A single crystal is pulled by the FZ method, in which in a first phase, a lower end of the polycrystal is melted by the melting apparatus, in a second phase, a monocrystalline seed is attached to the lower end of the polycrystal, and in a third phase, between a lower section of the seed and the polycrystal, a thin neck section is formed whose diameter is smaller than that of the seed, where the power of the melting apparatus before the third phase is dynamically adapted in dependence on a position of a lower phase boundary (P.sub.U) between liquid material and solid material on the part of the seed, and where the power of the melting apparatus during the third phase is dynamically adapted in dependence on the position of an upper phase boundary (P.sub.O) between liquid material and solid material on the part of the polycrystal plant.

An oxychloride infrared nonlinear optical crystal and the preparation method and use thereof, the optical crystal has a general chemical formula of Pb.sub.2+xOCl.sub.2+2x, therein 0<x<0.139 or 0.141<x<0.159 or 0.161<x0.6. The crystal is non-centrosymmetric, belongs to orthonormal system with space group of Fmm2, cell parameter is a=35.4963(14)0.05 , b=5.8320(2)0.05 , c=16.0912(6)0.05 . The crystal is prepared by high temperature melt method or flux method. The crystal has a strong second harmonic generation efficiency of 4 times that of KDP (KH.sub.2PO.sub.4) tested by Kurtz method, it is phase machable, transparent in the range of 0.34-7 m. The laser damage threshold is 10 times that of the current commercial infrared nonlinear optical crystal AgGaS.sub.2. No crystalline water exists in lead oxychloride, and it is stable in the air and has good thermal stability.

An oxychloride infrared nonlinear optical crystal and the preparation method and use thereof, the optical crystal has a general chemical formula of Pb.sub.2+xOCl.sub.2+2x, therein 0<x<0.139 or 0.141<x<0.159 or 0.161<x0.6. The crystal is non-centrosymmetric, belongs to orthonormal system with space group of Fmm2, cell parameter is a=35.4963(14)0.05 , b=5.8320(2)0.05 , c=16.0912(6)0.05 . The crystal is prepared by high temperature melt method or flux method. The crystal has a strong second harmonic generation efficiency of 4 times that of KDP (KH.sub.2PO.sub.4) tested by Kurtz method, it is phase machable, transparent in the range of 0.34-7 m. The laser damage threshold is 10 times that of the current commercial infrared nonlinear optical crystal AgGaS.sub.2. No crystalline water exists in lead oxychloride, and it is stable in the air and has good thermal stability.

A silicon-based molten composition according to an exemplary embodiment of the present invention is used in a solution growing method for forming silicon carbide single crystal, and is expressed in Formula 1 including silicon (Si), chromium (Cr), vanadium (V), and aluminum (Al).

Si.sub.aCr.sub.bV.sub.cAl.sub.d [Formula 1]

In Formula 1, a is equal to or greater than 0.4 and equal to or less than 0.9, b+c is equal to or greater than 0.1 and equal to or less than 0.6, c/(b+c) is equal to or greater than 0.05 and equal to or less than 0.95, and d is equal to or greater than 0.01 and equal to or less than 0.1.

A silicon-based molten composition according to an exemplary embodiment of the present invention is used in a solution growing method for forming silicon carbide single crystal, and is expressed in Formula 1 including silicon (Si), chromium (Cr), vanadium (V), and aluminum (Al).

Si.sub.aCr.sub.bV.sub.cAl.sub.d [Formula 1]

In Formula 1, a is equal to or greater than 0.4 and equal to or less than 0.9, b+c is equal to or greater than 0.1 and equal to or less than 0.6, c/(b+c) is equal to or greater than 0.05 and equal to or less than 0.95, and d is equal to or greater than 0.01 and equal to or less than 0.1.

A method of preparation of semiconductor material. The method includes: adding an organic substance containing a benzene ring and dodecacalcium hepta-aluminate (12CaO.7Al.sub.2O.sub.3 or C12A7) to a test tube, and sealing the test tube; heating the test tube to a temperature of 200-300 C., and holding the temperature for 1 to 3 hours; and continuously heating the test tube to a temperature of 900-1300 C., and holding the temperature for 10-120 hours.

A method of preparation of semiconductor material. The method includes: adding an organic substance containing a benzene ring and dodecacalcium hepta-aluminate (12CaO.7Al.sub.2O.sub.3 or C12A7) to a test tube, and sealing the test tube; heating the test tube to a temperature of 200-300 C., and holding the temperature for 1 to 3 hours; and continuously heating the test tube to a temperature of 900-1300 C., and holding the temperature for 10-120 hours.

Provided is a cylindrical ingot manufacturing method including: an operation of supplying a silicon raw material to an inside of a crucible and heating the crucible to melt the silicon raw material; an operation of supplying a seed crystal having one end fastened to a seed shaft to the inside of the crucible; and an operation of moving the seed crystal from a lower portion of the crucible to an upper portion thereof by the crucible rotating in one direction relative to the seed shaft and the seed shaft rotating in the other direction and moving upward. According to the present disclosure, since a ring-shaped seed crystal is grown, a cylindrical silicon ingot can be manufactured, and since a cylindrical silicon ingot having an inner diameter is formed, a wafer retaining ring can be manufactured from the ingot without a coring task.

Provided is a cylindrical ingot manufacturing method including: an operation of supplying a silicon raw material to an inside of a crucible and heating the crucible to melt the silicon raw material; an operation of supplying a seed crystal having one end fastened to a seed shaft to the inside of the crucible; and an operation of moving the seed crystal from a lower portion of the crucible to an upper portion thereof by the crucible rotating in one direction relative to the seed shaft and the seed shaft rotating in the other direction and moving upward. According to the present disclosure, since a ring-shaped seed crystal is grown, a cylindrical silicon ingot can be manufactured, and since a cylindrical silicon ingot having an inner diameter is formed, a wafer retaining ring can be manufactured from the ingot without a coring task.

Embodiments provide a method of growing a silicon single crystal ingot, the method including growing a silicon single crystal ingot having crystal orientation of (111) using the Czochralski method, measuring a diameter of the silicon single crystal ingot, calculating a length of a facet of the silicon single crystal ingot, calculating a correction formula for a rotation speed of a seed and a correction formula for a pulling speed of the silicon single crystal ingot based on the calculated facet length, and correcting the rotation speed of the seed and the pulling speed of the silicon single crystal ingot based on a result of the calculation.