JP6448181B2 - Method and apparatus for bonding ingot and work holder - Google Patents

Description

  The present invention relates to a method and an apparatus for bonding a work holder that is attached in advance to an ingot when a wafer is cut out from the ingot using a wire saw.

  The silicon wafer is completed by processing the ingot pulled up from the melt by the Czochralski method into a cylindrical shape, and then performing various processes such as slicing, lapping and polishing. In the ingot slicing step, a slice table is bonded to the circumferential surface of the ingot, and a work holder is bonded to the upper surface of the slice table. The ingot is attached to the wire saw through the work holder and sliced together with the slicing table.

  The crystal orientation of the ingot varies somewhat and does not necessarily coincide with the central axis of the ingot. Therefore, when the work holder is bonded in accordance with the direction of the central axis of the ingot, and attached to the wire saw and sliced, the cut surface of the wafer cut out from the ingot does not coincide with the crystal lattice plane, which causes the wafer characteristics to vary. There's a problem. As one method for solving this problem, a method using a gonio angle setting device is known. The gonio angle setting device is attached to a wire saw, and the attachment angle of the ingot attached to the wire saw can be adjusted in a plane orthogonal to the wire and in a horizontal plane. According to the gonio angle setting device, the traveling direction of the wire can be adjusted so as to be in an appropriate direction with respect to the crystal orientation of the ingot.

  On the other hand, a method that does not use a gonio angle setting device has also been proposed (see Patent Documents 1 and 2). In this method, the crystal orientation of the ingot is measured with a crystal orientation measuring device incorporated in the bonding apparatus, and the ingot The work holder is bonded according to the orientation of the crystal orientation, not the central axis. Specifically, the rotation angle α of the ingot until the crystal orientation of the ingot is rotated around the central axis of the ingot until it is positioned in the horizontal plane, and the inclination angle β of the crystal orientation with respect to the central axis of the ingot are calculated. The ingot is rotated about the central axis at a rotation angle α to perform crystal orientation alignment (Y-axis alignment) in the Y-axis direction. Next, a slice table is bonded to the ingot, an adhesive is applied to the work holder, and the work holder is bonded to the slice table. Before the adhesive is dried, the work holder is rotated in the horizontal direction at an inclination angle β to perform crystal orientation alignment (X-axis alignment) in the X-axis direction of the ingot. Thereafter, the adhesive is dried to completely bond the ingot and the work holder.

Japanese Patent Laid-Open No. 10-329133 Japanese Patent Laid-Open No. 10-100142

  However, in the conventional bonding methods described in Patent Documents 1 and 2, there are cases where crystal orientation is not always accurately aligned, and improvement in the accuracy of crystal orientation is required.

  Accordingly, an object of the present invention is to provide a bonding method and a bonding apparatus capable of bonding with a higher accuracy the work holder orientation with respect to the crystal orientation of the ingot when bonding the work holder to the ingot. is there.

  In order to solve the above-mentioned problem, the method for bonding an ingot and a work holder according to the present invention uses a first measurement step for measuring the crystal orientation of a cylindrical ingot and the measurement result of the first measurement step. A first rotation step for rotating the ingot in a circumferential direction so that the crystal orientation is parallel to a reference plane; and a second measurement for again measuring the crystal orientation of the ingot rotated in the first rotation step. When the measurement step and the first tilt angle formed by the crystal orientation with respect to the reference plane are not within an allowable range, the measurement result of the second measurement step is used to determine whether the crystal orientation is the reference plane. A second rotation step in which the ingot is rotated again in the circumferential direction so as to be parallel to a plane; and a slicing table bonding for bonding a slicing table on the circumferential surface of the ingot Using the measurement result of at least one of the step, the work holder temporary adhering step for temporarily adhering the work holder to the upper surface of the slice table, and the first and second measuring steps, the attachment axis of the work holder is the crystal An angle adjustment step of rotating the work holder in the reference plane so as to be parallel to an azimuth, and a work holder main bonding step of main bonding the work holder that has undergone the angle adjustment step to the slice table. Features.

  ADVANTAGE OF THE INVENTION According to this invention, the precision of crystal orientation alignment (Y-axis alignment) of an ingot with respect to a work holder can be improved. Therefore, the crystal orientation of the ingot can be made orthogonal to the traveling direction of the wire saw without using a gonio angle setting device. Thereby, the cut surface of the wafer cut out from the ingot can be exactly matched with the crystal lattice plane, and variations in the characteristics of the wafer can be suppressed.

