JP2009186181A - Crystal orientation measuring instrument, crystal processing apparatus, and crystal processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and accurately measure the crystal orientation of a crystal ingot to efficiently process the crystal ingot. <P>SOLUTION: The crystal orientation measuring instrument includes a table 121, on which a crystal W having a cylindrical shape before its side surface is ground and almost vertically cut along its cylindrical axis A is placed so that the cut surface Wa formed by cutting of the crystal W is turned downward, and a calculation means 127b which measures X rays 3b formed by throwing X rays 3a on the cut surface Wa to diffract them to calculate the crystal orientation of the crystal W from the cut surface Wa. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a crystal orientation measuring apparatus for measuring a crystal orientation during processing of a crystal ingot, a crystal processing apparatus and a crystal processing method for processing a crystal ingot by measuring the crystal orientation.

  Single crystal materials such as silicon are used in the semiconductor industry. A single crystal material used in a semiconductor manufacturing process is usually supplied as a thin disk-shaped wafer. This wafer is produced by, for example, thinly slicing a cylindrical crystal ingot grown using a manufacturing technique such as a chocolate ski pulling method. When slicing a crystal ingot into a wafer, the wafer is sliced so that the wafer surface matches the crystal orientation or is inclined at a predetermined angle with respect to the crystal orientation (off-cut).

  A conventional crystal processing method for processing from a crystal ingot to a wafer will be described using the flowchart shown in FIG.

  Although the shape of the crystal ingot generated by the pulling method or the like is substantially cylindrical, both end surfaces and side surfaces (cylindrical circumferential surface) are uneven. Therefore, first, the side surface is ground (cylindrical grinding) so that the cross section of the crystal ingot becomes circular with a cylindrical grinding machine (S1). Subsequently, the crystal orientation (radial crystal orientation) on the side surface of the crystal ingot is measured with the first crystal orientation measuring device (S2).

  When the radial crystal orientation is measured, a notch is machined on the side surface of the crystal ingot with a cylindrical grinding machine on the basis of the radial crystal orientation (S3). This notch (V groove) is a mark for discriminating the radial crystal orientation of the wafer when processed into a wafer. An orientation flat surface may be processed on the side surface of the crystal ingot instead of the notch.

  When the notch is processed in the crystal ingot, the both ends of the crystal ingot are cut by a cutting machine with a cut surface perpendicular to the cylindrical axis (S4). Subsequently, the second crystal orientation measuring device measures the crystal orientation (axial crystal orientation) of the cut surface appearing by cutting the crystal (S5). The crystal ingot is cylindrical by cylindrical grinding and cutting at both ends, but in general, the axial crystal orientation does not coincide with the cylindrical axis, and the relationship between the cut plane and the axial crystal orientation is unknown. In S5, it is necessary to measure the axial crystal orientation and determine the direction serving as the reference of the slice.

  The crystal ingot whose axial direction crystal orientation has been measured is bonded onto the plate with the axial direction crystal orientation aligned with the reference direction of the plate (S6). When generating an off-cut wafer, the crystal ingot is bonded to the plate with the axial crystal orientation inclined at the off-cut angle with respect to the reference direction of the plate.

  When the crystal ingot is bonded to the plate, the crystal ingot is sliced by a cutting machine having a wire saw to generate a plurality of wafers (S7). For example, this cutting machine includes a plurality of wire saws in parallel, and can slice a plurality of wafers from a crystal ingot at a time. At this time, by slicing with reference to the plate direction, the crystal orientation (axial crystal orientation) can be made perpendicular to the wafer surface of each wafer (in the case of off-cut, the off-cut angle is inclined). .

  When the wafer is sliced, the side surface of each sliced wafer is chamfered by a chamfering machine (S8). In the chamfering process, the side surface of each wafer is chamfered and ground, and at the same time, the notch is removed and the entire wafer is processed into a perfect circular disk shape with a specified diameter.

  As described above with reference to FIG. 22, in the conventional crystal processing method, the crystal ingot is first cylindrically ground (S1), then both ends of the crystal ingot are cut (S4), and the crystal orientation of the cut plane (axial crystal orientation). ) Is measured (S5). As shown in FIG. 23, the cylindrical grinding is performed before the measurement of the axial crystal orientation, as shown in FIG. 23, in which the second crystal orientation measuring device for measuring the axial crystal orientation supports the side surface of the crystal ingot. This is for measuring the azimuth (see, for example, Patent Document 1).

  Specifically, as shown in FIG. 23, the conventional crystal orientation measuring device has two guide rollers 68 and a guide plate 66 that support the crystal ingot 64. The guide roller 68 supports the crystal ingot 64 so that the cut surface 641 of the crystal ingot 64 placed on the guide roller 68 is pressed against the guide surface 661 of the guide plate 66 perpendicular to the guide roller 68. At this time, the guide plate 66 is rotated by a minute angle with respect to the point C, and the guide surface 661 and the cut surface 641 are in close contact with each other.

Further, the conventional crystal orientation measuring device has a rotating plate 67 perpendicular to the guide plate 66. The rotating plate 67 detects the X-ray tube 61 that irradiates the cut surface 641 of the crystal ingot 64 with the first X-ray 62a focused by the collimator 63 and the second X-ray 62b diffracted at the measurement point C on the cut surface 641. A line detector 65. As shown in FIG. 23, the X-ray tube 61 and the X-ray detector 65 are configured so that the angle formed between the first X-ray 62a and the second X-ray 62b is based on a Bragg angle θ ₀ corresponding to the type of crystal orientation. It arrange | positions so that it may become -2 (theta) ₀ . Therefore, the X-ray detector 65 detects the second X-ray 62b radiated to the measurement point C by the first X-ray 62a and diffracted at the Bragg angle θ ₀ .

In the crystal orientation measuring apparatus shown in FIG. 23, the rotating plate 67 is rotated with respect to the guide plate 66 on the axis of rotation that is perpendicular to the rotating plate 67 and passes through the measurement point C with the guide plate 66 in contact with the cut surface 641. The output of the X-ray detector 65 measures the peak rotation angle θ ₁ . When the peak rotation angle θ ₁ is measured, the crystal ingot 64 is fixed by rotating 90 ° with respect to the cylindrical axis on the guide roller 68, and the guide plate 66 is also in contact with the cut surface 641. The rotation plate 167 is rotated with the same rotation axis passing through the measurement point C, and the rotation angle θ _{2 at} which the output of the X-ray detector 65 reaches a peak is measured. The axial crystal orientation can be obtained from the measured rotation angles θ ₁ and θ ₂ .

  Conventionally, a crystal orientation measuring device has been used in which the guide roller 68 measures the crystal orientation by rotating the side surface of the crystal ingot 64 as a reference. In this case, if the side surface of the crystal ingot 64 is uneven, the orientation of the crystal ingot 64 is disturbed, adversely affecting the adhesion between the cut surface 641 and the guide surface 661, and the crystal orientation cannot be measured accurately. Therefore, first, cylindrical grinding was performed so that the cross section was circular to eliminate the irregularities on the side surface, and then the crystal orientation was measured by rotating with respect to the side surface.

  When the axial crystal orientation is measured in this way, a cylindrical crystal ingot is sliced with reference to the measured axial crystal orientation to obtain a wafer. Therefore, the shape of the wafer obtained by slicing becomes circular when the cylindrical axis of the crystal ingot coincides with the axial crystal orientation, and the short axis and long axis increase as the deviation between the cylindrical axis and the axial crystal orientation increases. The oval shape is large.

  If the obtained wafer is circular, the chamfering process may be performed simply by grinding along the side surface of the wafer, so that the chamfering process can be performed smoothly in a short time. On the other hand, if the wafer has an elliptical shape, it is necessary to grind the circular shape at the same time while chamfering the elliptical shape, the amount of grinding increases, the time required for the chamfering process is long, and the grinding amount varies in the circumferential direction. Therefore, processing is not smooth.

  A single element single crystal material such as silicon can be grown so that the cylindrical axis and the crystal orientation (axial crystal orientation) are in good agreement when a crystal ingot is generated. The wafer obtained by slicing the crystal ingot generated in this way has a substantially circular shape, and the chamfering can be performed smoothly in a short time.

In addition, even in the case of off-cut, it is possible to tilt the off-cut for the generation of the crystal ingot and attach the seed crystal and pull it up. Can be generated. Therefore, an off-cut wafer obtained by slicing the crystal ingot generated in this way also has a substantially circular shape, and the chamfering can be performed smoothly in a short time.
JP 7-146257 A

Conventionally, a single element such as silicon has been mainly used as a material for a semiconductor substrate. On the other hand, in recent years, there has been an increasing demand for compound single crystal semiconductor substrates having performance and applications that cannot be obtained with a single element. Examples of the compound used as a material for the semiconductor substrate include gallium arsenide (GaAs), indium phosphide (InP), and sapphire (Al ₂ O ₃ ). In addition, the compound semiconductor substrate includes high-speed transistors, high heat resistance transistors, light emitting diodes, semiconductor lasers, solar cells, and the like. Further, in addition to the semiconductor substrate, compound single crystals such as fluorite (CaF ₂ ) and quartz are used as lenses and oscillators.

