JP7586011B2 - Silicon single crystal manufacturing equipment - Google Patents

Description

The present invention relates to a silicon single crystal manufacturing apparatus.

The pulling of silicon single crystals by the Czochralski method (CZ method) is carried out by placing a seed crystal in molten silicon in a crucible and pulling the seed crystal upward with a pulling wire.
In pulling silicon single crystals, the temperature of the silicon melt surface in the crucible is one of the important parameters, and by accurately measuring the temperature of the silicon melt surface, it becomes possible to precisely control the quality of the silicon single crystal.
Patent Document 1 discloses a technique in which a radiation thermometer and a two-dimensional thermometer are disposed in the upper part of a pull chamber, and the temperature of the surface of the silicon melt is measured using these two thermometers.

JP 2014-218402 A

Incidentally, radiation thermometers are usually aligned to the measurement position by visually looking through an attached finder. However, the measurement distance from the finder of the radiation thermometer located at the top of the pull chamber to the crucible is long, and there is a problem that the measurement position is not stable when the measurer makes visual adjustments, as it fluctuates depending on the viewer's senses and viewing angle.
In addition, when there is no silicon melt in the chamber, the chamber is in darkness, and so far, visual adjustments have usually been performed in the presence of silicon melt (a luminous substance). However, in this case, although the markings can be seen by visual inspection, there is a problem in that the target position cannot be accurately determined.

The object of the present invention is to provide a silicon single crystal manufacturing apparatus that uses a radiation thermometer to measure the temperature of the silicon melt surface, and that can accurately align the measurement position of the radiation thermometer with the target position.

The silicon single crystal manufacturing apparatus of the present invention is characterized in comprising a chamber, a crucible disposed within the chamber, a radiation thermometer having a detection element for detecting radiant light from a measurement object, a lens for focusing the radiant light onto the detection element, and a viewfinder for visually viewing the measurement object, a light source for supplying light via the viewfinder and the lens toward the measurement object along an axis coinciding with the optical axis of the lens, and an adjustment device for supporting the radiation thermometer in a state in which the measurement position by the radiation thermometer can be adjusted.
In the silicon single crystal manufacturing apparatus, the light source may be a laser device that emits a laser beam.

In the silicon single crystal manufacturing apparatus, the radiation thermometer may have a marking whose center coincides with the optical axis of the lens, and the laser device may have a focus variable mechanism.

In the silicon single crystal manufacturing apparatus, the adjustment device may be a two-axis goniostage that supports the radiation thermometer.

The silicon single crystal manufacturing apparatus may include a base plate that supports the biaxial goniostage, a mount plate that is disposed between the radiation thermometer and the biaxial goniostage, a plurality of stopper bolts each having a shaft that screws into a female screw hole formed in the base plate and a head that contacts the lower surface of the mount plate, and a nut that fixes the height of the stopper bolt.

The silicon single crystal manufacturing apparatus may further comprise an optical path of the radiant light measured by the radiation thermometer and a reflecting section that reflects the light supplied from the light source in a direction perpendicular to the incident direction.
In the silicon single crystal manufacturing apparatus, the reflecting portion may have a mirror body formed of an aluminum evaporated mirror.

The silicon single crystal manufacturing apparatus may further include a crucible shaft to which the crucible is detachably attached and which rotates and raises and lowers the crucible, and a coordinate plate that is detachably attached to the crucible shaft and onto which the light supplied from the light source is irradiated.

In the silicon single crystal manufacturing apparatus, the light source has a light source body and a light source fixing jig for fixing the light source body to the finder, the light source fixing jig includes a cylindrical portion that houses the light source body and a connection nut that connects the cylindrical portion to the finder, the cylindrical portion has a cylindrical portion main body that is cylindrical and houses the light source body, and an enlarged diameter portion formed on the outer circumferential surface of the end of the cylindrical portion main body, the connection nut has a connection nut main body that covers the enlarged diameter portion from the outer circumferential side, and a locking portion that is formed on the inner circumferential surface of the connection nut main body and locks the enlarged diameter portion from the side opposite the finder, and the enlarged diameter portion and the locking portion may be formed so as to contact each other via a tapered surface that expands in diameter as it approaches the finder side.

According to the present invention, in a silicon single crystal manufacturing device that uses a radiation thermometer to measure the temperature of the silicon melt surface, the position measured by the radiation thermometer can be accurately aligned with the target position.

