JP2008018478A - Bar-like material cutting method and cutting device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting method which restrains the occurrence of cracks, improves cutting efficiency, and also improves yield and metal contamination in cutting a workpiece having internal stress. <P>SOLUTION: In the method for cutting a bar-like workpiece having an internal stress using a mechanical cutting means, while the workpiece is rotated around the axial section vertical to the longitudinal direction of the workpiece in the range equal to or larger than 100° and under 360°, the bar-like material is cut. A cutting device uses the above cutting method. In the cutting method, a fixed abrasive grain wire saw is used as a cutting means, while as a workpiece, a bar-like polysilicon manufactured by the Siemens method is used, and preferably load of 3-10 kgf per wire is applied to the fixed abrasive grain wire saw. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of cutting a rod-shaped material having internal stress and a cutting apparatus using the same, and more specifically, the Czochralski method (hereinafter referred to as “CZ method”) used for manufacturing single crystal silicon for semiconductors. )), A cutting method and apparatus capable of efficiently cutting polycrystalline silicon that can be used as a raw material for production from a rod-shaped workpiece without causing cracks in the cut surface.

  In the production of single crystal silicon for semiconductors, the rotational pulling method by the CZ method is frequently used. In this CZ method, polycrystalline silicon is melted in a crucible, a seed crystal of silicon is immersed in the melt, and the seed crystal is pulled while rotating to grow a single crystal used as a material for a semiconductor device. It is a method to do.

  The polycrystalline silicon used as the melting material of the CZ method is mainly rod-shaped polycrystalline silicon produced by the Siemens method, and is cut into an appropriate size using a cutting machine or crushed into a lump. According to the manufacturing raw material.

  The Siemens method is a method in which high-purity silicon seeds are energized and heated, silane-based gas and hydrogen are reacted on the seed surface, and polycrystalline silicon is grown by vapor phase growth. When polycrystalline silicon produced by the Siemens method is mechanically cut as a raw material for the CZ method, the internal stress remaining in the polycrystalline silicon becomes a problem.

  In the process of growing polycrystalline silicon by the Siemens method, heat is released from the surface of the vapor-grown polycrystalline silicon, so that the growing polycrystalline material has a higher temperature inside. For this reason, the obtained polycrystalline silicon takes a cooling form in which the surface is cooled first and contracts, and then the central portion contracts, and tensile stress is generated inside the rod-shaped material, and the surface of the rod-shaped material An internal stress in which compressive stress remains on the side is generated.

  In particular, in the Siemens method, a high reaction temperature, for example, a high temperature of 1000 ° C. or more is required to react the silane-based gas with hydrogen, so that the difference between the internal temperature of the crystal and the surface temperature increases during the cooling process after the growth reaction. As a result, the internal stress generated in the crystal also increases.

  As described above, rod-shaped polycrystalline silicon obtained by the Siemens method is used as a raw material for the production of the CZ method. When polycrystalline silicon is cut by a cutting machine, silicon is a brittle material with high hardness. When internal stress remains in the crystal, cracks are likely to occur on the cut surface.

  When cracks occur on the cut surface of the polycrystalline silicon, dirt inside the cracks is not removed even by acid cleaning after the cutting process, and the quality of the subsequent polycrystalline silicon is deteriorated. Further, when the acid itself remains inside the crack, a thick silicon oxide film is generated while embracing contamination (impurities) inside the crack, which further deteriorates the quality of the polycrystalline silicon.

  In the Siemens method, in order to improve production efficiency, a large amount of polycrystalline silicon is produced using a large-sized reactor. However, since the reaction rate of silane gas and hydrogen in the Siemens method depends on the ambient temperature, if the temperature distribution conditions and gas supply conditions in the furnace change as the reactor size increases, the growth rate of polycrystalline silicon (Precipitation) also varies depending on these conditions.

  For example, if a low temperature part occurs in the reactor, the growth of the silicon crystal at the low temperature part is hindered, resulting in thinning of the rod-like polycrystalline silicon, resulting in a polycrystalline silicon shape after growth. May cause ellipses and curves. In addition, even when a portion with a small gas supply amount is generated in the reaction furnace, the growth of the polycrystalline silicon crystal becomes insufficient, which may cause an ellipse or a curve.

