Single crystal pulling system
AssigneeKabushiki Kaisha Toshiba
InventorsKinya Matsutani, Katsutoki Sasaki
Life of this patent
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Abstract
A single crystal pulling system including a single crystal pulling apparatus, an electromagnet, and an electromagnet moving mechanism, wherein the single crystal pulling apparatus pulls a seed crystal from a single crystal material melt contained in a crucible at a specified constant speed. The electromagnet is disposed at the outer periphery of the crucible so as to apply a predetermined required strength of magnetic field to the crystal-melt interface of the melt. The magnet moving mechanism moves the electromagnet in a vertical direction with respect to the crucible as the level of the crystal-melt interface is lowered during seed growth so that a predetermined required strength of magnetic field is always applied to the crystal-melt interface.
Claims6
A single crystal pulling system comprising:
- a single crystal pulling apparatus;
- an electromagnet;
- a magnet moving mechanism;
- said single crystal pulling apparatus comprising a crucible containing a single crystal material melt, a heater for heating said crucible, and a constant speed pulling mechanism adapted to be coupled to a single crystal at a crystal-melt interface of said melt, said pulling apparatus adapted such that a seed crystal inserted in said melt is pulled from the melt at a specified constant speed by means of said constant speed pulling mechanism;
- said electromagnet disposed at an outer periphery of said crucible so as to apply a predetermined strength of magnetic field to the crystal-melt interface of said melt;
- and
- said magnet moving mechanism comprising means for moving said electromagnet at least in a vertical direction of vertical and horizontal directions with respect to said crucible based on a level of said crystal-melt interface in said crucible;
- wherein said magnet moving mechanism comprises:
- means for detecting a change in level of the crystal-melt interface of said melt;
- and
- means for moving said electromagnet in a vertical direction in accordance with the detected change in level of the crystal-melt interface of said melt, said moving means being connected to said detecting means.
A single crystal pulling system comprising:
- a single crystal pulling apparatus;
- an electromagnet;
- a magnet moving mechanism;
- said single crystal pulling apparatus comprising a crucible containing a single crystal material melt, a heater for heating said crucible, and a constant speed pulling mechanism adapted to be coupled to a single crystal at a crystal-melt interface of said melt, said pulling apparatus adapted such that a seed crystal inserted in said melt is pulled from the melt at a specified constant speed by means of said constant speed pulling mechanism;
- said electromagnet being a split type and disposed at opposite sides of said crucible so as to apply a predetermined strength of magnetic field to the crystal-melt interface of said melt;
- and
- said magnet moving mechanism comprising means for moving said electromagnet at least in a vertical direction of vertical and horizontal directions with respect to said crucible based on a level of said crystal-melt interface in said crucible;
- wherein said magnet moving mechanism comprises:
- means for detecting a change in level of the crystal-melt interface of said melt;
- and
- means for moving said electromagnet in a vertical direction in accordance with the detected change in level of the crystal-melt interface of said melt, said moving means being connected to said detecting means.
Dependencies are inferred from the claim text.