Abstract: A vacuum processing apparatus of this invention having a stage on which is disposed the to-be-processed substrate further has a lifting/rotation mechanism capable of lifting the to-be-processed substrate lying on the stage off from an upper surface of the stage to a predetermined height position so that, at this lifted position, the to-be-processed substrate is capable of rotation about a substrate center by a predetermined rotational angle. The lifting/rotation mechanism has: a driving rod built into the stage so as to be moveable up and down and also be rotatable; and a substrate supporting body having a base end plate part capable of contacting a central region, including the substrate center, of the to-be-processed substrate. The substrate supporting body further has at least two arm plate parts elongated from the base end plate part outward thereof.

Abstract: The silicon purification method uses a silicon purification device including at least a crucible for loading a silicon metal and a plasma torch, and purifies the silicon metal by injecting a plasma gas from the plasma torch toward a melt surface of the silicon metal loaded in the crucible in a state where an angle formed by the melt surface and the plasma gas is set in the range of 20° to 80°.

Abstract: The silicon purification method uses a silicon purification device including at least a crucible for loading a silicon metal and a plasma torch, and purifies the silicon metal by injecting a plasma gas from the plasma torch toward a melt surface of the silicon metal loaded in the crucible in a state where an angle formed by the melt surface and the plasma gas is set in the range of 20° to 80°.

Abstract: A technology for removing impurities from a silicon raw material at a low cost. A base material made of metallurgical silicon is arranged in a dissolution vessel, the base material arranged in the dissolution vessel is heated in a vacuum ambience and fully molten, silicon is solidified from a portion where an inner bottom surface of the dissolution vessel is in contact with molten silicon by cooling the outer bottom surface of the dissolution vessel in a state where the outer bottom surface faces the cooling means, spaced from the cooling means, the solidificated silicon is made to grow upward, and unsolidificated silicon located above the solidificated silicon is removed from the dissolution vessel.

Abstract: A silicon purification method includes: loading a base material that is a starting material made of metallic silicon into a graphite crucible, heating and melting all of the base material which is disposed in an acidic inert gas atmosphere, maintaining the molten base material in the graphite crucible, and thereby oxidatively purifying the base material; loading the oxidatively-purified base material into a water-cooled crucible, gradually solidifying the base material after the base material disposed in a high vacuum atmosphere is fully molten, and thereby removing an unsolidified portion; and fully melting the base material which is disposed in a high vacuum atmosphere and in which the unsolidified portion is removed, and maintaining the base material in the water-cooled crucible.

Abstract: A silicon purification method includes a solidification purification step comprising: preparing the base material to be purified, loading the base material into a crucible, irradiating part of the base material, and fully melting the base material; gradually solidifying the base material by gradually weakening an electron beam so that the solidification proceeds until the solidifying portion occupies a first predetermined ratio of the base material; loading the remnant of the base material into the crucible, and fully melting the remnant of the base material by irradiating the entire area of the remnant of the base material with the electron beam; gradually solidifying the molten metal portion by gradually weakening the electron beam so that the solidification proceeds until the solidifying portion occupies a second predetermined ratio of the molten metal portion; and removing an unsolidified molten metal portion.

Abstract: A method for refining a metal such that, after a base material derived from the metal is melted by being irradiated with an electron beam, the base material is refined by solidifying the base material which was melted, the method including: a step melting all of the base material by irradiating the electron beam over an entire surface of the base material loaded inside a water-cooled crucible placed inside a high vacuum atmosphere; a step gradually solidifying the base material which was melted from a molten metal bottom part of the base material which was melted toward a molten metal surface part at a side being irradiated by the electron beam by gradually weakening an output of the electron beam while maintaining a condition in which the base material which was melted is irradiated with the electron beam; and a step removing a molten metal part which is not solidified, after the base material which was melted is solidified to a certain percentage.

Abstract: The silicon purification method uses a silicon purification device including at least a crucible for loading a silicon metal and a plasma torch, and purifies the silicon metal by injecting a plasma gas from the plasma torch toward a melt surface of the silicon metal loaded in the crucible in a state where an angle formed by the melt surface and the plasma gas is set in the range of 20° to 80°.

Abstract: A silicon purification method includes: loading a base material that is a starting material made of metallic silicon into a graphite crucible, heating and melting all of the base material which is disposed in an acidic inert gas atmosphere, maintaining the molten base material in the graphite crucible, and thereby oxidatively purifying the base material; loading the oxidatively-purified base material into a water-cooled crucible, gradually solidifying the base material after the base material disposed in a high vacuum atmosphere is fully molten, and thereby removing an unsolidified portion; and fully melting the base material which is disposed in a high vacuum atmosphere and in which the unsolidified portion is removed, and maintaining the base material in the water-cooled crucible.

Abstract: A silicon purification method includes a solidification purification step in which metal impurities are removed by irradiating a base material made of metallic silicon with an electron beam.