  Therefore, when the reaction furnace is enlarged, the temperature distribution in the reaction furnace becomes non-uniform, and when it becomes difficult to supply gas uniformly and stably, the shape of the polycrystalline silicon grown by the Siemens method is elliptical. Or bend, and unevenness tends to occur on the crystal surface called popcorn.

  Thus, when an elliptical shape, a curved shape, and popcorn are generated in the polycrystalline silicon, a problem occurs when the obtained polycrystalline silicon is cut. Normally, rod-shaped polycrystalline silicon is cut while rotating to relieve internal stress, but when the shape of polycrystalline silicon is not a regular cylinder, but an ellipse, a curve, and an uneven shape on the surface, The work blade is displaced or displaced due to rotation, and stable cutting becomes difficult.

  For this reason, conventionally, various studies have been made on cutting methods capable of stably cutting polycrystalline silicon without generating cracks on the cut surface. For example, Patent Document 1 discloses an apparatus for cutting while suppressing vibration by rotating rod-shaped polycrystalline silicon using a rotary drive device and supporting the vicinity of the cutting portion using a fluid pressure cylinder mechanism and a roller. Is disclosed. According to this cutting device, the polycrystalline silicon can be cut with high efficiency without causing cracks or the like.

  However, the disclosed cutting apparatus has a very complicated structure and requires a large amount of equipment costs, and the cost required for cutting rod-shaped polycrystalline silicon is greatly increased. In addition, since an outer peripheral blade is used for cutting in the above apparatus, when cutting polycrystalline silicon, the metal blade may come into direct contact with the rod-shaped polycrystalline silicon. There is also.

  Further, Patent Document 2 discloses an endless wire saw with fixed abrasive, wherein an endless wire with fixed abrasive is attached to a swingable arm, and a material to be cut is swingable. Yes.

  However, the wire saw disclosed in Patent Document 2 moves the one end of the wire arm without changing the position of the material to be cut in order to reduce the size of the device, cut the wire, and adjust the cutting angle of the material to be cut. In this method, the material to be cut is rotated in one direction so that the cut amounts at both ends of the cut portion coincide. For this reason, since the swing angle is limited to 90 ° or less, when internal stress remains in the material to be cut, the internal stress cannot be sufficiently relaxed, and a crack is generated on the cut surface. There's a problem.

JP 2003-320520 A Japanese Patent Laid-Open No. 11-188602

  As described above, when polycrystalline silicon is cut out from a rod-like crystal and used as a production raw material in the CZ method, it is necessary to prevent cracks generated on the cut surface in order to ensure the quality of the produced single crystal silicon. . Furthermore, it is desirable to improve cutting efficiency by appropriately managing cutting conditions, to reduce cutting loss during cutting, and to improve production efficiency.

  The present invention has been made in view of the above-described situation, and at the time of cutting polycrystalline silicon, by reducing the internal stress remaining in the crystal, the generation of cracks in the cut surface is suppressed, and further cutting is performed. An object of the present invention is to provide a cutting method of a rod-shaped material excellent in production efficiency and a cutting apparatus using the same, which can improve the cutting efficiency by managing the load that is sometimes applied, and can also improve the cutting yield and metal contamination. It is said.

  In order to solve the above problems, the present inventors have made various studies on a method for cutting polycrystalline silicon. As a result, even when a rod-shaped workpiece having internal stress is cut, the workpiece is repeatedly rotated or reversed within an appropriate range, and is cut while performing a rotating motion that rotates in the forward and reverse directions. As a result, the concentration of internal stress on the cut surface can be alleviated, cracks can be suppressed, and the cutting blade can be misaligned even for workpieces with ellipses, curves, and uneven surfaces. It was clarified that stable cutting is possible without occurring.

  In addition, when cutting the rod-shaped workpiece, it is easy to adjust the load applied to the wire by using a fixed-abrasive wire saw, and cutting by managing the load load within an appropriate range The efficiency can be improved, the cutting cost can be reduced compared to the peripheral blade cutting machine, the cutting loss can be reduced, and the metal blade can be prevented from coming into direct contact with the work material, thereby preventing metal contamination. It has been found that an excellent cutting method can be realized.

  The present invention has been completed based on the above findings, and the method of cutting a rod-shaped material of the present invention is a method of cutting a rod-shaped workpiece having internal stress using a mechanical cutting means, The workpiece is cut while being rotated within a range of 100 ° or more and less than 360 ° with the axial cross-sectional center perpendicular to the longitudinal direction of the workpiece as a rotation center.

