JP7176327B2 - WAFER MANUFACTURING METHOD AND WAFER PRESSING JIG - Google Patents

Description

The present invention relates to a wafer manufacturing method and a wafer holding jig.

A wire saw device is conventionally known as a method for cutting a single crystal into wafers. For example, in a cutting method using a wire saw device described in Patent Document 1, there are three main shaft rollers, and grooves are formed on the outer periphery of the main shaft rollers at a pitch that matches the thickness of the target wafer. wire is wound along the groove of the main shaft roller. The main shaft roller is rotated to run the wire, and the main body table to which the single crystal is fixed is operated to press the single crystal against the wire, thereby simultaneously cutting the single crystal into a large number of wafers. In this machining method, the workpiece is pressed against a plurality of rows of extra-fine wires arranged in parallel at a constant pitch, and while the wires are fed in the line direction, a working fluid (also called slurry) containing abrasive grains is placed between the workpiece and the wires. ), and a method of polishing and cutting the workpiece while feeding a wire, to which diamond is electrodeposited or fixed by an adhesive, in the line direction.

A conventional procedure for slicing a single crystal into wafers involves fixing the single crystal to a slicing table of a wire saw device with an adhesive via a pedestal. After that, the slicing table is turned over and placed on the wire saw device. Next, processing is started by the wire saw device, the slicing table moves to the processing section, and the single crystal is cut by the wire. Cutting cuts the pedestal to about 5 mm. The cut wafer has a thickness of about 0.2 to 2 mm, and is held only by the adhesive on the edge of the wafer. In this state, the slicing table on which the wafers are held is taken out from the wire saw device, and after the slicing table is inverted, the wafers are taken out individually by peeling off the adhesive.

Japanese Patent Application Laid-Open No. 2001-001248

In the above method, the wafer formed by slicing the single crystal by the wire saw is removed from the wire saw while the slicing table is removed from the wire saw while the circumferential surface of the wafer is partially held only by the adhesive. , is transported to the place where the stripping operation is performed. This transportation is performed by a vehicle such as a lifter. When the wafers are removed from the slicing table and transported to the place where the peeling work is performed, the wafers may come into contact with each other or fall over due to vibrations, shocks, and the like, resulting in chipping or breakage. Moreover, when the slicing table is removed from the wire saw device as described above, the wafer may drop and be damaged.

In addition, in the peeling operation, since the adhesive force of the adhesive is lowered and the wafer is removed from the pedestal and recovered, the holding force of the wafer by the pedestal is further reduced, and the wafer falls down and is easily damaged. Due to the above-mentioned causes, there is a problem that the yield is lowered.

In recent years, the market for devices for mobile communication devices continues to expand due to the spread of smartphones and the like, and along with this, the demand for substrates such as Si, LT, and LN, which are materials for devices, is increasing. In addition, in order to reduce the cost of the substrate manufacturing process, the size of single crystal substrates such as Si, LT, and LN has also increased from conventional φ3 inches and φ4 inches to φ6 inches and φ8 inches, etc., increasing the area and length. crystals are becoming larger. As wafers become thinner and larger in diameter, damage due to contact, overturning, and falling of the wafers is becoming more pronounced. In particular, a product with a wafer thickness of 0.6 mm or less and a wafer diameter of 6 inches or more has a small adhesive area for fixing to the slicing table, and even a small vibration or impact causes the product to fall down, resulting in deterioration of productivity.
SUMMARY OF THE INVENTION Accordingly, the present invention is intended to solve such conventional problems. It provides

In order to solve the above-described conventional problems, the present inventors conducted extensive research, and found that a plurality of wafers formed by cutting the above-described single crystal are held between the plurality of wafers by a predetermined holding jig. We have found that by fixing the relative positions, it is possible to prevent contact, overturning, and falling of the wafer. The present invention has been completed based on such technical discoveries.

According to the first aspect of the present invention, a plurality of spaced apart wafers formed by cutting a cylindrical single crystal fixed to a pedestal are pressed at a part of the circumferential surface of each of the plurality of wafers. a pressing jig capable of fixing the relative position between the wafers, wherein the pressing portion is arranged vertically symmetrical with respect to a horizontal plane passing through the central axis of the single crystal fixed to the pedestal, Further, a holding jig is provided which is arranged symmetrically with respect to a vertical plane passing through the central axis of the single crystal fixed to the pedestal and which holds a portion of the circumferential surface of the wafer.

According to a second aspect of the present invention, in the first aspect, the pressing portion is movable in an arc around an axis parallel to the central axis of the single crystal fixed to the pedestal, and the length of the pressing portion provides a holding jig that is equal to or greater than the length of the pedestal in the central axis direction of the single crystal.

According to a third aspect of the present invention, in the first or second aspect, the pressing portion is arranged vertically symmetrical with respect to a horizontal plane passing through the central axis of the single crystal fixed to the pedestal, Further, a pressing jig is provided in which the position of the pressing portion is movable so as to be arranged symmetrically with respect to a vertical plane passing through the central axis of the single crystal fixed to the pedestal.

