Crystal pulling system having a housing and a crucible assembly are disclosed. The system includes a heat shield that defines a central passage through which an ingot passes during ingot growth. A cover member is moveable within the heat shield along a pull axis. The cover member may include an insulation layer. The cover member covers at least a portion of the charge during meltdown.

Crystal pulling system having a housing and a crucible assembly are disclosed. The system includes a heat shield that defines a central passage through which an ingot passes during ingot growth. A cover member is moveable within the heat shield along a pull axis. The cover member may include an insulation layer. The cover member covers at least a portion of the charge during meltdown.

Methods for producing single crystal silicon ingots in which an array of quartz particles are added to the crucible assembly before ingot growth are disclosed. The array may be disposed in the outer melt zone of the crucible assembly as in a continuous Czochralski (CCz) process. The array may be made of quartz particles that are interconnected by linking members.

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 (Gd.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, Dy, Gd, Ho, Tm, Yb, Lu, and Y.

A method for growing a single crystal silicon ingot by the continuous Czochralski method is disclosed. The melt depth and thermal conditions are constant during growth because the silicon melt is continuously replenished as it is consumed, and the crucible location is fixed. The critical v/G is determined by the hot zone configuration, and the continuous replenishment of silicon to the melt during growth enables growth of the ingot at a constant pull rate consistent with the critical v/G during growth of a substantial portion of the main body of the ingot. The continuous replenishment of silicon is accompanied by periodic or continuous nitrogen addition to the melt to result in a nitrogen doped ingot.

A method for growing a single crystal silicon ingot by the continuous Czochralski method is disclosed. The melt depth and thermal conditions are constant during growth because the silicon melt is continuously replenished as it is consumed, and the crucible location is fixed. The critical v/G is determined by the hot zone configuration, and the continuous replenishment of silicon to the melt during growth enables growth of the ingot at a constant pull rate consistent with the critical v/G during growth of a substantial portion of the main body of the ingot. The continuous replenishment of silicon is accompanied by periodic or continuous nitrogen addition to the melt to result in a nitrogen doped ingot.

A raw material supply system for supplying a fixed amount of raw material necessary for ingot growth is disclosed. The system includes a support unit, an enclosure, a fixed amount supply unit, a hopper for supplying raw material to the fixed amount supply unit, a dopant supply unit for supplying a predetermined amount of dopant into the enclosure, a supply pipe for supplying a fixed amount of raw material and dopant to a crucible, a lifting mechanism for moving the supply pipe upward and downward, a moving mechanism for protruding an inclined chute to an upper part of the supply pipe, and a load cell mounted between the support unit and the enclosure for sensing the weight of the supplied raw material and inputting the sensed weight of the raw material to a controller.

A raw material supply system for supplying a fixed amount of raw material necessary for ingot growth is disclosed. The system includes a support unit, an enclosure, a fixed amount supply unit, a hopper for supplying raw material to the fixed amount supply unit, a dopant supply unit for supplying a predetermined amount of dopant into the enclosure, a supply pipe for supplying a fixed amount of raw material and dopant to a crucible, a lifting mechanism for moving the supply pipe upward and downward, a moving mechanism for protruding an inclined chute to an upper part of the supply pipe, and a load cell mounted between the support unit and the enclosure for sensing the weight of the supplied raw material and inputting the sensed weight of the raw material to a controller.

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.

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.