  In the rod-shaped material cutting method of the present invention, it is desirable to use a fixed abrasive wire saw as the cutting means. It is easy to improve cutting efficiency and reduce cutting loss, prevent metal contamination, and improve cutting efficiency.

  In the rod-shaped material cutting method of the present invention, rod-shaped polycrystalline silicon produced by the Siemens method can be used as a workpiece. Even if it is rod-like polycrystalline silicon in which internal stress tends to remain, the internal stress can be relaxed and the occurrence of cracks can be suppressed.

  Furthermore, in the method for cutting a rod-shaped material of the present invention, it is desirable to apply a load of 3 to 10 kgf per wire to the wire of the fixed abrasive wire saw. Thereby, the cutting speed can be improved without causing wire breakage.

  The cutting device of the present invention is a cutting device that cuts rod-shaped polycrystalline silicon produced by the Siemens method substantially perpendicularly to the longitudinal direction using a fixed abrasive wire, and is capable of rotating the rod-shaped polycrystalline silicon. Means for holding the rod-shaped polycrystalline silicon in a normal / reverse direction within a range of 100 ° or more and less than 360 ° with the axial cross-sectional center perpendicular to the longitudinal direction as the rotation center; A means for feeding a fixed abrasive wire used for a fixed abrasive wire saw to cut the rod-like polycrystalline silicon; and a means for applying a load to the fed fixed abrasive wire. It is characterized by.

  The cutting device of the present invention has the above-described configuration, so that the cutting method of the present invention can be applied, and even when cutting rod-like polycrystalline silicon that retains internal stress, The crack which generate | occur | produces can be suppressed. In this case, in order to improve the cutting speed, it is desirable to apply a load of 3 to 10 kgf per said fixed abrasive wire.

  According to the rod-shaped material cutting method and the cutting device of the present invention, when cutting a workpiece having internal stress, the internal stress concentrated on the cut surface can be relaxed and the occurrence of cracks can be suppressed, and the load condition is appropriately set. Thus, the cutting efficiency can be improved, the cutting loss can be reduced, the yield can be improved, and the metal contamination on the cut surface can be suppressed.

  The method for cutting a rod-shaped material according to the present invention is intended to cut a rod-shaped workpiece having internal stress, and at the time of cutting, the workpiece is treated with the center of the axial cross section perpendicular to the longitudinal direction of the workpiece as the center of rotation. It is characterized by cutting while rotating within a range of 100 ° or more and less than 360 °.

  As described above, when cutting a material to be cut having internal stress, by cutting the material to be cut while rotating or reversing repeatedly, the concentration of internal stress on the cut surface can be alleviated and cracks are generated. Can be suppressed. In addition, by performing a rotating motion, even if the workpiece is an ellipse, a curve, or an uneven surface, the cutting blade is not displaced and smooth and stable cutting can be continued. .

  When cutting a workpiece having internal stress, if the rotation range of the workpiece is less than 100 °, the internal stress of the workpiece cannot be relaxed sufficiently, and a crack is generated on the cut surface. There are things to do. On the other hand, when the rotation range of the workpiece is 360 ° or more, a problem similar to that in the case of rotating the workpiece can be predicted. Misalignment occurs and stable cutting becomes difficult. Specifically, the cutting loss may increase or the cutting blade may be damaged.

  Therefore, in the cutting method of the present invention, the rotation range of the workpiece is limited to a range of 100 ° or more and less than 360 °. A more desirable rotation range is 180 ° or more and less than 360 ° because cracks can be sufficiently prevented when the object to be cut is rod-shaped polycrystalline silicon. Here, when the rotation range approaches 360 ° (for example, 359 °), the wire may come into contact with the cutting groove at a position different from the cutting portion, and wire breakage may occur. Therefore, when it is conceivable that the wire comes into contact with the cutting groove at a position different from the cutting portion, it is desirable to take care not to contact the cutting groove, for example, by increasing the straightness at both ends of the wire.

  In the cutting method of the present invention, it is desirable to use a fixed abrasive wire saw as the cutting means. Usually, the cutting method using a wire saw is divided into a free abrasive type wire saw and a fixed abrasive type wire saw. In the cutting method of the present invention, a cutting method using a fixed abrasive type wire saw is used. By adopting it, cutting loss can be reduced, metal contamination can be prevented, and cutting quality is improved along with cutting efficiency.

