Cylinder grinding apparatus, cylinder grinding method, and wafer manufacturing method

Abstract

A cylinder grinding device for manufacturing a single crystal for slicing by cylinder grinding for grinding the outer peripheral surface of a single crystal for grinding while rotating the single crystal for grinding around a rotation axis, the cylinder grinding device being provided with: a posture correction unit for correcting the posture of the single crystal for grinding; and a processing unit that performs, on the basis of the difference in the plane direction between the plane direction of the single crystal for grinding and the target plane direction of a wafer obtained by slicing the single crystal for slicing, a rotation process in which the single crystal for grinding is rotated about the central axis thereof, and a rotation process in which the single crystal for grinding is rotated about a rotation axis orthogonal to the central axis. In this way, the posture of the grinding single crystal is corrected in the mode that the center axis is inclined relative to the rotation axis. And a grinding unit that performs cylindrical grinding on the outer peripheral surface of the single crystal for grinding while rotating the single crystal for grinding, the posture of which has been corrected, around the rotation axis.

Description

Technical Field

[0001] The invention relates to a cylindrical grinding device, a cylindrical grinding method and a method for manufacturing a wafer. Background Art

[0002] It is said that in advanced logic products, an integration technology is used to configure the power supply wiring network under the device. Such logic products are composed of so-called bonded wafers, and are produced by forming devices and power supply wiring networks on separate wafers and then bonding the separate wafers together through an insulating film.

[0003] In wafer bonding, it is expected that the bonding accuracy of the wafer will affect the production of through silicon vias (TSVs) that connect devices and power supply wiring networks, so it is necessary to improve the bonding accuracy of the wafer.

[0004] As a method for improving the bonding accuracy of wafers, the following method is considered useful: in a wire saw process, a single crystal silicon (single crystal for slicing) is sliced ​​while the relationship between the position of a notch indicating the surface orientation and the starting position of slicing is always in the same specific relationship, so that the generation state of micro-undulations in the wafer surface based on the notch is consistent. Wafers with the same generation state of undulations are bonded in a manner in which the notches overlap each other, so that the concave and convex surfaces facing each other are fitted together, thereby improving the bonding accuracy.

[0005] However, when this method is applied, the following new problems arise.

[0006] In silicon single crystals produced by the Czochralski method, the central axis of the silicon single crystal may deviate from the target crystal axis. If a single crystal for slicing obtained from silicon single crystals having such a deviation is sliced ​​with a wire saw, a wafer having a plane orientation deviating from the target plane orientation may be obtained.

[0007] In order to solve such a problem, it is conceivable to use the method described in Patent Document 1 or Patent Document 2.

[0008] In the method described in Patent Document 1, before slicing a single crystal for slicing in a wire saw process, an orientation adjustment mechanism on which a single crystal for slicing is mounted is fixed to a slide table. Next, the crystal axis orientations in the vertical and horizontal directions of the single crystal for slicing are detected. Then, the orientation adjustment mechanism is adjusted based on the detected crystal axis orientations in the vertical and horizontal directions, so that the single crystal for slicing parallel to the plane formed by the wire array rotates around its central axis by a predetermined angle, and rotates horizontally around a rotation axis (e.g., a vertical axis) orthogonal to its central axis by a predetermined angle.

[0009] It is considered that by using this method, the surface orientation of the single crystal for slicing with respect to the wire array can be adjusted, and a wafer having a surface orientation that matches a target surface orientation can be obtained.

[0010] On the other hand, in the method described in Patent Document 2, when cylindrical grinding is performed on a silicon single crystal (grinding single crystal), the amount of axis misalignment between the crystal axis and the central axis is adjusted in advance.

[0011] It is believed that by using this method, a wafer whose surface orientation is consistent with the target surface orientation can be obtained.

[0012] Prior art literature

[0013] Patent Literature

[0014] Patent Document 1: Japanese Patent Application Laid-Open No. 10-100142

[0015] Patent Document 2: Japanese Patent Application Publication No. 2017-212268 Summary of the invention

[0016] Technical problem to be solved by the invention

[0017] However, in the method described in Patent Document 1, if the single crystal for slicing is to be sliced ​​in a state where the relationship between the surface orientation represented by the position of the notch and the starting position of slicing is set to a specific relationship, then in the case where the deviation between the central axis of the single crystal silicon and the target crystal axis is large, even if the single crystal for slicing is horizontally rotated to adjust the surface orientation, the deviation in the vertical direction between the surface orientation of the single crystal for slicing and the target surface orientation of the wafer cannot be eliminated.

[0018] Therefore, it is impossible to obtain a wafer in which the generation state of fluctuations with respect to the surface orientation is uniform.

[0019] Furthermore, the purpose of the method described in Patent Document 2 is to slice the single crystal silicon in a state where the angle between the wire and the cleavage direction of the wafer is within a maximum of ±5 degrees and the angle between the central axis of the single crystal silicon and the plane formed by the wire array is less than 0.1 degrees, thereby obtaining a wafer with good warp.

[0020] Therefore, in the method described in Patent Document 2, it is impossible to slice a silicon single crystal while setting the relationship between the surface orientation and the slicing start position to a specific relationship, and when the deviation between the central axis of the silicon single crystal and the target crystal axis is large, it is impossible to set the surface orientation of the wafer to the target surface orientation. Therefore, it is impossible to obtain a wafer with a consistent generation state of fluctuations with respect to the surface orientation.

[0021] The object of the present invention is to provide a cylindrical grinding device, a cylindrical grinding method and a wafer manufacturing method, which can produce a slicing single crystal for a wafer with a consistent undulation state relative to the surface orientation from a grinding single crystal with an arbitrary surface orientation.

[0022] Solutions for solving technical problems

[0023] The cylindrical grinding device of the present invention produces a slicing single crystal by cylindrical grinding in which the outer peripheral surface of the grinding single crystal is ground while the grinding single crystal is rotated around a rotation axis. The cylindrical grinding device comprises: a posture correction unit, which performs a rotation process of rotating the grinding single crystal around its central axis and a rotation process of rotating the grinding single crystal around a rotation axis orthogonal to the central axis based on the surface orientation difference between the surface orientation of the grinding single crystal and the target surface orientation of the wafer obtained by slicing the slicing single crystal, thereby correcting the posture of the grinding single crystal in such a way that the central axis is inclined relative to the rotation axis; and a grinding unit, which performs cylindrical grinding on the outer peripheral surface of the grinding single crystal while rotating the grinding single crystal whose posture has been corrected around the rotation axis.

[0024] In the cylindrical grinding device of the present invention, the following method is preferred: the grinding section comprises: a rotation processing section, which holds the single crystal for grinding and rotates it around the rotation axis; a grinding member, which grinds the outer peripheral surface of the single crystal for grinding; and a relative moving section, which causes the rotation processing section and the grinding member to move relative to each other along the rotation axis, and the posture correction section comprises: a rotation processing section, which performs the rotation processing; and a posture correction control section, which controls the rotation processing section in a manner of holding the single crystal for grinding in a state where the center axis is consistent with the rotation axis and performing the rotation processing, and controls the rotation processing section in a manner of receiving the single crystal for grinding from the rotation processing section and returning it to the rotation processing section after performing the rotation processing.

[0025] In the cylindrical grinding device of the present invention, the following method is preferred: it also includes: a correction amount calculation unit, which calculates the first rotation angle in the rotation process and the first rotation angle in the rotation process based on the surface orientation difference, the first rotation angle and the first rotation angle are angles that can make the surface orientation of the slicing single crystal consistent with the target surface orientation, and the cylindrical grinding device performs the following first cylindrical grinding process: after the posture correction unit performs the rotation process based on the first rotation angle and the rotation process based on the first rotation angle, the grinding unit performs cylindrical grinding on the outer peripheral surface of the grinding single crystal whose posture is corrected by the posture correction unit, thereby producing the slicing single crystal whose surface orientation is consistent with the target surface orientation.

[0026] In the cylindrical grinding device of the present invention, the following method is preferred: it comprises: a grinding feasibility judgment unit, which judges whether the entire circumference of the outer peripheral surface of the single crystal for grinding rotated by the first rotation angle can be cylindrically ground based on the length and diameter of the single crystal for grinding and the target diameter of the single crystal for slicing.

[0027] In the cylindrical grinding device of the present invention, preferably, the cylindrical grinding device performs the first cylindrical grinding process when the grinding feasibility determination unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle can be cylindrically ground.

[0028] In the cylindrical grinding device of the present invention, the following method is preferred: when the grinding feasibility judgment unit determines that it is impossible to perform cylindrical grinding on the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle, the correction amount calculation unit calculates the second rotation angle in the rotation process and the second rotation angle smaller than the first rotation angle in the rotation process based on the surface orientation difference, the second rotation angle and the second rotation angle are angles that cannot make the surface orientation of the slicing single crystal consistent with the target surface orientation, and the slicing single crystal is rotated around the target surface orientation by making the relationship between the surface orientation and the slicing start position be in a specified relationship. After the center axis rotates to set the rotation angle, the slicing single crystal is rotated around a rotation axis orthogonal to the center axis, so that when observed from the center axis direction before rotation, the surface orientation of the slicing single crystal can be made to coincide with the target surface orientation. The cylindrical grinding device performs the following second cylindrical grinding process: after the posture correction unit performs the rotation process based on the second rotation angle and the rotation process based on the second rotation angle, the grinding unit performs cylindrical grinding on the peripheral surface of the grinding single crystal whose posture is corrected by the posture correction unit, thereby producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation.

[0029] In the cylindrical grinding device of the present invention, the following method is preferred: the grinding feasibility judgment unit judges whether the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal.

[0030] In the cylindrical grinding device of the present invention, the following method is preferred: the cylindrical grinding device performs the second cylindrical grinding process when the grinding feasibility judgment unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground, and does not perform the second cylindrical grinding process when the grinding feasibility judgment unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle cannot be cylindrically ground.

[0031] The cylindrical grinding device of the present invention preferably further comprises a notch forming section that forms a notch indicating the target surface orientation in the slicing single crystal.

[0032] In the cylindrical grinding device of the present invention, the following method is preferred: it also comprises: a notch formation control unit, which selects the candidate formation position where the first rotation angle becomes the smallest from a plurality of candidate formation positions of the notch representing the orientation of the target surface; and a notch forming unit, which forms a notch at the candidate formation position in the single crystal for slicing selected by the notch formation control unit.

[0033] In the cylindrical grinding device of the present invention, the following method is preferred: it also comprises: a notch formation control unit, which selects the candidate formation position where the second rotation angle becomes the smallest from a plurality of candidate formation positions of the notch representing the orientation of the target surface; and a notch forming unit, which forms a notch at the candidate formation position in the single crystal for slicing selected by the notch formation control unit.

[0034] The cylindrical grinding method of the present invention produces a slicing single crystal by rotating the grinding single crystal around a rotation axis while performing cylindrical grinding on the outer peripheral surface of the grinding single crystal. The cylindrical grinding method includes: a posture correction step, which, based on the surface orientation difference between the surface orientation of the grinding single crystal and the target surface orientation of a wafer obtained by slicing the slicing single crystal, performs a rotation process of rotating the grinding single crystal around its central axis and a rotation process of rotating the grinding single crystal around a rotation axis orthogonal to the central axis, thereby correcting the posture of the grinding single crystal in a manner that the central axis is inclined relative to the rotation axis; and a grinding step, which rotates the grinding single crystal whose posture has been corrected around the rotation axis while performing cylindrical grinding on the outer peripheral surface of the grinding single crystal.