Further, according to a fourth aspect of the present invention, in any one of the first to third aspects, the movable mechanism includes a first adjusting portion that changes the vertical position of the pressing portion relative to the base; and a second adjuster for changing the relative position in the left-right direction with respect to the pedestal.

Further, according to a fifth aspect of the present invention, there is provided the pressing jig according to any one of the first to fourth aspects, wherein the portion of the pressing portion that contacts the circumferential surface of the wafer is an elastic body. be.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the pressing portion has a central axis of a single crystal fixed to the pedestal at a portion that contacts the circumferential surface of the wafer. A holding jig is provided which is a rotating body rotatable around an axis parallel to the .

Further, according to a seventh aspect of the present invention, there is provided a method for manufacturing a wafer by cutting a columnar single crystal, the method comprising bonding a part of the circumferential surface of the single crystal to a pedestal with an adhesive. , cutting the single crystal bonded to the pedestal with a cutting device to form a plurality of wafers bonded to the pedestal and arranged at intervals; , fixing the relative positions between the plurality of wafers, and peeling the plurality of wafers adhered to the pedestal from the pedestal.

Since the wafer holding jig and the wafer manufacturing method of the present invention hold the wafer from the end of the single crystal cutting to the peeling operation, the wafer can be prevented from contacting, falling, or falling. Furthermore, when the wafers are separated from the pedestal and removed individually in the peeling process, the wafers are taken out while being held down by part of the holding jig, so that the individual wafers are individually held down by the holding jig. As a result, the wafers can be taken out individually, and the wafers can be prevented from being damaged due to contact, overturning, or dropping.

It is a flow chart which shows an example of a manufacturing method of a wafer concerning this embodiment. It is a schematic diagram of a wire saw device. (A) and (B) are explanatory diagrams of the cutting process. FIG. 4 is a schematic diagram of a holding jig according to the present embodiment when viewed from the front; It is a figure which shows the state which removed one side of the holding jig of FIG. FIG. 5 is a schematic view of the holding jig of FIG. 4 when viewed from the side; (A) and (B) are explanatory diagrams of a second adjustment unit. It is a figure which shows operation|movement of the holding jig when the size of a wafer is changed. (A) and (B) are explanatory views of a peeling process.

Hereinafter, the present invention will be described with reference to the drawings. However, the present invention is not limited to this. In addition, in order to explain the embodiments in the drawings, the scale is changed as appropriate, such as by enlarging or emphasizing a portion. Also, in each of the following drawings, directions in the drawings will be explained using an XYZ coordinate system. In this XYZ coordinate system, the vertical direction is the Z direction, and the horizontal directions are the X direction and the Y direction. In each of the X direction, Y direction, and Z direction, the side indicated by the arrow will be referred to as the + side (eg, +X side), and the opposite side will be referred to as the - side (eg, -X side).

[Embodiment]
FIG. 1 is a flow chart showing an example of a method for manufacturing a wafer W according to this embodiment. As shown in FIG. 1, the method for manufacturing the wafer W of the present embodiment includes a bonding step (step S1) of bonding a single crystal to a pedestal, a cutting step (step S2) of cutting the single crystal bonded to the pedestal, It includes a fixing step (step S3) of fixing relative positions among a plurality of wafers formed by cutting a single crystal, and a peeling step (step S4) of peeling off the wafer bonded to the pedestal from the pedestal. In this embodiment, the "wafer" means a disk-shaped plate formed by cutting a cylindrical single crystal.

First, the single crystal cutting apparatus used in the wafer manufacturing method will be described. FIG. 2 is a schematic diagram of a wire saw device used in the wafer manufacturing method. A cutting device used in the wafer manufacturing method is, for example, a known wire saw device. In this embodiment, the single crystal cutting apparatus used in the wafer manufacturing method is described as the wire saw apparatus shown in FIG. 2, but this is only an example. cutting device may be used. For example, the cutting device may be a blade, a cutting device such as a wire electric discharge machine, or the like. Moreover, the wire saw device M shown in FIG. 2 is merely an example, and other types of wire saw devices may be used.

The wire saw device M shown in FIG. 2 is a so-called multi-wire saw device. The wire saw device M moves a wire row 4 made up of a plurality of wires 3 stretched between three sets of rotating rollers R1 to R3 with a predetermined interval between them relative to a cylindrical single crystal C. , while pressing the single crystal C in the cutting direction (the Z direction in the drawing), each wire 3 (wire row 4) is run in one direction or in a reciprocating direction for cutting. When the single crystal C is cut using such a multi-wire saw device, more parts of the single crystal C can be cut in one cutting operation, so the single crystal C can be cut efficiently.

In the cutting method by the wire saw device M, a method of supplying a working liquid containing abrasive grains to the portion where the wire 3 and the single crystal C are in contact (free abrasive grain method) and a wire 3 to which abrasive grains are fixed in advance are used. method (fixed abrasive grain method), any of the above cutting methods can be used in the wafer manufacturing method of the present embodiment.