  FIG. 1 is a diagram for explaining a contact state between a cutting blade and a workpiece according to a cutting means, where (a) shows a case where a wire saw is used as the cutting means, and (b) shows a case where an outer peripheral blade is used. Is shown. In FIG. 1, in the cutting using the wire saw, the contact length L with the workpiece 1 by the wire 2 becomes longer than in the case of using the outer peripheral blade, so that stable cutting is possible. Show.

  In the cutting using the outer peripheral blade 3 shown in FIG. 1 (b), the contact length L with the workpiece can be increased by setting the radius of the cutting blade to be equal to or larger than the diameter of the workpiece 1; In order to increase the size of the apparatus itself and to ensure the strength of the cutting blade, it is necessary to increase the thickness of the cutting blade. For this reason, in the cutting | disconnection using the outer periphery blade 3, since a cutting | disconnection loss increases, a cutting yield falls.

  Further, regarding metal contamination, for example, in cutting using the outer peripheral blade 3, it is predicted that the metal cutting blade directly contacts the workpiece during cutting, and in such a case, the metal impurities are processed. It will be taken into the cut surface of the material and cause metal contamination.

  Furthermore, even when cutting using a wire saw, using a fixed abrasive wire saw is effective in preventing metal contamination. That is, of the two types of wire saws, the free abrasive type wire saw uses a solution in which diamond abrasive grains are mixed in a cooling liquid such as a solvent as a grinding liquid, and is a wire that is cut while dripping the abrasive onto the cutting site. A fixed abrasive wire saw is a wire saw that uses a fixed abrasive wire wire that has diamond coated on the entire surface by electrodepositing diamond abrasive particles on the wire.

  Therefore, by using a fixed abrasive wire saw, unlike the cutting using a loose abrasive wire saw, the surface of the fixed abrasive wire is covered with diamond abrasive grains. Since the wire base is not in direct contact with silicon, metal contamination caused by the metal component contained in the fixed abrasive wire can be suppressed.

  Moreover, as shown in FIG. 1 (a), in the cutting using the wire 2, the contact length L with the workpiece 1 is increased, so that per unit length loaded on the wire 2 at the time of cutting is increased. Since the load can be reduced, the use of the fixed abrasive wire 2 can further prevent metal contamination.

  By cutting the workpiece while rotating the workpiece using a wire saw, the effects of internal stress can be reduced and cracking can be suppressed even for workpieces with internal stress. Accompanying pattern, so-called saw mark is produced. This saw mark shows a specific form depending on the cutting method and cutting conditions.

  FIG. 2 is a view showing saw marks generated on the cut surface of an object to be cut, and (a) shows a cut surface when the rotation range is set to a forward and reverse rotation of 350 ° by a cutting method using a wire saw. (B) is a cutting method using a wire saw with a rotation range of 160 ° forward and reverse rotation, (c) is a cutting surface by a cutting method using an outer peripheral blade, and (d) is a cutting surface. The cut surface by the cutting method using a band saw is shown, respectively.

  As shown in FIGS. 2 (a) and 2 (b), a saw mark formed by a cutting method using a wire saw has a shape of an arc having a curvature that varies depending on the rotation range, and is a surface portion that is not cut until the last cutting. There are some. This part can also be said to be a part for preventing damage such as cutting of the wire. On the other hand, the saw marks shown in FIGS. 2C and 2D show a substantially linear or curved form.

  In the cutting method of the present invention, rod-shaped polycrystalline silicon produced by the Siemens method can be used as a workpiece. In the rod-like polycrystalline silicon manufactured by the Siemens method, the internal stress is likely to remain in the cooling process after vapor phase growth, but even if the workpiece is likely to retain internal stress in the crystal, This is because the internal stress can be relaxed and the occurrence of cracks can be suppressed.

  In the cutting method of the present invention, it is desirable to apply a load of 3 to 10 kgf per wire to the wire of the fixed abrasive wire saw. If the load is less than 3 kgf, the cutting time becomes longer, the cutting efficiency is lowered, and if the load exceeds 10 kgf, the effect of shortening the cutting time is saturated, and the possibility that the fixed abrasive wire is cut increases. by.