[0035] In the cylindrical grinding method of the present invention, the following method is preferred: it uses a rotation processing unit and a rotation processing unit, the rotation processing unit holds the grinding single crystal and rotates it around the rotation axis, and the rotation processing unit performs the rotation processing. In the posture correction step, after controlling the rotation processing unit in a manner of holding the grinding single crystal in a state where the center axis is consistent with the rotation axis and performing the rotation processing, after receiving the grinding single crystal from the rotation processing unit and performing the rotation processing, the rotation processing unit is controlled in a manner of returning the grinding single crystal to the rotation processing unit in a posture where the center axis is inclined relative to the rotation axis.

[0036] In the cylindrical grinding method of the present invention, the following method is preferred: it also includes: a correction amount calculation step, which calculates the first rotation angle in the rotation processing and the first rotation angle in the rotation processing based on the surface orientation difference, the first rotation angle and the first rotation angle are angles that can make the surface orientation of the slicing single crystal consistent with the target surface orientation, in the posture correction step, after controlling the rotation processing unit in a manner of performing the rotation processing based on the first rotation angle, the rotation processing unit is controlled in a manner of performing the rotation processing based on the first rotation angle, in the grinding step, the outer peripheral surface of the grinding single crystal whose posture is corrected based on the first rotation angle and the first rotation angle is cylindrically ground, thereby producing the slicing single crystal whose surface orientation is consistent with the target surface orientation.

[0037] In the cylindrical grinding method of the present invention, the following method is preferred: it also includes: a grinding feasibility judgment step, which judges whether the entire circumference of the outer peripheral surface of the single crystal for grinding rotated by the first rotation angle can be cylindrically ground based on the length and diameter of the single crystal for grinding and the target diameter of the single crystal for slicing. When it is judged in the grinding feasibility judgment step that the entire circumference of the outer peripheral surface of the single crystal for grinding rotated by the first rotation angle can be cylindrically ground, the posture correction step and the grinding step are used to process the single crystal for slicing so that the surface orientation is consistent with the target surface orientation.

[0038] In the cylindrical grinding method of the present invention, the following method is preferred: in the correction amount calculation step, when it is determined in the grinding feasibility judgment step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle cannot be cylindrically ground, based on the surface orientation difference, the second rotation angle in the rotation process and the second rotation angle smaller than the first rotation angle in the rotation process are calculated, the second rotation angle and the second rotation angle are angles that cannot make the surface orientation of the slicing single crystal consistent with the target surface orientation, and after the rotation angle is set by rotating the slicing single crystal around its center axis so that the relationship between the surface orientation and the slicing start position is in a specified relationship, the slicing single crystal is rotated around the center axis to adjust the surface orientation of the slicing single crystal. The single crystal for slicing is rotated about a rotation axis orthogonal to an axis, thereby enabling the surface orientation of the single crystal for slicing to be consistent with the target surface orientation when observed from the direction of the central axis before rotation, and in the case where the second rotation angle and the second rotation angle are calculated in the correction amount calculation step, after the rotation processing unit is controlled in a manner to perform the rotation processing based on the second rotation angle in the posture correction step, the rotation processing unit is controlled in a manner to perform the rotation processing based on the second rotation angle, and in the grinding step, the outer peripheral surface of the single crystal for grinding whose posture is corrected based on the second rotation angle and the second rotation angle is cylindrically ground, thereby producing the single crystal for slicing whose surface orientation is inconsistent with the target surface orientation.

[0039] In the cylindrical grinding method of the present invention, the following method is preferred: in the grinding feasibility judgment step, based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal, it is judged whether the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground; when it is judged in the grinding feasibility judgment step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground, the posture correction step and the grinding step perform a process for producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation; and when it is judged in the grinding feasibility judgment step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle cannot be cylindrically ground, the posture correction step and the grinding step do not perform a process for producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation.

[0040] The cylindrical grinding method of the present invention preferably further comprises a notch forming step of forming a notch indicating the target surface orientation in the slicing single crystal.

[0041] In the cylindrical grinding method of the present invention, the following method is preferred: it also includes: a notch formation control process, which selects the candidate formation position where the first rotation angle becomes the smallest from a plurality of candidate formation positions of the notch representing the orientation of the target surface; and a notch formation process, which forms a notch at the candidate formation position in the single crystal for slicing selected in the notch formation control process.

[0042] In the cylindrical grinding method of the present invention, the following method is preferred: it also includes: a notch formation control process, which selects the candidate formation position where the second rotation angle becomes the smallest from a plurality of candidate formation positions of the notch representing the orientation of the target surface; and a notch formation process, which forms a notch at the candidate formation position in the single crystal for slicing selected in the notch formation control process.

[0043] In the wafer manufacturing method of the present invention, a single crystal for slicing is produced from a single crystal for grinding by the above-mentioned cylindrical grinding method, and the single crystal for slicing is sliced, thereby manufacturing a plurality of wafers whose surface orientation matches the target surface orientation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram showing the characteristics of a wafer according to one embodiment.

[0045] Figure 2 This is a block diagram showing a schematic configuration of a wafer manufacturing system according to one embodiment.

[0046] Figure 3 It is a plan view showing a schematic structure of a cylindrical grinding device according to one embodiment.

[0047] Figure 4 It is a side view showing a schematic structure of a horizontal rotation processing section constituting a cylindrical grinding device according to one embodiment.

[0048] Figure 5 This is a block diagram of a grinding control device constituting a cylindrical grinding device according to an embodiment.

[0049] Figure 6 It is an explanatory diagram of a method for calculating the maximum horizontal rotation angle of a single crystal for grinding according to one embodiment.

[0050] Figure 7 It is a schematic diagram showing a schematic structure of a slicing device according to one embodiment.

[0051] Figure 8 This is a flowchart showing a method for manufacturing a wafer according to an embodiment.

[0052] Fig. 91 is a flowchart showing a first wafer manufacturing process according to one embodiment.

[0053] Fig.10 FIG. 1 is a schematic diagram schematically showing a first wafer manufacturing process according to an embodiment.

[0054] Fig.11 1 is a flowchart showing a second wafer manufacturing process according to one embodiment.

[0055] Fig.12 It is a schematic diagram schematically showing a second wafer manufacturing process according to one embodiment.

[0056] Fig.13 It is a schematic diagram showing the first modification and the second modification.

[0057] Fig.14A This is a diagram showing in a graphical form the simulation results of the wafer manufacturing method of the comparative example, and shows the surface orientation of the single crystal for grinding that can manufacture the target wafer.

[0058] Fig. 14B This is a diagram showing in a graphical form the simulation results for the wafer manufacturing method of the comparative example, and shows the surface orientations of the single crystal for grinding that cannot produce the target wafer.

[0059] Fig.15A 1 is a diagram showing in a graphical form the simulation results of the wafer manufacturing method of the embodiment, and shows the surface orientation of the single crystal for grinding of which the wafer can be manufactured by the first wafer manufacturing process.

[0060] Fig. 15B The diagram is a diagram showing the simulation result of the wafer manufacturing method of the embodiment in the form of a graph, which shows the surface orientations of the single crystal for grinding that can manufacture the target wafer through the second wafer manufacturing process and the single crystal for grinding that cannot manufacture the target wafer through the second wafer manufacturing process. DETAILED DESCRIPTION

[0061] [Implementation Method]

[0062] Hereinafter, one embodiment of the present invention will be described.

[0063] <Wafer Characteristics>

[0064] First, the characteristics of a wafer manufactured by the wafer manufacturing method of the present embodiment will be described. Figure 1 It is a schematic diagram showing the characteristics of a wafer.

[0065] Figure 1 The wafer W shown is made of silicon, which is obtained by slicing a single crystal T2 (reference Figure 2) is sliced ​​to manufacture. Wafer W is used as a wafer constituting a bonded wafer, for example. In addition, wafer W can also be composed of germanium, silicon carbide, gallium arsenide, indium arsenide, gallium nitride or aluminum nitride.

[0066] The notch N indicating the surface orientation Mw of the wafer W (hereinafter, sometimes referred to as the "target surface orientation Mw") is located at the following position: in a coordinate system with the axis parallel to the slicing direction as the Y axis and the axis orthogonal to the center axis Cw of the wafer W and parallel to the horizontal direction as the X axis, the angle formed by the virtual line connecting the slicing start position P on the Y axis and the virtual line connecting the notch N and the center axis Cw becomes the position where the rotation angle φs is set. That is, the positional relationship between the target surface orientation Mw of the wafer W and the slicing start position P has a specific relationship. In addition, undulations U orthogonal to the slicing direction are generated on the wafer W.

[0067] In addition, the set rotation angle φs can be changed according to the characteristics of the bonded wafer, for example.

[0068] <Structure of wafer manufacturing system>

[0069] Next, the configuration of a wafer manufacturing system for manufacturing the wafer W will be described. Figure 2 This is a block diagram showing a schematic structure of a wafer manufacturing system.

[0070] exist Figure 2 In the wafer manufacturing system 1 shown in the figure, a silicon single crystal ingot T manufactured by the Czochralski method or the like is used to manufacture the following wafer W. Figure 1 As shown, the generation state of the undulation U based on the notch N and the target surface orientation Mw is consistent. The wafer manufacturing system 1 includes a block processing device 2 , a cylindrical grinding device 3 , and a slicing device 4 .

[0071] The block processing device 2 is provided with a cylindrical grinding device and a band saw for temporary grinding, which are not shown. The cylindrical grinding device for temporary grinding grinds the outer peripheral surface of the silicon single crystal ingot T to form a temporary notch Nk at a position corresponding to the crystal orientation (for example, refer to Fig.10 ). The band saw cuts the silicon single crystal ingot T into a plurality of cylindrical single crystals T1 for grinding.

[0072] The cylindrical grinding device 3 is configured to grind the single crystal T1 by making the central axis Ct1 relative to the rotation axis C (reference Figure 3 ) is tilted, the outer peripheral surface of the grinding single crystal T1 is cylindrically ground, thereby processing it into a slicing single crystal T2 with a corrected surface orientation. In the cylindrical grinding step of the cylindrical grinding device 3, the grinding single crystal T1 is processed into a surface orientation M2 (hereinafter sometimes referred to as "grinding back surface orientation M2") (for example, refer to Fig.10) The slicing single crystal T2 which is consistent with the target surface orientation Mw of the wafer W or the slicing single crystal T2 whose orientation M2 after grinding is inconsistent with the target surface orientation Mw.

[0073] The slicing device 4 slices the slicing single crystal T2 by, for example, using a wire saw, thereby processing it into a plurality of wafers W whose surface orientation is consistent with the target surface orientation Mw. In the slicing process of the slicing device 4, the slicing single crystal T2 whose rear surface orientation M2 after grinding is consistent with the target surface orientation Mw is sliced ​​in a state where the slicing plane of the slicing single crystal T2 is orthogonal to the central axis Ct2 of the slicing single crystal T2. In addition, in the slicing process, the slicing single crystal T2 whose rear surface orientation M2 after grinding is inconsistent with the target surface orientation Mw is sliced ​​in a manner where the surface orientation of the wafer W is consistent with the target surface orientation Mw and the slicing plane of the slicing single crystal T2 is not orthogonal to the central axis Ct2 of the slicing single crystal T2.

