Abstract: By specifying an initial oxygen concentration in a silicon single crystal and a concentration of thermal donors produced according to a thermal history from 400° C. to 550° C. that the silicon single crystal undergoes during crystal growth, a nucleation rate of oxygen precipitates produced in the silicon single crystal while the silicon single crystal is subjected to a heat treatment is determined. Further, by specifying the heat treatment condition of the silicon single crystal, an oxygen precipitate density and an amount of precipitated oxygen under a given heat treatment condition are predicted by calculation.

Abstract: An upper side heater 10 is configured so that a current passage width becomes larger at a heater lower part than at a heater upper part. Thus, the upper side heater 10 has a current-carrying cross-sectional area which becomes larger at the heater lower part than at the heater upper part, a resistance value becomes accordingly smaller at the heater lower part than at the heater upper part, and a heat generation amount becomes relatively smaller at the heater lower part than at the heater upper part. Meanwhile, a lower side heater 20 is configured so that the current passage width becomes larger at the heater upper part than at the heater lower part. Thus, the current-carrying cross-sectional area of the lower side heater 20 becomes larger at the heater upper part than at the heater lower part, a resistance value becomes accordingly smaller at the heater upper part than at the heater lower part, and a heat generation amount becomes relatively smaller at the heater upper part than at the heater lower part.

Abstract: A device controls an object in a time variant system with a dead time such as a Czochralski method single crystal production device (CZ equipment). The dead time, time constant, and process gain value of an object (CZ equipment) are set. The process gain preset value has time variant characteristics. An output value and its first-order and second-order time differentiated values serve as the state variable. A nonlinear state predicting unit predicts a state variable value at a future time, based upon the current output value, dead time, time constant, and process gain preset value. A gain scheduled sliding mode control unit performs a gain scheduled sliding mode control operation based upon the state variable value at the future time, an output deviation at the future time, the time constant, and the set value of the process gain at the future time, to determine the manipulated variable of the object.

Abstract: To accurately control controlled object in a time variant system with a dead time such as a Czochralski method single crystal production device (CZ equipment). The dead time, the time constant, and the process gain value of a controlled object (CZ equipment) (200) are set. The process gain preset value has specified time variant characteristics. An output value y and its first-order and second-order time differentiated values are used as the state variable x of the controlled object (200). A nonlinear state predicting unit (206) predicts a state variable value x(t+Ld) at a future point in time after the dead time, based upon the current output value y, the dead time, the time constant, and the process gain preset value.

Abstract: By specifying an initial oxygen concentration in a silicon single crystal and a concentration of thermal donors produced according to a thermal history from 400° C. to 550° C. that the silicon single crystal undergoes during crystal growth, a nucleation rate of oxygen precipitates produced in the silicon single crystal while the silicon single crystal is subjected to a heat treatment is determined. Further, by specifying the heat treatment condition of the silicon single crystal, an oxygen precipitate density and an amount of precipitated oxygen under a given heat treatment condition are predicted by calculation.

Abstract: An upper side heater 10 is configured so that a current passage width becomes larger at a heater lower part than at a heater upper part. Thus, the upper side heater 10 has a current-carrying cross-sectional area which becomes larger at the heater lower part than at the heater upper part, a resistance value becomes accordingly smaller at the heater lower part than at the heater upper part, and a heat generation amount becomes relatively smaller at the heater lower part than at the heater upper part. Meanwhile, a lower side heater 20 is configured so that the current passage width becomes larger at the heater upper part than at the heater lower part. Thus, the current-carrying cross-sectional area of the lower side heater 20 becomes larger at the heater upper part than at the heater lower part, a resistance value becomes accordingly smaller at the heater upper part than at the heater lower part, and a heat generation amount becomes relatively smaller at the heater upper part than at the heater lower part.

Abstract: A semiconductor single crystal manufacturing apparatus which can manufacture a single crystal of high oxygen concentration to that of low oxygen concentration within a prescribed standard range of oxygen concentration, as a wafer material for semiconductor integrated circuits, with a high yield, is provided. Heat shields 20, 21 are provided in the entire annular area between respective adjacent heaters of the heaters 4a, 4b, 4c for heating the crucible 3 from the outside periphery side. By using the heat shields 20, 21 for localizing the respective heating regions for the heaters to actively control the temperature distribution for the crucible 3 and melt 8 in the crucible, a single crystal of high oxygen concentration to that of low oxygen concentration can be manufactured within a prescribed standard range of oxygen concentration with a high yield.

Abstract: A semiconductor single crystal manufacturing apparatus which can manufacture a single crystal of high oxygen concentration to that of low oxygen concentration within a prescribed standard range of oxygen concentration, as a wafer material for semiconductor integrated circuits, with a high yield, is provided. Heat shields 20, 21 are provided in the entire annular area between respective adjacent heaters of the heaters 4a, 4b, 4c for heating the crucible 3 from the outside periphery side. By using the heat shields 20, 21 for localizing the respective heating regions for the heaters to actively control the temperature distribution for the crucible 3 and melt 8 in the crucible, a single crystal of high oxygen concentration to that of low oxygen concentration can be manufactured within a prescribed standard range of oxygen concentration with a high yield.