  However, the conventional crystal processing method described above using the flowchart shown in FIG. 22 is not suitable for processing a crystal ingot of a compound single crystal.

  First, it is difficult to make the cylindrical axis of the crystal ingot coincide with the slice plane (cut plane) orientation when generating an off-cut wafer. In the case of a compound single crystal material, the processing time of the wafer is difficult. This is because the length is longer than that of a single element crystal material wafer.

  This is because, as a general feature of a compound semiconductor, it is easy to be irregular when a crystal grows, and it becomes inhomogeneous or has a defect, so that it is difficult to make a large crystal.

  In other words, a single element such as silicon can be tilted off-cut to grow a crystal ingot, whereas a compound single crystal is difficult to grow tilted because the crystal becomes inhomogeneous. become. Further, in the case of a single element crystal ingot such as silicon, the offcut is about 0 ° to 4 °, whereas in the case of a compound single crystal crystal ingot, the offcut is about 0 ° to 15 °. Because it ’s big.

  Accordingly, the deviation between the cylindrical axis of the generated crystal ingot and the slice plane orientation becomes large. A wafer obtained by slicing such a crystal ingot is far from a circular shape and has an elliptical shape in which the major axis and the minor axis are greatly different. If the sliced wafer is elliptical, the time required for chamfering will be longer than in the case of a circular single element wafer. Multiple wafers (for example, several hundred wafers) can be obtained from one crystal ingot. The number of wafers obtained from one crystal ingot is m, and the time extended by chamfering of one wafer is n. If the time is seconds, the time required for chamfering the wafer is extended by m × n (seconds), which hinders smooth crystal processing.

  In particular, many compound single crystals are hard and difficult to process. If the compound single crystal has an elliptical shape, the processing time is remarkably increased.

  Second, it is difficult to bond the crystal ingot to the plate due to the large deviation between the cylindrical axis of the crystal ingot and the slice plane orientation.

  For example, in the processing method described with reference to the flowchart of FIG. 22, a crystal ingot whose axial direction crystal orientation has been measured is bonded to the plate with the slice plane orientation aligned with respect to the reference direction of the plate. At this time, a plurality of crystal ingots can be bonded to one plate. However, since the direction of the cylindrical axis of each crystal ingot is different from the slice plane orientation, the crystal ingots are aligned and bonded on the plate. It is difficult to adhere the crystal ingot to the plate.

  Third, the compound single crystal is hard and difficult to process, and therefore has a problem that a defective wafer is likely to occur.

  When slicing a crystal ingot having a large deviation between the cylindrical axis and the slice plane orientation, the wire saw is obliquely applied to the crystal ingot bonded to the plate and sliced.

  Since compound single crystals are hard and difficult to process, when a wire saw passes through the surface of the crystal ingot when such a crystal ingot is cut, a side-slip force is applied, causing the slice surface to shake due to the deflection of the wire saw, resulting in a defective wafer. is there.

  In addition, as described above with reference to FIG. 23, the conventional crystal orientation measuring apparatus measures the crystal ingot after cylindrical grinding, and therefore cannot measure the crystal orientation of the crystal ingot before cylindrical grinding. there were.

  In view of the above problems, the present invention provides a crystal orientation measuring apparatus capable of measuring the crystal orientation of a crystal ingot efficiently and accurately, and a crystal processing apparatus and a crystal processing method capable of processing a crystal ingot efficiently. For the purpose.

  In order to solve the above problem, the crystal orientation measuring apparatus according to claim 1 irradiates the crystal with X-rays generated from an X-ray source, detects X-rays diffracted from the crystal with an X-ray detector, and A crystal orientation measuring apparatus for measuring a crystal orientation of a crystal, wherein a crystal having a cylindrical shape before side faces are ground and cut substantially perpendicularly to a cylindrical axis has a cut surface generated by the cutting down. The gist of the invention is to include a table to be placed and a calculating means for measuring the X-ray diffracted by irradiating the cut surface with X-rays and calculating the crystal orientation of the crystal with respect to the cut surface.

  In the crystal orientation measuring apparatus having the above configuration, the cut surface of the crystal is placed on the table, and X-rays diffracted by applying X-rays to the cut surface can be detected. Therefore, it is possible to measure the axial crystal orientation based on the cut surface with respect to the crystal ingot before cylindrical grinding.

  Further, the crystal measuring apparatus according to claim 2 generates the first X-ray from an X-ray source and irradiates the crystal, detects the second X-ray diffracted at the measurement point of the crystal with an X-ray detector, and A crystal orientation measuring apparatus for measuring a crystal orientation of a crystal, wherein a crystal having a cylindrical shape before side faces are ground and cut substantially perpendicularly to a cylindrical axis has a cut surface generated by the cutting down. In addition to having a table surface to be placed, the table surface has a through-hole through which the first X-ray generated from the X-ray source and the second X-ray diffracted at the measurement point on the cut surface pass. A table, φ rotation means that rotates the table φ by a predetermined angle about a φ axis that is perpendicular to the table surface and passes through the center of the table, and a measurement surface in which the first X-ray is orthogonal to the cut surface At a predetermined angle Support means for supporting the X-ray source and the X-ray detector in a positional relationship with respect to the measurement point so that the second X-ray to be folded is detected, and the measurement point perpendicular to the measurement plane Θ rotation means for rotating the support means by θ at a rotation angle within a predetermined range with the θ axis passing through the rotation axis, the φ rotation means and the θ rotation means so as to rotate θ for each angle of the φ rotation And a calculating means for calculating a crystal orientation of the crystal with reference to the cut surface from the detection data of the X-ray detector and the rotation angle of θ rotation.

  In the crystal orientation measuring apparatus having the above configuration, the cut surface of the crystal is placed on the table, and X-rays diffracted by applying X-rays to the cut surface can be detected. Therefore, it is possible to measure the axial crystal orientation based on the cut surface with respect to the crystal ingot before cylindrical grinding.

  The crystal processing apparatus according to claim 3 is configured to intersect the crystal orientation measuring apparatus according to any one of claim 1 or claim 2 and the cut plane with the measured crystal orientation at a predetermined angle. The gist is provided with a cut surface grinder for grinding and a cylindrical grinder for grinding the side surface of the crystal into a cylindrical shape perpendicular to a new cut surface ground by the cut surface grinder.

  In the crystal processing apparatus having the above configuration, the grinding is performed with the cut surface aligned with the surface direction of the wafer before cylindrical grinding, and cylindrical grinding is performed with respect to the cylindrical axis perpendicular to the cut surface aligned with the surface direction of the wafer after grinding. Therefore, when slicing in the direction parallel to the cut surface after cylindrical grinding, the sliced wafer becomes a perfect circle. Therefore, since it is a perfect circle, the wafer can be chamfered efficiently in a short time. In addition, since the cut surface after grinding and the sliced surface of the wafer are parallel to each other, it is possible to easily perform alignment during plate bonding and slicing.

  5. The crystal processing method according to claim 4, wherein a crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicularly to a cylindrical axis is positioned on a table with a cut surface generated by the cutting being directed downward. Measuring the X-ray diffracted by irradiating the cut surface with X-rays and calculating the crystal orientation of the crystal with reference to the cut surface; and calculating the crystal of the cut surface Grinding so as to intersect the orientation at a predetermined angle, grinding the side surface of the crystal into a cylindrical shape perpendicular to the new cut surface, and grinding the crystal ground into the cylindrical shape And a step of obtaining a plurality of wafers by cutting in parallel with an appropriate cut surface.

  In the crystal processing method having the above-described configuration, the grinding is performed by aligning the cut surface with the wafer surface direction before cylindrical grinding, and cylindrical grinding with respect to the cylindrical axis perpendicular to the cut surface according to the wafer surface direction after grinding. Therefore, if the wafer is sliced parallel to the cut surface after cylindrical grinding, the sliced wafer becomes a perfect circle. Therefore, since it is a perfect circle, it becomes possible to chamfer the wafer efficiently in a short time. In addition, since the cut surface after grinding and the sliced surface of the wafer are parallel to each other, it is possible to easily perform alignment during plate bonding and slicing.

  6. The crystal processing method according to claim 5, wherein a crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicularly to the cylindrical axis is positioned on a table with a cut surface generated by the cutting being directed downward. Generating a first X-ray that irradiates a measurement point on the cut surface; and a step of rotating the table by a predetermined angle by a φ axis perpendicular to the table and passing through the center of the table as a rotation axis Support means for supporting the X-ray source and the X-ray detector for detecting the second X-ray diffracted from the measurement point in a positional relationship with the measurement point as a reference includes the first X-ray and is orthogonal to the cut surface. A step of rotating θ at a rotation angle within a predetermined range using a θ axis perpendicular to the measurement plane and passing through the measurement point as a rotation axis; and the φ rotation means to rotate θ for each angle of the φ rotation; The θ rotation means is controlled. A step of calculating a crystal orientation of the crystal based on the cut surface based on detection data of the X-ray detector and a rotation angle of θ rotation; and the calculated crystal orientation of the cut surface Grinding the crystal so that it intersects at a predetermined angle, grinding the side surface of the crystal into a cylindrical shape perpendicular to the new cut surface, and grinding the crystal ground into the cylindrical shape And a step of obtaining a plurality of wafers by cutting in parallel with the cut surface.