[0074] <Structure of cylindrical grinding device>

[0075] Next, the structure of the cylindrical grinding device will be described. Figure 3 It is a plan view showing a schematic structure of a cylindrical grinding device. Figure 4 This is a side view showing a schematic structure of a horizontal rotation processing section constituting the cylindrical grinding device. Figure 5 This is a block diagram of a grinding control device constituting a cylindrical grinding device. Figure 6 This is a diagram for explaining the method of calculating the maximum horizontal rotation angle of a single crystal for grinding.

[0076] like Figure 3 As shown, the cylindrical grinding device 3 includes a grinding unit 31, a horizontal rotation processing unit 32 as a rotation processing unit, a position measuring unit 33, and a length measuring unit 34 (see Figure 5 )、Notch forming portion 35 (reference Figure 5 ) and a grinding control device 36. In addition, Figure 3 and Figure 4 The arrangement position of each structure of the cylindrical grinding device 3 will be described based on the shown direction.

[0077] The grinding section 31 includes a rotation processing section 311, a grinding unit 312, and a relative moving section 313 (see Figure 5 ).

[0078] The rotation processing section 311 performs a rotation processing for holding the grinding single crystal T1 and rotating the grinding single crystal T1 around a rotation axis C extending in the left-right direction. The rotation processing section 311 includes: a pair of rotation holding units 314; and a rotation holding unit moving section (not shown) that moves the pair of rotation holding units 314 closer or farther along the rotation axis C.

[0079] Each of the rotation and holding units 314 includes a chuck 315 that holds an end portion of the grinding single crystal T1 in the direction of the central axis Ct1 , and a chuck driving unit 316 that rotates the chuck 315 around the rotation axis C.

[0080] The rotation processing section 311 holds the grinding single crystal T1 by means of the chuck 315 of each rotation holding unit 314 so that the center axis Ct1 of the grinding single crystal T1 is aligned with the rotation axis C or the center axis Ct1 is inclined relative to the rotation axis C, and rotates it around the rotation axis C.

[0081] The grinding unit 312 includes a grinding member 317 and a grinding member moving unit (not shown) that moves the grinding member 317 toward or away from the outer peripheral surface of the grinding single crystal T1. The grinding member 317 contacts a portion behind the outer peripheral surface of the grinding single crystal T1 that is rotated by the rotation processing unit 311, thereby grinding the outer peripheral surface of the grinding single crystal T1.

[0082] The relative moving section 313 moves the grinding unit 312 relative to the rotation holding unit 314 along the rotation axis C. The grinding unit 312 is moved along the rotation axis C while the grinding member 317 is in contact with the outer peripheral surface of the rotating single crystal T1 for grinding, so that the outer peripheral surface of the single crystal T1 for grinding can be cylindrically ground.

[0083] In addition, when performing cylindrical grinding, the rotation holding unit 314 may be moved along the rotation axis C without moving the grinding unit 312 , or both the grinding unit 312 and the rotation holding unit 314 may be moved along the rotation axis C.

[0084] The horizontal rotation processing section 32 receives the grinding single crystal T1 from the rotation processing section 311, horizontally rotates the grinding single crystal T1 around a vertical axis D1 as a rotation axis that is orthogonal to and intersects the central axis Ct1 thereof, and returns the grinding single crystal T1 to the rotation processing section 311 while maintaining the horizontally rotated posture. The horizontal rotation processing section 32 includes: a horizontal rotation unit 321; and a horizontal rotation unit moving section (not shown) that moves the horizontal rotation unit 321 forward, backward, left, and right.

[0085] In the present embodiment, the case where the grinding single crystal T1 is horizontally rotated about the vertical axis D1 is exemplified, but the grinding single crystal T1 may be rotated about a rotation axis that is orthogonal to or intersects with the central axis Ct1 and is inclined with respect to the vertical axis D1.

[0086] The horizontal rotation unit 321 includes: a pair of arms 322, which hold the front side or the rear side of the side surface of the grinding single crystal T1; an arm driving unit 323, which makes the pair of arms 322 approach or move away from each other; and a lifting and rotating driving unit 324, such as Figure 4As shown, the arm driving unit 323 is moved up and down and horizontally rotated around the vertical axis D1.

[0087] The details of the processing performed by the horizontal rotation processing unit 32 will be described later.

[0088] The orientation measuring unit 33 measures the surface orientation M1 (hereinafter sometimes referred to as “grinding front surface orientation M1”) of the single crystal T1 for grinding held by the rotation processing unit 311 (for example, refer to Fig.10 ) and the notch orientation of the single crystal T2 for slicing. The orientation measuring unit 33 includes: an X-ray unit 331, which measures the grinding front orientation M1 and the notch orientation; and an X-ray unit moving unit (not shown) which moves the X-ray unit 331 left and right.

[0089] The X-ray unit 331 measures the grinding front face position M1 or the notch position by irradiating X-rays, and outputs a signal indicating the measurement result to the grinding control device 36 .

[0090] The length measuring unit 34 measures the axial length L1 of the grinding single crystal T1 (reference Figure 6 ) and diameter R1 (reference Figure 6 ) and outputs a signal indicating the measurement result to the grinding control device 36.

[0091] The notch forming portion 35 forms a notch N (for example, see Fig.10 ).

[0092] like Figure 5 As shown, the grinding control device 36 is configured to be able to send and receive various information between the grinding unit 31, the horizontal rotation processing unit 32, the orientation measuring unit 33, the length measuring unit 34, and the notch forming unit 35. The grinding control device 36 includes an input unit 361, a storage unit 362, and an overall control unit 363.

[0093] The input unit 361 is constituted by, for example, a touch panel or physical buttons. The input unit 361 is used, for example, by an operator to input various settings related to cylindrical grinding, and outputs a signal corresponding to the input operation to the overall control unit 363 .

[0094] The storage unit 362 stores various information related to cylindrical grinding so that the overall control unit 363 can read the information. As information related to cylindrical grinding, the target diameter R2 of the slicing single crystal T2 (see Figure 6 ), target surface orientation Mw and set rotation angle φs.

[0095] The overall control unit 363 includes a CPU, and various functions are realized by the CPU executing a program stored in the storage unit 362. The overall control unit 363 includes a measurement result acquisition unit 364, a maximum horizontal rotation angle calculation unit 365, a correction amount calculation unit 366, a grinding feasibility determination unit 367, a posture correction control unit 368, a grinding control unit 369, and a notch formation control unit 370.

[0096] The measurement result acquisition unit 364 controls the orientation measurement unit 33 to acquire the measurement result of the grinding front orientation M1 or the notch orientation of the slicing single crystal T2 from the orientation measurement unit 33. Furthermore, the length measurement unit 364 controls the length measurement unit 34 to acquire the measurement result of the length L1 and the diameter R1 of the grinding single crystal T1.

[0097] Furthermore, the measurement result acquisition unit 364 may acquire information indicating the length L1 and the diameter R1 of the grinding single crystal T1 input by the operator using the input unit 361 .

[0098] The maximum horizontal rotation angle calculation unit 365 calculates the maximum horizontal rotation angle θm when the grinding single crystal T1 is horizontally rotated around the vertical axis D1 based on the length L1 and diameter R1 of the grinding single crystal T1 and the target diameter R2 of the slicing single crystal T2. The maximum horizontal rotation angle θm satisfies Figure 6 The angle of the conditions shown.

[0099] like Figure 6 As shown in the uppermost figure, when the horizontal rotation angle θ of the grinding single crystal T1 is less than the maximum horizontal rotation angle θm, and as shown in the central figure, when the horizontal rotation angle θ is equal to the maximum horizontal rotation angle θm, the entire circumference of the outer peripheral surface of the grinding single crystal T1 can be cylindrically ground to the target diameter R2 and processed into the slicing single crystal T2 without generating any waste material.

[0100] On the other hand, Figure 6 As shown in the bottom figure, when the horizontal rotation angle θ exceeds the maximum horizontal rotation angle θm, the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground to the target diameter R2 and processed into the slicing single crystal T2, and excess material will be generated.

[0101] That is, the maximum horizontal rotation angle θm is a threshold value that serves as a criterion for determining whether or not the entire circumference of the outer peripheral surface of the grinding single crystal T1 can be cylindrically ground to the target diameter R2.

[0102] The correction amount calculation unit 366 calculates a first correction amount and a second correction amount for obtaining a slicing single crystal T2 with a corrected surface orientation from the grinding single crystal T1. The first correction amount includes a first rotation angle φ1 (reference Fig.10 ) and the first horizontal rotation angle θ1 as the first rotation angle (reference Fig.10The second correction amount includes the second rotation angle φ2 (reference Fig.12 ) and the second horizontal rotation angle θ2 (reference Fig.12 ). The first rotation angle φ1 and the second rotation angle φ2 are rotation angles of the grinding single crystal T1 around the central axis Ct1. The first horizontal rotation angle θ1 and the second horizontal rotation angle θ2 are horizontal rotation angles of the grinding single crystal T1 around the vertical axis D1.

[0103] The correction amount calculation unit 366 calculates the first correction amount and the second correction amount based on the difference between the grinding front surface orientation M1 and the target surface orientation Mw (hereinafter sometimes referred to as "surface orientation difference"). The calculation method of the first correction amount and the second correction amount will be described later.

[0104] The grinding feasibility determination unit 367 determines, based on the size relationship between the first horizontal rotation angle θ1 or the second horizontal rotation angle θ2 and the maximum horizontal rotation angle θm, whether the entire circumference of the outer peripheral surface of the grinding single crystal T1 can be cylindrically ground to the target diameter R2 when the grinding single crystal T1 is horizontally rotated by the first horizontal rotation angle θ1 or the second horizontal rotation angle θ2.

[0105] The posture correction control unit 368, together with the rotation processing unit 311 and the horizontal rotation processing unit 32, constitute the posture correction unit 38. The posture correction control unit 368 controls the rotation processing unit 311 to perform a rotation process of rotating the grinding single crystal T1 around the central axis Ct1, and controls the horizontal rotation processing unit 32 to perform a horizontal rotation process of horizontally rotating the grinding single crystal T1 around the vertical axis D1, thereby correcting the posture of the grinding single crystal T1 in such a manner that the central axis Ct1 is inclined relative to the rotation axis C of the grinding unit 31.

[0106] Here, “correcting the posture of the single crystal T1 for grinding” means correcting (adjusting) the axial direction of the central axis Ct1 of the single crystal T1 for grinding with respect to the rotation axis C of the grinding unit 31 to a predetermined direction.

[0107] Specifically, the posture correction control unit 368 rotates the grinding single crystal T1 (held by the pair of rotation holding units 314) by the first rotation angle φ1, and then moves the pair of arms 322 located at the initial position to hold the grinding single crystal T1. The posture correction control unit 368 releases the pair of rotation holding units 314 from holding the single crystal T1.

[0108] The posture correction control unit 368 drives the lifting and rotating driving unit 324 to raise the grinding single crystal T1, and then horizontally rotates it by the first horizontal rotation angle θ1, and directly moves the grinding single crystal T1 between the pair of rotation holding units 314 while maintaining the posture of the grinding single crystal T1 being horizontally rotated. After the grinding single crystal T1 is held by the pair of rotation holding units 314, the posture correction control unit 368 releases the holding of the grinding single crystal T1 by the pair of arms 322. Finally, the posture correction control unit 368 returns the pair of arms 322 to the initial position.