Abstract: A method for eliminating slip dislocations in producing single crystal silicon, a seed crystal capable of eliminating the slip dislocations, a single crystal silicon ingot from which the slip dislocations have been eliminated and a single crystal silicon wafer, are disclosed. Single crystal silicon is produced by dipping a seed crystal in a melt and pulling the seed crystal up along the axis of the seed crystal, using a single crystal (1) in which the <110> crystal orientation (10) is inclined at a predetermined angle ? with respect to the axial direction (9) so that the edge direction (8) of the {111} crystal plane is inclined with respect to the axial direction (9). When single crystal silicon is grown while pulling up a seed crystal by the CZ method, a single crystal silicon ingot of a large diameter and a heavy weight can be pulled up by eliminating slip dislocations from the thick crystal.

Abstract: A method for eliminating slip dislocations in producing single crystal silicon, a seed crystal capable of eliminating the slip dislocations, a single crystal silicon ingot from which the slip dislocations have been eliminated and a single crystal silicon wafer, are disclosed. Single crystal silicon is produced by dipping a seed crystal in a melt and pulling the seed crystal up along the axis of the seed crystal, using a single crystal (1) in which the <110> crystal orientation (10) is inclined at a predetermined angle ? with respect to the axial direction (9) so that the edge direction (8) of the {111} crystal plane is inclined with respect to the axial direction (9). When single crystal silicon is grown while pulling up a seed crystal by the CZ method, a single crystal silicon ingot of a large diameter and a heavy weight can be pulled up by eliminating slip dislocations from the thick crystal.

Abstract: There is described an apparatus for producing a single crystal ingot capable of stably manufacturing a single crystal ingot by means of the Czochralski method, without being affected by influence of variation in extension of wires or an offset in points clamped by a clamping member. The clamping member is engaged with an engagement step formed in a single crystal which is being pulled by the CZ method, and the single crystal is pulled. The single crystal ingot manufacturing apparatus is provided with a flexible mechanism for absorbing variation in extension of the wires, in intermediate portions of the wires. Variation in extension of the wires is eliminated by means of the flexible mechanism, thereby retaining the single crystal in an upright position. Further, a sacrifice member which deforms so as to conform to the circumference of the engagement step is interposed between the clamping member and the engagement step, thereby preventing occurrence of cracking or deformation in the single crystal.

Abstract: In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080° C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0° C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0×106/cm3 or a FPD density of larger than 6.0×105/cm3. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 &mgr;m from the wafer surface.

Abstract: A value of electric current flowing a neck to a melt is detected, and it is judged that a breaking of the neck occurs when the detected value has been zero, and then a seed is lowered to dip a broken part on the melt. After that the seed is lifted again to restart a pulling operation.

Abstract: This invention provides a method and a apparatus capable of manufacturing single crystals with an oxygen density of less than 12×1017 atoms/cm3 or less than 10×1017 atoms/cm3, and wherein the oxygen density of the single crystal produced is uniformly distributed along its longitudinal axis. The electrical power inputted into the main heater 6 surrounding the quartz crucible 4 and the top heater 9 shaped like a reverse frustrated cone and disposed above the quartz crucible 4, is controlled to keep the temperature of the melt 5 in a preset range during the process of pulling up the single crystal silicon 10. When combining the main heater 6 and the top heater 9, the heat emitted from the main heater 6 can be kept small, and the heat load on the quartz crucible 4 and the amount of oxygen released from the quartz crucible 4 and dissloved into melt 5 can be reduced.

Abstract: This invention provides a method for manufacturing silicon single crystals. The method is capable of eliminating void defects existing in deep regions of a silicon single crystal despite the size of the silicon single crystal. The silicon single crystals according to this invention are pulled the radius of a ring-shaped oxidation induced stacking fault (OSF ring) of a wafer is larger than half the radius of the wafer during the process of thermal oxidation treatment.

Abstract: A seed crystal 1 for manufacturing a single crystal incorporating an unconformity portion B formed at a predetermined position apart from a leading end thereof and structured to conduct the heat of melt and interrupt propagation of dislocation caused from thermal stress produced when dipping in the melt has been performed.

Abstract: An object of the invention is to provide a single crystal clamping device and a single crystal supporting method. The single crystal clamping device does not become inclined and does not vibrate, and the center of the single crystal clamping device is congruous to the center of the growing single crystal.

Abstract: In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080.degree. C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0.degree. C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0.times.10.sup.6 /cm.sup.3 or a FPD density of larger than 6.0.times.10.sup.5 /cm.sup.3. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 .mu.m from the wafer surface.

Abstract: A single crystal pulling method includes the steps of: immersing seed crystal in a melt; growing single crystal around the seed crystal and reducing its diameter to remove dislocation in the single crystal; prior to forming a straight waist product portion of single crystal having a prescribed diameter, forming a straight waist holding portion having a diameter smaller than the prescribed diameter; holding the straight waist holding portion by using a single crystal holding device; and pulling the straight waist product portion while the straight waist holding portion is held. Preferably the step of forming the straight waist holding portion includes a step of varying a pulling speed to make unevenness in the surface thereof.

Abstract: This invention provides a method and a apparatus capable of manufacturing single crystals with an oxygen density of less than 12.times.10.sup.17 atoms/cm.sup.3 or less than 10.times.10.sup.17 atoms/cm.sup.3, and wherein the oxygen density of the single crystal produced is uniformly distributed along its longitudinal axis. The electrical power inputted into the main heater 6 surrounding the quartz crucible 4 and the top heater 9 shaped like a reverse frustrated cone and disposed above the quartz crucible 4, is controlled to keep the temperature of the melt 5 in a preset range during the process of pulling up the single crystal silicon 10. When combining the main heater 6 and the top heater 9, the heat emitted from the main heater 6 can be kept small, and the heat load on the quartz crucible 4 and the amount of oxygen released from the quartz crucible 4 and dissloved into melt 5 can be reduced.