1 is a vertical sectional view showing a schematic configuration of a silicon single crystal manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a partially exploded perspective view of a radiation thermometer unit fixed to a pull chamber lid according to an embodiment of the present invention. FIG. 2 is a partially exploded perspective view of the adjustment device according to the embodiment of the present invention. FIG. 2 is a side view, partially in section, illustrating the structure of a radiation thermometer and a reflecting portion according to the embodiment of the present invention. 1 is a cross-sectional view of a laser device according to an embodiment of the present invention. 1A and 1B are plan and side views of a coordinate plate according to an embodiment of the present invention. 11A and 11B are schematic diagrams illustrating a fixed state of the coordinate plate in a disk fixing step. 13A and 13B are diagrams illustrating how markings are projected onto a coordinate plate by a diffused laser beam pattern during the irradiation process.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 is a vertical cross-sectional view showing a schematic configuration of a silicon single crystal manufacturing apparatus 1 according to an embodiment of the present invention. The silicon single crystal manufacturing apparatus 1 manufactures a silicon single crystal SM by using the CZ method.
As shown in FIG. 1 , the silicon single crystal manufacturing apparatus 1 includes a chamber 50 , a crucible 51 , a heater 52 , a pulling section 53 , a heat shield 54 , a heat insulator 55 , a crucible shaft 56 , and a radiation thermometer unit 2 .

The chamber 50 comprises a main chamber 57 in which the crystal is pulled, and a pull chamber 58 connected to the upper part of the main chamber 57 and in which the pulled crystal is housed. The pull chamber 58 is provided with a gas inlet 59 for introducing an inert gas such as argon (Ar) gas into the main chamber 57. A gas exhaust port (not shown) is provided at the bottom of the main chamber 57 for discharging gas from the main chamber 57 by driving a vacuum pump.
The pull chamber 58 has a cylindrical pull chamber body 58A and a pull chamber lid 58B that covers the upper end of the pull chamber body 58A. The pull chamber lid 58B is provided with a measurement window 58C. The measurement window 58C can be made of a material that transmits radiant light from the silicon melt M, such as quartz. The main chamber 57 is provided with an observation window 57A for observing the inside of the main chamber 57.

The radiation thermometer unit 2 is fixed to the pull chamber lid 58B, and measures the temperature of the silicon melt surface at a measurement position through the measurement window 58C. The distance from the radiation thermometer unit 2 to the silicon melt surface is about 6 m.
A maintenance deck 60 is provided above the pull chamber 58. An operator can perform work (adjustments, measurements, etc.) related to the radiation thermometer unit 2 on the maintenance deck 60.

The crucible 51 is disposed in the main chamber 57 and stores the silicon melt M therein.
The heater 52 is disposed at a predetermined interval outside the crucible 51 and heats the silicon melt M in the crucible 51. The pulling unit 53 includes a cable 61 having a seed crystal SC attached to one end thereof and a pulling drive unit 62 that raises, lowers, and rotates the cable 61.

The heat shield 54 is provided to surround the silicon single crystal SM being pulled up, and blocks radiant heat from the heater 52 to the silicon single crystal SM. The crucible shaft 56 is a support shaft that supports the crucible 51 from below, and is connected to a drive device (not shown) that rotates and raises and lowers the crucible 51 at a predetermined speed. The crucible 51 is removably attached to the crucible shaft 56, and a coordinate plate 35 (described later) can be removably attached to the crucible shaft 56 in place of the crucible 51.

Next, the radiation thermometer unit 2 will be described.
The radiation thermometer unit 2 is a unit including a radiation thermometer 3 that measures the temperature of the surface of the silicon melt in the crucible 51 during the production of the silicon single crystal SM.
2 is a partially exploded perspective view of the radiation thermometer unit 2 fixed to the pull chamber lid 58B. Note that Fig. 2 shows a state in which the laser device 5 is not attached to the radiation thermometer 3 so that the viewfinder 17 of the radiation thermometer 3 can be seen.

2, the radiation thermometer unit 2 includes a radiation thermometer 3 that measures the temperature of the silicon melt surface in a non-contact manner, an adjustment device 4 that adjusts the measurement position by the radiation thermometer 3, a laser device 5 that emits a laser beam, and a reflecting section 6. The reflecting section 6 reflects the optical path P of the radiant light measured by the radiation thermometer 3 and the laser beam emitted from the laser device 5 in a direction perpendicular to the incident direction.
The finder 17 of the radiation thermometer 3 is usually used for visual temperature measurement, but in the radiation thermometer unit 2 of the present invention, the laser device 5 is attached to the finder 17. The laser device 5 is a device that functions as a light source that supplies light such as a laser beam. By attaching the laser device 5 to the finder, the laser device 5 emits a laser beam along an axis that coincides with the optical axis A of the lens 15 (see FIG. 4) of the radiation thermometer 3. This laser beam is reflected in an orthogonal direction by the reflecting portion 6 and irradiated onto the surface of the silicon melt M. On the other hand, the optical path P of the radiated light (infrared rays) from the silicon melt M measured by the radiation thermometer 3 is reflected in an orthogonal direction by the reflecting portion 6 and enters the lens 15. Therefore, the optical path P coincides with the optical path of the laser beam reflected by the reflecting portion 6, and the irradiation position of the laser beam corresponds to the measurement position of the radiation thermometer 3, so that it can be used to adjust the measurement position of the radiation thermometer 3.

The radiation thermometer 3 is fixed to the pull chamber lid 58B via the adjustment device 4. In the radiation thermometer unit 2 of this embodiment, the radiation thermometer 3 is arranged so that the optical axis A of the lens 15 is approximately horizontal, and the optical path P is converted to a substantially vertical direction via the reflector 6.