[0109] By the processing of the posture correcting unit 38 as described above, the grinding single crystal T1 is rotated by the first rotation angle φ1 with respect to the posture in which the central axis Ct1 coincides with the rotation axis C, and is held by the pair of rotation holding units 314 in the posture in which it is horizontally rotated by the first horizontal rotation angle θ1.

[0110] Then, the posture correcting section 38 performs the same processing as described above to rotate the grinding single crystal T1 by the second rotation angle φ2 with respect to the central axis Ct1 and the rotation axis C so as to coincide with each other, and to hold the grinding single crystal T1 by the pair of chucks 315 in the posture of being horizontally rotated by the second horizontal rotation angle θ2.

[0111] The grinding control unit 369 controls the grinding unit 31 to rotate the grinding single crystal T1 whose posture is corrected by the control of the posture correction control unit 368, and to perform cylindrical grinding while the grinding member 317 is in contact with the outer peripheral surface of the grinding single crystal T1 and moves along the rotation axis C. The cylindrical grinding obtains the slicing single crystal T2.

[0112] The notch formation control unit 370 controls the notch forming unit 35 based on the measurement result of the notch orientation of the slicing single crystal T2 to form a notch N at a position corresponding to the notch orientation on the outer peripheral surface of the slicing single crystal T2. That is, the notch formation control unit 370 forms the notch N indicating the rear grinding orientation M2 of the slicing single crystal T2 on the slicing single crystal T2.

[0113] <Structure of the slicing device>

[0114] Next, the structure of the slicing device will be described. Figure 7 It is a schematic diagram showing the schematic structure of a slicing device.

[0115] like Figure 7 As shown, the slicing device 4 is a so-called wire saw and includes a total of three main rollers 41 , two of which are arranged on the same horizontal plane, and one of which is arranged below the middle of the two main rollers 41 .

[0116] Wires 42 are wound around these three main rollers 41 along their axial directions. By winding the wires 42 around the main rollers 41 in this way, a wire row in which a plurality of wires 42 are arranged at a constant pitch along the axial directions of the main rollers 41 is formed between the two upper main rollers 41 (hereinafter sometimes referred to as "upper main rollers 411").

[0117] Wire reels 44 and 45 for feeding out or winding up the wire 42 via guide rollers 43 are arranged on both ends of the wire 42 .

[0118] Nozzles 46 for supplying the slurry G to the middle position between the two upper main rolls 411 are arranged above the upper main rolls 411 .

[0119] Furthermore, a lifting unit 48 for lifting and lowering the slicing single crystal T2 held on the holding member 47 is arranged above the nozzle 46 .

[0120] The holding member 47 includes a working plate 471 having one main surface fixed to the lifting unit 48 , and a slicing table 472 fixed to the other main surface of the working plate 471 .

[0121] The working plate 471 is a rectangular plate-like member whose two main surfaces are flat.

[0122] The slicing table 472 is a substantially rectangular plate-shaped member, and is cut together with the slicing single crystal T2 by the wire 42. The slicing table 472 has a holding surface 473 that holds the slicing single crystal T2 in an arc shape by an adhesive. The holding surface 473 holds the slicing single crystal T2 in a state where the length direction of the slicing table 472 is parallel to the center axis Ct2 direction of the slicing single crystal T2. The flat surface of the slicing table 472 on the side opposite to the holding surface 473 is fixed to the working plate 471.

[0123] The slicing device 4 rotates a plurality of main rollers 41 to cause the wire 42 to move in a direction (left-right direction) approximately orthogonal to the axial direction of the main rollers 41, and supplies slurry G between the two upper main rollers 411 while lowering the slicing single crystal T2 and pressing it onto the wire array, thereby slicing the slicing single crystal T2 to manufacture a plurality of wafers W.

[0124] <Wafer manufacturing method>

[0125] Next, a method for manufacturing the wafer W using the wafer manufacturing system 1 will be described. Figure 8 This is a flowchart showing a method for manufacturing a wafer.

[0126] First, a cylindrical single crystal T1 for grinding in which a temporary notch Nk is formed is prepared.

[0127] Then, if Figure 8As shown, the measurement result acquisition unit 364 of the cylindrical grinding device 3 controls the length measuring unit 34 to acquire the measurement results of the length L1 and the diameter R1 of the grinding single crystal T1 (step S1).

[0128] Next, the measurement result acquisition unit 364 controls the orientation measurement unit 33 to acquire the measurement result of the front-surface-of-grinding orientation M1 of the single crystal T1 for grinding (step S2 ).

[0129] Then, the maximum horizontal rotation angle calculation unit 365 calculates the maximum horizontal rotation angle θm (step S3 ).

[0130] Thereafter, the correction amount calculation unit 366 calculates a first correction amount including the first rotation angle φ1 and the first horizontal rotation angle θ1 (step S4 ).

[0131] For example, the correction amount calculation unit 366 obtains the deviation between the grinding front surface orientation M1 of the grinding single crystal T1 when the grinding single crystal T1 is viewed from the center axis Ct1 direction and the target surface orientation Mw (reference Fig.10 Next, when the grinding single crystal T1 is rotated about the center axis Ct1 while observing the grinding single crystal T1 from the center axis Ct1, the correction amount calculation unit 366 calculates the following angle as the first rotation angle φ1 (reference Fig.10 The angle is the angle that can make the vertical direction (Y-axis direction) of the grinding front surface orientation M1 and the target surface orientation Mw equal. Moreover, when the grinding single crystal T1 is horizontally rotated around the vertical axis D1 when the grinding single crystal T1 is observed from the center axis Ct1 direction before horizontal rotation, the correction amount calculation unit 366 calculates the following angle as the first horizontal rotation angle θ1 (reference Fig.10 This angle is the angle that can make the horizontal direction (X-axis direction) of the grinding surface direction M1 and the target surface direction Mw equal.

[0132] After the process of step S4 , the grinding feasibility determination unit 367 determines whether the first horizontal rotation angle θ1 is equal to or smaller than the maximum horizontal rotation angle θm (step S5 ).

[0133] When the grinding feasibility determination unit 367 determines that the first horizontal rotation angle θ1 is less than the maximum horizontal rotation angle θm (step S5: "Yes"), that is, when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 can be cylindrically ground when the grinding single crystal T1 is horizontally rotated by the first horizontal rotation angle θ1, the cylindrical grinding device 3 and the slicing device 4 perform the first wafer manufacturing process (step S6).

[0134] On the other hand, when the grinding feasibility determination unit 367 determines that the first horizontal rotation angle θ1 exceeds the maximum horizontal rotation angle θm (step S5: "No"), that is, when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground when the grinding single crystal T1 is horizontally rotated by the first horizontal rotation angle θ1, the cylindrical grinding device 3 and the slicing device 4 perform the second wafer manufacturing process (step S7).

[0135] Through the first wafer manufacturing process or the second wafer manufacturing process, a Figure 1 The characteristics of wafer W are shown.

[0136] <1st wafer manufacturing process>

[0137] Next, the details of the first wafer manufacturing process in step S6 will be described. Fig. 9 : is a flowchart showing the first wafer manufacturing process. Fig.10 FIG. 1 is a schematic diagram schematically showing the first wafer manufacturing process.

[0138] in addition, Fig.10 The four figures in the upper row in FIG. 1 represent the first cylindrical grinding process, and the four figures in the lower row represent the first slicing process.

[0139] Fig.10 In the 1st to 3rd figures from the left in the upper row, the X-axis represents the horizontal deviation of the surface orientation relative to the center axis Ct1 when observing the grinding single crystal T1 before posture correction from the center axis Ct1, and the Y-axis represents the vertical deviation of the surface orientation relative to the center axis Ct1. Fig.10 The X-axis in the fourth figure from the left in the upper row represents the horizontal deviation of the surface orientation relative to the center axis Ct2 when observing the slicing single crystal T2 from the center axis Ct2 direction, and the Y-axis represents the vertical deviation of the surface orientation relative to the center axis Ct2.

[0140] Fig.10 In the 1st to 3rd figures from the left in the lower row, the X-axis represents the horizontal deviation of the surface orientation relative to the center axis Ct2 when observing the slicing single crystal T2 before posture correction from the center axis Ct2 direction, and the Y-axis represents the vertical deviation of the surface orientation relative to the center axis Ct2. Fig.10 The X-axis in the fourth figure from the left in the lower row represents the horizontal deviation of the surface orientation relative to the center axis Cw when the wafer W is observed from the center axis Cw direction, and the Y-axis represents the vertical deviation of the surface orientation relative to the center axis Cw.

[0141] Fig. 9 The first wafer manufacturing process shown includes a first cylindrical grinding process consisting of processes of steps S10 to S13 and a first slicing process consisting of processes of steps S14 to S18 .

[0142] In the first cylindrical grinding process, the single crystal T1 for grinding is processed into the single crystal T2 for slicing in which the rear surface orientation M2 after grinding coincides with the target surface orientation Mw.

[0143] In the first slicing process, a plurality of wafers W are manufactured using the single crystal T2 for slicing whose rear surface orientation M2 after grinding coincides with the target surface orientation Mw.

[0144] First, the first cylindrical grinding process will be described.

[0145] The posture correcting unit 38 of the cylindrical grinding device 3 corrects the posture of the grinding single crystal T1 based on the first correction amount (step S10 ).

[0146] For example, the posture correction unit 38 makes Fig.10 The first figure from the left in the upper row (the figure before the posture change in the first cylindrical grinding process) shows that the grinding single crystal T1 is rotated by the first rotation angle φ1, thereby correcting the posture of the grinding single crystal T1 to Fig.10 The posture shown in the second figure from the left in the upper row (a figure showing the vertical direction correction in the first cylindrical grinding process). Next, the posture correction unit 38 horizontally rotates the grinding single crystal T1 by the first horizontal rotation angle θ1, thereby correcting the posture of the grinding single crystal T1 to Fig.10 The posture shown in the third figure from the left in the upper row (figure showing horizontal direction correction in the first cylindrical grinding process).

[0147] Then, for example, Figure 6 As shown in the top figure, the central axis Ct1 is tilted at a first horizontal rotation angle θ1 relative to the rotation axis C, and as shown in Fig.10 As shown in the third figure from the left in the upper row, when the grinding single crystal T1 is observed from the rotation axis C, the front grinding surface orientation M1 is consistent with the target surface orientation Mw, and the posture correction section 38 holds the grinding single crystal T1 by a pair of rotation holding units 314.

[0148] After the processing of step S10, Fig. 9 As shown, the grinding control unit 369 controls the grinding unit 31 to perform cylindrical grinding on the outer peripheral surface of the single crystal for grinding T1 whose posture has been corrected to obtain the single crystal for slicing T2 (step S11).

[0149] Next, the measurement result acquisition unit 364 controls the orientation measurement unit 33 to acquire the measurement result of the notch orientation of the slicing single crystal T2 (step S12 ).

[0150] Thereafter, the notch formation control unit 370 controls the notch forming unit 35 to form a notch N indicating the post-grinding orientation M2 of the slicing single crystal T2 at a position in the slicing single crystal T2 corresponding to the notch orientation (step S13 ).

