METHOD AND APPARATUS FOR PULLING SINGLE CRYSTAL

WIPO Patent Application WO/1998/009007

A1

In a conventional method of pulling a large-sized single crystal, an expanded portion and a contracted portion are formed on the lower side of a neck, and the contracted portion is engaged with the single crystal, which is then pulled. During the formation of the contracted portion, the diameter thereof is reduced sharply in a usual case. Even when the diameter of this portion is controlled by using an optical measuring means, a fusion ring on the contracted portion which is hidden behind the expanded portion cannot be observed, so that it is difficult to control the diameter of the crystal. A single crystal pulling apparatus used in this method has a complicated structure and is liable to get out of order at high temperature. According to the present invention, a contracted portion is formed under the condition where the diameter thereof can be measured constantly with an optical measuring means. This method uses a single crystal pulling apparatus which is provided with a pressing means which constitutes a single crystal retaining means, and which is adapted to move a locking portion engaged with a contracted portion of the crystal from a standby position to a contracted portion engaging position.

FUJIWARA HIDEKI (JP)

PCT/JP1997/003015

March 05, 1998

August 29, 1997

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SUMITOMO SITIX CORP (JP)
FUJIWARA HIDEKI (JP)

C30B15/26; C30B15/00; C30B15/22; C30B15/30; (IPC1-7): C30B15/26; C30B15/32; C30B29/06

JPH08225391A	1996-09-03
JPH09183694A	1997-07-15
JPH03285893A	1991-12-17
JPS63252991A	1988-10-20
JPS61122187A	1986-06-10
JPS58135197A	1983-08-11
JPH09249489A	1997-09-22
JPH09202691A	1997-08-05

Iuchi, Ryuji (18-1 Asahi-machi Izumiohtsu-shi, Osaka 595, JP)

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