Methods for forming a single crystal silicon ingot with reduced crucible erosion are disclosed. Solid-phase quartz is added to the melt to reduce erosion at the crucible-melt surface interface. The quartz may be synthetic quartz such as synthetic quartz rods. The quartz may be disposed near the crucible-melt surface interface. Quartz dissolves and suppresses the amount of quartz that dissolves from the crucible at the crucible-melt surface interface.

Methods for forming a single crystal silicon ingot with reduced crucible erosion are disclosed. Solid-phase quartz is added to the melt to reduce erosion at the crucible-melt surface interface. The quartz may be synthetic quartz such as synthetic quartz rods. The quartz may be disposed near the crucible-melt surface interface. Quartz dissolves and suppresses the amount of quartz that dissolves from the crucible at the crucible-melt surface interface.

A cold crucible usable in the field of high-temperature production of monocrystalline materials. The cold crucible includes: a cold cage which has sectors made of a material having good electrical conductivity and in which a charge is melted, and a cooling device with heat transfer fluid, configured to cool each segment of the cold cage from the inside. The cold crucible is essentially such that it further includes at least one device for generating a static magnetic field, each generating device being housed inside one of the sectors of the cold crucible. Each static magnetic field thus generated having the effect of slowing down the electromagnetic stirring of the molten charge, such that it is possible to produce monocrystalline ingots of significantly larger diameter than the diameter of the seed initiating their growth.

The present invention provides a method and an apparatus of monocrystal growth. The method comprises providing an apparatus comprising a crucible, a first lifting device for lifting the crucible, a deflector tube and a second lifting device for lifting the deflector tube; setting a theoretical distance between the deflector tube and the melt surface, determining a theoretical ratio of the crucible lifting rate relative to the monocrystal lifting rate based on sizes of the crucible and the monocrystal, and starting to grow the monocrystal. During the growth, the position of one or more of the crucible, the deflector tube and the monocrystal is adjusted, the actual distance between the deflector tube and the melt surface is real-time detected, the deviation value between the theoretical and the actual distances is calculated, a variation of the ratio is obtained by the deviation value, and the theoretical ratio is adjusted based on the variation. Based on the variation of the ratio of the crucible lifting rate relative to the monocrystal lifting rate, the speeds of the lifting devices are adjusted to maintain the process lifting rate during the crystal growth without change. The process lifting rate is the lifting rate of the monocrystal ingot relative to the melt surface. The present invention can facilitate to produce the monocrystal with high quality.

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.

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.

A lift assembly includes a lift housing, a drum with a helical groove about its exterior surface, and a drive shaft coupled to the drum to cause the drum to rotate. A roller guide mounted to the lift housing engages the helical groove of the drum such that rotation of the drum causes the drum to translate due to the engagement of the helical groove of the drum with the roller guide. The roller guide can be part of a roller guide assembly that includes a mounting plate and a shaft.

A lift assembly includes a lift housing, a drum with a helical groove about its exterior surface, and a drive shaft coupled to the drum to cause the drum to rotate. A roller guide mounted to the lift housing engages the helical groove of the drum such that rotation of the drum causes the drum to translate due to the engagement of the helical groove of the drum with the roller guide. The roller guide can be part of a roller guide assembly that includes a mounting plate and a shaft.

A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 mΩ-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 mΩ-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 mΩ-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 mΩ-cm and a striation height that is equal to or more than 13 mm.

A semiconductor wafer including a single crystal doped with a dopant, wherein a resistivity of the wafer is 0.7 mΩ-cm or less, and wherein a striation height of the wafer is 6 mm or more. The resistivity of the wafer may be 0.8 mΩ-cm or less, and the striation height may be 13 mm or more. The resistivity of the wafer may be 0.7 mΩ-cm or less, and the striation may be 22 mm or more. Example features relate to a method of making a semiconductor wafer that includes adding a dopant to a silicon melt, rotationally pulling a crystal from the silicon melt, and applying a magnetic field of 3000 G or more such that the semiconductor wafer has a resistivity that is equal to or less than 0.8 mΩ-cm and a striation height that is equal to or more than 13 mm.