3 is a partially exploded perspective view of the adjustment device 4. The adjustment device 4 is fixed to the pull chamber lid 58B, supports the radiation thermometer 3, and adjusts the measurement position of the radiation thermometer 3.
The adjustment device 4 includes a base plate 7 fixed to the pull chamber lid 58B, a two-axis goniostage 8 fixed on the base plate 7, and a mount plate 9 fixed on the two-axis goniostage 8 and supporting the radiation thermometer 3.

The base plate 7 is a plate-like member that is fixed to the pull chamber lid 58B by a fastening member such as a bolt B1 (see FIG. 2). The base plate 7 can be formed from a plate that has sufficient strength to support the radiation thermometer 3 and the two-axis goniostage 8. The base plate 7 is fixed to the pull chamber lid 58B so that its upper surface is horizontal. The two-axis goniostage 8 is fixed to the upper surface of the base plate 7 by, for example, a bolt (not shown).

A number of stopper bolts 10 can be attached to the base plate 7. The stopper bolts 10 are bolts having a shaft 10A that screws into the female threaded hole of the base plate 7 and a head 10B on which a resin pad is provided. The stopper bolts 10 are adjusted so that the pad on the head 10B comes into contact with the underside of the mount plate 9.

The two-axis goniostage 8 is a device used for adjusting the attitude of the radiation thermometer 3 supported by the adjustment device 4. By adjusting the attitude of the radiation thermometer 3 by the two-axis goniostage 8, the angle of the optical axis A of the lens 15 is adjusted, and the measurement position by the radiation thermometer 3 is adjusted.
The two-axis goniostage 8 is a combination of two one-axis goniostages (tilt stages) whose centers of rotation are perpendicular to each other, and comprises a first goniostage 11 arranged on the base plate 7, and a second goniostage 12 connected above the first goniostage 11.

The first goniostage 11 has a first fixed stage 11A, a first movable stage 11B connected above the first fixed stage 11A, and a first handle 11C. The upper surface of the first fixed stage 11A is a cylindrical curved surface centered on an axis parallel to the Y axis (see FIG. 3), and the lower surface of the first movable stage 11B is a curved surface that follows the upper surface of the first fixed stage 11A. By rotating the first handle 11C, the first movable stage 11B rotates about an axis parallel to the Y axis.

The second goniostage 12 has a second fixed stage 12A, a second movable stage 12B connected to the upper part of the second fixed stage 12A, and a second handle 12C. The upper surface of the second fixed stage 12A is a cylindrical curved surface centered on an axis parallel to the X-axis (see FIG. 3), and the lower surface of the second movable stage 12B is a curved surface that follows the upper surface of the second fixed stage 12A. By rotating the second handle 12C, the second movable stage 12B rotates about an axis parallel to the X-axis.
Here, the X-axis is an axis that passes through the center of the chamber 50 and extends horizontally, and the Y-axis is an axis that is perpendicular to the X-axis and extends horizontally.

The mount plate 9 is a plate-like member that is fixed to the upper surface of the second goniostage 12 by a fastening member such as a bolt B2, and is disposed between the radiation thermometer 3 and the two-axis goniostage 8. The mount plate 9 can be formed of a plate having sufficient strength to support the radiation thermometer 3. The mount plate 9 has a plurality of radiation thermometer fixing holes 9A formed therein, which are used when fixing the radiation thermometer 3 onto the mount plate 9.

Next, a description will be given of the configuration of the radiation thermometer 3. Fig. 4 is a side view, partly in cross section, illustrating the structures of the radiation thermometer 3 and the reflecting portion 6.
As shown in FIG. 4 , the radiation thermometer 3 includes a substantially cylindrical casing 14 , a lens 15 arranged in the casing 14 , a detection element 16 arranged in the casing 14 , and a finder 17 .

The lens 15 is disposed so that its optical axis A coincides with the central axis of the casing 14. That is, by installing the radiation thermometer 3 so that the central axis of the casing 14 is horizontal, the optical axis A of the lens 15 can be made horizontal.
The radiation thermometer 3 is a type of radiation thermometer that focuses radiant light of a measurement object, which is taken in through an opening 14A formed in a casing 14, on a detection element 16 via a lens 15 and a beam splitter 18. The beam splitter 18 is for separating radiant light from visible light, and may be, for example, a half mirror.

The detection element 16 is an element that is sensitive to radiant light and generates an electrical signal corresponding to the energy of the radiant light.
The radiation thermometer 3 has a marking (e.g., a black circle) whose center coincides with the optical axis A of the lens 15. The marking is written so that its center is the measurement center. This marking is usually formed directly on the lens 15, but may be formed on a part other than the lens 15. The distance coefficient of the radiation thermometer 3 is selected according to the measurement distance (for example, 6,000 mm in this embodiment) and the size of the measurement object.