The wire saw device M is equipped with a slicing table 7 to which the single crystal C is fixed, and moves the mounted slicing table 7 relative to the wire row 4 in the vertical direction, thereby cutting the single crystal C with the wire row 4. disconnect. The single crystal C is fixed via a pedestal 8 to a slicing table holder 6 and a slicing table 7 fixed together. The slicing table holder 6 is detachable from the wire saw device M, and the slicing table holder 6 can be removed from the wire saw device M to individually fix the single crystal C and remove the cut wafer W.

Each step will be described in detail. It should be noted that the following description of each process is an example, and does not limit the wafer manufacturing method of the present embodiment. In the bonding step (step S1 in FIG. 1), a portion of the circumferential surface Sc of the single crystal C is bonded to the pedestal 8 with the adhesive 9 . The single crystal C is fixed to the slicing table 7 via the pedestal 8 . First, the slicing table holder 6 to which the slicing table 7 is attached is removed from the wire saw device M, and the single crystal C to be cut is fixed to the slicing table 7 . The shape of the single crystal C is generally columnar. For identification, the single crystal C may be processed with an orientation flat (also called an orientation flat) obtained by grinding a part of the circumferential surface Sc into a flat shape, a notch obtained by cutting a part of the circumferential surface Sc, or the like. be. In this specification, a shape obtained by processing an orientation flat or a notch in a columnar single crystal C is included in the columnar shape.

When the single crystal C is placed on the slicing table 7, the pedestal 8 is interposed therebetween. In order to reliably cut the single crystal C when forming the wafer W by cutting the single crystal C in the next cutting step (step S2 in FIG. 1), part of the pedestal 8 is cut at the same time as the single crystal C. (See FIG. 3(B)). Therefore, the material of the base 8 is preferably resin, glass, or the like. The thickness of the pedestal 8 is preferably 10 mm or more, more preferably about 20 mm, because the pedestal 8 is cut to about 5 mm. Note that the pedestal 8 may be provided with a supporting portion for supporting the end surface of the single crystal C. As shown in FIG.

The slicing table 7 and the pedestal 8, and the pedestal 8 and the single crystal C are adhered and fixed with an adhesive 9, respectively. Although the adhesive 9 is not particularly limited, it is preferable to use an epoxy-based adhesive so that the wafer W formed after cutting the single crystal C can be easily peeled off. Further, in connecting the pedestal 8 and the single crystal C, if the single crystal C has an orientation flat, the surface of the orientation flat may be aligned with the pedestal 8 and bonded. By bonding the face of the orientation flat to the base 8, the bonding area increases and the bonding becomes stronger.

In the cutting step (step S2 in FIG. 1), the slicing table holder 6 to which the single crystal C is fixed is installed in the wire saw device M, and cutting is performed. 3A and 3B are explanatory diagrams of the cutting process. As described above, the slicing table 7 is moved to the processing portion of the wire 3 (wire row 4), and the single crystal C is pressed against the wire 3 (wire row 4) to form a plurality of wafers W. cut at the same time. As a result, the single crystal C bonded to the base 8 is cut in the Z direction to form a plurality of wafers W bonded to the base 8 and arranged in the X direction at intervals. As described above, at this time, as shown in FIG. 3B, the single crystal C and a portion (lower surface) of the pedestal 8 are cut by about 5 mm. The thickness of the wafer W to be formed is not particularly limited, but is, for example, 0.2 mm to 1.0 mm. The thickness of the wafer W can be adjusted to a predetermined thickness by adjusting the diameter, pitch, etc. of the wires 3 .

The fixing step (step S3 in FIG. 1) fixes relative positions between the plurality of wafers W formed by the cutting step. The wafer W cut in the previous step is adhered to a pedestal 8 sliced to a depth of about 5 mm with an adhesive 9 having about the thickness of the wafer W. As shown in FIG. Therefore, the wafer W is likely to fall even with a small vibration or impact. In particular, due to the reduction in thickness and the increase in diameter of the wafer W, the above tilting is conspicuous in products having a thickness of the wafer W of 0.6 mm or less and a diameter of the wafer W of 6 inches or more, for example. Therefore, in the present invention, a pressing jig Z is used to hold a plurality of wafers W in the central axis AX1 direction of the single crystal C while maintaining the gap between the wafers W. , to fix the relative position between the plurality of wafers W formed by the cutting process.

The pressing jig Z according to this embodiment will be described below with reference to FIGS. 4 to 9. FIG. FIG. 4 is a schematic diagram showing the front of the holding jig Z according to this embodiment when viewed from the +X direction. FIG. 5 is a diagram showing a state in which one side (+Y side) of the holding jig Z in FIG. 4 is removed. FIG. 6 is a schematic diagram showing a side view of the holding jig Z in FIG. 4 when viewed from the +Y direction.