  In the crystal processing method having the above-described configuration, the grinding is performed by aligning the cut surface with the wafer surface direction before cylindrical grinding, and cylindrical grinding with respect to the cylindrical axis perpendicular to the cut surface according to the wafer surface direction after grinding. Therefore, if the wafer is sliced parallel to the cut surface after cylindrical grinding, the sliced wafer becomes a perfect circle. Therefore, since it is a perfect circle, the wafer can be chamfered efficiently in a short time. In addition, since the cut surface after grinding and the sliced surface of the wafer are parallel to each other, it is possible to easily perform alignment during plate bonding and slicing.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to measure the crystal orientation of a crystal ingot efficiently, a crystal ingot can be processed efficiently.

<Crystal processing equipment>
As shown in the block diagram of FIG. 1, the crystal processing apparatus 1 according to the best embodiment of the present invention includes a first storage shelf 10a for storing a crystal ingot before processing, and cylindrical ends of a substantially cylindrical crystal ingot. A first cutting machine 11 that cuts perpendicularly to the axis, a crystal orientation measuring device 12 that measures the crystal orientation (axial crystal orientation h) of the cut surface (cross section) of the crystal ingot that appears by cutting both ends, and Cut surface grinding machine 13 for grinding the cut surface perpendicular to the axial crystal orientation h, and cylindrical grinding for crystal ingot to be cylindrical by grinding the side surface (periphery) of the crystal ingot perpendicularly to the ground cut surface , A second storage shelf 10b for storing a crystal ingot during or after processing, a first storage shelf 10a, a first cutting machine 11, a crystal orientation measuring device 12, a cut surface grinding machine 13, and a cylindrical grinding machine 1 And it has a first transfer device 18a for conveying the crystal ingot between the second storage shelf 10b. The first transport device 18a is a device such as an automatic guided vehicle or a belt conveyor that transports the crystal W along the track.

  The crystal processing apparatus 1 also includes an adhesion stage 15 that bonds the crystal ingot stored in the second storage shelf 10b to the plate, and a second cutting machine 16 that cuts (slices) the crystal ingot into a wafer having a predetermined thickness. A chamfering machine 17 for chamfering the wafer obtained by cutting, a third storage shelf 10c for storing the wafer, a second storage shelf 10b, an adhesion stage 15, a second cutting machine 16, a chamfering machine 17 and a third It has the 2nd conveying apparatus 18b which conveys a crystal ingot or a wafer between the storage shelves 10c. Similarly to the first transfer device 18a, the second transfer device 18b is a device such as an automatic guided vehicle or a belt conveyor that transfers a crystal ingot or a wafer along a track.

  Below, the structure of the main apparatuses (Crystal orientation measuring apparatus, a cut surface grinding machine, a cylindrical grinding machine, a chamfering machine) which the crystal processing apparatus 1 has is demonstrated using drawing.

《Crystal orientation measuring device》
The crystal orientation measuring device 12 will be described with reference to the front view of FIG. 2A and the plan view of FIG. The crystal orientation measuring device 12 measures an axial crystal orientation h of a crystal ingot W (hereinafter referred to as “crystal W”).

  As shown in FIG. 2, the crystal orientation measuring device 12 includes a table 121 on which the crystal W is placed and rotated about the φ axis 20 as a rotation axis, a φ rotating mechanism 122 that rotates the table 121, and a measurement point of the crystal W. An X-ray tube 123 that irradiates C with the first X-ray 3a, an X-ray detector 124 that detects the second X-ray 3b diffracted at the measurement point C, the X-ray tube 123 and the X-ray detector 124 are fixed, and θ A frame 125 that rotates by a predetermined angle with the shaft 21 as a rotation axis, a θ rotation mechanism 126 that rotates the frame 125, and detection data of the X-ray detector 124 are input, and the φ rotation mechanism 122 and the θ rotation mechanism 126 are controlled. And a control processing unit 127.

  2B, the table 121 includes a table surface 121a on which the crystal W is placed, and a jig member 121b that is perpendicular to the table surface 121a and serves as a reference for positioning the crystal W on the table 121. And a through hole 121c through which the first X-ray 3a and the second X-ray 3b pass.

  When the crystal W is placed on the table 121, the crystal W is positioned so that a first cut surface Wa1 described later and the table surface 121a are in contact with each other, and a temporary orientation flat surface Wb1 described later is in contact with the vertical surface 121d. The In the crystal W described below, the cut surface on which the temporary orientation flat surface Wb1 is processed is described as a first cut surface Wa1, and the opposite cut surface is described as a second cut surface Wa2.

  The φ axis 20 that is the rotation axis of the table 121 is an axis that is perpendicular to the table surface 121a and passes through the center of the table 121 (table surface 121a). Further, the center of the through hole 121 c coincides with the center of the table 121.

  The through hole 121c is a hole provided so as not to hinder the progress of the first X-ray 3a and the second X-ray 3b, and the diameter thereof is determined by the positional relationship with the X-ray tube 123 and the X-ray detector 124. The shape of the through-hole 121c shown in FIG. 2A is a truncated cone shape in which the diameter on the table surface 121a side and the diameter on the bottom surface side are different.

  As shown in FIG. 2B, the φ rotation mechanism 122 includes, for example, a gear 122a and a belt 122b, and the φ shaft 20 is moved by the movement of the belt 122b that is interlocked with the gear 122a that is rotated by driving of a motor (not shown). The table 121 is rotated about the rotation axis.

  The X-ray tube 123 irradiates the measurement point C of the crystal W with the first X-ray 3a narrowed by the collimator 123a, and the X-ray detector 124 detects the second X-ray 3b diffracted at the measurement point C. This measurement point C is set at the intersection of the first cut surface Wa1 and the φ axis 20 when the crystal W is placed on the table 121, as shown in FIG. Even if it does not do, it should just be a position near an intersection.

When a plane including the measurement point C and perpendicular to the table surface 121a (in FIG. 2A, a plane parallel to the paper surface) is the measurement plane, the frame 125 is a crystal to be measured as shown in FIG. The angle formed by the first X-ray 3a and the second X-ray 3b diffracted at the measurement point C is 180 ° −2θ ₀ where the Bragg angle of the surface is θ ₀ , and the first X-ray 3a is included in the measurement surface. An X-ray tube 123 and an X-ray detector 124 are supported. The second X-ray 3b is diffracted substantially along the measurement surface, but is shifted from the measurement surface due to the deviation of the crystal orientation to be measured from the side surface. For this reason, the X-ray detector 124 has such a size that the second X-ray 3b can be detected even if it slightly deviates from the measurement surface. The Bragg angle θ ₀ varies depending on the type of crystal plane of the crystal W. Therefore, the frame 125 has the measurement point C and the table 121 so that the angle formed by the first X-ray 3a and the second X-ray 3b is 180 ° −2θ ₀ according to the type of crystal plane (cut plane Wa) of the crystal W. As a reference, the positional relationship between the X-ray tube 123 and the X-ray detector 124 is adjusted.

  The θ rotation mechanism 126 rotates the frame 125 that supports the X-ray tube 123 and the X-ray detector 124 by a predetermined angle about the θ axis 21 as a rotation axis. The θ-axis 21 is an axis that is orthogonal to the measurement surface described above and passes through the measurement point C.

  The control processing unit 127 receives the detection data of the second X-ray 3b from the X-ray detector 124 and the control unit 127a that controls the φ rotation mechanism 122 and the θ rotation mechanism 126 so that the θ rotation scan is performed at a plurality of φ rotation positions. Calculation means for calculating the tilt angle δx in the x direction and the tilt angle δy in the y direction as the axial crystal orientation h with respect to the first cut surface Wa1 based on the detection data input and input from the X-ray detector 124. 127 b and a computer having an interface (not shown) of the X-ray detector 124. Here, the θ rotation scan means that the X-ray detector 124 detects the second X-ray 3b while rotating the frame 125 with respect to the θ axis.

Specifically, the control means 127a rotates the table 121 by φ every 90 °. Further, the control means 127a performs θ rotation scanning at each φ rotation position, and measures θ at which the detection value of the second X-ray 3b reaches a peak. The initial position of φ rotation is set to 0 °, and the φ measured by changing the φ rotation angle into four directions of 0 °, 90 °, 180 ° and 270 ° are θ ₁ , θ ₂ , θ ₃ and θ ₄ , respectively. In this case, the calculating unit 127b obtains the inclination angle δx in the x direction by the equation (1) and obtains the inclination angle δy in the y direction by the equation (2).