Next, a description will be given of the reflecting portion 6. The reflecting portion 6 is a mechanism for bending the optical path P of the radiated light at a right angle.
4, the reflecting section 6 has a mirror casing 30 fixed to the casing 14 of the radiation thermometer 3, a mirror body 31 fixed inside the mirror casing 30, and a shield pipe 32 connected to the lower part of the mirror casing 30 and providing shielding between the mirror casing 30 and the measurement window 58C. A small gap is provided between the shield pipe 32 and the measurement window 58C so that the shield pipe 32 does not collide with the measurement window 58C when the radiation thermometer 3 is tilted by the two-axis goniostage 8.
The mirror casing 30 is a casing that houses the mirror body 31 so that the mirror body 31 is at an appropriate angle with respect to the optical axis A of the lens 15. The mirror casing 30 has a function of blocking external light.

The mirror body 31 is formed of a material capable of reflecting radiant light (infrared light) and laser light. The mirror body 31 can be formed of, for example, an aluminum-deposited mirror. An aluminum-deposited mirror has a wider wavelength band than a gold-deposited glass mirror, which is made of quartz glass with a gold-deposited coating on one side, and is also suitable for laser reflection. The mirror body 31 is not limited to an aluminum-deposited mirror, and a gold-deposited mirror may be used, for example. A gold-deposited mirror has a high reflectance under the best conditions for infrared and near-infrared wavelengths, but silicon is said to have a wavelength of about 0.6 μm (600 nm) at about 600° C., and at higher temperatures it has a shorter wavelength. In that range, there is not much difference in reflectance between the aluminum-deposited mirror and the gold-deposited mirror. For this reason, an aluminum-deposited mirror, which is less expensive than a gold-deposited mirror, can be used.
The shield pipe 32 is a cylindrical member connected to the lower portion of the mirror casing 30. The shield pipe 32 has a function of blocking external light between the mirror casing 30 and the measurement window 58C.

Next, the laser device 5 will be described.
5, the laser device 5 has a laser projector 19 (light source body) and a laser fixing jig 20 (light source fixing jig) for fixing the laser projector 19 to the finder 17 of the radiation thermometer 3. The laser projector 19 is fixed by the laser fixing jig 20 so that the axis B of the laser beam coincides with the optical axis A of the lens 15. As a result, the laser beam emitted from the laser projector 19 is irradiated onto the center of the measurement position (target) of the radiation thermometer 3 when the pattern shape is a spot pattern (light spot).

The laser projector 19 is a device that emits a laser beam and irradiates an irradiation target with a laser pattern. The laser projector 19 is cylindrical and has a laser irradiation port 19A at one end. The laser projector 19 emits a laser beam in the axial direction of the laser projector 19.
Laser projector 19 can adjust the focus by operating focus adjustment unit 19B to change the pattern shape to a spot pattern or a diffuse pattern with a wide area. In other words, laser projector 19 has a focus variable mechanism. Laser projector 19 can be supplied with power from, for example, a battery pack consisting of multiple batteries. Power is supplied to laser projector 19 via cable 19C.
The laser projector 19 may be, for example, an LDS series laser projector manufactured by Takenaka Optonic Co., Ltd.

The laser fixing jig 20 includes a cylindrical section 21 that houses the laser projector 19, a connecting nut 22 that is attached to one end of the cylindrical section 21 and fixed to the finder 17 of the radiation thermometer 3, and a retaining nut 23 that closes the other end of the cylindrical section 21 and supports the other end of the laser projector 19.

The tube section 21 is a cylindrical member and has a tube section main body 24 with a cylindrical inner peripheral surface into which the laser projector 19 is fitted, a protrusion portion 25 formed on the inner peripheral surface at one end of the tube section main body 24, an enlarged diameter portion 26 formed on the outer peripheral surface at one end of the tube section main body 24, and an adjustment opening 27 that penetrates between the outer peripheral surface and the inner peripheral surface of the tube section main body 24.

The protrusion 25 is formed on the inner periphery of the cylindrical body 24 so as to protrude around the entire circumference of the inner periphery of the cylindrical body 24. The protrusion 25 is a portion that comes into contact with the tip of the laser projector 19 housed in the cylindrical body 21 and restricts the laser projector 19 from moving along the axis B toward one end of the cylindrical body 24 (in the direction of B1).

The enlarged diameter portion 26 is a portion where the cylindrical body 24 is enlarged in diameter, and the outer diameter of the enlarged diameter portion 26 is slightly larger than the outer diameter of the cylindrical body 24, and is sized to fit with the inner peripheral surface of the connection nut body 22A described below. The surface of the enlarged diameter portion 26 facing the B2 direction and abutting against the connection nut 22 described below is a tapered surface 26A that has a tapered shape that gradually enlarges in diameter as it approaches the B1 direction. Note that the B2 direction is the opposite direction to the B1 direction.

The adjustment opening 27 is an opening that allows operation of the focus adjustment section 19B of the laser projector 19 housed in the cylindrical section 21.