As shown in FIGS. 4 and 5, the pressing jig Z of this embodiment has a symmetrical structure with respect to a vertical plane PL2 passing through the central axis AX1 of the single crystal C fixed to the pedestal 8. As shown in FIG. In the following description, the structure on the +Y side of the holding jig Z will be described as a representative, and the structure on the -Y side will be the same as the structure on the +Y side.

The pressing jig Z includes a supporting portion that supports each portion, and a pressing portion 12 that presses the circumferential surface Sc of the wafer W. As shown in FIG.

The support includes an attachment member 14 (attachment) and a support 15 . The mounting member 14 is detachably connected to the slicing table 7 with a fixing member T1 such as a bolt and nut. As shown in FIG. 5, the holding jig Z can be removed from the wafer W by removing the mounting member 14 from the slicing table 7 . Two mounting members 14 are arranged on the +Y side and the -Y side of the slicing table 7 . The mounting member 14 has a shape longer than the single crystal C (wafer W) in the central axis AX1 direction of the single crystal C (wafer W). The mounting member 14 supports the strut 15 . Mounting member 14 will be further described below. Note that the attachment member 14 may be configured to be connected to the slice table holder 6 .

Two supports 15 are attached to the mounting member 14 on the +Y side along the central axis AX1 (hereinafter abbreviated as "central axis AX1") direction (X direction) of the single crystal C fixed to the pedestal 8. . These two struts 15 have the same configuration. Each support 15 has a shape extending in the vertical direction (Z direction). Each column 15 is detachably connected to the mounting member 14 via a column base 26, which will be described later, by a fixing member T4 such as a bolt and nut. The two support columns 15 on the +Y side and the two support columns 15 on the -Y side are arranged to surround the pedestal 8 (single crystal C, wafer W) from all sides. It should be noted that three or more pillars 15 on the +Y side may be provided. In this case, when the length of the single crystal C to be cut is long, the holding portion 12 and the like can be stably supported.

As shown in FIG. 4, the pressing jig Z has a pressing portion 12 that presses the circumferential surface Sc of the wafer W. As shown in FIG. The pressing portion 12 is vertically symmetrical with respect to a horizontal plane PL1 (hereinafter abbreviated as “horizontal plane PL1”, XY plane) passing through the central axis AX1, and is positioned along a vertical plane PL2 (hereinafter “vertical plane PL2”) passing through the central axis AX1. abbreviated as XZ plane) so as to be symmetrical (in the Y direction, the horizontal direction, and the direction orthogonal to the central axis AX1). Each of the four pressing portions 12 has a shape extending in a direction parallel to the central axis AX1 (a direction parallel to the X direction).

In the following description, the pressing portion 12 arranged above the horizontal plane PL1 is referred to as the "upper pressing portion 12a", and the pressing portion 12 disposed below the horizontal plane PL1 is referred to as the "lower pressing portion 12b". When the “upper pressing portion 12a” and the “lower pressing portion 12b” are not distinguished from each other, they are collectively referred to as the “pressing portion 12”.

An upper arm 17a that supports the upper pressing portion 12a and a lower arm 17b that supports the lower pressing portion 12b are connected to the two columns 15 on the +Y side. Both ends (+X side and -X side ends) of the upper pressing portion 12a are connected to two upper arms 17a on the +X side and the -X side. Both ends (+X side and -X side ends) of the lower pressing portion 12b are connected to the two lower arms 17b on the +X side and the -X side. That is, each pressing portion 12 is formed longer than the pedestal 8 in the central axis AX1 direction. The maximum length of the single crystal C to be cut is the length of the pedestal 8. Therefore, in the configuration in which each pressing portion 12 is formed longer than the pedestal 8, even if the length of the single crystal C to be cut is increased, the length of the pressing can be increased. All the wafers W can be securely fixed by the portion 12. That is, the holding jig Z of the present embodiment is not limited to the length of the single crystal C, and can be used for single crystals C of various lengths. is possible.

Each upper arm 17a (+X side, −X side) and each lower arm 17b (+X side, −X side) are rotatably connected to the column 15 . In the following description, the "upper arm 17a" and the "lower arm 17b" are collectively referred to as the "arm 17" when not distinguished from each other.

Each upper arm 17a is connected to the strut 15 so as to be rotatable about a rotation axis AX2 parallel to the central axis AX1. As a result, the upper pressing portion 12a can rotate in an arc around the rotation axis AX2 parallel to the central axis AX1.

Each lower arm 17b is connected to the post 15 so as to be rotatable about a rotation axis AX3 parallel to the central axis AX1. Thereby, the lower pressing portion 12b can rotate in an arc shape around the rotation axis AX3 parallel to the central axis AX1.

As described above, when the pressing portion 12 is movable in an arc around the rotation axes AX2 and AX3 parallel to the central axis AX1, the pressing portion 12 presses the wafer W from the tangential direction of the circumference of the wafer W. It can be held vertically and the wafer W can be effectively fixed.