[0151] Through the above first cylindrical grinding process (processing of steps S10 to S13), as Fig.10 As shown in the fourth figure from the left in the upper row (the figure after cylindrical grinding in the first cylindrical grinding process), a single crystal T2 for slicing is obtained whose orientation M2 after grinding is consistent with the target surface orientation Mw.

[0152] Next, the first slicing process will be described. Note that the processes of steps S15 to S17 may be performed by a processing device or by an operator.

[0153] First, if Fig. 9 As shown, the surface orientation M2 of the ground rear surface of the slicing single crystal T2 is measured using a surface orientation measuring device (not shown) (step S14).

[0154] Then, the slicing table 472 is placed on the working plate 471 in a state where the holding surface 473 faces upward and the longitudinal directions of the two are parallel to each other.

[0155] Next, the slicing single crystal T2 is placed on the holding surface 473 of the slicing table 472 in a set posture (step S15). Fig.10 As shown in the first figure from the left in the lower row (the figure before the posture change in the first slicing process), when observing the slicing single crystal T2 from the center axis Ct2 direction, the set posture in this embodiment is the posture in which the notch N is at the highest position, that is, the posture in which the notch N is located at the slicing starting position P.

[0156] Next, the slicing single crystal T2 is rotated around the central axis Ct2 on the slicing table 472 to set the rotation angle φs, and after the relationship between the grinding back position M2 and the slicing starting position P is set to a specific relationship, the slicing single crystal T2 is bonded to the slicing table 472 (step S16).

[0157] Through the processing of step S16, Fig.10 The second figure from the left in the lower row (the figure showing the vertical direction correction in the first slicing process) shows the positional relationship between the notch N, the grinding back face position M2, and the slicing start position P when viewed from the center axis Ct2. Figure 1 The positional relationship among the notch N, the target surface orientation Mw, and the slicing start position P when the wafer W is viewed from the center axis Cw direction is the same.

[0158] Thereafter, the slicing stage 472 is bonded to the work plate 471 without being horizontally rotated about a vertical axis serving as a rotation axis that is orthogonal to and intersects the central axis Ct1 of the slicing single crystal T2 (step S17 ).

[0159] Through the processing of step S17, the slicing single crystal T2 is fixed to the working plate 471 in a state where the central axis Ct2 is parallel to the longitudinal direction of the working plate 471. Fig.10 As shown in the third figure from the left in the lower row (a figure in which horizontal direction correction is not performed in the first slicing process), the posture of the slicing single crystal T2 does not change before and after the process of step S17.

[0160] Next, the work plate 471 is fixed to the lifting part 48 in a predetermined state, and the slicing single crystal T2 is sliced ​​with the slicing start position P as the starting point, with the central axis Ct2 of the slicing single crystal T2 being orthogonal to the wires 42 of the wire array (step S18).

[0161] Through the processing of step S18, Fig.10 The fourth image from the left in the bottom row (image after slicing in the first slicing process) and Figure 1 As shown, a plurality of wafers W are obtained, the surface orientation of which is consistent with the target surface orientation Mw, the surface orientation of which has a specific relationship with the slicing start position P, and the generation state of the fluctuation with respect to the surface orientation is consistent.

[0162] <Second wafer manufacturing process>

[0163] Next, the details of the second wafer manufacturing process in step S7 will be described. Fig.11 : is a flowchart showing the second wafer manufacturing process. Fig.12 It is a schematic diagram showing an outline of the second wafer manufacturing process.

[0164] in addition, Fig.12 The 4 figures in the upper row represent the second cylindrical grinding process, and the 4 figures in the lower row represent the second slicing process.

[0165] Fig.12 The 8 figures represent Fig.10 The figures shown at the same position in the figure have the same content.

[0166] Fig.11 The second wafer manufacturing process shown includes a second cylindrical grinding process consisting of processes of steps S20 to S26 , and a second slicing process consisting of processes of steps S27 to S31 .

[0167] In the second cylindrical grinding process, the single crystal T1 for grinding is processed into the single crystal T2 for slicing in which the rear surface orientation M2 after grinding does not coincide with the target surface orientation Mw.

[0168] In the second slicing process, a plurality of wafers W are manufactured using the slicing single crystal T2 whose rear surface orientation M2 after grinding does not coincide with the target surface orientation Mw.

[0169] First, the second cylindrical grinding process will be described.

[0170] The correction amount calculation unit 366 calculates a second correction amount including a second rotation angle φ2 and a second horizontal rotation angle θ2 (step S20 ).

[0171] The correction amount calculation unit 366 sets, for example, Fig.12 The linear correctable range K indicated by the dotted line in the second figure from the left in the lower row (figure of vertical direction correction in the second slicing process). The correctable range K is set so that when the slicing single crystal T2 is observed from the center axis Ct2 direction, the target surface orientation Mw is included in the correctable range K. The details of when the target surface orientation Mw and the grinding back surface orientation M2 are included in the correctable range K will be described later, but the correctable range K is set so that when the slicing single crystal T2 placed on the slicing table 472 in a set posture is rotated around the center axis Ct2 by a set rotation angle φs (refer to Fig.12 (The second figure from the left in the lower row) shows that, when viewed from the center axis Ct2 direction, the vertical value of the grinding back direction M2 and the target surface direction Mw can be made equal.

[0172] After the correctable range K is set, the correction amount calculation unit 366 calculates the deviation between the grinding front surface orientation M1 of the grinding single crystal T1 and the target surface orientation Mw when the grinding single crystal T1 is viewed from the center axis Ct1 direction (reference Fig.12 Next, when the grinding single crystal T1 is rotated about the center axis Ct1 while observing the grinding single crystal T1 from the center axis Ct1, the correction amount calculation unit 366 calculates the following angle as the second rotation angle φ2 (reference Fig.12 The second figure from the left in the upper row of FIG. 3 is an angle that enables the correctable range K including the target surface orientation Mw to be parallel to the vertical direction. In addition, when the grinding single crystal T1 is horizontally rotated around the vertical axis D1 while observing the grinding single crystal T1 from the center axis Ct1 direction before horizontal rotation, the correction amount calculation unit 366 calculates the following angle as the second horizontal rotation angle θ2 (reference Fig.12 This angle is an angle that enables the front grinding surface orientation M1 to be included in the correctable range K and not coincide with the target surface orientation Mw.

[0173] The second horizontal rotation angle θ2 thus obtained becomes smaller than the first horizontal rotation angle θ1. Therefore, in the processing of step S21 described later, when the grinding single crystal T1 is horizontally rotated by the second horizontal rotation angle θ2, it is determined that the possibility of cylindrical grinding of the entire circumference of the outer peripheral surface of the grinding single crystal T1 to the target diameter R2 becomes high.

[0174] After the process of step S20 , the grinding feasibility determination unit 367 determines whether the second horizontal rotation angle θ2 is equal to or smaller than the maximum horizontal rotation angle θm (step S21 ).

[0175] When the grinding feasibility determination unit 367 determines that the second horizontal rotation angle θ2 exceeds the maximum horizontal rotation angle θm (step S21: No), that is, when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground to the target diameter R2 when the grinding single crystal T1 is horizontally rotated by the second horizontal rotation angle θ2, it is determined that the grinding single crystal T1 cannot be processed into the slicing single crystal T2 (step S22). After the processing of step S22, the processing is terminated without manufacturing the wafer W from the grinding single crystal T1.

[0176] On the other hand, when the grinding feasibility determination unit 367 determines that the second horizontal rotation angle θ2 is less than the maximum horizontal rotation angle θm (step S21: “Yes”), that is, when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 can be cylindrically ground to the target diameter R2 when the grinding single crystal T1 is horizontally rotated by the second horizontal rotation angle θ2, the posture correction unit 38 corrects the posture of the grinding single crystal T1 based on the second correction amount (step S23).

[0177] For example, the posture correction unit 38 makes Fig.12 The first figure from the left in the upper row (the figure before the posture change in the second cylindrical grinding process) shows that the grinding single crystal T1 is rotated by the second rotation angle φ2, thereby correcting the posture of the grinding single crystal T1 to Fig.12 The posture shown in the second figure from the left in the upper row (a figure showing the vertical direction correction in the second cylindrical grinding process). Next, the posture correction unit 38 horizontally rotates the grinding single crystal T1 by the second horizontal rotation angle θ2, thereby correcting the posture of the grinding single crystal T1 to Fig.12 The posture shown in the third figure from the left in the upper row (figure showing horizontal direction correction in the second cylindrical grinding process).

[0178] Then, the central axis Ct1 is tilted at a second horizontal rotation angle θ2 relative to the rotation axis C, and as shown in FIG. Fig.12 As shown in the third figure from the left in the upper row, when the single crystal T1 for grinding is observed from the direction of the rotation axis C, the posture correction unit 38 holds the single crystal T1 for grinding by means of a pair of rotation holding units 314, so that the state in which the front grinding surface orientation M1 is inconsistent with the target surface orientation Mw is included in the correctable range K horizontally relative to the vertical direction.

[0179] After the processing of step S23, Fig.11As shown, the grinding control unit 369 performs the same processing as that of step S11, and cylindrically grinds the outer peripheral surface of the single crystal for grinding T1 whose posture has been corrected to obtain the single crystal for slicing T2 (step S24).

[0180] Next, the measurement result acquisition unit 364 performs the same processing as that of step S12 to acquire the measurement result of the notch orientation of the slicing single crystal T2 (step S25 ).

[0181] Thereafter, the notch formation control unit 370 performs the same processing as that of step S13 to form a notch N indicating the post-grinding orientation M2 of the slicing single crystal T2 at a position in the slicing single crystal T2 corresponding to the notch orientation (step S26 ).

[0182] Through the above second cylindrical grinding process (processing of steps S20 to S26), Fig.12 As shown in the fourth figure from the left in the upper row (a figure after cylindrical grinding in the second cylindrical grinding process), a slicing single crystal T2 can be obtained in which the pre-grinding orientation M1 and the target surface orientation Mw are not consistent but are within the correctable range K.

[0183] Next, the second slicing process will be described. Note that the processes of steps S28 to S30 may be performed by the processing device or by the operator.

[0184] First, if Fig.11 As shown, similarly to the process of step S14, the rear surface orientation M2 of the single crystal T2 for slicing after grinding is measured (step S27).

[0185] Then, similarly to the first slicing process, the slicing table 472 is placed on the work plate 471 .

[0186] Next, similarly to the process of step S15 , the single crystal T2 for slicing is placed on the slicing stage 472 in a set posture (step S28 ).

[0187] Next, similarly to the process of step S16, the slicing single crystal T2 is rotated on the slicing stage 472 around the central axis Ct2 at a set rotation angle φs, and is bonded to the slicing stage 472 (step S29).

[0188] Through the processing of step S29, Fig.12 As shown in the second figure from the left in the lower row (the figure of the vertical direction correction in the second slicing process), the positional relationship between the notch N and the slicing start position P when viewed from the center axis Ct2 direction is Figure 1 The positional relationship between the notch N and the slicing start position P when the wafer W is viewed from the center axis Cw is the same as shown in FIG. However, the positional relationship between the grinding back surface position M2 and the slicing start position P when viewed from the center axis Ct2 is different from Figure 1 The positional relationship between the target surface direction Mw when the wafer W is viewed from the center axis Cw direction and the slicing start position P is different. In addition, the vertical value of the grinding back surface direction M2 and the target surface direction Mw when viewed from the center axis Ct2 direction becomes equal.