The retaining nut 23 has a retaining nut body 23A that screws into a male screw groove 24A formed on the outer circumferential surface of the cylindrical body 24, and a nut protrusion 23B formed on the inner circumferential surface of the retaining nut body 23A. The nut protrusion 23B is formed around the entire inner circumferential surface of the retaining nut body 23A.
The retaining nut 23 is a member that restricts the movement of the laser projector 19 in the B1 direction.
The laser fixing jig 20 also has a rubber ring 28 that is disposed between the laser projector 19 and the nut protrusion 23B of the retaining nut 23 and functions as a buffer material.

The connecting nut 22 is a member that holds the cylindrical portion 21 and is screwed onto the finder 17 of the radiation thermometer 3 .
Specifically, the connection nut 22 is a union nut that covers the expanded diameter portion 26 of the tubular portion 21 from the outer circumferential side and has a connection nut main body 22A that screws into a male thread groove formed on the outer circumferential surface of the finder 17 of the radiation thermometer 3, and a locking portion 22B formed on the inner circumferential surface of the connection nut main body 22A and locks the expanded diameter portion 26 from the side opposite the finder 17.
The locking portion 22B is formed around the entire inner circumferential surface of the connection nut body 22A. The inner diameter of the locking portion 22B is smaller than the outer diameter of the enlarged diameter portion 26 of the cylindrical portion 21 and slightly larger than the outer diameter of the cylindrical portion body 24.

The surface of the locking portion 22B facing the B1 direction and coming into contact with the enlarged diameter portion 26 of the tubular portion 21 is a tapered surface 22C that gradually increases in diameter in the B1 direction. The tapered surface 26A of the enlarged diameter portion 26 and the tapered surface 22C of the locking portion 22B are formed to be in surface contact with each other.
In this way, since the cylindrical portion 21 and the connecting nut 22 are in contact with each other via the tapered surfaces 26A and 22C, it is possible to improve the reproducibility of the angle of the cylindrical portion 21 when attaching and detaching the laser fixing jig 20. This makes it easy to reuse the laser projector 19 and the laser fixing jig 20, which can be used only when adjusting the measurement position of the radiation thermometer 3, and one laser projector 19 can be reused by multiple silicon single crystal manufacturing apparatuses 1, thereby reducing costs.
Furthermore, since the cylindrical portion 21 and the connecting nut 22 are in contact via the tapered surfaces 26A, 22C, the angle of the cylindrical portion 21 can be easily fine-tuned when the axis B of the laser beam and the optical axis A of the lens 15 do not coincide.

The laser fixing jig 20 has a ring member 29 that is placed between the end face of the cylindrical portion 21 and the finder 17 when the laser projector 19 is attached to the radiation thermometer 3 using the laser fixing jig 20. The ring member 29 is formed so that its outer diameter is approximately the same as the outer diameter of the expanded diameter portion 26 of the cylindrical portion 21, and its inner diameter is approximately the same as the inner diameter of the cylindrical portion main body 24. The ring member 29 is formed from a resin such as polytetrafluoroethylene (PTFE).

Next, a method for mounting the laser projector 19 using the laser fixing jig 20 will be described.
First, the ring member 29 is attached to the end face of the cylindrical portion 21 in the direction B1 with an adhesive so that the inner peripheral surface of the cylindrical portion 21 and the inner peripheral surface of the ring member 29 do not shift from each other. Next, the cylindrical portion 21 is inserted into the connecting nut 22, and the connecting nut 22 and the cylindrical portion 21 are combined.
Next, the laser projector 19 is inserted into the inside of the cylindrical portion 21. Next, the rubber ring 28 is affixed to the retaining nut 23, and then the retaining nut 23 is attached to the cylindrical portion 21. In this manner, the laser fixing jig 20 incorporating the laser projector 19 is assembled.
Then, the connecting nut 22 of the laser fixing jig 20 is attached to the finder 17 of the radiation thermometer 3. In this way, the laser projector 19 is attached to the radiation thermometer 3.

Next, we will explain the coordinate plate 35 used when adjusting the measurement position of the radiation thermometer 3 using the adjustment device 4. The coordinate plate 35 is a circular plate that is fixed to the upper end of the crucible shaft 56 after the crucible 51 is removed when adjusting the measurement position of the radiation thermometer 3, and functions as a virtual liquid surface that mimics the surface of the silicon melt.

Fig. 6 is a plan view and a side view of the coordinate plate 35. As shown in Fig. 6, the coordinate plate 35 is a disk-shaped member. The coordinate plate 35 is fixed to the upper end of the crucible shaft 56 so that its main surface is horizontal.
The coordinate plate 35 is preferably made of a material that does not cause any problems even if it comes into contact with the crucible shaft 56, for example, a resin such as polytetrafluoroethylene.
The coordinate plate 35 has a pattern formed by groove machining on one side, which functions as a coordinate when marking a target position. The pattern may be a lattice pattern (FIG. 6(a)), or a pattern consisting of a plurality of concentric circles and a plurality of lines extending radially from the center (FIG. 6(b)). Furthermore, each of these patterns may be formed on the front and back surfaces of the coordinate plate 35.

Next, a method for adjusting the temperature measurement position using the silicon single crystal manufacturing apparatus 1 will be described.
The method for producing a silicon single crystal includes a target position determining step, a coordinate plate fixing step, an irradiation step, and an adjustment step.