δx = (θ ₁ −θ ₃ ) / 2 (1)
δy = (θ ₂ −θ ₄ ) / 2 (2)
The tilt angles δx and δy represent the tilt angles in the x and y directions of the axial crystal orientation h with respect to the φ axis 20 (that is, the normal line of the first cut surface Wa1 (cylindrical axis A)). In addition, in the example of the measurement of the inclination angle described above using the equations (1) and (2), the θ rotation scan is performed in four directions (0 °, 90 °, 180 °, 270 °). As described in Japanese Patent No. 3847913, θ rotation scanning may be performed only in two directions (0 °, 90 °).

<Cut surface grinding machine>
The cut surface grinding machine 13 that grinds the cut surfaces Wa1 and Wa2 of the crystal W and processes the temporary orientation flat surface Wb1 will be described with reference to FIG. 3A is a front view of the cut surface grinding machine 13, FIG. 3B is a plan view of the cut surface grinding machine 13 for explaining the fixing method of the crystal W, and FIG. 3C is a cut surface Wa of the crystal W. It is sectional drawing of the cut surface grinding machine 13 explaining grinding of (Wa1-Wa4).

  The cut surface grinder 13 grinds the cut surface Wa of the crystal W by moving the grindstone 131 along the grinding surface 23 (xy plane in FIG. 3) while rotating the grindstone 131 and the grindstone 131 about the shaft 22 as a rotation axis. Or it has the grindstone drive part 132 which processes the temporary orientation flat surface Wb1 in the 1st cut surface Wa1 of the crystal | crystallization W temporarily. Further, the cut surface grinding machine 13 is fixed to the fixed portion 133 by tilting the fixed portion 133 and the fixed portion 133 that fixes the crystal W with the grindstone 131 and the cut surface Wa facing each other on the grindstone driving unit 132. And a tilting mechanism 134 for tilting the crystal W.

  As shown in FIGS. 3A and 3B, the fixing unit 133 holds the side surface of the crystal W and fixes the crystal W. The tilt mechanism 134 tilts the crystal W by tilting the fixing portion 133 that fixes the crystal W. Here, when the first cut surface Wa1 is temporarily ground, the tilt mechanism 134 tilts the fixed portion 133 so that the first cut surface Wa1 having irregularities substantially orthogonal to the approximate cylindrical axis A ′ of the crystal W is the ground surface 23. Adjust so that it is approximately parallel to Further, when machining the temporary orientation flat surface Wb1, the tilt mechanism 134 temporarily fixes the fixed portion 133 from the state during temporary grinding so that the first cut surface Wa1 is orthogonal to the grinding surface 23 after the first cut surface Wa1 is temporarily ground. Tilt 90 °.

  When the temporary grinding of the first cut surface Wa1 is completed, the cylindrical axis A is defined. As shown in FIGS. 3A and 3C, the cylindrical axis A is a line perpendicular to the first cut surface Wa1 and passing through the center of the crystal W on average.

  On the other hand, when the first cut surface Wa1 is temporarily ground and the first cut surface Wa1 is ground after measuring the axial crystal orientation h, the tilt mechanism 134 starts from a position where the first cut surface Wa1 is parallel to the grinding surface 23. The fixing portion 133 is tilted and adjusted so that the axial crystal orientation h of the crystal W is perpendicular to the grinding surface 23. Specifically, the axial crystal orientation h is measured as the tilt angle δx in the x direction and the tilt angle δy in the y direction with reference to the cylindrical axis A perpendicular to the first cut surface Wa1. Therefore, in order to grind the first cut surface Wa1 perpendicular to the axial crystal orientation h, as shown in FIG. 4, the cylindrical axis A of the crystal W is orthogonal to the grinding surface 23, that is, the cut surface Wa1 is a grinding surface. Grinding may be performed by inclining the angle of inclination δx in the negative x direction and inclining the angle of inclination δy in the negative y direction with reference to a position parallel to. In the new first cut surface Wa3 in which the first cut surface Wa1 is ground perpendicularly to the axial crystal orientation h, as shown in FIG. 5, the axial crystal orientation h is orthogonal to the first cut surface Wa3 ( Coincides with the z axis in FIG. 4 and does not coincide with the cylindrical axis A.

  Further, when the second cut surface Wa2 is ground after grinding the first cut surface Wa1, the tilt mechanism 134 is inclined (rotated) by 180 ° from the tilted state when the first cut surface Wa1 is ground. The second cut surface Wa4 can be ground in parallel to the new first cut surface Wa3.

  The grindstone 131 has a cylindrical shape, and the cylinder axis of the grindstone 131 coincides with the axis 22 that is the rotation axis (parallel to the x-axis in FIG. 3). When the grindstone 131 rotates, the portion in contact with the uppermost portion of the side surface of the grindstone 131 is ground, so that the surface in contact with the uppermost portion of the side surface of the grindstone 131 is ground as shown in FIGS. The ground surface 23 is used.

  When the cut surface grinding machine 13 temporarily grinds or grinds the cut surface Wa, after the tilt mechanism 134 tilts the fixing portion 133, the cut surface Wa of the crystal W and the ground surface 23 are separated as shown in FIG. The tilt mechanism 134 is moved downward so as to come into contact, or the grindstone drive unit 132 is moved upward to align. Since the grinding surface 23 is the uppermost part of the side surface of the grindstone 131, the grindstone 131 is in contact with the cut surface Wa when the cut surface Wa and the grinding surface 23 are in contact. Therefore, in the cut surface grinding machine 13, the grindstone driving unit 132 grinds the cut surface Wa by moving the grindstone 131 along the grinding surface 23 while rotating the grindstone 131. At this time, the grindstone driving unit 132 drives the range in which the uppermost portion of the side surface of the grindstone 131 can grind the cut surface Wa as the moving range of the grindstone 131.

  Moreover, in the cut surface grinding machine 13, when processing the temporary orientation flat surface Wb1, the position where the temporary orientation flat surface Wb1 of the crystal W is provided is aligned so as to contact the grinding surface 23, and the grindstone driving unit 132 is provided with the temporary orientation flat surface Wb1. The grindstone 131 is moved along the grinding surface 23 while rotating the grindstone 131 until is formed. At this time, the grindstone driving unit 132 drives the range in which the uppermost portion of the side surface of the grindstone 131 can process the temporary orientation flat surface Wb1 as a movement range.

  The cut surface grinding machine 13 may be configured such that the grindstone driving unit 132 itself moves, or the grindstone driving unit 132 may be fixed and only the grindstone 131 may move.

《Cylinder grinding machine》
A cylindrical grinder 14 for grinding the side surface of the cylindrical crystal W will be described with reference to FIG. FIG. 6A is a front view of the cylindrical grinder 14, and FIG. 6B is a diagram of the cylindrical grinder 14 for explaining the method of measuring the crystal orientation (radial crystal orientation k) of the crystal W and the grinding of the crystal W. It is sectional drawing. Although the crystal W generated by the pulling method or the like has a cylindrical shape, since the side surface has irregularities as shown in FIG. 6, the cylindrical grinding machine 14 grinds the side surface of the crystal W to form a cylindrical shape without irregularities (FIG. 6). (B) Wn).

  The cylindrical grinder 14 moves the grindstone 141 along the grinding surface 25 (xz plane in FIG. 6) while grinding the grindstone 141 and the grindstone 141 about the shaft 24 as a rotation axis, and grinds the side surface of the crystal W. And a drive unit 142. Further, the cylindrical grinding machine 14 fixes the crystal W on the grindstone driving unit 142 so that the side faces the grindstone 141 and rotates the crystal W about the axis 26 parallel to the grinding surface 25 as a rotation axis; A grinding wheel driving unit 142 and a crystal orientation measuring device 144 positioned above the crystal W are included.

  The grindstone 141 is cylindrical, and the cylinder axis of the grindstone 141 coincides with the axis 24 that is a rotation axis (parallel to the z-axis in FIG. 6). When the grindstone 141 rotates, the portion in contact with the uppermost portion of the side surface of the grindstone 141 is ground, so that the surface in contact with the uppermost portion of the side surface of the grindstone 141 is shown in FIG. 6 (a) and FIG. This is a grinding surface 25.

  As shown in FIG. 6A, in the rotation mechanism 143, the first support portion 143a includes a first pad 143c, and the second support portion 143b includes a second pad 143d in parallel to the first pad 143c. The distance between the first pad 143c and the second pad 143d can be adjusted by a cylinder or a spring (not shown). In the rotation mechanism 143, the distance between the first pad 143c and the second pad 143d is such that one of the cut surfaces Wa of the crystal W is in contact with the first pad 143c and the other of the cut surfaces Wa of the crystal W is in contact with the second pad 143d. To support the crystal W. In the rotation mechanism 143 that supports the crystal W, the motor 143e rotates the crystal W about the axis 26 (parallel to the z axis in FIG. 6) as the rotation axis. Here, the surfaces of the first pad 143c and the second pad 143d that support the crystal W are always vertical when changing the interval and when rotating.