  In the bonding method according to the present invention, it is preferable that the second measurement step and the second rotation step are repeatedly performed within a preset number of times until the first inclination angle falls within an allowable range. . According to this, the precision of crystal orientation alignment of the ingot with respect to the work holder can be further enhanced.

  In the present invention, the angle adjustment step measures a displacement amount of the work holder in a direction parallel to the reference plane, and a second inclination formed by an attachment axis of the work holder with respect to the crystal orientation from the displacement amount. It is preferable that the work holder is rotated again in the reference plane so that the attachment axis is parallel to the crystal orientation when the angle is obtained and the second tilt angle is not within an allowable range. According to this, the precision of crystal orientation alignment (X-axis alignment) of the ingot with respect to the work holder can be improved.

  In the bonding method according to the present invention, it is preferable that the angle adjustment step is repeatedly performed within a preset number of times until the second inclination angle falls within an allowable range. According to this, the precision of crystal orientation alignment (X-axis alignment) of the ingot with respect to the work holder can be further increased.

  In the present invention, it is preferable that in the first and second rotating steps, the ingot is rotated in accordance with rotation of a roller in contact with a circumferential surface of the ingot. When the roller slips, the ingot cannot be rotated correctly, which may cause the roller rotation amount and the ingot rotation amount not to coincide with each other. Such an ingot rotation error occurs suddenly and cannot be confirmed at a glance. However, according to the present invention, since the crystal orientation of the ingot is remeasured, the rotation error can be detected easily and accurately, and the rotation accuracy of the ingot can be increased.

  The bonding apparatus according to the present invention is an apparatus for bonding a work holder to a circumferential surface of a cylindrical ingot via a slicing table, and measures the crystal orientation of the ingot using X-ray diffraction. A measuring device; a rotation support mechanism for rotating the ingot in a circumferential direction while supporting the ingot in parallel with a reference plane; a slicing base mounting mechanism for bonding a slicing base to an upper portion of the ingot; and an upper surface of the slicing base A work holder mounting mechanism for bonding a work holder, the orientation measuring device measures a crystal orientation of an ingot, and the rotation support mechanism is configured to determine the crystal orientation based on a measurement result by the orientation measuring device. The ingot is rotated in the circumferential direction by using the rotation support mechanism so as to be parallel to the reference plane, and the azimuth measuring device has the rotated ingot. When the first tilt angle formed by the crystal orientation with respect to the reference plane is not within an allowable range, the rotation support mechanism is parallel to the reference plane. The ingot is rotated again in the circumferential direction so that

  ADVANTAGE OF THE INVENTION According to this invention, the precision of crystal orientation alignment (Y-axis alignment) of an ingot with respect to a work holder can be improved. Therefore, the crystal orientation of the ingot can be made orthogonal to the traveling direction of the wire saw without using a gonio angle setting device. Thereby, the cut surface of the wafer cut out from the ingot can be exactly matched with the crystal lattice plane, and variations in the characteristics of the wafer can be suppressed.

  In the present invention, the work holder attachment mechanism includes an angle adjustment mechanism that rotates the work holder in the reference plane so that an attachment axis of the work holder is parallel to the crystal orientation, and the angle adjustment mechanism includes: A displacement amount of the work holder in a direction parallel to the reference plane is measured, a second inclination angle formed by the attachment axis with respect to the crystal orientation is determined from the displacement amount, and the second inclination angle is within an allowable range. Preferably, the work holder is rotated again in the direction within the reference plane so that the attachment axis is parallel to the crystal orientation when it is not within. According to this, the precision of crystal orientation alignment (X-axis alignment) of the ingot with respect to the work holder can be further increased.

  ADVANTAGE OF THE INVENTION According to this invention, when adhere | attaching a work holder on an ingot, the adhesion method and the adhesion | attachment apparatus which can adjust and adhere | attach the work holder with respect to the crystal orientation of an ingot with higher precision can be provided.