  The cutting device of the present invention is a cutting device that cuts rod-shaped polycrystalline silicon produced by the Siemens method substantially perpendicularly to its longitudinal direction using a fixed abrasive wire saw, and rotates the rod-shaped polycrystalline silicon. Means for holding in a possible state, and rotating means for rotating the rod-shaped polycrystalline silicon in the forward and reverse directions within a range of 100 ° or more and less than 360 °, with the axial cross-sectional center perpendicular to the longitudinal direction as the rotation center; Means for feeding a fixed abrasive wire used in the fixed abrasive wire saw to cut the rod-like polycrystalline silicon, and means for applying a load to the fed fixed abrasive wire It is characterized by that.

  FIG. 3 is a diagram showing a configuration example of the rod-shaped polycrystalline silicon holding means and the rotating means in the cutting apparatus of the present invention. A holder 4 is used as a holding means, and the polycrystalline silicon 1 is fixed rotatably by a plurality of chucks 5 supported by the holder 4. In addition, the holder 4 is provided with a rotation shaft as a rotation means, and is connected to the rotation shaft of the rotation motor 7 by a coupling 6 so that the polycrystalline silicon 1 can be rotated within a specified range.

  FIG. 4 is a schematic configuration diagram of a main part for explaining a method of cutting rod-shaped polycrystalline silicon using the cutting apparatus of the present invention. The polycrystalline silicon 1 fixed by the holding means and the rotation means shown in FIG. 3 is configured to be rotatable within a range of 100 ° or more and less than 360 ° with the axial cross-sectional center perpendicular to the longitudinal direction as the rotation center. The At this time, the wire 2 which is a cutting means is supported via the guide roll 9 and is fed by a driving means (not shown) to cut the rod-like polycrystalline silicon 1. Further, at the time of cutting, it is possible to apply a load to the rod-like polycrystalline silicon 1 using a tensioner 8 as a loading means.

  In the cutting apparatus of the present invention, the holding means and the rotating means are not limited to the structure shown in FIG. 3, but the workpiece is polycrystalline silicon or the like, and metal contamination due to direct contact with the metal is a problem. In this case, it is desirable to coat the direct contact portion with a synthetic resin such as nylon or fluorine resin. Moreover, the rotation means can adjust the rotation speed by a pulley, a gear, an inverter, etc. according to the material of the workpiece, the cutting means, etc., and the cutting resistance can be monitored.

  The cutting device of the present invention adopts a method of reversing the fixed abrasive wire by reversing the rotation direction of the take-up drum when the wire reaches the end instead of the endless wire. it can. In this case, when the fixed abrasive wire is turned over, the cutting speed of the fixed abrasive wire changes with respect to the rotational speed of the rod-like polycrystalline silicon, so the fixed abrasive wire becomes overloaded, and is broken or entangled. May occur. For this reason, when the fixed abrasive wire is reversed, the rotation of the rod-like polycrystalline silicon is stopped, and after the fixed abrasive wire is reversed, the rod-like polycrystalline silicon is rotated again.

  Moreover, in the cutting device of the present invention, when cutting with a fixed abrasive wire, after cutting an object to be cut, a block made of an adhesive containing a dressing material is cut with the fixed abrasive wire. Therefore, it is desirable to carry out a dressing dress of diamond abrasive grains. By performing such dressing, cutting resistance can be reduced, cracking during cutting can be prevented, and the yield and production efficiency of polycrystalline silicon can be improved.

Using the cutting apparatus shown in FIG. 3 and FIG. 4 and using the rod-like polycrystalline silicon produced by the Siemens method as a test material, a crack generation state confirmation test (Example 1) and a cutting speed confirmation test (Example 2) Carried out.
(Example 1)
The test workpiece was polycrystalline silicon having a diameter of 130 mm, and was cut under the cutting conditions shown in Table 1 and the rotation range shown in Table 2. After cutting the test workpiece, the crack generation state on the cut surface was confirmed, and the crack generation rate (%) was calculated by expressing the ratio of the number of cracks generated as a percentage of the total number of cuts. The number of repetitions was 20 times. The results are shown in Table 2.