  In the cylindrical grinding machine 14, when grinding the side surface of the crystal W, the rotating mechanism 143 and the grindstone driving unit 142 are brought close to each other so that the side surface of the crystal W supported by the rotating mechanism 143 comes into contact with the grinding surface 25. The rotation mechanism 143 rotates the crystal W in a state where the side surface of the crystal W and the grinding surface 25 are in contact with each other, and the grindstone driving unit 142 moves the grindstone 141 while reciprocating a plurality of times along the grinding surface 25. The crystal W can be ground into a cylindrical shape. Specifically, the grindstone driving unit 142 reciprocates the grindstone 141 on a straight line in the height direction of the cylinder of the crystal W (in the z-axis direction in FIG. 6), and the cross section of the crystal W is shown in FIG. As shown, grind until circular cylindrical Wn.

  Since the surfaces of the first pad 143c and the second pad 143d that are in contact with the crystal are perpendicular to the shaft 26, the crystal W is supported so that the cut surface Wa is perpendicular to the shaft 26, and is rotated by the shaft 26 while being rotated by the shaft 26. Since it is ground by the parallel grinding surface 25, the crystal W is ground into a cylinder having a cylindrical axis perpendicular to the cut surface Wa by this cylindrical grinding.

When the crystal W is ground into a cylindrical shape, the crystal orientation measuring device 144 measures the crystal orientation (radial crystal orientation k) on the side surface of the crystal W. Specifically, as shown in FIG. 6 (b), the crystal orientation measuring apparatus 144 applies an X-ray tube 144 a that radiates the first X-ray 3 c to the side surface of the crystal W and the second X-ray 3 d diffracted from the side surface of the crystal W. An X-ray detector 144b for detection is provided. The angle formed by the first X-ray 3c and the second X-ray 3d is set to 180 ° −2θ ₀ with reference to the Bragg angle θ ₀ determined according to the type of crystal plane. Then, while rotating the crystal W with respect to the axis 26, the radial crystal orientation k is measured by searching for the rotation position of the crystal W where the second X-ray 3d detected by the X-ray detector 144b has a peak value.

  When the radial crystal orientation k is measured, the rotation mechanism 143 rotates the crystal W and aligns it so that the direction of processing the orientation flat surface Wb2 of the crystal W is below the grindstone driving unit 142. When the direction of processing the orientation flat surface Wb2 of the crystal W faces the grindstone driving unit 142, the grindstone driving unit 142 moves in parallel along the grinding surface 25 while rotating the grindstone, thereby processing the orientation flat surface Wb2 on the crystal W. . At this time, the grindstone driving unit 142 drives the range in which the uppermost portion of the side surface of the grindstone 141 can grind the orientation flat surface Wb2 as the moving range of the grindstone 141.

《Chamfering machine》
A chamfering machine 17 that chamfers the side surface of the wafer Ww will be described with reference to FIG.

  The chamfering machine 17 has a configuration as described in, for example, Japanese Patent Laid-Open No. 9-102474, and as shown in FIG. 7, a wafer rotating unit 171 that supports and rotates the wafer Ww, and a circular shape on the side surface. A grindstone 172 having a U-shaped groove 172a and a grindstone driving unit 173 that rotates the grindstone 172 about a shaft 28 passing through the center of the grindstone 172 are provided.

  Wafer rotating portion 171 has a first support portion 171a and a second support portion 171b that have surfaces parallel to each other and the interval of which can be adjusted by a cylinder or a spring (not shown). In the wafer rotating unit 171, when the wafer Ww is supported between the first support unit 171a and the second support unit 171b, the wafer Ww is aligned so that the center of the wafer Ww is positioned on the shaft 27. In addition, the wafer rotating unit 171 rotates the wafer Ww around the shaft 27 while supporting the wafer Ww.

  In the chamfering machine 17, the wafer rotating unit 171 and the grindstone driving unit 173 are brought close to each other and the groove 172a of the grindstone 172 is pressed against the side surface of the wafer Ww. With the groove 172a pressed against the side surface of the wafer Ww, the wafer rotating unit 171 rotates the wafer Ww, the grindstone driving unit 173 rotates the grindstone 172, chamfers the corners of the side surface of the wafer Ww, and from the direction of the axis 27 Processing is performed so that the shape of the viewed wafer Ww becomes a perfect circle except for the orientation flat surface Wb2. Since the orientation flat surface Wb2 of the wafer Ww is a straight line, the wafer Ww can be chamfered by moving linearly along the orientation flat surface Wb2 while rotating only the grindstone 172 without rotating the wafer Ww.

  The chamfering machine 17 has a wafer handling means for performing operations such as taking out the wafer Ww from the wafer case and setting it in the wafer rotating unit, but the illustration is omitted.

<Crystal processing method>
Next, a crystal processing method until the wafer Ww is processed from the crystal W in the crystal processing apparatus 1 will be described. First, as a first processing of crystal processing in the crystal processing apparatus 1 using the flowchart shown in FIG. 8, processing until the crystal W stored in the first storage shelf 10a is processed and stored in the second storage shelf 10b. Will be described.

  First, when the crystal W stored in the first storage shelf 10a is transported to the first cutting machine 11 by the first transport device 18a, both ends of the crystal W transported by the band saw included in the first cutting machine 11 are cut. (S001). As shown in FIG. 9A, the crystal W stored in the first storage shelf 10a has a substantially cylindrical shape with unevenness generated by a pulling method or the like. When this crystal W is cut along a plane substantially perpendicular to the cylindrical axis A ′ of the crystal as shown in FIG. 9B, saw-tooth irregularities remain at both ends as shown in FIG. 9C. Further, substantially plane cut surfaces Wa1 and Wa2 are generated.

  When the crystal W cut in step S001 is transferred to the cut surface grinder 13 by the first transfer device 18a, the cut surface grinder 13 cuts the irregularities on the first cut surface Wa1 generated by the cutting in step S001. While temporarily grinding to a flat plane, the temporary orientation flat surface Wb1 is processed on the side surface of the crystal W (S002). As a result, a smooth first cut surface Wa1 suitable for measuring the crystal orientation is obtained. Further, since the temporary orientation flat surface Wb1 is provided as a reference for grasping the crystal orientation of the crystal W, it is not necessary to process the entire side surface of the cylinder, and the side surface is short as shown in FIG. What is necessary is just to process in the range.

  The crystal W on which the first cut surface Wa1 is temporarily ground and the temporary orientation flat surface Wb1 is processed is transported to the crystal orientation measuring device 12 by the first transport device 18a, and the crystal orientation measuring device 12 performs the first cut of the crystal W. The plane Wa1 axial direction crystal orientation h is measured (S003). The axial crystal orientation h is not aligned with the cylindrical axis A of the crystal W as shown in FIG. Here, the cylindrical axis A is a line perpendicular to the ground first cut surface Wa1 and passing through the center of the crystal W on average.

  The crystal W for which the axial crystal orientation h is measured in step S003 is again transported to the cut surface grinding machine 13 by the first transport device 18a, and the first cut surface is perpendicular to the axial crystal orientation h by the cut surface grinding machine 13. Wa1 is ground (S004). At this time, the tilting mechanism 134 of the cut surface grinding machine 13 uses the axial crystal orientation h measured in step S003 as a reference with respect to the temporary orientation flat surface Wb1 processed in step S002. The fixed part 133 is inclined so that the directional crystal orientation h is vertical.

  Further, after the grinding of the first cut surface Wa1, the cut surface grinding machine 13 grinds the second cut surface Wa2 parallel to the new first cut surface Wa3 (S005). When the grinding in steps S004 and S005 is completed, the new cut surfaces Wa3 and Wa4 that appear in the grinding of the cut surfaces Wa1 and Wa2 become perpendicular to the axial crystal orientation h as shown in FIG.

  The crystal W after the cut surfaces Wa1 and Wa2 are ground is transported to the cylindrical grinding machine 14 by the first transport device 18a, and the cylindrical grinding machine 14 turns the side surface of the crystal W into a cylindrical surface perpendicular to the new cut surfaces Wa3 and Wa4. By grinding, it is ground into a cylindrical shape (S006). The crystal W shown in FIG. 10G is an example obtained by grinding the side surface of the crystal W shown by the dotted line Wn in FIG. The temporary orientation flat surface Wb1 is also ground by this cylindrical grinding.

  After the cylindrical grinding in step S006, the crystal orientation measuring device 144 of the cylindrical grinding machine 14 measures the radial crystal orientation k of the crystal W (S007). When the radial direction crystal orientation k is measured by the crystal orientation measuring device 144, the cylindrical grinding machine 14 processes the orientation flat surface Wb2 on the crystal W as shown in FIG. 10 (h) using the radial direction crystal orientation k as a reference (S008). ).