FIG. 1 is a schematic perspective view showing an example of the configuration of a wire saw. FIG. 2 is a schematic perspective view showing the relationship between the ingot and the work holder. FIG. 3 is a block diagram schematically showing the configuration of the bonding apparatus. FIG. 4 is a schematic diagram showing the configuration of the azimuth measuring apparatus. FIG. 5 is a schematic diagram showing the configuration of the rotation support mechanism. FIG. 6 is a schematic plan view showing the configuration and operation of the horizontal angle adjusting mechanism. FIG. 7 is a flowchart showing a method for bonding the ingot and the work holder. FIG. 8 is a schematic diagram of the ingot after Y-axis alignment. FIG. 9 is a schematic plan view showing the relationship between the ingot after the crystal orientation is aligned and the wire saw.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing an example of the configuration of a wire saw.

  As shown in FIG. 1, the wire saw 1 supplies three grooved rollers 2a, 2b, and 2c, one wire 3 wound around the rollers 2a, 2b, and 2c, and a coolant liquid to the traveling wire 3. Nozzle units 4a and 4b, and a lifting device 8 that lifts and lowers an ingot 5 that is a workpiece (workpiece).

  The ingot 5 is, for example, single crystal silicon. Single crystal silicon is capable of mass production of large-diameter ingots, and it is particularly necessary to use a wire saw for slicing large-diameter ingots. The diameter of the ingot 5 is preferably 300 mm or more, and particularly preferably 450 mm or more. This is because the error in crystal orientation is increased with the increase in diameter of the ingot, and the effect of the present invention is particularly remarkable in an ingot having a diameter of 450 mm.

  The wire saw 1 in this embodiment is a fixed abrasive method, and the wire 3 is a diamond abrasive wire in which diamond abrasive particles are fixed on a core wire via a binder. The wire 3 wound around one wire reel 6a is repeatedly wound around the rollers 2a, 2b, 2c via the guide roller 7a and then wound around the other wire reel 6b via the guide roller 7b. Taken.

  In the fixed abrasive method, a back-and-force method is adopted in which the wire 3 is fed out little by little while reversing the traveling direction of the wire 3 in the middle (crossing movement). Therefore, the wire 3 is caused to travel by alternately rotating the rollers 2a and 2b in the normal direction and the reverse direction. In addition, you may employ | adopt the free abrasive grain system cut | disconnected while supplying the processing liquid (slurry) which disperse | distributed the abrasive grain with respect to the wire 3 which drive | works at high speed.

  The nozzle units 4a and 4b are nozzles arranged along the rotation axis direction of the rollers 2a, 2b and 2c, and the coolant liquid is applied to the wire rows which are wound around the rollers 2a, 2b and 2c and run. Thus, it has a plurality of nozzle holes. The nozzle units 4a and 4b need to be arranged in front of the traveling direction of the wire 3 when viewed from the ingot 5, but since the wire 3 travels in both directions, the two nozzle units 4a and 4b are connected to the ingot 5. It is arranged on each side.

  The ingot 5 is disposed above the wire saw 1 and is fixed to the lifting device 8 via a slicing base 9 and a work holder 11. By lowering the elevating device 8, the ingot 5 is pressed against the wire row 3A spanned between the rollers 2a and 2b and cut.

  In order to cut the ingot 5 correctly, it is necessary to maintain the center axis of the ingot 5 in a horizontal state. In addition, in order for the cut surface of the wafer to have a predetermined crystal lattice plane, it is necessary to align the crystal orientation so that the crystal orientation of the ingot 5 is oriented in a direction orthogonal to the wire row 3A. The crystal orientation is adjusted by rotating the ingot 5 in the circumferential direction by a predetermined angle to make the crystal orientation horizontal, and by rotating the ingot 5 in the horizontal direction by a predetermined angle to make the crystal orientation orthogonal to the wire row 3A. .

  FIG. 2 is a schematic perspective view showing the relationship between the ingot 5 and the work holder 11.

  As shown in FIG. 2, a slicing base 9 is attached to the circumferential surface of the upper part of a columnar ingot 5 placed so that the central axis is horizontal by an adhesive. The slicing base 9 is made of a material such as carbon that can be cut together with the ingot 5. A curved surface that fits around the circumferential surface of the ingot 5 is formed on the lower surface of the slicing base 9, and adhesion with the ingot 5 is enhanced. Further, a work holder 11 is attached to the upper surface of the slicing base 9. In FIG. 2, the slicing base 9 and the work holder 11 are sequentially attached above the ingot 5 in accordance with FIG. 1, but the slicing base 9 and the work holder 11 can also be attached in order from below the ingot 5. Further, an insulating plate may be interposed between the slicing base 9 and the work holder 11.

