A bismuth-substituted rare earth iron garnet single crystal suitable for Faraday rotators and optical isolators with reduced insertion loss due to suppressed valence fluctuation of Fe ions is provided. The bismuth-substituted rare earth iron garnet single crystal of the present invention is characterized by the composition formula (Tb.sub.aLn.sub.bBi.sub.cMg.sub.3−(a+b+c))(Fe.sub.dGa.sub.eTi.sub.fPt.sub.5−(d+e+f))O.sub.12. In the composition formula above, 0.02≤f≤0.05, 0.02≤{3−(a+b+c)}≤0.08, and −0.01≤{3−(a+b+c)}−{f+5−(d+e+f)}≤0.01. Ln is a rare earth element and may be selected from Eu, Gd, Ho, Tm, Yb, Lu, and Y.

A system and a method for controlling temperature of semiconductor single crystal growth. The system includes: an image collection apparatus, configured to capture an image of an edge line of a crystal rod that grows at a solid-liquid interface, so as to determine the width of the edge fine at the interface; a heating apparatus, configured to heat a crucible; and a temperature control apparatus, configured to control the heating power of the heating apparatus, and the temperature control apparatus controls the heating power of the heating apparatus according to the width of the edge line.

A system and a method for controlling temperature of semiconductor single crystal growth. The system includes: an image collection apparatus, configured to capture an image of an edge line of a crystal rod that grows at a solid-liquid interface, so as to determine the width of the edge fine at the interface; a heating apparatus, configured to heat a crucible; and a temperature control apparatus, configured to control the heating power of the heating apparatus, and the temperature control apparatus controls the heating power of the heating apparatus according to the width of the edge line.

Provided is a wire sawing device comprising an ingot temperature controller, the wire sawing device comprising: a chamber; an ingot clamp supporting an ingot inside the chamber; a first roller and a second roller; a wire which is wound around the first roller and the second roller and cuts the ingot into a plurality of wafers by rotating; a temperature measuring unit which is mounted inside the chamber, in which the ingot is cut, and measures the temperature of the ingot; and a heater unit mounted inside the chamber.

Provided is a wire sawing device comprising an ingot temperature controller, the wire sawing device comprising: a chamber; an ingot clamp supporting an ingot inside the chamber; a first roller and a second roller; a wire which is wound around the first roller and the second roller and cuts the ingot into a plurality of wafers by rotating; a temperature measuring unit which is mounted inside the chamber, in which the ingot is cut, and measures the temperature of the ingot; and a heater unit mounted inside the chamber.

A method of evaluating metal contamination by measuring the amount of metal contaminants to a silicon wafer in a rapid thermal processing apparatus includes steps of obtaining a Si single crystal grown by the Czochralski method at a pulling rate of 1.0 mm/min or lower, the crystal having oxygen concentration of 1.3×10.sup.18 atoms/cm.sup.3 or less, slicing silicon wafers from the Si single crystal except regions of 40 mm toward the central portion from the head of the single crystal and 40 mm toward the central portion from the tail, heat-treating the silicon wafer with a rapid thermal processing apparatus and transferring contaminants from members in a furnace of the rapid thermal processing apparatus to the silicon wafer, and measuring a lifetime of the silicon wafer to which contaminants are transferred.

A method of evaluating metal contamination by measuring the amount of metal contaminants to a silicon wafer in a rapid thermal processing apparatus includes steps of obtaining a Si single crystal grown by the Czochralski method at a pulling rate of 1.0 mm/min or lower, the crystal having oxygen concentration of 1.3×10.sup.18 atoms/cm.sup.3 or less, slicing silicon wafers from the Si single crystal except regions of 40 mm toward the central portion from the head of the single crystal and 40 mm toward the central portion from the tail, heat-treating the silicon wafer with a rapid thermal processing apparatus and transferring contaminants from members in a furnace of the rapid thermal processing apparatus to the silicon wafer, and measuring a lifetime of the silicon wafer to which contaminants are transferred.

Disclosed are a Czochralski single crystal furnace for preparing monocrystalline silicon and a method for preparing monocrystalline silicon using the same. The Czochralski single crystal furnace is switchable between a first operation state and a second operation state. In response to the Czochralski single crystal furnace being switched between the first operation state and the second operation state, a first heat-preserving barrel moves relative to a second heat-preserving barrel. In response to the Czochralski single crystal furnace being in the first operation state, a side wall of the second heat-preserving barrel covers a first opening so as to isolate a reaction chamber from outside Czochralski single crystal furnace. In response to the Czochralski single crystal furnace being in the second operation state, the second heat-preserving barrel exposes the first opening, so that the reaction chamber is connected to the outside through the first opening.

Disclosed are a Czochralski single crystal furnace for preparing monocrystalline silicon and a method for preparing monocrystalline silicon using the same. The Czochralski single crystal furnace is switchable between a first operation state and a second operation state. In response to the Czochralski single crystal furnace being switched between the first operation state and the second operation state, a first heat-preserving barrel moves relative to a second heat-preserving barrel. In response to the Czochralski single crystal furnace being in the first operation state, a side wall of the second heat-preserving barrel covers a first opening so as to isolate a reaction chamber from outside Czochralski single crystal furnace. In response to the Czochralski single crystal furnace being in the second operation state, the second heat-preserving barrel exposes the first opening, so that the reaction chamber is connected to the outside through the first opening.

Provided is a device for manufacturing monocrystalline silicon and a cooling method thereof. The device includes a crystal puller and a cooling apparatus. A heating apparatus and a first thermal insulation structure are arranged in the crystal puller. The first thermal insulation structure is located above the heating apparatus. The cooling apparatus includes a jacking mechanism and a cooling pipe. The cooling pipe is capable of moving into or out of the crystal puller. When the cooling pipe enters the crystal puller, the cooling pipe is connected to the first thermal insulation structure, and the cooling pipe lifts the first thermal insulation structure through the jacking mechanism to increase a distance between the first thermal insulation structure and the heating apparatus, and a cooling medium is output to the cooling pipe to cool the crystal puller. The cooling medium may be liquid or gas.