  The crystal W whose orientation flat surface Wb2 has been processed in step S008 is transported to the second storage shelf 10b by the first transport device 18a and stored in the second storage shelf 10b. The processes in steps S001 to S008 are the first process of crystal processing.

  Next, as a second process of crystal processing using the flowchart shown in FIG. 11, the wafer Ww is processed from the crystal W stored in the second storage shelf 10b, and the wafer Ww is stored in the third storage shelf 10c. The process will be described.

  First, in the crystal processing apparatus 1, the crystal W stored in the second storage shelf 10b is transported to the bonding stage 15 by the second transport apparatus 18b, and the crystal W is bonded to the plate P by the bonding stage 15 (S009). . At this time, as shown in FIG. 10 (i), the first cut surfaces Wa 3 and the second cut surfaces Wa 4 of the plurality of crystals W are arranged so as to contact each other, and the orientation flat surface Wb 2 is bonded to the plate P. Since the cut surfaces Wa3 and Wa4 are ground perpendicular to the axial crystal orientation h, even if the crystals W are bonded so that the cut surfaces Wa3 and Wa4 are in contact with each other, the axial directions of all the crystals W The crystal orientation h is directed in the same direction.

  The crystal W adhered to the plate P is transported to the second cutting machine 16 by the second transport device 18b, and the second cutting machine 16 cuts the crystal W into a plurality of wafers Ww (S010). The 2nd cutting machine 16 has a wire saw as described in Unexamined-Japanese-Patent No. 9-19920, for example. In the 2nd cutting machine 16, the conveyed crystal | crystallization W is positioned with respect to a wire saw, hold | maintained, and it cut | disconnects. When the crystal W is cut in parallel with a wire saw as shown in FIG. 10J, a plurality of wafers Ww having the same thickness as shown in FIG. The plate P bonded to the crystal W is stripped from the wafer Ww simultaneously with the cutting in step S010, or is stripped from the wafer Ww after the cutting.

  Each wafer Ww cut in step S010 is transferred to the chamfering machine 17 by the second transfer device 18b, and the chamfering machine 17 chamfers each wafer Ww (S011). Since the second cutting machine 16 generates a plurality of wafers Ww at the same time, a large number of wafers Ww are housed in a wafer case and transferred to the chamfering machine 17 for chamfering. The chamfering machine 17 takes out the wafers Ww one by one from the wafer case, chamfers them, and stores them again in the wafer case.

  The wafer Ww chamfered in step S011 is transferred to the third storage shelf 10c by the second transfer device 18b and stored in the third storage shelf 10c. The processes in steps S009 to S011 are the second process of crystal processing.

  In the crystal orientation measuring device 12 described above, the cut surface Wa1 of the crystal W before cylindrical grinding is placed on the table surface 121a with the cut surface Wa1 facing down, and the second X-ray diffracted by irradiating the cut surface Wa1 with the first X-ray 3a. 3b is detected. Therefore, since the crystal W is held not on the side but on the cut surface Wa, positioning of the cut surface is ensured even with respect to the crystal before cylindrical grinding, and the axial crystal orientation h with respect to the cut surface Wa1 is accurately set. Can be measured. In addition, since the table 121 is rotated by placing it on the table 121 with the cut surface Wa1 facing down, and the measurement point C is aligned with the vicinity of the φ axis 20, the deviation of the measurement point C every φ rotation is prevented. The axial crystal orientation h can be accurately measured. Further, since the temporary orientation flat surface Wb1 is processed on the crystal W on which the first cut surface Wa1 has been temporarily ground to define the mark (reference position) of the cut surface Wa, the crystal orientation h in the axial direction of the first cut surface Wa1 Measurement and positioning when grinding the first cut surface Wa1 can be ensured.

  In the crystal processing apparatus 1 described above, before the cylindrical grinding, the cut surfaces Wa1 and Wa2 are ground as new cut surfaces Wa3 and Wa4 in accordance with the axial crystal orientation h which is the surface direction of the wafer Ww, and this new cut surface Wa3. , Sliced in the direction of the cut surfaces Wa3 and Wa4 after cylindrical grinding with respect to the cylindrical axis orthogonal to Wa4, the wafer Ww obtained by slicing becomes a perfect circular disk shape excluding the orientation flat surface Wb2. . Therefore, compared to the conventional case where an elliptical wafer Ww is obtained by slicing, cylindrical grinding can be performed with a diameter very close to the final target diameter at the time of cylindrical grinding. It is small and can be chamfered efficiently in a short time.

  In the crystal processing apparatus 1, the cut surfaces Wa3, Wa4 of all the crystals W to be processed are perpendicular to the axial crystal orientation h, and each slice surface of the wafer Ww is parallel to the ground cut surfaces Wa3, Wa4. It is. Therefore, when bonding a plurality of crystals W to the plate P, each crystal W may be abutted on the cut surfaces Wa3 and Wa4 and bonded to the plate P. Therefore, the alignment of the crystal W on the plate P can be facilitated. Further, since the wire saw is not applied obliquely with respect to the cut surfaces Wa3 and Wa4 at the time of slicing, a defective wafer is not generated, and an efficient wafer can be generated.

<First Modification>
A crystal processing apparatus according to a first modification of the present invention will be described with reference to FIGS. The crystal processing apparatus according to the first modification can process an off-cut wafer. Since the configuration of the crystal processing apparatus according to the first modification is the same as that of the crystal processing apparatus 1 described above, the description will be made using the same reference numerals.

  The flowchart shown in FIG. 12 is a flowchart for explaining the first process of the crystal processing apparatus 1 according to the first modification, and the same processes as those described above with reference to FIG. Omitted. Compared with the flowchart of FIG. 8, the flowchart of FIG. 12 is different in that the first cut surface Wa <b> 1 is ground off-cut in step S <b> 104 instead of step S <b> 004.

  The cut surface grinder 13 to which the crystal W is conveyed tilts the offcut angle θi with respect to the axial crystal orientation h measured in S003 when the tilt mechanism 134 tilts the fixed portion 133 to which the crystal W is fixed. The first cut surface Wa1 is ground so as to be perpendicular to the direction h ′ (S104). Therefore, as shown in FIG. 13, the new first cut surface Wa3 after grinding is perpendicular to the direction h '.

  Referring to FIG. 14, for example, when the offcut angle θi is represented by an angle δox in the x-axis direction and an angle δoy in the y-axis direction, the offcut is calculated from the measured tilt angles δx and δy of the axial crystal orientation h. The inclination angles δx ′ and δy ′ in the direction h ′ inclined by the angle θi are also stopped by the expressions (3) and (4).

δx ′ = δx−δox (3)
δy ′ = δy−δoy (4)
The value obtained by inverting the signs of δx ′ and δy ′ obtained here is the amount of tilt adjustment in the tilt mechanism 134. That is, if the first cut surface Wa1 is ground with the inclination mechanism 134 inclined by δx ′ in the negative x direction and δy ′ in the negative y direction with respect to the cylindrical axis A, a new cut surface Wa3 is obtained. It becomes perpendicular to the direction h ′.

  After grinding the first cut surface Wa1 in step S104, if the tilt mechanism 134 tilts (rotates) the fixing portion 133 by 180 ° and grinds the second cut surface Wa2 in step S005, both new cut surfaces Wa3, Wa4 is ground at an off-cut angle. Therefore, the wafer Ww generated using the crystal W processed in the subsequent processing from 006 is an off-cut wafer Ww.

<Second modification>
A crystal processing apparatus according to a second modification of the present invention will be described with reference to FIG. If the new ground cut surfaces Wa3 and Wa4 are not perpendicular to the axial crystal orientation h, an appropriate wafer Ww cannot be generated. Therefore, the crystal processing apparatus according to the second modification confirms whether or not the new first cut surface Wa3 has been ground in the correct direction, and prevents the generation of defective wafers. Since the configuration of the crystal processing apparatus according to the second modification is the same as that of the crystal processing apparatus 1 described above, the description will be made using the same reference numerals.

  FIG. 15 is a flowchart for explaining the first process of the crystal processing apparatus 1 according to the second modification, and the same processes as those described above with reference to FIG. 15 is different from the flowchart of FIG. 8 in that steps S201 and S202 are included after the first cut surface Wa1 is ground in step S004.

  Specifically, in the crystal processing apparatus 1 according to the second modification, the crystal W whose first cut surface Wb1 has been ground in step S004 is transported again to the crystal orientation measuring apparatus 12 by the first transport apparatus 18a and ground. After the axial crystal orientation h of the new cut surface Wa3 is measured for confirmation (S201), it is determined whether the axial crystal orientation h is accurate (S202).

  When the axial crystal orientation h measured in step S201 is not perpendicular to the new first cut surface Wa3 (NO in S202), the cut surface grinding machine 13 uses the first cut surface Wa3 relative to the axial crystal orientation h. Steps S004 and S201 are repeated until it becomes vertical.