  As shown in the figure, the normal line of the crystal lattice plane of the ingot 5, that is, the crystal orientation 12 is inclined with respect to the central axis 13 of the ingot 5. Usually, the inclination angle β of the crystal orientation 12 with respect to the central axis 13 of the ingot 5 is about ± 3 ° at the maximum. Further, the crystal orientation 12 of the ingot 5 placed in an arbitrary direction is not necessarily horizontal, and has an inclination angle γ with respect to the horizontal plane.

  In the bonding method of the present embodiment, the attachment axis 11 a of the work holder 11 is set parallel to the crystal orientation 12 of the ingot 5 and bonded. Here, the attachment axis 11a of the work holder 11 refers to a virtual axis extending in the longitudinal direction of the work holder 11, and the left and right side surfaces 11b and 11c parallel to the longitudinal direction of the work holder 11 are parallel to the attachment axis 11a. . The attachment surface 11d of the work holder 11 is a plane including the attachment axis 11a, and is usually set horizontally. In the wire saw 1, the workpiece is set so that the attachment axis 11a is orthogonal to the wire row 3A. In order to make the crystal orientation 12 of the ingot 5 parallel to the attachment axis 11a of the work holder 11, the ingot 5 is rotated at the rotation angle α so that the crystal orientation 12 is horizontal, and then at an angle β in the horizontal direction. Need to rotate. The rotation angle α can be obtained from the relationship sin α = sin γ / sin β.

  Next, a bonding apparatus for bonding the work holder 11 to the ingot 5 will be described.

  FIG. 3 is a block diagram schematically showing the configuration of the bonding apparatus 20 according to the present embodiment.

  As shown in FIG. 3, the bonding apparatus 20 includes an orientation measuring apparatus 21 that measures the crystal orientation of the ingot using X-ray diffraction, and a rotational support that rotates the ingot 5 in the circumferential direction while supporting the ingot 5 horizontally. A mechanism 22, a slicing base attaching mechanism 23 for attaching the slicing base 9 to the upper part of the ingot 5, and a work holder attaching mechanism 24 for attaching the work holder 11 to the upper surface of the slicing base 9 are provided. The work holder attachment mechanism 24 has a horizontal angle adjustment mechanism 25 that rotates the work holder 11 in a horizontal plane so that the attachment axis 11 a of the work holder 11 is parallel to the crystal orientation 12 of the ingot 5. Further, the bonding apparatus 20 has a control unit 26, which controls the azimuth measuring device 21, the rotation support mechanism 22, the slicing table mounting mechanism 23, the work holder mounting mechanism 24, and the horizontal angle adjusting mechanism 25.

  FIG. 4 is a schematic diagram showing the configuration of the orientation measuring device 21.

  As shown in FIG. 4, the azimuth measuring device 21 has a measuring head 27 supported so as to be rotatable about a horizontal rotating shaft 27a. The measurement head 27 is provided with an X-ray projector 28 that emits X-rays toward the reference end surface of the ingot 5 at a predetermined inclination angle, and an X-ray receiver 29 that receives the irradiated X-rays. The line projector 28 and the X-ray receiver 29 are attached at a predetermined angle. The measuring head 27 is rotationally driven by a motor (not shown) connected to the end of the rotating shaft 27a. A measuring device 26a for measuring the output of reflected X-rays is connected to the X-ray receiver 29, and an arithmetic device 26b is connected to the measuring device 26a. Note that the measuring instrument 26a and the arithmetic device 26b may be part of the control unit 26 or may be other devices.

  In measuring the crystal orientation of the ingot 5, with the ingot 5 positioned at the measurement reference position Ko fixed, the measuring head 27 is rotated by 90 degrees to irradiate the end surface of the ingot 5 with X-rays from four directions, and the reflected X Crystal orientation measurement data is calculated based on the line output data. As for the crystal orientation, an inclination angle γ with respect to the horizontal plane and an inclination angle β of the crystal orientation 12 with respect to the central axis 13 of the ingot 5 are obtained. As described above, the inclination angle γ has a relationship of sin α = sin γ / sin β with respect to the rotation angle α in the circumferential direction of the ingot 5 necessary until the crystal orientation 12 of the ingot 5 becomes horizontal. .