Note that the rotation radius r (see FIG. 4) when the pressing portion 12 is rotated by the upper arms 17a and the lower arms 17b is not particularly limited, and is appropriately set according to the diameter of the wafer W to be fixed. However, it is preferably about 60 to 90 mm.

The movable range of the arm 17 is restricted by a long hole-shaped guide G1. The guide G1 is formed in an arc shape to move the arm 17 in an arc shape. Although the movable range of the arm 17 is not particularly limited, it is about 35 degrees to 40 degrees in this embodiment. When the range of motion of the arm 17 is within the range described above, the arm 17 is prevented from moving to unnecessary positions, so that the handling of the arm 17 is improved. In addition, the range of motion of each upper arm 17a and each lower arm 17b may be different from each other.

Note that the arm 17 (holding portion 12) does not have to move in an arc shape. For example, the arm 17 can move in a horizontal direction (Y direction), a vertical direction (Z direction), these two directions (Y direction, Z direction), a combined direction (YZ direction), or the like. may be moved.

Also, the arm 17 can be fixed to the post 15 by a fixing member T2 such as a bolt and nut. When a mechanism for fixing the relative position of the arm 17 with respect to the base 8 is provided, the strength when the wafer W is pressed by the pressing portion 12 can be stabilized. The strength with which the wafer W is pressed by the pressing portion 12 may be such a strength that the wafer W does not drop from the pedestal 8 and a gap (space) between the cut wafers W is maintained. Each upper arm 17a and each lower arm 17b presses (biases) the pressing portion 12 in the direction of the circumferential surface Sc of the wafer W (in the direction of the central axis AX1) by a mechanism using an elastic member such as a spring. may be configured.

In addition, the portion of each pressing portion 12 that contacts the circumferential surface Sc of the wafer W (hereinafter referred to as “contact portion 19”) is rotatable around an axis parallel to the central axis AX1 (an axis parallel to the X direction). preferably a rotating body. Each pressing portion 12 of the present embodiment has a cylindrical rod shape and rotates around a rotation axis AX4 parallel to the central axis AX1. If the portion of each pressing portion 12 that contacts the circumferential surface Sc of the wafer W is a rotating body that can rotate about an axis parallel to the central axis AX1, the contact portion 19 can effectively contact the circumferential surface Sc of the wafer W. In addition, the friction and impact when the wafer W and the contact portion 19 come into contact can be reduced.

Also, the contact portion 19 of each pressing portion 12 is an elastic body. The elastic body is provided on the outer peripheral surface of the pressing portion 12 . The elastic body is silicon, soft rubber, or the like. When the contact portion 19 of the pressing portion 12 is an elastic body, the elastic body enters between the cut wafers W, making it possible to stably maintain the spacing (gap) between the cut wafers W. and the contact portion 19 can reduce the impact.

Further, the pressing jig Z of the present embodiment includes an end face pressing portion 27 that supports the end face of the wafer W. As shown in FIG. The end surface pressing portion 27 is provided via a guide member 20 extending in the X direction supported by the two support columns 15 on the +Y side (see FIG. 6). The end face pressing portions 27 are provided two each on the +X side and the -X side on each of the -Y side and the +Y side, for a total of four. The end surface pressing portions 27 are movable in the direction of the central axis AX1 via the guide member 20 in order to press the surfaces of the wafer W located at both ends of the wafer W. As shown in FIG. The end face pressing portion 27 can be fixed at an arbitrary position on the guide member 20 by a fixing member T6. The edge pressing portion 27 has an elastic body at the contact portion with the wafer W. As shown in FIG. The elastic body is silicon, soft rubber, or the like. If the contact portion between the end face pressing portion 27 and the wafer W is made of an elastic body, it is possible to reduce the impact when the wafer W and the contact portion 19 come into contact with each other.

Note that the guide member 20 may be configured to be connected to the arm 17 . Further, the pressing portion 12 may be attached to the guide member 20 and may be configured to be rotatable around the guide member 20 as a central axis. Moreover, the end surface pressing part 27 is an arbitrary structure and may be omitted.

Further, the pressing jig Z of the present embodiment is arranged such that the pressing portions 12 are arranged vertically symmetrically with respect to the horizontal plane PL1 and are arranged so as to be left-right symmetrically with respect to the vertical plane PL2. has a movable mechanism 22 that can move the position of . The movable mechanism 22 of this embodiment includes a first adjusting section 23 and a second adjusting section 24 .