[0189] Thereafter, the slicing table 472 is horizontally rotated relative to the working plate 471 around a vertical axis that is orthogonal to and intersects the center axis Ct2 of the single crystal T2 for slicing, so that the back surface orientation M2 of the grinding surface when viewed from the center axis Ct2 is consistent with the target surface orientation Mw, and is bonded to the working plate 471 (step S30).

[0190] Through the processing of step S30, the slicing single crystal T2 is fixed to the working plate 471 in a state where the central axis Ct2 is inclined relative to the longitudinal direction of the working plate 471. Fig.12 As shown in the third figure from the left in the lower row (a figure showing horizontal direction correction in the second slicing process), the posture of the slicing single crystal T2 changes before and after the process of step S30.

[0191] Next, similarly to the process of step S17, the working plate 471 is fixed to the lifting part 48 in a predetermined state, and the single crystal T2 for slicing is sliced ​​with the slicing starting position P as the starting point, while the center axis Ct2 of the single crystal T2 for slicing is tilted relative to the wire 42 of the wire row (step S31).

[0192] Through the processing of step S31, Fig.12 The fourth image from the left in the bottom row (image after slicing in the second slicing process) and Figure 1 As shown, a plurality of wafers W are obtained, the surface orientation of which is consistent with the target surface orientation Mw, the surface orientation of which has a specific relationship with the slicing start position P, and the generation state of the fluctuation with respect to the surface orientation is consistent.

[0193] [Effects of Embodiment]

[0194] According to the above-mentioned embodiment, the cylindrical grinding device 3 comprises: a posture correction unit 38, which performs self-rotation processing and horizontal rotation processing on the single crystal T1 for grinding based on the surface orientation difference between the front grinding surface orientation M1 of the single crystal T1 for grinding and the target surface orientation Mw of the wafer W, thereby correcting the posture of the single crystal T1 for grinding in such a way that the central axis Ct1 is inclined relative to the rotation axis C; and a grinding unit 31, which performs cylindrical grinding on the outer peripheral surface of the single crystal T1 for grinding whose posture has been corrected.

[0195] Therefore, by cylindrical grinding, the deviation between the grinding rear orientation M2 of the slicing single crystal T2 obtained from the grinding single crystal T1 having an arbitrary grinding front orientation M1 and the target surface orientation Mw can be controlled to a specified state. Therefore, by rotating the slicing single crystal T2 to set the rotation angle φs so that the relationship between the grinding rear orientation M2 and the slicing start position P becomes a specified relationship, and slicing after horizontally rotating it as needed, it is possible to obtain a plurality of wafers W having a specific relationship between the surface orientation and the slicing start position P and having the same generation state of undulation relative to the surface orientation. That is, the following cylindrical grinding device 3 can be provided, which can produce a slicing single crystal T2 (with the same generation state of undulation relative to the surface orientation) from the grinding single crystal T1 having an arbitrary grinding front orientation M1.

[0196] The posture correction unit 38 includes a posture correction control unit 368, which controls the rotation processing unit 311 in a manner of maintaining the single crystal T1 for grinding in a state where the central axis Ct1 is consistent with the rotation axis C and performing rotation processing, and controls the horizontal rotation processing unit 32 in a manner of receiving the single crystal T1 for grinding from the rotation processing unit 311, performing horizontal rotation processing, and then returning it to the rotation processing unit 311.

[0197] In this way, by using the rotation processing unit 311 that rotates the grinding single crystal T1 during cylindrical grinding as a structure for correcting the posture of the grinding single crystal T1 , it is possible to suppress the structure of the cylindrical grinding device 3 from becoming complicated.

[0198] The correction amount calculation unit 366 obtains the first rotation angle φ1 and the first horizontal rotation angle θ1 that can make the grinding rear surface orientation M2 of the slicing single crystal T2 consistent with the target surface orientation Mw. Then, the cylindrical grinding device 3 performs the first cylindrical grinding process as follows: after the posture correction unit 38 rotates the grinding single crystal T1 by the first rotation angle φ1 and horizontally rotates it by the first horizontal rotation angle θ1, the grinding unit 31 grinds the outer peripheral surface of the grinding single crystal T1, thereby processing the slicing single crystal T2 whose grinding rear surface orientation M2 is consistent with the target surface orientation Mw.

[0199] By manufacturing wafers W using the slicing single crystal T2 whose rear grinding back surface orientation M2 matches the target surface orientation Mw, a plurality of wafers W having the same fluctuation state with respect to the surface orientation can be obtained without horizontally rotating the slicing single crystal T2. Therefore, an increase in the number of processes constituting the slicing process can be suppressed.

[0200] The grinding feasibility determination unit 367 determines whether the entire circumference of the outer peripheral surface of the grinding single crystal T1 horizontally rotated by the first horizontal rotation angle θ1 can be cylindrically ground based on the length L1 and diameter R1 of the grinding single crystal T1 and the target diameter R2 of the slicing single crystal T2. Thereafter, if it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 horizontally rotated by the first horizontal rotation angle θ1 can be cylindrically ground, the posture correction unit 38 and the grinding unit 31 perform the first cylindrical grinding process, and if it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground, the posture correction unit 38 and the grinding unit 31 do not perform the first cylindrical grinding process.

[0201] Here, if the slicing single crystal T2 that has not been partially cylindrically ground is sliced, a non-disk-shaped wafer W is produced.

[0202] In the present embodiment, the first cylindrical grinding process is performed only when the entire outer peripheral surface of the grinding single crystal T1 horizontally rotated by the first horizontal rotation angle θ1 can be cylindrically ground, so that the production of non-disc-shaped wafers W can be suppressed.

[0203] When it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground, the correction amount calculation unit 366 calculates the second rotation angle φ2 and the second horizontal rotation angle θ2. The second horizontal rotation angle θ2 is an angle smaller than the first horizontal rotation angle θ1. The second rotation angle φ2 and the second horizontal rotation angle θ2 are angles at which the grinding back surface orientation M2 of the slicing single crystal T2 cannot be made consistent with the target surface orientation Mw, and are angles that are set by rotating the slicing single crystal T2 around the central axis Ct2 so that the relationship between the grinding back surface orientation M2 and the slicing start position P is in a predetermined relationship, and horizontally rotating the slicing single crystal T2 around the vertical axis orthogonal to the central axis Ct2, thereby making the grinding back surface orientation M2 consistent with the target surface orientation Mw when viewed from the direction of the central axis Ct2 before horizontal rotation. Then, the cylindrical grinding device 3 performs the following second cylindrical grinding process: after the posture correction unit 38 rotates the single crystal T1 for grinding by the second rotation angle φ2 and rotates it horizontally by the second horizontal rotation angle θ2, the grinding unit 31 grinds the outer peripheral surface of the single crystal T1 for grinding, thereby processing it into a single crystal T2 for slicing whose rear orientation M2 after grinding is inconsistent with the target surface orientation Mw.

[0204] In this way, when it is impossible to perform cylindrical grinding on the entire circumference of the outer peripheral surface of the grinding single crystal T1 that has been horizontally rotated by the first horizontal rotation angle θ1, a wafer W is manufactured by using a slicing single crystal T2 whose rear orientation M2 after grinding is inconsistent with the target surface orientation Mw, and by horizontally rotating the slicing single crystal T2, a plurality of wafers W having the same generation state of undulations relative to the surface orientation can be obtained.

[0205] The grinding feasibility determination unit 367 determines whether the entire circumference of the outer peripheral surface of the grinding single crystal T1 horizontally rotated by the second horizontal rotation angle θ2 can be cylindrically ground. Thereafter, when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 horizontally rotated by the second horizontal rotation angle θ2 can be cylindrically ground, the posture correction unit 38 and the grinding unit 31 perform the second cylindrical grinding process, and when it is determined that the entire circumference of the outer peripheral surface of the grinding single crystal T1 cannot be cylindrically ground, the posture correction unit 38 and the grinding unit 31 do not perform the second cylindrical grinding process.

[0206] In this way, the second cylindrical grinding process is performed only when the entire circumference of the outer peripheral surface of the grinding single crystal T1 horizontally rotated by the second horizontal rotation angle θ2 can be cylindrically ground, so that the production of non-disc-shaped wafers W can be suppressed.

[0207] [Modifications]

[0208] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the embodiments, and various improvements and design changes that do not depart from the gist of the present invention are also included in the present invention.

[0209] <First Modification>

[0210] In step S13 , when controlling the notch forming unit 35 to form the notch N, the notch formation control unit 370 preferably selects a formation position of the notch N so that the first horizontal rotation angle θ1 becomes minimum.

[0211] Specifically, the notch N is formed so as to be aligned with the crystal axis existing on the outer peripheral surface of the grinding single crystal T1. For example, in the case of the grinding single crystal T1 whose crystal orientation of the central axis Ct1 is <100>, Fig.13 As shown in the first figure above, four crystal axes with a crystal orientation of <110> exist at intervals of 90° along the circumferential direction on the outer peripheral surface of the grinding single crystal T1. These four crystal axes become candidate positions for the formation of the notch N (hereinafter, each candidate position is sometimes referred to as "the first candidate position for notch formation Q1", "the second candidate position for notch formation Q2", "the third candidate position for notch formation Q3", "the fourth candidate position for notch formation Q4").

[0212] Furthermore, since the surface orientation is represented by the position of the notch N, if there are four candidate notch formation positions, there are also four ways of representing the surface orientation. Therefore, the first temporary target surface orientation Mx1 when the notch N is formed at the first notch formation candidate position Q1, the second temporary target surface orientation Mx2 when the notch N is formed at the second notch formation candidate position Q2, the third temporary target surface orientation Mx3 when the notch N is formed at the third notch formation candidate position Q3, and the fourth temporary target surface orientation Mx4 when the notch N is formed at the fourth notch formation candidate position Q4 are as shown in FIG. Fig.13 As shown in the second picture from the top.

[0213] Before the grinding of the single crystal T1, the grinding direction M1 is as follows Fig.13 In the case shown in the second figure from the top, among the first to fourth temporary target surface orientations Mx1 to Mx4, the deviation of the second temporary target surface orientation Mx2 relative to the grinding front orientation M1 becomes the smallest. That is, when the second temporary target surface orientation Mx2 is set as the target surface orientation Mw, the first horizontal rotation angle θ1 becomes the smallest.

[0214] Therefore, it is preferable that the notch formation control unit 370 selects a position corresponding to the second notch formation candidate position Q2 in the slicing single crystal T2 as the formation position of the notch N, and controls to form the notch N at the selected position. Furthermore, it is preferable that the correction amount calculation unit 366 sets the second temporary target surface orientation Mx2 at which the first horizontal rotation angle θ1 becomes the smallest as the target surface orientation Mw in step S4, and then obtains the first rotation angle φ1 and the first horizontal rotation angle θ1.

[0215] In this way, by selecting the formation position of the notch N so that the first horizontal rotation angle θ1 becomes minimum, the number of non-disk-shaped wafers W obtained from the slicing single crystal T2 can be reduced.

[0216] <Second Modification>

[0217] For example, in step S26, it is preferable that the notch formation control unit 370 selects the formation position of the notch N so that the second horizontal rotation angle θ2 becomes minimum when controlling the notch forming unit 35 to form the notch N. As described in the first modification, for example, in the case of the grinding single crystal T1 whose crystal orientation of the central axis Ct1 is <100>, the four crystal axes whose crystal orientation is <110> become the first to fourth notch formation candidate positions Q1 to Q4.