The target position determination step is a step of determining a target position on the surface of the silicon melt at which effective crystal quality control is possible by measuring the temperature.
In the target position determination step, the temperature distribution of the silicon melt surface is measured, for example, by a two-dimensional thermometer. Then, based on the measured temperature distribution, a normal low temperature region where the temperature remains lower than other regions is identified. Then, the target position is set inside this normal low temperature region.

In the coordinate plate fixing process, as shown in FIG. 7, the crucible 51 is removed and the coordinate plate 35 is attached to the upper end of the crucible shaft 56. Next, the crucible shaft 56 is moved up and down to move the coordinate plate 35 so that the top surface of the coordinate plate 35 is at the same height as the silicon melt surface.

In the irradiation process, after the radiation thermometer unit 2 is attached to the pull chamber 58, power is supplied to the laser device 5 and the focus variable mechanism is operated to irradiate the diffused laser beam onto the coordinate plate 35. As shown in FIG. 8, the marking of the radiation thermometer 3 is projected onto the coordinate plate 35 by the pattern LP of the diffused laser beam. If the axis B of the laser beam (see FIG. 5) and the optical axis A of the lens 15 (see FIG. 4) do not coincide, i.e., if the projected marking is not located at the center of the pattern LP of the diffused laser beam, the angle of the cylindrical portion 21 of the laser fixing jig 20 is fine-tuned.

In the adjustment step, the adjustment device 4 is operated so that the target position determined in the target position determination step coincides with the center of the projected marking. At this time, it is preferable to arrange an operator who observes the coordinate plate 35 through the observation window 57A, separately from the operator on the maintenance deck 60.
Specifically, first, the head of the stopper bolt 10 that contacts the lower surface of the mount plate 9 is lowered by screwing the screw of the stopper bolt 10 into the base plate 7, and is spaced about 5 to 10 mm from the lower surface of the mount plate 9. Next, the radiation thermometer 3 is rotated about an axis along the Y axis by rotating the first handle 11C of the two-axis goniostage 8, and the radiation thermometer 3 is rotated about an axis along the X axis by rotating the second handle 12C. By using the two-axis goniostage 8, a tilt of, for example, 0.1° moves the measurement position 6 m away by about 10.5 mm (tan 0.1°×6,000 mm). This allows the measurement position of the radiation thermometer 3 to be precisely adjusted.
After completing the adjustment to the target position, the head of the stopper bolt 10 is raised by loosening the screwing of the stopper bolt 10 from the base plate 7. When the head of the stopper bolt 10 comes into contact with the lower surface of the mount plate 9, the two hexagonal nuts 10C disposed between the stopper bolt 10 and the base plate 7 are tightened toward the base plate 7 to fix the height of the stopper bolt 10.
Next, the coordinate plate 35 is removed from the crucible shaft 56, and the crucible 51 is attached. Also, the laser fixing jig 20 is removed from the finder 17.

By performing the above steps, the measurement position of the radiation thermometer 3 can be accurately aligned to the target position. This makes it possible to pull up a silicon single crystal while measuring the temperature of the silicon melt surface at the desired position.

In addition, by using the two-axis goniostage 8 as the adjustment device 4, it is possible to finely adjust the measurement position by the radiation thermometer 3. Furthermore, since the measurement position of the radiation thermometer 3 is changed simply by adjusting the angle by the two-axis goniostage 8, there is no need to tighten the bolts that secure the mount plate 9 etc. after adjustment, and there is no fluctuation in the measurement position.
Furthermore, after adjusting the biaxial goniometer stage 8, the stopper bolt 10 is fixed with its head in contact with the underside of the mount plate 9, thereby preventing fluctuations in the temperature measurement position caused by fluctuations in the biaxial goniometer stage 8 due to changes over time or mechanical micro-vibrations generated by the silicon single crystal manufacturing apparatus 1.

Furthermore, since it is recommended that the goniostage be installed on a horizontal surface, the optical path P of the radiated light is reflected in an orthogonal direction by the reflector 6, making it possible to carry out adjustment work using the two-axis goniostage 8. Furthermore, the combination of the reflector 6 and the two-axis goniostage 8 makes it possible to carry out work on the maintenance deck 60, making the adjustment work easier.
Furthermore, by using an aluminum-evaporated mirror as the mirror of the reflecting portion 6, the reflecting portion 6 can be made suitable for reflecting not only radiant light but also laser beams.
In addition, by configuring the irradiated laser beam to project the marking using a diffused laser beam, the marking that accurately matches the target can be effectively utilized, thereby improving the accuracy of adjustment.
Furthermore, by using a laser projector 19 that can be powered by a battery pack consisting of multiple batteries, the portability of the laser projector 19 can be increased, making it easier to work at high altitudes.
In addition, during the adjustment process, by using a coordinate plate 35 that functions as a virtual liquid surface simulating the surface of the silicon melt, the measurement position can be accurately grasped by the marking projected onto the coordinate plate 35 by the laser beam, and this measurement position can be accurately aligned with the target position.