The first adjustment section 23 adjusts the arm 17 (holding section 12) in the vertical direction. The vertical position of the pressing portion 12 relative to the pedestal 8 is changed. The first adjustment portion 23 changes the vertical position of the pressing portion 12 relative to the base 8 . According to the diameter of the single crystal C to be cut, the pressing portion 12 can be adjusted to be vertically symmetrical with respect to the horizontal plane PL1 by the first adjusting portion 23 . The first adjusting portion 23 of the present embodiment adjusts the vertical position of the arm 17 (pressing portion 12) by vertically moving the upper member 15U of the support 15 with respect to the lower member 15L. In this embodiment, the upper member 15U of the column 15 is movable with respect to the lower member 15L, and the upper member 15U is fixed to the lower member 15L by the guide G2 formed in an elongated hole shape and the fixing member T3 such as a bolt. fixed to A fixing member T3 is inserted into the guide G2, and by fixing with the fixing member T3, the upper member 15U is fixed to the lower member 15L. In this configuration, the relative position of the pressing portion 12 to the pedestal 8 (single crystal C) in the vertical direction can be changed continuously, so that it can be applied to single crystals C of any diameter.

In addition, the first adjustment unit 23 is not particularly limited to the configuration of the above example. For example, if the size of the single crystal C to be cut is fixed to some extent, it is A configuration using a member may be used. In this case, a fixing member is inserted into the through-hole, and the position in the vertical direction is fixed by the fixing member.

The second adjuster 24 will be described. FIGS. 7A and 7B are explanatory diagrams of the second adjustment section. FIG. 7A is a diagram showing a state in which the second adjustment section is assembled. FIG. 7B is a diagram showing a disassembled state of the second adjuster. FIGS. 7A and 7B are diagrams of the second adjuster viewed from below (−Z direction).

The second adjuster 24 adjusts the arm 17 (presser 12) in the horizontal direction and in the direction perpendicular to the central axis AX1 of the single crystal C (Y direction). The second adjusting portion 24 changes the relative position of the pressing portion 12 to the base 8 in the horizontal direction (Y direction). Although the configuration of the second adjusting portion 24 is not particularly limited, in this embodiment, as shown in FIGS. including. The guide G3 is provided in the mounting member 14 as an elongated hole parallel to the Y direction. The column 15 is fixed to the +X side and -X side ends of the column base 26 via fixing members T4 such as bolts. A column base 26 to which the column 15 is attached is attached to the mounting member 14 via a fixing member T5 such as a bolt. be. With this configuration, the column base 26 to which the column 15 is attached moves in the Y direction with respect to the mounting member 14 . Further, the column base 26 to which the column 15 is attached can be fixed at any position on the guide G3 by the fixing member T5. In the case of the above configuration, the relative position of the pressing portion 12 to the pedestal 8 in the left-right direction can be changed continuously, and it can be applied to single crystals C of any diameter.

The second adjustment unit 24 is not particularly limited to the configuration of the above example. For example, if the size of the single crystal C to be cut is fixed to some extent, a A configuration using a member may be used.

The pressing jig Z of this embodiment adjusts the position of the pressing portion 12 vertically and horizontally by the movable mechanism 22 including the first adjusting portion 23 and the second adjusting portion 24, so that the pressing portion 12 is The position of the pressing portion 12 can be moved so that it is arranged vertically symmetrically with respect to the horizontal plane PL1 and horizontally symmetrically arranged with respect to the vertical plane PL2. In the case of the above configuration, the relative position of the pressing portion 12 to the pedestal 8 in the vertical direction and the horizontal direction can be changed continuously.

FIG. 8 shows the operation of the holding jig Z when the size of the wafer is changed. A two-dot chain line in FIG. 8 shows a state in which the wafer W having the diameter shown in FIG. A solid line in FIG. 8 indicates a state when a wafer W having a diameter smaller than that shown in FIG.

When a wafer W having a diameter smaller than that of the wafer W shown in FIG. , and the position of the pressing portion 12 is moved in a direction toward the wafer W by the second adjustment portion 24 . As described above, the holding jig Z of the present embodiment can handle crystals having different sizes of single crystals C, from small to large diameters, and elongated crystals, due to the above configuration. As a result, single crystals C having different sizes can be handled with a single pressing jig Z of the present embodiment.

Further, in the pressing jig Z of the present embodiment, the four pressing portions 12 are arranged vertically symmetrically with respect to the horizontal plane PL1 and horizontally symmetrically with respect to the vertical plane PL2, so that the wafer W can be held at four locations. It becomes possible to fix them evenly and in good balance. When four holding portions 12 are provided, the wafer W can be securely fixed in a well-balanced manner. In addition, since both ends of the pressing portion 12 are fixed by the arms 17, the plurality of wafers W can be moved in the entire length direction in the direction of the central axis AX1 compared to a mechanism in which the pressing portion 12 is supported by the supporting portion only on one side. It is possible to effectively hold down over Moreover, the pressing jig Z of this embodiment can be easily assembled by the above configuration.

It is preferable that the holding jig Z is attached before the single crystal C is cut in the wire saw device M and the slicing table 7 is removed from the wire saw device M. In this case, since the wafer W is fixed before moving the plurality of wafers W formed by slicing the single crystal C, it is possible to effectively suppress the contact, falling, and falling of the wafer W after the single crystal C has been cut. be able to.

