Patent classifications
C30B30/04
Semiconductor crystal growth apparatus
The invention provides a semiconductor crystal growth device comprising a furnace body; a crucible; a pulling device; a horizontal magnetic field applying device; and a deflector, being barrel-shaped and disposed above the silicon melt in the furnace body in a vertical direction, and the pulling device pulls the silicon ingot through the deflector in the vertical direction; wherein the bottom of the deflector has different thermal reflection coefficients at different positions, and the thermal reflection coefficient of the bottom of the deflector in the direction of the horizontal magnetic field is smaller than that in the direction perpendicular to the horizontal magnetic field. According to the semiconductor crystal growth device of the present invention, the temperature distribution inside the melt silicon and quality of the semiconductor crystal are improved.
SINGLE-CRYSTAL PULLING APPARATUS AND SINGLE-CRYSTAL PULLING METHOD
A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle α having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.
SINGLE-CRYSTAL PULLING APPARATUS AND SINGLE-CRYSTAL PULLING METHOD
A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle α having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.
APPARATUS AND METHOD FOR GROWING SILICON SINGLE CRYSTAL INGOT
An embodiment provides a method for growing a silicon single crystalline ingot that may include: preparing a silicon melt solution in a crucible; probing a seed in the silicon melt solution; rotating the seed and the crucible while applying a horizontal magnetic field to the crucible; and pulling up an ingot grown from the silicon melt solution, wherein an interface between the growing ingot and the silicon melt solution is formed downward from a horizontal plane at 1 to 5 millimeters, and a bulk micro defects (BMD) size of the grown ingot is between 55 and 65 nanometers.
APPARATUS AND METHOD FOR GROWING SILICON SINGLE CRYSTAL INGOT
An embodiment provides a method for growing a silicon single crystalline ingot that may include: preparing a silicon melt solution in a crucible; probing a seed in the silicon melt solution; rotating the seed and the crucible while applying a horizontal magnetic field to the crucible; and pulling up an ingot grown from the silicon melt solution, wherein an interface between the growing ingot and the silicon melt solution is formed downward from a horizontal plane at 1 to 5 millimeters, and a bulk micro defects (BMD) size of the grown ingot is between 55 and 65 nanometers.
SINGLE-CRYSTAL PULLING APPARATUS AND SINGLE-CRYSTAL PULLING METHOD
The present invention is a single-crystal pulling apparatus including: a pulling furnace which has a heater and a crucible arranged and which has a central axis; and a magnetic field generation device having superconducting coils, where the magnetic field generation device has four of the superconducting coils, two of the superconducting coils are arranged in each of two regions divided by a cross section that includes an X axis, the X axis being a direction of lines of magnetic force at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the central axis of the pulling furnace so as to have line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle within a range of more than −30° and less than 30° relative to a Y axis, the direction of the lines of magnetic force thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate lines of magnetic force in opposite directions. This provides a single-crystal pulling apparatus with which there is no need to move the magnetic field generation device when dismantling and setting up the single-crystal pulling apparatus, and the oxygen concentration in the single crystal to be grown can be reduced, and at the same time, growth striations in the single crystal to be grown can be suppressed.
SINGLE-CRYSTAL PULLING APPARATUS AND SINGLE-CRYSTAL PULLING METHOD
The present invention is a single-crystal pulling apparatus including: a pulling furnace which has a heater and a crucible arranged and which has a central axis; and a magnetic field generation device having superconducting coils, where the magnetic field generation device has four of the superconducting coils, two of the superconducting coils are arranged in each of two regions divided by a cross section that includes an X axis, the X axis being a direction of lines of magnetic force at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the central axis of the pulling furnace so as to have line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle within a range of more than −30° and less than 30° relative to a Y axis, the direction of the lines of magnetic force thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate lines of magnetic force in opposite directions. This provides a single-crystal pulling apparatus with which there is no need to move the magnetic field generation device when dismantling and setting up the single-crystal pulling apparatus, and the oxygen concentration in the single crystal to be grown can be reduced, and at the same time, growth striations in the single crystal to be grown can be suppressed.
Method of controlling convection patterns of silicon melt and method of manufacturing silicon single crystal
A method of controlling a convection pattern of a silicon melt includes applying a horizontal magnetic field having an intensity of 0.2 tesla or more to the silicon melt in a rotating quartz crucible to fix a direction of a convection flow in a plane orthogonal to an application direction of the horizontal magnetic field in the silicon melt, the horizontal magnetic field being applied so that a central magnetic field line passes through a point horizontally offset from a center axis of the quartz crucible by 10 mm or more.
Method of controlling convection patterns of silicon melt and method of manufacturing silicon single crystal
A method of controlling a convection pattern of a silicon melt includes applying a horizontal magnetic field having an intensity of 0.2 tesla or more to the silicon melt in a rotating quartz crucible to fix a direction of a convection flow in a plane orthogonal to an application direction of the horizontal magnetic field in the silicon melt, the horizontal magnetic field being applied so that a central magnetic field line passes through a point horizontally offset from a center axis of the quartz crucible by 10 mm or more.
Systems and methods for production of low oxygen content silicon
A method for producing a silicon ingot includes withdrawing a seed crystal from a melt that includes melted silicon in a crucible that is enclosed in a vacuum chamber containing a cusped magnetic field. At least one process parameter is regulated in at least two stages, including a first stage corresponding to formation of the silicon ingot up to an intermediate ingot length, and a second stage corresponding to formation of the silicon ingot from the intermediate ingot length to the total ingot length. During the second stage process parameter regulation may include reducing a crystal rotation rate, reducing a crucible rotation rate, and/or increasing a magnetic field strength relative to the first stage.