[Modification]
The present invention is not limited to the configurations described in the above embodiments, and modifications within the scope of the present invention that can achieve the object of the present invention are included in the present invention.
In the above embodiment, the laser device 5 including the laser projector 19 is used as a light source, but the present invention is not limited to this, and any light source that emits light with a certain degree of linearity may be used. For example, a light source such as an LED light source may be used.
In the above embodiment, a two-axis goniostage is used as the adjustment device 4, but other configurations may be used as long as the device is capable of adjusting the measurement position of the radiation thermometer 3. For example, the adjustment device 4 may be a stage device having an independent structure for the X-axis, Y-axis, and θ-axis.
In the above embodiment, the pattern shape of the laser beam emitted from the laser projector 19 is a diffuse pattern, but it may be a spot pattern. This makes it possible to apply the present invention to a radiation thermometer that does not have a marking.
In the above embodiment, the reflecting section 6 is provided to reflect the radiated light, but the present invention is not limited to this, and the radiation thermometer 3 may directly receive the radiated light. For example, the reflecting section 6 can be omitted by mounting an L-shaped bracket on the two-axis goniostage and mounting the radiation thermometer 3 on the L-shaped bracket so that the optical axis is aligned vertically.
Furthermore, the coordinate plate 35 does not have to be a disk, but may be a polygon. The markings on the radiation thermometer 3 are not limited to black circles, and the shape and color of the markings can be set appropriately.

1...silicon single crystal manufacturing device, 2...radiation thermometer unit, 3...radiation thermometer, 4...adjustment device, 5...laser device (light source), 6...reflection section, 7...base plate, 8...two-axis goniostage, 9...mount plate, 10...stopper bolt, 10A...shaft section, 10B...head, 10C...nut, 15...lens, 16...detection element, 17...finder, 19...laser projector (light source body), 19B...focus adjustment section, 20...laser fixing jig (light source fixing jig), 21...tubular section, 22...connecting nut, 22A...connecting nut body, 22B...locking section, 24...tubular section body, 26...expansion section, 31...mirror body, 35...coordinate plate, 50...chamber, 51...crucible 51, 53...pulling section, A...optical axis, B...axis of laser beam, M...silicon melt, P...optical path, SM...silicon single crystal.

Claims (16)

