Silicon single crystal growth method and apparatus

Patent metadata

Field	Value
Publication number	US-2021372002-A1
Application number	US-201916959852-A
Country	US
Kind code	A1
Filing date	Jan 18, 2019
Priority date	Jan 19, 2018
Publication date	Dec 2, 2021
Grant date	—

Abstract

An embodiment provides a silicon single crystal growth method comprising the steps of: (a) allowing the shoulder of a single crystal to grow vertically; (b) allowing the shoulder to grow horizontally after the vertical growth; and (c) allowing the shoulder to grow in a downward convex shape after the horizontal growth of the shoulder, wherein the shoulder grows at a preset rate on the basis of the final diameter of the shoulder and the shoulder growth height according to steps (b) and (c).

First claim

1 . A silicon single crystal growth method comprising steps of:
(a) allowing a shoulder of a single crystal to grow vertically; (b) allowing the shoulder to grow horizontally after the vertical growth; and (c) allowing the shoulder to grow in a downwardly convex shape after the horizontal growth of the shoulder, wherein the shoulder grows to realize a preset ratio between a final diameter of the shoulder and a growth height of the shoulder according to the steps (b) and (c).

2 . The silicon single crystal growth method according to claim 1 , wherein:
in the step (a), the shoulder grows at a first puling speed; and in the steps (b) and (c), the shoulder grows at a second pulling speed.

3 . The silicon single crystal growth method according to claim 2 , wherein the first pulling speed is an average pulling speed at which the shoulder reaches 70% of a final height of the shoulder.

4 . The silicon single crystal growth method according to claim 3 , wherein the second pulling speed is 1.125-1.375 times the first pulling speed.

5 . The silicon single crystal growth method according to claim 1 , wherein a height of the shoulder grown in the step (b) is greater than a height of the shoulder grown in the step (c).

6 . The silicon single crystal growth method according to claim 1 , wherein a ratio of a height of the shoulder grown in the step (b) to the final diameter of the shoulder is 0.3 or more.

7 . The silicon single crystal growth method according to claim 1 , wherein a height of the shoulder grown in the step (b) is 90 mm or more.

8 . A silicon single crystal growth apparatus comprising:
a crucible configured to receive a silicon melt; a pulling unit configured to pull a single crystal from the silicon melt received in the crucible; and a controller configured to control a pulling speed of the single crystal, wherein the controller controls the pulling unit such that: a shoulder of the single crystal grows vertically; the shoulder grows horizontally after the vertical growth; and the shoulder grows in a downwardly convex shape after the horizontal growth of the shoulder.

9 . The silicon single crystal growth apparatus according to claim 8 , wherein the controller controls the pulling speed of the single crystal using the pulling unit such that a final diameter of the shoulder and a height of the shoulder from a horizontal growth starting portion of the shoulder up to a point in time of growth completion of the shoulder realize a preset ratio therebetween.

Assignees

• Sk Siltron Co Ltd

Inventors

• Kang Jong Min
• Choi Ii Soo

Classifications

• C30B15/203 Primary

  the relationship of pull rate (v) to axial thermal gradient (G) · CPC title

• C30B29/06

  Silicon · CPC title

• C30B15/22 Primary

  Stabilisation or shape controlling of the molten zone near the pulled crystal; Controlling the section of the crystal · CPC title

• C30B15/10

  Crucibles or containers for supporting the melt · CPC title

• C30B15/36

  characterised by the seed, e.g. its crystallographic orientation · CPC title