  When the axial crystal orientation h measured in step S201 becomes perpendicular to the new first cut surface Wa3 (YES in S202), the cut surface grinder 13 grinds the second cut surface Wa2 in step S005, and crystal processing In the apparatus 1, the subsequent processing continues to generate the wafer Ww.

  As described above, in the crystal processing apparatus 1 according to the second modification, it is determined whether or not the new first cut surface Wa3 is perpendicular to the axial crystal orientation h. If the process proceeds to step (2) and the first cut surface Wa3 is ground again if it is not perpendicular to the axial crystal orientation h, an appropriate wafer Ww can be generated.

  In the crystal processing apparatus 1 according to the second modification, the process of step S004 is replaced with step S104 described above with reference to FIG. 12, and it is determined whether or not the offcut angle θi is inclined by the confirmation in step S202. Accordingly, the present invention can be applied to processing of an off-cut wafer Ww.

<Third Modification>
A crystal processing apparatus according to a third modification of the present invention will be described with reference to FIGS. The crystal processing apparatus according to the third modification processes the temporary orientation flat surface in the same direction as the crystal direction in which the orientation flat surface is actually processed. The configuration of the crystal processing apparatus according to the third modification is the same as that of the crystal processing apparatus 1 described above, and will be described using the same reference numerals. In the crystal processing apparatus 1 described above, the temporary orientation flat surface Wb1 is processed regardless of the radial crystal orientation k before measuring the radial crystal orientation k, and is different from the orientation flat surface Wb2 to be finally processed. Has been processed. On the other hand, in the crystal processing apparatus 1 according to the third modification, the temporary orientation flat surface Wb1 is processed in the same direction as the orientation flat surface Wb2 to be finally processed.

  The flowchart shown in FIG. 16 is a flowchart for explaining the first process of the crystal processing apparatus according to the third modified example. The same processes as those described above with reference to FIG. Omitted.

  As shown in the flowchart of FIG. 16, in the crystal processing apparatus 1 according to the third modification, the crystal W cut in step S001 is transported to the cut surface grinder 13 by the first transport device 18a, and cut surface grinding is performed. In the machine 13, the cut surfaces Wa1 and Wa2 are temporarily ground parallel to each other (S301).

  The crystal W on which the cut surfaces Wa1 and Wa2 have been temporarily ground in step S301 is transported to the cylindrical grinding machine 14 by the first transport device 18a, and is subjected to temporary cylindrical grinding in the cylindrical grinding machine 14 (S302). Here, the length of the provisional cylindrical grinding is not limited as long as the radial crystal orientation k can be measured, and may be about 5 mm as shown in FIG. That is, it is only necessary to irradiate the first X-ray 3c with respect to the side surface E that appears in the temporary grinding, and to secure a length for diffracting the second X-ray 3d from the side surface E.

  When provisional cylindrical grinding is performed in step S302, the rotation mechanism 143 rotates the crystal W, and measures the radial crystal orientation k of the crystal W by using the side surface E without unevenness caused by the provisional cylindrical grinding (S303). .

  When the radial crystal orientation k of the crystal W is measured in step S303, the rotating mechanism 143 makes the direction of processing the orientation flat surface Wb2 of the crystal W face the grindstone driving unit 142, and the grindstone driving unit 142 drives the grindstone 141. Then, the temporary orientation flat surface Wb1 is processed (S304). In step S304, the temporary orientation flat surface Wb1 is not processed with respect to the entire range of the crystal W, but may be processed with a length of about 10 mm, for example, as shown in FIG.

  When the temporary orientation flat surface Wb1 is processed in step S304, the axial crystal orientation h is measured in step S003, and the subsequent processing is continued in the crystal processing apparatus 1 to generate the wafer Ww.

  In this way, the temporary orientation flat surface Wb1 is also processed in the same direction as the actual orientation flat surface Wb2, thereby facilitating off-cut processing based on the orientation flat surface Wb2.

<Fourth modification>
A crystal processing apparatus according to a fourth modification of the present invention will be described with reference to FIGS. The crystal processing apparatus according to the fourth modification cuts a crystal into a plurality of pieces, and generates a wafer from each cut crystal. Since the configuration of the crystal processing apparatus according to the fourth modification is the same as that of the crystal processing apparatus 1 described above, the description will be made using the same reference numerals.

  The flowchart shown in FIG. 18 is a flowchart for explaining the first process of the crystal processing apparatus 1 according to the fourth modification. The same processes as those described above with reference to FIG. Is omitted.

  As shown in FIG. 9D, the axial crystal orientation h of the unprocessed crystal W stored in the first storage shelf 10a and the approximate cylindrical axis A 'are often shifted. Therefore, as shown in FIG. 19A, the region Wr that can be used as the wafer Ww after cylindrical grinding from the crystal W before processing is limited. Further, the diameter D1 of the wafer Ww may be shortened, and there is a possibility that the generally prescribed diameter of the wafer cannot be satisfied. Accordingly, as shown in FIG. 19B, when the crystal W is cut along the cut surfaces Wa1 and Wa2, it is possible to secure a wide region Wr (Wr1, Wr2, Wr3) to be the wafer Ww by cutting into a plurality of pieces. The diameter D2 of the obtained wafer Ww can also be increased.

  As shown in the flowchart shown in FIG. 18, in the crystal processing apparatus 1 according to the fourth modification, the first cutting machine 11 cuts the crystal W into a plurality of regions Wr when cutting both end faces of the transferred crystal W. Disconnect (S401). At this time, the first cutting machine 11 sets the cut surfaces Wa <b> 1 and Wa <b> 2 perpendicular to the approximate cylindrical axis A ′ of the crystal W.

  After cutting the crystal W into a plurality of regions Wr in step S401, the crystal processing apparatus 1 performs steps S002 to S008 on each of the crystals W in each region Wr (S402), and then generates a wafer Ww. To do.

  In addition, when the crystal W is cut into a plurality of regions, it is wasteful to increase the number of cuts by shortening the length L2 at the time of cutting as the inclination angle α of the cut surfaces Wa1 and Wa2 with respect to the cylindrical axis A ′ is larger. Less. At this time, the length L2 can be obtained as shown in Expression (5). Note that the inclination angle α is an angle represented by the inclination angles δx and δy.

L2 = D2 · sin α + (Dw−D2 · cos α) / tan α
≒ (Dw-D2) / tanα
≒ margin of crystal W with respect to final wafer diameter D2 / tan (α) (5)
In the formula (5), D2 is the diameter of the final wafer, Dw is the effective diameter obtained by removing the irregularities from the crystal W, and the “room” is (Dw−D2).

  In the crystal processing apparatus 1 according to the above-described fourth modification, a region where the wafer Ww is generated can be widened by cutting the crystal W into a plurality of regions Wr.

  When the off-cut wafer Ww is processed, the above-described inclination angle α is roughly an angle represented by inclination angles δx ′ and δy ′ in the inclined direction h ′. In this case, FIG. h is replaced with h '.

<Fifth Modification>
A crystal processing apparatus according to a fifth modification of the present invention will be described with reference to FIGS. The crystal processing apparatus according to the fifth modified example cuts a plurality of crystals along a plane substantially perpendicular to the axial crystal orientation, and generates a wafer from each cut crystal. Since the configuration of the crystal processing apparatus according to the fifth modification is the same as that of the crystal processing apparatus 1 described above, the description will be made using the same reference numerals.

  The flowchart shown in FIG. 20 is a flowchart for explaining the first process of the crystal processing apparatus 1 according to the fifth modification, and the same processes as those described above with reference to FIG. Is omitted.

  As shown in the flowchart of FIG. 20, in the crystal processing apparatus 1 according to the fifth modification, the first cutting machine 11 cuts one end surface of the transferred crystal W perpendicularly to, for example, the cylindrical axis A ′ ( S001). Thereafter, the cut surface grinding machine 13 temporarily grinds the first cut surface Wa1 and processes the temporary orientation flat surface Wb1 (S002). Subsequently, the crystal orientation measuring device 12 measures the axial crystal orientation h (S003). When the axial crystal orientation h is measured, the cut surface grinding machine 13 grinds the first cut surface Wa1 as a new first cut surface Wa3 perpendicular to the axial crystal orientation h (S004).

  The crystal W having the new first cut surface Wa3 ground perpendicular to the axial crystal orientation h is transported to the first cutting machine 11, and the first cutting machine 11 moves to the axial crystal orientation h as shown in FIG. In addition, the crystal W is cut into a plurality of regions Wr (Wr1, Wr2, Wr3) (S501).

  After cutting the crystal W into a plurality of regions Wr in step S501, the crystal processing apparatus 1 performs steps S002 to S008 on each crystal W in each region Wr (S502), and then generates a wafer Ww. To do.

  When cutting the crystal W into a plurality of regions, the greater the inclination angle α of the cut surfaces Wa1 and Wa2 with respect to the cylindrical axis A ′, the less waste is achieved by shortening the length L3 when cutting. The length L3 at this time can be obtained as shown in Expression (6) using α. Note that the inclination angle α is an angle represented by the inclination angles δx and δy.

