Method for producing a silicon single crystal

Patent metadata

Field	Value
Publication number	US-9410262-B2
Application number	US-201313969818-A
Country	US
Kind code	B2
Filing date	Aug 19, 2013
Priority date	Sep 4, 2012
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A silicon single crystal is produced by a method wherein
a silicon plate is inductively heated; granular silicon is melted on the silicon plate; and the molten silicon thus produced flows through a flow conduit in the center of the plate to a phase boundary at which a silicon single crystal crystallizes, wherein a silicon ring having a lower resistivity than the plate, and lying on the plate, is inductively heated prior to inductively heating the plate, and melting the ring.

First claim

What is claimed is:

1. A method for producing a silicon single crystal, comprising
inductively heating a silicon plate having an outer diameter;
melting granular silicon on the silicon plate; and
feeding molten silicon through a flow conduit having an inner diameter and located in the center of the plate, to a phase boundary, crystallizing molten silicon at the phase boundary to form a silicon single crystal, wherein
a silicon ring lying on the plate and having a lower resistivity than the plate and having an inner and an outer diameter is inductively heated before inductively heating the plate, and
melting the ring.

2. The method of claim 1 , wherein the ring has a resistivity of not more than 80 mΩcm.

3. The method of claim 1 , wherein the plate has a resistivity of not less than 1 Ωcm.

4. The method of claim 2 , wherein the plate has a resistivity of not less than 1 Ωcm.

5. The method of claim 1 , wherein the outer diameter of the ring is less than the outer diameter of the plate.

6. The method of claim 2 , wherein the outer diameter of the ring is less than the outer diameter of the plate.

7. The method of claim 3 , wherein the outer diameter of the ring is less than the outer diameter of the plate.

8. The method of claim 4 , wherein the outer diameter of the ring is less than the outer diameter of the plate.

9. The method of claim 1 , wherein the inner diameter of the ring is the same as the inner diameter of the flow conduit.

10. The method of claim 2 , wherein the inner diameter of the ring is the same as the inner diameter of the flow conduit.

11. The method of claim 3 , wherein the inner diameter of the ring is the same as the inner diameter of the flow conduit.

12. The method of claim 5 , wherein the inner diameter of the ring is the same as the inner diameter of the flow conduit.

13. The method of claim 1 , wherein the thickness of the ring is less than the thickness of the plate.

14. The method of claim 2 , wherein the thickness of the ring is less than the thickness of the plate.

15. The method of claim 3 , wherein the thickness of the ring is less than the thickness of the plate.

16. The method of claim 5 , wherein the thickness of the ring is less than the thickness of the plate.

17. The method of claim 9 , wherein the thickness of the ring is less than the thickness of the plate.

Assignees

• Siltronic Ag

Inventors

• Lobmeyer Josef
• Brenninger Georg
• Stein Waldemar

Classifications

• C30B13/20 Primary

  by induction, e.g. hot wire technique (C30B13/18 takes precedence) · CPC title

• C30B13/10

  with addition of doping materials · CPC title

• C30B13/08

  adding crystallising materials or reactants forming it in situ to the molten zone · CPC title

• C30B29/06 Primary

  Silicon · CPC title

• C30B13/16

  Heating of the molten zone · CPC title