  FIG. 5 is a schematic diagram showing the configuration of the rotation support mechanism 22.

  As shown in FIG. 5, the rotation support mechanism 22 includes a pair of rollers 31 a and 31 b driven by a servo motor 32. The rollers 31 a and 31 b are drive rollers that rotate the ingot 5 by rotating while contacting the circumferential surface of the ingot 5. A rotary encoder is attached to the servo motor 32 to detect the rotation angle of the ingot 5 in proportion to the rotation speed. Only one of the rollers 31a and 31b may be driven by the servo motor 32, and the other roller may be driven. Under the instruction from the control unit 26, the rotation support mechanism 22 adjusts the crystal orientation 12 to be positioned in the horizontal plane by rotating the ingot 5 based on the measurement data after measuring the crystal orientation. The rotation support mechanism 22 is preferably provided so as to be capable of reciprocating between a measurement position where the crystal orientation is measured by the orientation measuring device 21 and a work position where the slice base 9 is bonded by the slice base mounting mechanism 23.

  The slicing base mounting mechanism 23 is a handling device that handles the slicing base 9 and mounts it on the top of the ingot 5. The slicing base 9 is attached so as to be parallel to the central axis 13 of the ingot 5. Adhesive is applied to the lower surface of the slicing base 9, and after mounting on the upper surface of the ingot 5, the adhesive is dried to complete the attachment of the slicing base 9.

  The work holder mounting mechanism 24 is also a handling device that handles the work holder 11 and mounts it on the upper surface of the slicing base 9 fixed on the ingot. The work holder 11 needs to be mounted so that its mounting axis 11 a is parallel to the crystal orientation 12 of the ingot 5. An adhesive for bonding to the slicing base 9 is applied to the lower surface of the work holder 11. After the work holder 11 is mounted on the upper surface of the slicing base 9 by the work holder mounting mechanism 24, the mounting angle is adjusted by the horizontal angle adjusting mechanism 25.

  FIG. 6 is a schematic plan view showing the configuration and operation of the horizontal angle adjusting mechanism 25.

  As shown in FIG. 6, the horizontal angle adjustment mechanism 25 includes a horizontal support plate 33, a horizontal angle adjustment plate 34 connected to the horizontal support plate 33, and a linear scale that measures the amount of displacement of the work holder 11 in the horizontal plane. 35.

  The horizontal angle adjusting plate 34 is connected to a connecting shaft 33a provided on the upper surface of the horizontal support plate 33, and is supported rotatably in a horizontal plane. A screw rod 39 is connected to the output shaft of the servo motor 36 via a universal joint 37 and an operating piece 38, and the tip of the screw rod 39 is connected to the horizontal angle adjusting plate 34 via a rotor 40. When the screw rod 39 is rotated by the servo motor 36, the horizontal angle adjusting plate 34 rotates in the horizontal direction around the connecting shaft 33a, and the horizontal orientation of the work holder 11 can be adjusted. Thereby, the attachment axis 11 a is adjusted to be parallel to the crystal orientation 12 of the ingot 5.

  The linear scale 35 measures the horizontal displacement amount W (position) of the work holder 11. As will be described later, the amount of rotation of the work holder 11 can be known from the amount of displacement of the work holder 11, and when the angle error of the mounting axis 11 a of the linear scale 35 with respect to the crystal orientation 12 is not within the allowable range, it is horizontal. Readjustment by the angle adjustment mechanism 25 is performed.

  Next, a method for bonding the ingot 5 and the work holder 11 using the bonding apparatus 20 will be described with reference to the flowchart of FIG.

  As shown in FIG. 7, in this bonding method, first, the crystal orientation of the ingot 5 is measured using the orientation measuring device 21 (step S11), and the Y axis of the ingot 5 is aligned based on the measurement result (step S12). To S15). In Y-axis alignment, the ingot 5 is rotated at an angle α in the circumferential direction so that the crystal orientation 12 is horizontal. When the tilt angle γ of the crystal orientation 12 is already within the allowable range at the first measurement (step S12Y), it is not necessary to rotate the ingot 5, and the Y-axis alignment is completed immediately.

