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AssigneeShin-Etsu Handotai Co., Ltd.
InventorsRyouji Hoshi, Masashi Sonokawa, Izumi Fusegawa, Tomohiko Ohta
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A single crystal production apparatus based on an HMCZ method for production a large-diametered single crystal having a uniform microscopic oxygen concentration distribution in its crystal growth direction to thereby provide a wafer having a high in-plane uniformity of oxygen concentration distribution. In the single crystal production apparatus based on the HMCZ method, when B denotes a vertical position of the bottom surface of a melt within a crucible and L denotes the depth of the melt at the time of starting crystal pulling operation, a vertical position of the coil central axis Cc of superconducting electromagnets 12 and 15 is controlled to be a proper value included in a range from a position below the position B by {(1/3).times.L} to a position above the position B by {(1/3).times.L} to pull the single crystal. Thereby the intensity of a magnetic field applied to the melt in the vicinity of the interface of the crystal growth within the crucible is weakened to increase the degree of freedom of the convection of the melt, while the intensity of the magnetic field applied to the melt in the vicinity of the bottom part of the crucible is strengthened to suppress the convection.
A single crystal production method for pulling a single crystal from a raw material melt contained in a crucible based on a horizontal magnetic field applied CZ method, in which the crucible is provided within a pulling chamber, a heater surrounds the crucible, coils comprising electromagnets in magnetic field applying device are disposed outside the pulling chamber as coaxially opposed to each other with the crucible disposed therebetween, so that the single crystal is pulled while a horizontal magnetic field is applied to the melt within the crucible;
A single crystal production apparatus for pulling a single crystal from a raw material melt contained in a crucible based on a horizontal magnetic field applied CZ method, in which the crucible is provided within a pulling chamber, a heater surrounds the crucible, coils comprising electromagnets in magnetic field applying device are disposed outside the pulling chamber as coaxially opposed to each other with the crucible disposed therebetween, so that the single crystal is pulled while a horizontal magnetic field is applied to the melt within the crucible;
Dependencies are inferred from the claim text.