Next, the peeling process will be described. The peeling process (step S<b>4 in FIG. 1 ) is a process for peeling the wafer W from the pedestal 8 . 9A and 9B are diagrams showing an example of the peeling process. In the peeling process, the slicing table holder 6 to which the pressing jig Z is attached is removed in the wire saw device M, and the adhesive 9 between the wafer W on the slicing table 7 and the pedestal 8 and the adhesive 9 between the pedestal 8 and the slicing table 7 are removed. The adhesive 9 is peeled off, and the wafer W is taken out.

As described above, the slicing table 7 needs to be removed from the wire saw device M, transported to the stripping bath T, and immersed in the stripping bath T. During this transportation and movement, the wafer W is likely to fall due to vibrations and impacts. When the slicing table 7 is removed from the wire saw device M, when the slicing table 7 is pressed against the wire 3 from above as shown in FIG. It is in the lower state. In this case, when the slicing table 7 is transported, it is necessary to rotate the slicing table 7 by 180°, and the wafer W is especially prone to fall during this rotation. Therefore, it is preferable that the holding jig Z is attached before the slicing table 7 is removed from the wire saw device M after the single crystal C has been cut. You can prevent it from falling over.

The peeling of the adhesive 9 depends on the type of the adhesive 9. For example, in the case of an epoxy-based adhesive 9, it can be peeled off by applying a temperature of 60.degree. C. to 100.degree. In this case, as shown in FIGS. 9A and 9B, the wafer W, the pedestal 8, and the slicing table 7 are fixed by the holding jig Z in the stripping tank T filled with the high-temperature stripping liquid LQ. is done by immersing the In this peeling operation, the wafer W, the pedestal 8, and the slicing table 7 fixed by the pressing jig Z are immersed in the peeling bath T for a predetermined time. The adhesive force of the adhesive 9 is lowered by immersing the wafer W for a predetermined time, and the wafer W is recovered. In addition, since the adhesive force is lowered, the holding force of the wafer W is further lowered, and the wafer W is more likely to fall. Therefore, the peeling process may be performed while the holding jig Z is installed.

The wafer W may be taken out in the peeling tank T as shown in FIGS. For taking out the wafer W, for example, as shown in FIG. 9(A), the upper pressing portion 12a of the pressing jig Z is opened at two positions and removed. As a result, the side from which the wafer W is taken out is released, two points on the lower side of the circumferential surface Sc of the wafer W are held by the lower holding portion 12b, and the side (Y direction) of the wafer W is held by the holding portion 12b. Since there is a gap with the jig Z, the side (Y direction) of the wafer W does not interfere with the holding jig Z when the wafer W is taken out, and the wafer W can be easily taken out without stress.

When the wafer W is thin or the diameter of the wafer W is large and the wafer W is likely to come into contact with or fall down, the upper pressing portion of the four pressing portions 12 may be used as shown in FIG. 9(B). By removing one of the holding portions 12a and fixing the wafer W with the remaining three holding portions 12, the wafer W can be prevented from falling down. In this case, the wafer W can be lifted obliquely upward and taken out.

As described above, the pressing jig Z for the wafer W and the wafer manufacturing method of the present embodiment hold the wafer W from the end of the single crystal cutting to the peeling operation, so that the wafer W is prevented from coming into contact with, falling over, or falling. can be suppressed. Furthermore, when the wafer W is separated from the pedestal 8 and removed individually in the peeling process (step S4 in FIG. 1), the wafer W is taken out while being held down by a part of the holding jig Z. Since the individual wafers W are held individually by the holding jig Z, the wafers W can be taken out individually, and the wafers W can be prevented from being damaged due to contact, overturning, or dropping.

EXAMPLES The present invention will be described in detail below based on examples and comparative examples, but the present invention is not limited by the examples.

[Example 1]
A single crystal C of lithium tantalate (hereinafter referred to as LT) having a size of φ150 mm and a length of 100 mm was prepared. A slicing table was fixed to a pedestal 8 having a thickness of 20 mm with an epoxy-based adhesive 9 . An orientation flat portion of the single crystal C was fixed on the pedestal 8 with an epoxy-based adhesive 9 so as to match the surface of the pedestal 8 .

Next, the slicing table on which the single crystal was fixed was attached to a wire saw device, and wafers W were cut. The cutting conditions were a wafer thickness of 0.6 mm and a pitch between wafers of 0.85 mm.

After finishing the cutting, the holding jig Z was attached to the slicing table 7 . Since the total length of the holding jig Z varies depending on the maximum cutting length of the wire saw device M, in this test, one that can handle a crystal length of 300 mm was used. The pressing jig Z is installed as shown in FIGS. 4 and 5, and the height of the pressing portion 12 and the width of the pressing portion 12 (position in the Y direction) are adjusted by the first adjusting portion 23 and the second adjusting portion 24. After that, four pressing portions 12 and four end surface pressing portions 27 were installed. Further, silicon rubber was provided on the contact portion between each pressing portion 12 and the wafer W and the contact surface between the end face pressing portion 27 and the wafer W. FIG.

