Shin-etsu Handotai Co., Ltd.

Shin-estu Handotai Co., Ltd.

Tomohiro Kakegawa

Atsushi Ozaki

Masahiko Urano

Hideki Nakano

Yoshihiro Hirano

Nobuo Katsuoka

Isamu Harada

An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt. These operations are automatically performed.

Method for adjusting initial position of melt surface

An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt These operations are automatically performed.

Apparatus for adjusting initial position of melt surface

A crystal pulling apparatus is disclosed which employs the Czochralski method. The crystal pulling apparatus is operated while a heater for heating a material melt in a crucible is controlled by the main controller of a main system. When maintenance of a heating state is disabled for some reason, a relay of a signal changeover circuit is switched so as to maintain the heating state under control of the backup controller of a backup system, thereby maintaining the material melt in a molten state. Thus, even when it becomes impossible for the main system to heat the material melt within the crucible, the material melt can be prevented from becoming solidified.

Crystal pulling apparatus

An apparatus is used in the production of a monocrystalline rod by Czochralski method and is adapted for measuring the diameter of the monocrystalline rod at the melt surface of the melt by processing image signal derived from an image sensor. The measurement of the diameter is conducted by determining the diameter of the monocrystalline rod at the melt surface by processing the output signal from the image sensor, and multiplying the rod image diameter with a function of the difference between the initial melt surface level and a melt surface corrected in accordance with a change in the temperature in the apparatus chamber or a change in the leval of the electrical power supplied to a heater for heating a crucible.

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Tomioka, Japan

Tomohiro Kakegawa