  Next, the crystal orientation 12 of the ingot 5 is measured again (steps S14N and S15), and it is confirmed whether or not the Y axis alignment of the ingot has been performed correctly. In FIG. 5, rollers 31 a and 31 b horizontally support the ingot 5 from below, and abut against the ingot 5 while receiving the load of the ingot 5. Therefore, in most cases, the ingot 5 rotates in accordance with the rotation of the rollers 31a and 31b. However, for some reason, the rollers 31a and 31b may slightly slip (slip), which may cause the rotation amount of the rollers 31a and 31b and the rotation amount of the ingot 5 not to coincide with each other.

  Such a rotation error of the ingot 5 is remarkable in a large-diameter ingot having a diameter of 450 mm. In manufacturing a large diameter ingot with a diameter of 450 mm, it is difficult to obtain a long ingot like an ingot with a diameter of 300 mm. Therefore, it is assumed that the rollers 31a and 31b are likely to run idle. The occurrence of such an ingot rotation error is abrupt and cannot be confirmed at first glance.

  In addition, the diameter of the ingot 5 varies somewhat from ingot to ingot, and when the rollers 31a and 31b are rotated by a certain amount, the rotation amount of the ingot having a large diameter is smaller than the rotation amount of the ingot having a small diameter. The variation in the amount of rotation of the ingot caused by the variation in diameter increases as the diameter increases, and the variation in the amount of rotation is significant in a large-diameter ingot having a diameter of 450 mm. Therefore, in the present embodiment, the crystal orientation of the ingot 5 is re-measured to prevent the occurrence of the above error and increase the rotation accuracy of the ingot 5.

  As a result of the re-measurement, when the tilt angle γ (first tilt angle) of the crystal orientation 12 with respect to the horizontal plane is within an allowable range (for example, 0.1 degrees or less), the Y-axis alignment is finished (step S12Y If not, the ingot 5 is rotated again to perform Y-axis alignment (steps S12N and S13). Thus, the Y-axis alignment is repeated until the inclination angle γ of the crystal orientation 12 falls within the allowable range. However, when the number of repetitions reaches a predetermined limit (for example, 3 times) (step S14Y), the Y-axis alignment is forcibly terminated even if the inclination angle γ is not within the allowable range. It is preferable to output a warning by sound or light at the time of forced termination.

  FIG. 8 is a schematic diagram of the ingot 5 after Y-axis alignment. As shown in the figure, the crystal orientation 12 of the ingot 5 on which the Y-axis alignment has been performed is a horizontal line included in the XZ plane (horizontal plane), and the inclination angle γ≈0. The inclination angle β of the crystal orientation 12 with respect to the central axis 13 of the ingot 5 is also an angle in the XZ plane.

  Next, the slice table 9 is bonded to the upper part of the circumferential surface of the ingot 5, and the work holder 11 is temporarily bonded to the upper surface of the slice table 9.

  Next, the X axis alignment of the work holder 11 and the ingot 5 is performed based on the measurement result of the crystal orientation (steps S17 to S22). The crystal orientation measurement result used at this time may be the first measurement result, the second or subsequent measurement result, or a combination of the plurality of measurement results.

  In the X axis alignment, the work holder 11 is rotated in the horizontal direction so that the attachment axis 11a of the work holder 11 is parallel to the crystal orientation 12 of the ingot 5 (step S18). Thereafter, the displacement amount (position) of the work holder 11 in the horizontal plane is measured with the linear scale 35 (step S19), and the inclination angle (second inclination angle) of the attachment axis 11a with respect to the crystal orientation 12 is within an allowable range (for example, Check if it is within 0.1 degrees or less.

  There is a gear in the servomotor 36 of the horizontal angle adjusting mechanism 25 that rotates the work holder 11 in the horizontal direction, and the horizontal rotation angle varies due to backlash of the gear. In order to adjust this backlash, readjust the offset angle on the linear scale. In X-axis alignment, high accuracy of 0.1 degrees or less is required, and it is very effective when the backlash of the gear in the servo motor 36 is large.