A chamber;
a crucible disposed within the chamber;
a radiation thermometer having a detection element for detecting radiant light from a measurement object, a lens for collecting the radiant light on the detection element, a finder for visually recognizing the measurement object, and a beam splitter for separating the radiant light from visible light;
a laser device that emits a laser beam along an axis that coincides with an optical axis of the lens toward the measurement target through the finder and the lens;
an adjustment device that supports the radiation thermometer in a state in which the measurement position of the radiation thermometer can be adjusted ;
the radiation thermometer has a marking whose center coincides with the optical axis of the lens;
The laser device is a silicon single crystal manufacturing device having a focus variable mechanism . A chamber;
a crucible disposed within the chamber;
a radiation thermometer having a detection element for detecting radiant light from a measurement object, a lens for collecting the radiant light on the detection element, a finder for visually recognizing the measurement object, and a beam splitter for separating the radiant light from visible light;
a laser device that emits a laser beam along an axis that coincides with an optical axis of the lens toward the measurement target through the finder and the lens;
an adjustment device that supports the radiation thermometer in a state in which the measurement position of the radiation thermometer can be adjusted;
A silicon single crystal manufacturing apparatus having an optical path of radiant light measured by the radiation thermometer and a reflecting section that reflects the laser beam emitted from the laser device in a direction perpendicular to the direction of incidence. The silicon single crystal manufacturing apparatus according to claim 2 ,
The reflecting portion is a silicon single crystal manufacturing apparatus having a mirror body formed of an aluminum evaporated mirror. The silicon single crystal manufacturing apparatus according to claim 2 or 3 ,
The silicon single crystal manufacturing apparatus, wherein the adjustment device is a two-axis goniostage that supports the radiation thermometer. The silicon single crystal manufacturing apparatus according to claim 4 ,
A base plate supporting the two-axis goniostage;
a mount plate disposed between the radiation thermometer and the two-axis goniostage;
a plurality of stopper bolts each having a shaft portion that screws into a female screw hole formed in the base plate and a head portion that contacts the lower surface of the mount plate;
and a nut that fixes the height of the stopper bolt. A chamber;
a crucible disposed within the chamber;
a radiation thermometer having a detection element for detecting radiant light from a measurement object, a lens for collecting the radiant light on the detection element, a finder for visually recognizing the measurement object, and a beam splitter for separating the radiant light from visible light;
a laser device that emits a laser beam along an axis that coincides with an optical axis of the lens toward the measurement target through the finder and the lens;
an adjustment device that supports the radiation thermometer in a state in which the measurement position of the radiation thermometer can be adjusted;
a crucible shaft to which the crucible is detachably attached and which rotates and lifts the crucible;
a coordinate plate that is detachably attached to the crucible shaft and onto which the laser beam emitted from the laser device is irradiated. 7. The silicon single crystal manufacturing apparatus according to claim 6 ,
the laser device includes a light source body and a light source fixing jig for fixing the light source body to the finder,
The light source fixing jig is
A cylindrical portion that accommodates the light source body;
a connecting nut for connecting the cylindrical portion to the viewfinder,
The cylindrical portion has a cylindrical body that is cylindrical and accommodates the light source body, and an expanded diameter portion formed on an outer circumferential surface of an end portion of the cylindrical body,
The connection nut has a connection nut body that covers the enlarged diameter portion from an outer circumferential side, and a locking portion that is formed on an inner circumferential surface of the connection nut body and locks the enlarged diameter portion from a side opposite to the finder,
The silicon single crystal manufacturing apparatus, wherein the enlarged diameter portion and the locking portion are formed so as to come into contact with each other via a tapered surface that enlarges in diameter toward the finder side. A chamber;
a crucible disposed within the chamber;
a radiation thermometer having a detection element for detecting radiant light from a measurement object, a lens for collecting the radiant light on the detection element, a finder for visually recognizing the measurement object, and a beam splitter for separating the radiant light from visible light;
a laser device that emits a laser beam along an axis that coincides with an optical axis of the lens toward the measurement target through the finder and the lens;
an adjustment device that supports the radiation thermometer in a state in which the measurement position of the radiation thermometer can be adjusted;
the laser device includes a light source body and a light source fixing jig for fixing the light source body to the finder,
The light source fixing jig is
A cylindrical portion that accommodates the light source body;
a connecting nut for connecting the cylindrical portion to the viewfinder,
The cylindrical portion has a cylindrical body that is cylindrical and accommodates the light source body, and an expanded diameter portion formed on an outer circumferential surface of an end portion of the cylindrical body,
The connection nut has a connection nut body that covers the enlarged diameter portion from an outer circumferential side, and a locking portion that is formed on an inner circumferential surface of the connection nut body and locks the enlarged diameter portion from a side opposite to the finder,
The silicon single crystal manufacturing apparatus, wherein the enlarged diameter portion and the locking portion are formed so as to come into contact with each other via a tapered surface that enlarges in diameter toward the finder side. The silicon single crystal manufacturing apparatus according to any one of claims 6 to 8,
The silicon single crystal manufacturing apparatus, wherein the adjustment device is a two-axis goniostage that supports the radiation thermometer. 10. The silicon single crystal manufacturing apparatus according to claim 9,
A base plate supporting the two-axis goniostage;
a mount plate disposed between the radiation thermometer and the two-axis goniostage;
a plurality of stopper bolts each having a shaft portion that screws into a female screw hole formed in the base plate and a head portion that contacts a lower surface of the mount plate;
and a nut that fixes the height of the stopper bolt. 2. The silicon single crystal manufacturing apparatus according to claim 1,
The silicon single crystal manufacturing apparatus, wherein the adjustment device is a two-axis goniostage that supports the radiation thermometer. The silicon single crystal manufacturing apparatus according to claim 11,
A base plate supporting the two-axis goniostage;
a mount plate disposed between the radiation thermometer and the two-axis goniostage;
a plurality of stopper bolts each having a shaft portion that screws into a female screw hole formed in the base plate and a head portion that contacts a lower surface of the mount plate;
and a nut that fixes the height of the stopper bolt. In the silicon single crystal manufacturing apparatus according to any one of claims 1 to 12,
A silicon single crystal manufacturing apparatus having an optical path of radiant light measured by the radiation thermometer and a reflecting section that reflects the laser beam emitted from the laser device in a direction perpendicular to the direction of incidence. The silicon single crystal manufacturing apparatus according to claim 13,
The reflecting portion is a silicon single crystal manufacturing apparatus having a mirror body formed of an aluminum evaporated mirror. In the silicon single crystal manufacturing apparatus according to any one of claims 1 to 5 and claims 11 to 14,
a crucible shaft to which the crucible is detachably attached and which rotates and lifts the crucible;
a coordinate plate that is detachably attached to the crucible shaft and onto which the laser beam emitted from the laser device is irradiated. In the silicon single crystal manufacturing apparatus according to any one of claims 1 to 5 and claims 11 to 15,
the laser device includes a light source body and a light source fixing jig for fixing the light source body to the finder,
The light source fixing jig is
A cylindrical portion that accommodates the light source body;
a connecting nut for connecting the cylindrical portion to the viewfinder,
The cylindrical portion has a cylindrical body that is cylindrical and accommodates the light source body, and an expanded diameter portion formed on an outer circumferential surface of an end portion of the cylindrical body,
The connection nut has a connection nut body that covers the enlarged diameter portion from an outer circumferential side, and a locking portion that is formed on an inner circumferential surface of the connection nut body and locks the enlarged diameter portion from a side opposite to the finder,
The silicon single crystal manufacturing apparatus, wherein the enlarged diameter portion and the locking portion are formed so as to come into contact with each other via a tapered surface that enlarges in diameter toward the finder side.

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