From Table 2, the test No. in which the rotation range of the workpiece is outside the specified range of the present invention. In 1 to 3, it is difficult to suppress the occurrence of cracks. On the other hand, the test No. in which the rotation range of the test workpiece satisfies the specified range of the present invention. It confirmed that 4-10 can suppress generation | occurrence | production of a crack. Further, even in the present invention example, the test No. In 7-10, it confirmed that the generation | occurrence | production of a crack was completely prevented at the time of a cutting | disconnection by making the rotation range of a test material into 180 degrees-350 degrees.
(Example 2)
Next, when cutting the polycrystalline silicon having a diameter of 130 mm under the cutting conditions of Example 1, the weight applied per fixed abrasive wire is changed in the range of 1 to 15 kgf, and the cutting is performed. The effect of loading conditions on speed and wire breakage was confirmed. The results are shown in Table 3.

  From Table 3, the test No. with a small load is shown. Test Nos. 1 and 2 have a long cutting time and a large load. In 8, a wire break occurred. Regarding the cutting time, considering the cutting efficiency of polycrystalline silicon, it is desirable that the cutting time is within 30 minutes. As the results of 3 to 7 show, it was confirmed that a suitable load is 3 to 10 kgf per fixed abrasive wire.

  According to the cutting method and the cutting apparatus of the present invention, when a workpiece having internal stress is cut, the internal stress concentrated on the cut surface can be relaxed and the generation of cracks can be suppressed, and the load condition is appropriately managed. As a result, cutting efficiency can be improved, cutting loss can be further reduced, yield can be improved, and metal contamination on the cut surface can also be suppressed. Thus, it can be widely applied as a means for cutting polycrystalline silicon used as a raw material for producing single crystal silicon for semiconductors.

It is a figure explaining the contact condition of the cutting blade according to a cutting means, and a workpiece, (a) shows the case where a wire saw is used as a cutting means, (b) shows the case where an outer periphery blade is used. . It is a figure which shows the saw mark which generate | occur | produces in the cut surface of a to-be-cut object, (a) is a cut surface at the time of making the rotation range into 350 degree | times by the cutting method using a wire saw, (b) is a figure. A cutting surface when the rotation range is 160 ° forward / reverse rotation by a cutting method using a wire saw, (c) a cutting surface by a cutting method using an outer peripheral blade, and (d) a band saw. The cut surface by the cutting method is shown respectively. It is a figure which shows the structural example of the holding means and rotation means of a rod-shaped polycrystalline silicon in the cutting device of this invention. It is a schematic block diagram of the principal part explaining the method of cut | disconnecting rod-shaped polycrystalline silicon using the cutting device of this invention.

Explanation of symbols

1: Material to be cut, 2: Wire, Fixed abrasive type wire 3: Peripheral blade, 4: Holding tool 5: Chuck, 6: Coupling 7: Motor, 8: Tensioner 9: Guide roll

Claims (6)

  A method of cutting a rod-like workpiece having internal stress using a mechanical cutting means, wherein the workpiece is set to a center of rotation about an axial section center perpendicular to the longitudinal direction of the workpiece. A method of cutting a rod-shaped material, characterized by cutting while rotating within a range of not less than ° and less than 360 °.   The method for cutting a rod-shaped material according to claim 1, wherein a fixed abrasive wire saw is used as the cutting means.   The method for cutting a rod-shaped material according to claim 1 or 2, wherein the workpiece is a rod-shaped polycrystalline silicon manufactured by a Siemens method.   The cutting method according to claim 2 or 3, wherein a load of 3 to 10 kgf is applied to each wire of the fixed abrasive wire saw. A cutting device that cuts rod-shaped polycrystalline silicon produced by the Siemens method substantially perpendicularly to its longitudinal direction using a fixed-abrasive wire saw,
Means for holding the rod-like polycrystalline silicon in a rotatable state;
Rotation means for rotating the rod-like polycrystalline silicon in the forward and reverse directions within a range of 100 ° or more and less than 360 °, with the axial cross-sectional center perpendicular to the longitudinal direction as the rotation center;
Means for feeding the fixed abrasive wire used in the fixed abrasive wire saw to cut the rod-like polycrystalline silicon;
And a means for applying a load to the fixed-abrasive wire to be fed to suppress cracks generated on the cut surface of the rod-like polycrystalline silicon. The cutting device according to claim 5, wherein the load applied by the loading means is 3 to 10 kgf per one fixed abrasive wire.

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