  Then, as a result of measurement by the linear scale 35, when the inclination angle (second inclination angle) of the mounting axis 11a with respect to the crystal orientation 12 is within an allowable range (for example, 0.1 degrees or less), the X-axis alignment is finished. (Step S20Y), if not, the work holder 11 is rotated again to perform X-axis alignment (Steps S20N, S21, S22N, S18). Thus, the X-axis alignment is repeated until the inclination angle of the mounting axis 11a with respect to the crystal orientation 12 falls within the allowable range. However, when the number of repetitions reaches a predetermined limit (for example, 3 times), the X-axis alignment is forcibly terminated even if the crystal orientation 12 is not within the allowable range (step S22Y). It is preferable to output a warning by sound or light at the time of forced termination.

  Thereafter, the adhesive is dried and the work holder is permanently bonded to complete crystal orientation alignment (step S23).

  FIG. 9 is a schematic plan view showing the relationship between the ingot 5 and the wire saw 1 after crystal orientation alignment.

  As shown in FIG. 9, when the work holder 11 is attached to the wire saw 1 so that the attachment axis 11a is orthogonal to the wire row 3A, the crystal orientation 12 of the ingot 5 parallel to the attachment axis 11a is also parallel to the wire row 3A. On the other hand, the central axis 13 of the ingot 5 has an inclination angle β with respect to the direction orthogonal to the wire row 3A. Thus, when the work holder 11 is bonded in accordance with the orientation of the crystal orientation 12 of the ingot 5 and is placed on the wire saw 1 and sliced, the cut surface of the wafer cut out from the ingot 5 matches the crystal lattice plane. Variations in wafer characteristics can be eliminated.

  As described above, the method for bonding the ingot 5 and the work holder 11 according to the present embodiment rotates the ingot in the circumferential direction so that the crystal orientation 12 is horizontal based on the measurement result of the crystal orientation 12 of the ingot 5. Then, the crystal orientation 12 of the ingot is measured again. If the first tilt angle formed by the crystal orientation with respect to the horizontal plane is not within the allowable range, the ingot 5 is rotated again. Y-axis alignment can be performed with high accuracy. In the present embodiment, after the work holder 11 is rotated in the horizontal direction so that the attachment axis 11a of the work holder 11 is parallel to the crystal orientation 12, the horizontal displacement of the work holder 11 is measured. The tilt angle of the mounting axis 11a with respect to the crystal orientation 12 is obtained from this displacement amount. When the tilt angle is not within the allowable range, the work holder 11 is rotated again, so that the X axis alignment of the ingot is performed with high accuracy. be able to.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above-described embodiment, a single crystal silicon ingot is given as a representative example of the ingot, but the present invention is not limited to the single crystal silicon ingot, and various ingots can be targeted.

  Moreover, in the said embodiment, although the case where the angle which the crystal orientation of an ingot and a cut surface make was perpendicular | vertical was described, this invention is not limited to such a case. For example, depending on the use of the silicon wafer, the angle formed by the crystal orientation of the ingot and the cut surface may be slightly inclined from the vertical, but the present invention is also applicable to such a case. In this case, the attachment axis of the work holder may be attached with a slight inclination with respect to the crystal orientation, or the work holder may be attached with a slight inclination with respect to the wire saw.

  In the above embodiment, the horizontal plane is the reference plane, and in the Y-axis alignment, the ingot 5 is rotated in the circumferential direction so that the crystal orientation 12 is parallel to the horizontal plane, and in the X-axis alignment, the attachment axis of the work holder 11 Although the work holder 11 is rotated in a direction parallel to the horizontal plane so that 11a is parallel to the crystal orientation 12, the present invention is not limited to the case where the reference plane is a horizontal plane. That is, the orientation of the reference plane can be arbitrarily set as long as it is parallel to the mounting surface 11d of the work holder 11. However, it is most reasonable to use the horizontal plane as the reference plane.

DESCRIPTION OF SYMBOLS 1 Wire saw 2a, 2b Roller 3 Wire 3A Wire row | line | column 4a, 4b Nozzle unit 5 Ingot 6a, 6b Wire reel 7a, 7b Guide roller 8 Lifting device 9 Slice stand 11 Work holder 11a Mounting axis 11b, 11c Work holder side surface 11d Work holder Mounting surface 12 Crystal orientation 13 Central axis 20 Bonding device 21 Orientation measuring device 22 Rotation support mechanism 23 Slice base mounting mechanism 24 Work holder mounting mechanism 25 Horizontal angle adjustment mechanism 26 Control unit 26a Measuring device 26b Computing device 27 Measuring head 27a Rotating shaft 28 X-ray projector 29 X-ray receiver 31a, 31b Roller 32 Servo motor 33 Horizontal support plate 33a Connection shaft 34 Horizontal angle adjustment plate 35 Linear scale 36 Servo motor 37 Universal joint 38 Actuating piece 39 Screw rod 40 Rotor