L3 = (Dw−D3 · cos α) / sin α
≒ (Dw-D3) / sin α
≒ margin of crystal W with respect to final wafer diameter D3 / sin (α) (6)
In Expression (6), D3 is the diameter of the final wafer, Dw is the effective diameter obtained by removing the irregularities from the crystal W, and the “margin” is (Dw−D3).

  In the crystal processing apparatus 1 according to the above-described fifth modification, when the crystal W is cut into a plurality of regions Wr, the fourth modification shown in FIG. 19 is performed by cutting in a direction perpendicular to the axial crystal orientation h. Compared to the case of the example, the region Wr for generating the wafer Ww can be widened.

  When processing the off-cut wafer Ww, when cutting the crystal W, it is cut in accordance with a direction h ′ inclined by an off-cut angle from the axial crystal orientation h. The crystal cutting state in this case is a state in which h is replaced with h ′ in FIG. In this case, the inclination angle α is roughly an angle represented by inclination angles δx ′ and δy ′ in the inclined direction h ′.

<Sixth Modification>
In the above-described best embodiment, the orientation flat surface is used as a mark for discriminating the crystal orientation in the radial direction, but it is obvious to those skilled in the art that a notch (V groove) may be used instead of the orientation flat surface. That is.

It is a block diagram explaining the structure of the crystal processing apparatus which concerns on the best embodiment of this invention. It is a figure explaining the structure of the crystal orientation measuring apparatus with which the crystal processing apparatus of FIG. 1 is provided. It is a figure explaining the structure of the cut surface grinding machine with which the crystal processing apparatus of FIG. 1 is provided. It is a figure explaining the axial direction crystal orientation of the crystal | crystallization before grinding. It is a figure explaining the axial direction crystal orientation of the crystal | crystallization after grinding. It is a figure explaining the structure of the cylindrical grinding machine with which the crystal processing apparatus of FIG. 1 is provided. It is a figure explaining the structure of the chamfering machine with which the crystal processing apparatus of FIG. 1 is provided. It is a flowchart explaining the 1st process of the crystal processing in the crystal processing apparatus concerning the best embodiment of this invention. It is a figure showing the state of each process of the crystal processed in the crystal processing apparatus of this invention. It is a figure showing the state of each process of the crystal processed with the crystal processing apparatus following FIG. It is a flowchart explaining the 2nd processing following the 1st processing of crystal processing in the crystal processing device concerning the best embodiment of the present invention. It is a flowchart explaining the 1st process in the crystal processing apparatus of the 1st modification. It is a figure explaining the offcut in the crystal processing apparatus of the 1st modification. It is a figure explaining the adjustment amount adjusted with the crystal processing apparatus of a 1st modification. It is a flowchart explaining the 1st process in the crystal processing apparatus of the 2nd modification. It is a flowchart explaining the 1st process in the crystal processing apparatus of the 3rd modification. It is a figure showing the state of the crystal processed with the crystal processing apparatus of the 3rd modification. It is a flowchart explaining the 1st process in the crystal processing apparatus of the 4th modification. It is a figure explaining the crystal processed in the crystal processing apparatus of the 4th modification. It is a flowchart explaining the 1st process in the crystal processing apparatus of the 5th modification. It is a figure explaining the crystal processed in the crystal processing apparatus of the 5th modification. It is a flowchart explaining the process in the conventional crystal processing apparatus. It is a figure explaining the structure of the crystal orientation measuring apparatus of the conventional crystal processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Crystal processing apparatus 10a-10c ... Storage shelf 11 ... 1st cutting machine 12 ... Crystal orientation measuring apparatus 121 ... Table 121a ... Table surface 121b ... Jig member 121c ... Through-hole 121d ... Vertical surface 122 ... φ rotation mechanism (φ Rotating means)
122a ... gear 122b ... belt 123 ... X-ray tube (X-ray source)
123a ... Collimator 124 ... X-ray detector 125 ... Frame (support means)
126 ... θ rotation mechanism (θ rotation means)
127 ... Control processing unit 127a ... Control means 127b ... Calculation means A, A '... Cylindrical axis C ... Measurement point W ... Crystal Wa ... Cut surface Wb ... Oriental flat surface 20 ... φ-axis 21 ... θ-axis 3a, 3c ... First X-ray 3b, 3d ... 2nd X-ray 13 ... Cut surface grinder 131 ... Grinding wheel 132 ... Grinding wheel drive part 133 ... Fixed part 134 ... Inclination mechanism 14 ... Cylindrical grinding machine 141 ... Grinding stone 142 ... Grinding wheel drive part 143 ... Rotation mechanism 143a, 143b ... Support part 143c, 143d ... Pad 143e ... Motor 144 ... Crystal orientation measuring device 144a ... X-ray tube 144b ... X-ray detector 15 ... Adhesion stage 16 ... Second cutting machine 17 ... Chamfering machine 171 ... Wafer rotating part 171a, 171b ... Support unit 172 ... Whetstone 172a ... Groove 173 ... Wheel drive unit 18a, 18b ... Conveyor

Claims (5)

A crystal orientation measuring apparatus for irradiating a crystal with X-rays generated from an X-ray source, detecting the X-ray diffracted from the crystal with an X-ray detector, and measuring the crystal orientation of the crystal,
A crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicularly to the cylinder axis is irradiated with X-rays on a table placed on the cut surface generated by the cutting and the cut surface. Calculating means for measuring the X-rays diffracted and calculating the crystal orientation of the crystal with respect to the cut surface;
A crystal orientation measuring apparatus comprising: A crystal orientation measuring apparatus that generates a first X-ray from an X-ray source, irradiates the crystal, detects a second X-ray diffracted at a measurement point of the crystal with an X-ray detector, and measures the crystal orientation of the crystal. And
The crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicularly to the cylindrical axis has a table surface placed with the cut surface generated by the cutting down, and from the X-ray source. A table having a through hole at the center of the table surface through which the generated first X-ray and the second X-ray diffracted at the measurement point on the cut surface pass;
Φ rotating means for rotating the table by φ at a predetermined angle with a φ axis perpendicular to the table surface passing through the center of the table as a rotation axis;
The X-ray source is in a positional relationship with respect to the measurement point so that the first X-ray is along a measurement surface orthogonal to the cut surface and the second X-ray diffracted at a predetermined angle is detected. And support means for supporting the X-ray detector;
Θ rotation means for rotating the support means by θ at a rotation angle within a predetermined range with a θ axis perpendicular to the measurement surface and passing through the measurement point as a rotation axis;
Control means for controlling the φ rotation means and the θ rotation means so as to rotate θ for each angle of the φ rotation;
From the detection data of the X-ray detector and the rotation angle of θ rotation, calculation means for calculating the crystal orientation of the crystal with reference to the cut surface;
A crystal orientation measuring apparatus comprising: The crystal orientation measuring device according to any one of claims 1 and 2,
A cut surface grinding machine for grinding the cut surface so as to intersect the measured crystal orientation at a predetermined angle;
A cylindrical grinding machine for grinding a side surface of the crystal into a cylindrical shape perpendicular to a new cut surface ground by the cut surface grinding machine;
A crystal processing apparatus comprising: Positioning a crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicular to the cylindrical axis on a table with the cut surface generated by the cutting down;
Measuring the X-ray diffracted by irradiating the cut surface with X-rays and calculating the crystal orientation of the crystal with respect to the cut surface;
Grinding the cut surface to intersect the calculated crystal orientation at a predetermined angle;
Grinding the side of the crystal into a cylinder perpendicular to the ground new cut surface;
Cutting the crystal ground into a cylindrical shape in parallel with the new cut surface to obtain a plurality of wafers;
A crystal processing method comprising: Positioning a crystal having a cylindrical shape before the side surface is ground and cut substantially perpendicular to the cylindrical axis on a table with the cut surface generated by the cutting down;
Rotating the table by a predetermined angle by a φ axis that is perpendicular to the table and passing through the center of the table;
An X-ray source that generates a first X-ray irradiated to a measurement point on the cut surface and an X-ray detector that detects a second X-ray diffracted from the measurement point are supported in a positional relationship based on the measurement point. Rotating the support means at a rotation angle within a predetermined range about a θ axis that is perpendicular to a measurement plane that includes the first X-ray and is perpendicular to the cut surface and that passes through the measurement point;
Controlling the φ rotation means and the θ rotation means so as to rotate θ for each angle of the φ rotation;
From the detection data of the X-ray detector and the rotation angle of θ rotation, calculating the crystal orientation of the crystal with reference to the cut surface;
Grinding the cut surface to intersect the calculated crystal orientation at a predetermined angle;
Grinding the side of the crystal into a cylinder perpendicular to the ground new cut surface;
Cutting the crystal ground into a cylindrical shape in parallel with the new cut surface to obtain a plurality of wafers;
A crystal processing method characterized by comprising:

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