core; and

an upper electrode located on the lower electrode, and comprising a securing portion of a core holder that holds the silicon core on an upper surface side,

wherein the upper electrode is slidable in all directions in a placement surface that is a contact surface with an upper surface of the lower electrode.

2. The carbon electrode according to claim 1, wherein the upper electrode comprises a hole extending from an upper surface to a lower surface, a lower end of a rod-shaped fastening member inserted into the hole is secured to the lower electrode, a diameter of the hole is larger than a diameter of a straight body portion of the rod-shaped fastening member, and a gap is located between an inside of the hole and the straight body portion.

3. The carbon electrode according to claim 2, wherein the diameter of the hole is at least 1 mm larger than the diameter of the straight body portion.

4. The carbon electrode according to claim 1, wherein the upper electrode is located on the lower electrode so that a protrusion located in an upper part of the lower electrode is inserted into a recess located in a lower part of the upper electrode, an inner size of the recess is larger than an outer size of the protrusion, and a gap is located between the recess and the protrusion.

5. The carbon electrode according to claim 1, wherein the upper electrode is located on the lower electrode so that a protrusion located in a lower part of the upper electrode is inserted into a recess located in an upper part of the lower electrode, an inner size of the recess is larger than an outer size of the protrusion, and a gap is located between the recess and the protrusion.

6. The carbon electrode according to claim 4, wherein the gap between the recess and the protrusion is 1 mm or more.

7. The carbon electrode according to claim 1, wherein the upper electrode and the lower electrode comprise graphite.

8. The carbon electrode according to claim 1, wherein a coefficient of static friction of the contact surface between the upper electrode and the lower electrode is 0.3 or less.

9. An apparatus comprising a pair of metal electrodes, wherein electric power is supplied from the pair of metal electrodes to opposite ends of a silicon core assembled into an inverted U-shape to grow polycrystalline silicon from vapor phase on the silicon core,

wherein both opposite ends of the silicon core assembled into the inverted U-shape are respectively held by securing portions provided in carbon electrodes, and at least one of the carbon electrodes is the carbon electrode according to claim 1.

10. The carbon electrode according to claim 5, wherein the gap between the recess and the protrusion is 1 mm or more.

11. The carbon electrode according to claim 2, wherein the upper electrode and the lower electrode comprise graphite.

12. The carbon electrode according to claim 4, wherein the upper electrode and the lower electrode comprise graphite.

13. The carbon electrode according to claim 5, wherein the upper electrode and the lower electrode comprise graphite.

14. The carbon electrode according to claim 2, wherein a coefficient of static friction of the contact surface between the upper electrode and the lower electrode is 0.3 or less.

15. The carbon electrode according to claim 4, wherein a coefficient of static friction of the contact surface between the upper electrode and the lower electrode is 0.3 or less.

16. The carbon electrode according to claim 5, wherein a coefficient of static friction of the contact surface between the upper electrode and the lower electrode is 0.3 or less.

17. An apparatus comprising a pair of metal electrodes, wherein electric power is supplied from the pair of metal electrodes to opposite ends of a silicon core assembled into an inverted U-shape to grow polycrystalline silicon from vapor phase on the silicon core,

wherein both opposite ends of the silicon core assembled into the inverted U-shape are respectively held by securing portions provided in carbon electrodes, and at least one of the carbon electrodes is the carbon electrode according to claim 2.

18. An apparatus comprising a pair of metal electrodes, wherein electric power is supplied from the pair of metal electrodes to opposite ends of a silicon core assembled into an inverted U-shape to grow polycrystalline silicon from vapor phase on the silicon core,

wherein both opposite ends of the silicon core assembled into the inverted U-shape are respectively held by securing portions provided in carbon electrodes, and at least one of the carbon electrodes is the carbon electrode according to claim 4.

19. An apparatus comprising a pair of metal electrodes, wherein electric power is supplied from the pair of metal electrodes to opposite ends of a silicon core assembled into an inverted U-shape to grow polycrystalline silicon from vapor phase on the silicon core,

wherein both opposite ends of the silicon core assembled into the inverted U-shape are respectively held by securing portions provided in carbon electrodes, and at least one of the carbon electrodes is the carbon electrode according to claim 5.

20. The carbon electrode according to claim 3, wherein:

the upper electrode and the lower electrode comprise graphite; and

a coefficient of static friction of the contact surface between the upper electrode and the lower electrode is 0.3 or less.