Claims (6)

A method of adhering a work holder on a circumferential surface of a cylindrical ingot,
A first measuring step for measuring the crystal orientation of the ingot;
Using the measurement result of the first measurement step, a first rotation step of rotating the ingot in a circumferential direction so that the crystal orientation is parallel to a reference plane;
A second measuring step for measuring again the crystal orientation of the ingot rotated in the first rotating step;
When the first tilt angle formed by the crystal orientation with respect to the reference plane is not within an allowable range, the measurement result of the second measurement step is used to make the crystal orientation parallel to the reference plane. A second rotation step for rotating the ingot again in the circumferential direction so that
A slicing table bonding step of bonding a slicing table to the ingot;
A work holder temporary bonding step of temporarily bonding a work holder to the upper surface of the slice table;
An angle adjusting step of rotating the work holder in the reference plane so that an attachment axis of the work holder is parallel to the crystal orientation using a measurement result of at least one of the first and second measuring steps; ,
A work holder main bonding step for main bonding the work holder that has undergone the angle adjustment step to the slice table ,
In the first and second rotating steps, the pair of rollers abutting on the lower circumferential surface of the ingot is used to support the ingot only from below, and at least one of the pair of rollers rotates. A method for bonding an ingot and a work holder, wherein the ingot is rotated in accordance with   The ingot and the workpiece according to claim 1, wherein the second measurement step and the second rotation step are repeatedly performed within a limited number of preset times until the first inclination angle falls within an allowable range. How to attach the holder.   The angle adjustment step measures a displacement amount of the work holder in a direction parallel to the reference plane, and determines a second inclination angle formed by an attachment axis of the work holder with respect to the crystal orientation from the displacement amount, The work holder is rotated again in the reference plane so that the attachment axis is parallel to the crystal orientation when the second tilt angle is not within an allowable range. Method of bonding ingots and work holders.   The method of bonding an ingot and a work holder according to claim 3, wherein the angle adjustment step is repeated within a preset number of times until the second inclination angle falls within an allowable range. A bonding apparatus for bonding a work holder to a circumferential surface of a cylindrical ingot via a slice table,
An orientation measuring device for measuring the crystal orientation of an ingot using X-ray diffraction;
A pair of rollers for supporting the ingot only from below by contacting the lower circumferential surface of the ingot; and rotating the at least one of the pair of rollers to make the ingot a reference plane A rotation support mechanism that rotates in the circumferential direction while supporting in parallel;
A slicing base mounting mechanism for bonding a slicing base to the top of the ingot;
A work holder mounting mechanism for bonding the work holder to the upper surface of the slicing table ;
A controller for controlling the orientation measuring device, the rotation support mechanism, the slicing table mounting mechanism, and the work holder mounting mechanism;
The controller is
Based on the first measurement result obtained by causing the orientation measuring device to measure the crystal orientation of the ingot, the ingot is rotated in the circumferential direction using the rotation support mechanism so that the crystal orientation is parallel to the reference plane. Let
Based on the second measurements, wherein was measured crystal orientation of the rotated ingot again the azimuth measuring device, a first inclination angle crystal orientation of the ingot with respect to the said reference plane falls within the allowable range When the first tilt angle is not within the allowable range, the ingot is circularly moved using the rotation support mechanism so that the crystal orientation is parallel to the reference plane. A bonding apparatus characterized in that it is rotated again in the circumferential direction. The work holder mounting mechanism includes an angle adjustment mechanism that rotates the work holder in a reference plane so that a mounting axis of the work holder is parallel to the crystal orientation,
The control unit obtains a second inclination angle formed by the attachment axis with respect to the crystal orientation from a measurement result of a displacement amount of the work holder in a direction parallel to the reference plane, and the second inclination angle is allowable. The bonding apparatus according to claim 5 , wherein the work holder is rotated again in the reference plane by using the angle adjusting mechanism so that the attachment axis is parallel to the crystal orientation when the mounting axis is not within the range. .

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