[0218] Furthermore, when the notches N are formed at the first to fourth notch forming candidate positions Q1 to Q4, the first to fourth temporary target surface directions Mx1 to Mx4 are as follows: Fig.13In addition, the first, second, third and fourth temporary correctable ranges K1, K2, K3 and K4 corresponding to the first, second, third and fourth temporary target surface orientations Mx1, Mx2, Mx3 and Mx4 are shown as follows: Fig.13 It is set as shown in the third figure from the top.

[0219] Before the grinding of the single crystal T1, the grinding direction M1 is as follows Fig.13 In the case shown in the third figure from the top, in the first to fourth temporarily correctable ranges K1 to K4, the deviation of the third temporarily correctable range K3 relative to the front grinding surface orientation M1 becomes the smallest. That is, when the third temporary target surface orientation Mx3 corresponding to the third temporarily correctable range K3 is set as the target surface orientation Mw, the second horizontal rotation angle θ2 becomes the smallest.

[0220] Therefore, it is preferable that the notch formation control unit 370 selects a position corresponding to the third notch formation candidate position Q3 in the slicing single crystal T2 as the formation position of the notch N, and controls to form the notch N at the selected position. Furthermore, it is preferable that the correction amount calculation unit 366 sets the third temporary target surface orientation Mx3 at which the second horizontal rotation angle θ1 becomes the smallest as the target surface orientation Mw in step S20, and then obtains the second rotation angle φ2 and the second horizontal rotation angle θ2.

[0221] In this way, by selecting the formation position of the notch N so that the second horizontal rotation angle θ2 becomes minimum, the number of non-disk-shaped wafers W obtained from the slicing single crystal T2 can be reduced.

[0222] <Other Modifications>

[0223] Although the rotation processing unit 311 is used as a structure for correcting the posture of the single crystal T1 for grinding, another structure for rotating the single crystal T1 for grinding for correcting the posture may be provided in the cylindrical grinding device 3 .

[0224] Although a structure is illustrated in which the first cylindrical grinding process is not performed when the first horizontal rotation angle θ1 exceeds the maximum horizontal rotation angle θm, the first cylindrical grinding process may be performed regardless of the size relationship between the first horizontal rotation angle θ1 and the maximum horizontal rotation angle θm, and the first cylindrical grinding process may be performed using an input operation of the operator to the input unit 361 as a trigger.

[0225] Although the configuration in which the second cylindrical grinding process is performed based on the magnitude relationship between the second horizontal rotation angle θ2 and the maximum horizontal rotation angle θm when the first horizontal rotation angle θ1 exceeds the maximum horizontal rotation angle θm is illustrated, it may be determined that the grinding single crystal T1 cannot be processed into the slicing single crystal T2.

[0226] Although the configuration in which the second cylindrical grinding process is not performed when the second horizontal rotation angle θ2 exceeds the maximum horizontal rotation angle θm is exemplified, the second cylindrical grinding process may be performed regardless of the magnitude relationship between the second horizontal rotation angle θ2 and the maximum horizontal rotation angle θm.

[0227] When the first horizontal rotation angle θ1 is equal to or smaller than the maximum horizontal rotation angle θm, the second cylindrical grinding process may be performed instead of the first cylindrical grinding process.

[0228] Example

[0229] Next, examples of the present invention will be described. However, the present invention is not limited to the examples.

[0230] As an example, a simulation was performed to confirm that in the wafer manufacturing method of the embodiments and comparative examples of the present invention, a proportion of multiple wafers W (hereinafter sometimes referred to as "target wafers W") whose surface orientation is consistent with the target surface orientation Mw and whose generation state of undulation relative to the surface orientation is consistent can be manufactured from a grinding single crystal T1 having an arbitrary grinding front surface orientation M1.

[0231] [Wafer Manufacturing Method of Example]

[0232] First, a method for manufacturing a wafer according to an embodiment will be described.

[0233] The method for manufacturing the wafer of the embodiment is Figure 8 to Figure 12 The wafer manufacturing method of the above-described embodiment includes the cylindrical grinding method of the present invention (the first cylindrical grinding process and the second cylindrical grinding process of the above-described embodiment).

[0234] [Method for Manufacturing Wafer of Comparative Example]

[0235] Next, a method for manufacturing a wafer according to a comparative example will be described.

[0236] The manufacturing method of the wafer of the comparative example does not include the cylindrical grinding method of the present invention. In the cylindrical grinding method in the manufacturing method of the wafer of the comparative example, regardless of the surface orientation difference between the front grinding orientation M1 and the target surface orientation Mw, all the single crystals T1 for grinding are cylindrically ground in a state where the rotation axis C of the cylindrical grinding device is aligned with the central axis Ct1, and processed into single crystals T2 for slicing. Then, a notch N indicating the rear grinding orientation M2 is formed on the single crystals T2 for slicing.

[0237] The slicing method in the wafer manufacturing method of the comparative example is similar to the processing of steps S15 and S16 of the above-described embodiment, and the slicing single crystal T2 having a set posture is rotated on the slicing stage 472 by the set rotation angle φs.

[0238] Then, when the rear grinding surface orientation M2 after rotation is equal to the horizontal value of the target surface orientation Mw, the same processing as step S18 of the above embodiment is performed, and the slicing single crystal T2 is sliced ​​in a state where the central axis Ct2 is orthogonal to the wire 42 of the wire row.

[0239] Here, even when the horizontal values ​​of the rear grinding direction M2 and the target surface direction Mw after the rotation are equal, there are cases where the vertical values ​​are equal or different depending on the front grinding direction M1 of the grinding single crystal T1. When the horizontal values ​​of the rear grinding direction M2 and the target surface direction Mw are equal, the target wafer W can be obtained, but when the horizontal values ​​are different, the target wafer W cannot be obtained.

[0240] On the other hand, when the horizontal values ​​of the grinding rear surface orientation M2 and the target surface orientation Mw after the rotation are different, the same processing as step S30 of the above embodiment is performed, so that the horizontal values ​​of the grinding rear surface orientation M2 and the target surface orientation Mw when viewed from the center axis Ct2 direction are consistent, the slicing table 472 is horizontally rotated around the vertical axis and bonded to the work plate 471. Then, the same processing as step S31 of the above embodiment is performed, and the slicing single crystal T2 is sliced ​​in a state where the center axis Ct2 is tilted relative to the wire 42 of the wire array.

[0241] Here, even when the horizontal values ​​of the rear grinding direction M2 and the target surface direction Mw after horizontal rotation are equal, there are cases where the vertical values ​​are equal and cases where they are different, depending on the front grinding direction M1 of the single crystal T1 for grinding. When the vertical values ​​of the rear grinding direction M2 and the target surface direction Mw are equal, the target wafer W can be obtained, but when the vertical values ​​are different, the target wafer W cannot be obtained.

[0242] [Simulation method]

[0243] Next, the simulation method will be described.

[0244] The conditions of the simulation were set as follows.

[0245] Target surface orientation Mw: X = 0.30°, Y = 0.00°

[0246] ·Set rotation angle φs: 45°

[0247] Maximum horizontal rotation angle θm: less than 0.5°

[0248] ·Crystal orientation of central axis Ct1: <100>

[0249] ·Crystal orientation of candidate notch formation position: <110>

[0250] Then, the following simulation was performed: using the wafer manufacturing method of the comparative example or the embodiment, whether the target wafer W can be manufactured from 1000 single crystals T1 for grinding (at least one of the values ​​of the horizontal direction (X direction) and the vertical direction (Y direction) of the surface orientation based on the center axis Ct1 when viewed from the center axis Ct1 is different from each other). And, the formation position of the notch N in the single crystal T2 for slicing is selected in such a way that the first horizontal rotation angle θ1 or the second horizontal rotation angle θ2 becomes the smallest.

[0251] [Simulation results and investigation]

[0252] Next, the simulation results are described.

[0253] As shown in Table 1 below, in the wafer manufacturing method of the comparative example, the yield rate (the probability that the target wafer W can be manufactured) is 18.9%, whereas in the wafer manufacturing method of the embodiment, the yield rate is 99.9%.

[0254] [Table 1]

[0255]

[0256] Next, the simulation results will be described in detail. Fig.14A This is a diagram showing in a graphical form the simulation results of the wafer manufacturing method of the comparative example, and shows the surface orientation of the single crystal for grinding that can manufacture the target wafer. Fig. 14B This is a diagram showing in a graphical form the simulation results for the wafer manufacturing method of the comparative example, and shows the surface orientations of the single crystal for grinding that cannot produce the target wafer. Fig.15A 1 is a diagram showing in a graphical form the simulation results of the wafer manufacturing method of the embodiment, and shows the surface orientation of the single crystal for grinding of which the wafer can be manufactured by the first wafer manufacturing process. Fig. 15B The diagram is a diagram showing the simulation result of the wafer manufacturing method of the embodiment in the form of a graph, which shows the surface orientations of the single crystal for grinding that can manufacture the target wafer through the second wafer manufacturing process and the single crystal for grinding that cannot manufacture the target wafer through the second wafer manufacturing process.

[0257] In the wafer manufacturing method of the comparative example, Fig.14A and Fig. 14B In the coordinate system shown, grinding single crystals T1 (those whose horizontal and vertical values ​​of the front grinding position M1 are within a specified range inclined at an angle corresponding to the set rotation angle φs) are qualified, and other grinding single crystals T1 are unqualified.

[0258] In contrast, Fig.15A and Fig. 15B As shown, in the wafer manufacturing method of the example, almost all the single crystals T1 for grinding were acceptable regardless of the front grinding surface orientation M1.

[0259] In particular, the values ​​of the horizontal and vertical directions of the grinding front face M1 are included in Fig.15A The single crystal T1 for grinding in the four circular ranges H1, H2, H3 and H4 in the coordinate system shown is qualified after the first wafer manufacturing process. Here, as described above, when the crystal orientation of the central axis Ct1 is <100>, there are four candidate positions for notch formation. In addition, the center (X, Y) of each of the circular ranges H1, H2, H3 and H4 is (0.30°, 0.00°), (0.00°, -0.30°), (-0.30°, 0.00°), (0.00°, 0.30°) corresponding to the target surface orientation Mw. In addition, the radius of each of the circular ranges H1, H2, H3 and H4 is 0.5° corresponding to the maximum horizontal rotation angle θm.

[0260] Right now, Fig.15A This shows that in the first wafer manufacturing process, the formation position of the notch N in the slicing single crystal T2 is selected from a plurality of notch formation candidate positions so that the first horizontal rotation angle θ1 becomes minimum, thereby manufacturing the target wafer W from the grinding single crystal T1.

[0261] Furthermore, for the single crystal T1 for grinding whose values ​​of the horizontal and vertical directions of the position M1 before grinding are not included in the four circular ranges H1 to H4, or the single crystal T1 for grinding whose values ​​of the horizontal and vertical directions of the position M1 before grinding are included near the outer edges of the four circular ranges H1 to H4, except one, all passed the second wafer manufacturing process.