Next, the slicing table 7 on which the pressing jig Z was installed was removed from the wire saw device M, transported by a lifter, and immersed in the peeling tank T. As shown in FIG. The stripping tank T was filled with stripping liquid LQ heated to a high temperature, and the adhesive 9 was stripped using this stripping liquid LQ. After that, as shown in FIG. 9A, the upper holding part 12a of the holding jig Z on the side opposite to the surface where the single crystal C and the pedestal 8 are bonded is removed in the peeling tank T, and the wafers W are separated one by one. It was removed and stored in a wafer W carrier case. During this time, no problem such as the tilting of the wafer W occurred.

[Example 2]
The same test as in Example 1 was performed except that the single crystal C having a size of LT of φ100 mm and a length of 250 mm, the thickness of the wafer W was 0.28 mm, and the pitch between the wafers W was 0.42 mm.

As a result, the wafers W formed by cutting could be fixed by the pressing jig Z, and in the peeling operation, the wafers W could be removed one by one and recovered without causing any problems.

[Example 3]
A test was conducted in the same manner as in Example 2, except that the single crystal C was a glass column having a size of φ250 mm and a length of 50 mm.

As a result, the wafers W formed by cutting could be fixed by the pressing jig Z, and in the peeling operation, the wafers W could be removed one by one and recovered without causing any problems.

It should be noted that the technical scope of the present invention is not limited to the aspects described in the above embodiments and the like. One or more of the requirements described in the above embodiments and the like may be omitted. Also, the requirements described in the above-described embodiments and the like can be combined as appropriate. In addition, as long as it is permitted by laws and regulations, the disclosure of all the documents cited in the above-described embodiments and the like is used as part of the description of the text.

C... Single crystal W... Wafer Z... Holding jig M... Wire saw device Sc... Circumferential surface (single crystal C, wafer W)
AX1... Central axis (single crystal, wafer)
AX2...Rotating axis (upper arm)
AX3...Rotating axis (lower arm)
AX4... Rotating shaft (holding part)
PL1... Horizontal plane PL2... Vertical plane 3... Wire 4... Wire row 6... Slicing table holder 7... Slicing table 8... Pedestal 9... Adhesive R1 to R3... Rotary roller 12... Pressing part 12a... Upper pressing part 12b... Lower pressing part Part 14... Attachment member (attachment)
Reference Signs List 15 Support column 15L Lower member 15U Upper member 17 Arm 17a Upper arm 17b Lower arm 19 Contact portion 20 Guide member 22 Movable mechanism 23 First adjusting portion 24 Second adjusting portion 26 Strut base 27...End face pressing part G1...Guide (arm)
G2... Guide (first adjustment unit)
G3... Guide (second adjustment unit)
T1...Fixing member (mounting member)
T2: Fixed member (arm)
T3... Fixed member (first adjustment unit)
T4...Fixing member (strut)
T5... Fixed member (second adjustment unit)
T... stripping tank LQ... stripping solution

Claims (6)

A plurality of wafers formed by cutting a cylindrical single crystal fixed to a pedestal, and holding a part of the circumferential surface of each of the plurality of wafers arranged at intervals to fix the relative positions of the plurality of wafers. A holding jig comprising a holding portion,
The pressing portion is arranged vertically symmetrical with respect to a horizontal plane passing through the central axis of the single crystal fixed to the pedestal, and a vertical plane passing through the central axis of the single crystal fixed to the pedestal. A holding jig, wherein the position of the holding part is movable so as to be arranged symmetrically with respect to the wafer, and holds a part of the circumferential surface of the wafer. The pressing portion is movable in an arc around an axis parallel to the central axis of the single crystal fixed to the pedestal,
2. The pressing jig according to claim 1, wherein the length of said pressing portion is equal to or greater than the length of said pedestal in the central axis direction of said single crystal. It comprises a first adjuster for changing a vertical position of the pressing part relative to the base, and a second adjusting part for changing a lateral position of the pressing part relative to the base. Item 3. The holding jig according to any one of items 2 . The pressing jig according to any one of claims 1 to 3 , wherein a portion of the pressing portion that contacts the circumferential surface of the wafer is an elastic body. 5. The pressing part is a rotating body whose part in contact with the circumferential surface of the wafer is rotatable about an axis parallel to the central axis of the single crystal fixed to the pedestal . The holding jig according to any one of . A method for manufacturing a wafer by cutting a cylindrical single crystal,
bonding a portion of the circumferential surface of the single crystal to a pedestal with an adhesive;
cutting the single crystal bonded to the pedestal with a cutting device to form a plurality of the wafers bonded to the pedestal and arranged at intervals;
Fixing relative positions between the plurality of wafers by the pressing jig according to any one of claims 1 to 5 ;
and peeling off the plurality of wafers adhered to the pedestal from the pedestal.

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