[0262] From the above, it is confirmed that by using the wafer manufacturing method including the cylindrical grinding method of the present invention, a plurality of wafers W whose surface orientation is consistent with the target surface orientation Mw and whose undulation generation state with respect to the surface orientation is consistent can be manufactured from a grinding single crystal T1 having an arbitrary grinding front surface orientation M1.

[0263] Description of Reference Numerals

[0264] 3-cylinder grinding device, 31-grinding unit, 311-rotation processing unit, 313-relative movement unit, 317-grinding component, 32-horizontal rotation processing unit, 35-notch forming unit, 36-grinding control device, 38-posture correction unit, 366-correction amount calculation unit, 367-grinding feasibility determination unit, 368-posture correction control unit, 370-notch formation control unit, C-rotation axis, Ct1, Ct2, Cw-center axis, M1-grinding front direction, M2-grinding back direction, Mw-target surface direction, N-notch, P-slicing start position, T1-grinding single crystal, T2-slicing single crystal, W-wafer.

Claims

1. A cylindrical grinding device for producing a single crystal for slicing by cylindrical grinding in which the outer peripheral surface of a single crystal for grinding is ground while the single crystal for grinding is rotated about a rotation axis, the cylindrical grinding device comprising: a posture correction section that performs a rotation process of rotating the single crystal for grinding around its central axis and a rotation process of rotating the single crystal for grinding around a rotation axis orthogonal to the central axis based on a surface orientation difference between the surface orientation of the single crystal for grinding and a target surface orientation of a wafer obtained by slicing the single crystal for slicing, thereby correcting the posture of the single crystal for grinding in such a manner that the central axis is tilted relative to the rotation axis; and The grinding section performs cylindrical grinding on the outer peripheral surface of the grinding single crystal while rotating the grinding single crystal whose posture has been corrected about the rotation axis.

2. The cylindrical grinding device according to claim 1, wherein: The grinding section comprises: A rotation processing unit that holds the grinding single crystal and rotates the grinding single crystal around the rotation axis; a grinding member for grinding the outer peripheral surface of the grinding single crystal; and a relative moving portion for relatively moving the rotation processing portion and the grinding member along the rotation axis, The posture correction unit comprises: a rotation processing unit that performs the rotation processing; and A posture correction control unit controls the rotation processing unit in such a manner that the single crystal for grinding is held in a state where the center axis is aligned with the rotation axis and the single crystal for grinding is performed, and controls the rotation processing unit in such a manner that the single crystal for grinding is received from the rotation processing unit and the single crystal for grinding is returned to the rotation processing unit after the single crystal for grinding is performed.

3. The cylindrical grinding device according to claim 2, further comprising: a correction amount calculation unit for calculating a first rotation angle in the rotation process and a first rotation angle in the rotation process based on the surface orientation difference; The first rotation angle and the first rotation angle are angles that can make the surface orientation of the slicing single crystal coincide with the target surface orientation. The cylindrical grinding device performs the following first cylindrical grinding process: after the posture correction unit performs the rotation process based on the first rotation angle and the rotation process based on the first rotation angle, the grinding unit performs cylindrical grinding on the peripheral surface of the grinding single crystal whose posture has been corrected by the posture correction unit, thereby producing the slicing single crystal whose surface orientation is consistent with the target surface orientation.

4. The cylindrical grinding device according to claim 3, comprising: The grinding feasibility determination unit determines whether or not the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle can be cylindrically ground based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal.

5. The cylindrical grinding device according to claim 4, wherein: The cylindrical grinding device performs the first cylindrical grinding process when the grinding feasibility determination unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle can be cylindrically ground.

6. The cylindrical grinding device according to claim 5, wherein: The correction amount calculation unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle cannot be cylindrically ground, based on the surface orientation difference, a second rotation angle in the rotation process and a second rotation angle smaller than the first rotation angle in the rotation process. The second rotation angle and the second rotation angle are angles at which the surface orientation of the single crystal for slicing cannot be made consistent with the target surface orientation, and are angles at which the surface orientation of the single crystal for slicing cannot be made consistent with the target surface orientation, and are angles at which the surface orientation of the single crystal for slicing can be made consistent with the target surface orientation when observed from the direction of the center axis before rotation after the rotation angle is set by rotating the single crystal for slicing so that the relationship between the surface orientation and the slicing start position is in a specified relationship about its center axis, and then rotating the single crystal for slicing about a rotation axis orthogonal to the center axis, The cylindrical grinding device performs the following second cylindrical grinding process: after the posture correction unit performs the rotation process based on the second rotation angle and the rotation process based on the second rotation angle, the grinding unit performs cylindrical grinding on the peripheral surface of the grinding single crystal whose posture has been corrected by the posture correction unit, thereby producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation.

7. The cylindrical grinding device according to claim 6, wherein: The grinding feasibility determination unit determines whether or not the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal.

8. The cylindrical grinding device according to claim 7, wherein: The cylindrical grinding device performs the second cylindrical grinding process when the grinding feasibility determination unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground. On the other hand, when the grinding feasibility determination unit determines that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle cannot be cylindrically ground, the second cylindrical grinding process is not performed.

9. The cylindrical grinding device according to any one of claims 1 to 8, further comprising: A notch forming portion forms a notch indicating the target surface orientation in the slicing single crystal.

10. The cylindrical grinding device according to any one of claims 3 to 5, further comprising: a notch formation control unit that selects the candidate notch formation position at which the first rotation angle becomes the smallest from among a plurality of candidate notch formation positions indicating the target surface orientation; and A notch forming section forms a notch at the formation candidate position in the slicing single crystal selected by the notch formation control section.

11. The cylindrical grinding device according to any one of claims 6 to 8, further comprising: a notch formation control unit that selects the candidate notch formation position at which the second rotation angle becomes the smallest from among a plurality of candidate notch formation positions indicating the target surface orientation; and A notch forming section forms a notch at the formation candidate position in the slicing single crystal selected by the notch formation control section.

12. A cylindrical grinding method, wherein a single crystal for slicing is produced by cylindrically grinding the outer peripheral surface of a single crystal for grinding while rotating the single crystal for grinding about a rotation axis, the cylindrical grinding method comprising: a posture correction step, which performs a rotation process of rotating the single crystal for grinding around its central axis and a rotation process of rotating the single crystal for grinding around a rotation axis orthogonal to the central axis based on a surface orientation difference between the surface orientation of the single crystal for grinding and a target surface orientation of a wafer obtained by slicing the single crystal for slicing, thereby correcting the posture of the single crystal for grinding in such a manner that the central axis is tilted relative to the rotation axis; and The grinding step is to cylindrically grind the outer peripheral surface of the grinding single crystal while rotating the grinding single crystal whose posture has been corrected about the rotation axis.

13. The cylindrical grinding method according to claim 12, wherein: using a rotation processing unit and a rotation processing unit, wherein the rotation processing unit holds the single crystal for grinding and rotates it around the rotation axis, and the rotation processing unit performs the rotation processing, In the posture correction step, after controlling the rotation processing unit in a manner such that the single crystal for grinding is held in a state where the center axis is aligned with the rotation axis and the rotation processing is performed, after receiving the single crystal for grinding from the rotation processing unit and performing the rotation processing, the rotation processing unit is controlled in a manner such that the single crystal for grinding is returned to the rotation processing unit in a posture in which the center axis is inclined relative to the rotation axis.

14. The cylindrical grinding method according to claim 13, further comprising: a correction amount calculation step of calculating a first rotation angle in the rotation process and a first rotation angle in the rotation process based on the surface orientation difference, The first rotation angle and the first rotation angle are angles that can make the surface orientation of the slicing single crystal coincide with the target surface orientation. In the posture correction step, after the rotation processing unit is controlled so as to perform the rotation processing based on the first rotation angle, the rotation processing unit is controlled so as to perform the rotation processing based on the first rotation angle. In the grinding step, the outer peripheral surface of the grinding single crystal whose posture is corrected based on the first rotation angle and the first rotation angle is cylindrically ground, thereby manufacturing the slicing single crystal whose surface orientation matches the target surface orientation.

15. The cylindrical grinding method according to claim 14, further comprising: a grinding feasibility determination step of determining whether cylindrical grinding can be performed on the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal, When it is determined in the grinding feasibility determination step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle can be cylindrically ground, the posture correction step and the grinding step perform processing for producing the slicing single crystal whose surface orientation is consistent with the target surface orientation.

16. The cylindrical grinding method according to claim 15, wherein: In the correction amount calculation step, when it is determined in the grinding feasibility determination step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the first rotation angle cannot be cylindrically ground, a second rotation angle in the rotation process and a second rotation angle smaller than the first rotation angle in the rotation process are determined based on the surface orientation difference. The second rotation angle and the second rotation angle are angles at which the surface orientation of the single crystal for slicing cannot be made consistent with the target surface orientation, and are angles at which the surface orientation of the single crystal for slicing cannot be made consistent with the target surface orientation, and are angles at which the surface orientation of the single crystal for slicing can be made consistent with the target surface orientation when observed from the direction of the center axis before rotation after the rotation angle is set by rotating the single crystal for slicing so that the relationship between the surface orientation and the slicing start position is in a specified relationship about its center axis, and then rotating the single crystal for slicing about a rotation axis orthogonal to the center axis, In the case where the second self-rotation angle and the second rotation angle are calculated in the correction amount calculation process, in the posture correction process, after the self-rotation processing unit is controlled in a manner to perform the self-rotation processing based on the second self-rotation angle, the rotation processing unit is controlled in a manner to perform the rotation processing based on the second rotation angle, and in the grinding process, the outer peripheral surface of the grinding single crystal whose posture is corrected based on the second self-rotation angle and the second rotation angle is cylindrically ground, thereby producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation.

17. The cylindrical grinding method according to claim 16, wherein: In the grinding feasibility determination step, it is determined whether the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground based on the length and diameter of the grinding single crystal and the target diameter of the slicing single crystal. When it is determined in the grinding feasibility determination step that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle can be cylindrically ground, the posture correction step and the grinding step are performed to process the slicing single crystal in which the surface orientation is inconsistent with the target surface orientation. When it is determined in the grinding feasibility determination process that the entire circumference of the outer peripheral surface of the grinding single crystal rotated by the second rotation angle cannot be cylindrically ground, the posture correction process and the grinding process do not perform processing for producing the slicing single crystal whose surface orientation is inconsistent with the target surface orientation.

18. The cylindrical grinding method according to any one of claims 12 to 17, further comprising: A notch forming step is to form a notch indicating the target surface orientation in the slicing single crystal.

19. The cylindrical grinding method according to claim 14 or 15, further comprising: a notch formation control step of selecting the candidate notch formation position at which the first rotation angle becomes the smallest from a plurality of candidate notch formation positions indicating the target surface orientation; and a notch forming step of forming a notch at the candidate formation position in the single crystal for slicing selected in the notch formation controlling step.

20. The cylindrical grinding method according to claim 16 or 17, further comprising: a notch formation control step of selecting the candidate notch formation position at which the second rotation angle becomes the smallest from a plurality of candidate notch formation positions indicating the target surface orientation; and a notch forming step of forming a notch at the candidate formation position in the single crystal for slicing selected in the notch formation controlling step.

21. A method for manufacturing a wafer, comprising producing a single crystal for slicing from a single crystal for grinding by the cylindrical grinding method according to claim 12, The slicing single crystal is sliced ​​to produce a plurality of wafers whose surface orientation is consistent with the target surface orientation.

Images