Fixture jig of polishing pad and attaching method of polishing pad

Abstract

To accurately attach a polishing pad on a polishing machine platen so that the center of the polishing pad may coincide with that of the polishing machine platen.SOLUTION: A flat tabular insertion member 22 constituting an attachment jig 21 is placed on the attachment surface 4a of a polishing machine platen 4 having a circular form to bring a platen side engaging projection 24 provided on the underside of the insertion member 22 into contact along the outer peripheral surface 4b of the polishing machine platen 4 (a). When a polishing pad 3 having a disk form is to be placed on the polishing machine platen 4, the insertion member 22 is interposed between the polishing pad 3 and the polishing machine platen 4, and further the outer peripheral edge 3b of the polishing pad 3 is brought into contact along a pad side engaging projection 23 provided on the top face of the insertion member 22 (b). When a part of release paper is removed from an adhesion layer of the polishing pad 3 to make an exposed adhesion layer adhere to the attachment surface 4a (c), the attachment jig 21 is removed as well as all of the release paper 14 to make the whole of the adhesion layer of the polishing pad 3 adhere to the attachment surface (d).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a mounting jig for a polishing pad and a method for mounting a polishing pad, and more particularly to a mounting jig and a method for mounting a disc-shaped polishing pad having an adhesive layer formed on its back surface to a polishing platen having a circular mounting surface formed on its upper surface. [Background technology]

[0002] Conventionally, a known polishing device for polishing a workpiece such as a semiconductor wafer includes a holding platen arranged above to hold the workpiece, and a polishing platen arranged below to hold a polishing pad, and rotates the holding platen and polishing platen to bring the workpiece and the polishing pad into sliding contact with each other to polish the workpiece (Patent Document 1). When polishing an object using the polishing device, a slurry containing chemical components is supplied between the object and the polishing pad, and chemical mechanical polishing is performed by the relative movement between the object and the polishing pad and the chemical components of the slurry. The polishing pad is generally disc-shaped and is attached to a cylindrical polishing table with a circular mounting surface on the top surface. An adhesive layer is formed on the back surface of the polishing pad, and after removing the release paper from the adhesive layer, the adhesive layer is attached to the mounting surface of the polishing table (Patent Document 2). It is known that by forming grooves in a predetermined pattern on the polishing surface of the polishing pad, slurry can be supplied and discharged between the workpiece and the polishing pad, which is expected to improve the required polishing accuracy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-8577 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-90106 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, as a result of research conducted by the applicant, it has been found that when polishing is performed using a disc-shaped polishing pad having grooves formed on the polishing surface, higher polishing accuracy can be achieved if the center of the polishing pad coincides with the center of rotation of the polishing table. In cited document 2, the polishing pad is positioned using positioning marks or the like, but because these operations are performed by the worker relying on visual inspection and tactile sense, slight positional deviations may occur, which not only prevents the desired polishing performance from being obtained, but also increases the risk of variations in polishing results each time the polishing pad is attached to the polishing platen. In view of these problems, the present invention provides a polishing pad mounting jig and a polishing pad mounting method that can accurately mount a polishing pad on a polishing table, thereby fully utilizing the performance of the polishing pad. [Means for solving the problem]

[0005] That is, the polishing pad mounting jig according to the invention of claim 1 is a polishing pad mounting jig for mounting a disc-shaped polishing pad on a cylindrical polishing surface plate having a circular mounting surface formed on the upper surface thereof, It is characterized by comprising a flat insert member that is placed on the mounting surface of the polishing table and is interposed between the polishing table and the polishing pad, a table-side engaging protrusion provided on the underside of the insert member that abuts along the outer peripheral surface of the polishing table, and a pad-side engaging protrusion provided on the upper surface of the insert member that abuts along the outer peripheral edge of the polishing pad. A method for attaching a polishing pad according to the invention of claim 6 is a method for attaching a disc-shaped polishing pad having an adhesive layer formed on the back surface to a polishing table having a circular attachment surface on the upper surface, the method comprising removing a release paper from the adhesive layer while attaching the polishing pad to the polishing table, a flat insert member is placed on the mounting surface of the polishing table, and a platen-side engaging protrusion provided on the lower surface of the insert member is brought into contact with the outer peripheral surface of the polishing table; When the polishing pad is placed on the mounting surface of the polishing table, the inserting member is interposed between the polishing pad and the polishing table, and the outer peripheral edge of the polishing pad is brought into contact with the pad-side engaging protrusion provided on the upper surface of the inserting member, removing the release paper from the adhesive layer of the polishing pad in the area where the insert member is not interposed, and adhering the exposed adhesive layer to the mounting surface; The insert member is removed from between the polishing platen and the polishing pad, and all the release paper is removed from the adhesive layer, so that the entire adhesive layer of the polishing pad is adhered to the mounting surface. [Effects of the Invention]

[0006] According to the polishing pad mounting jig of the invention of claim 1, by placing a flat insertion member on the polishing table and abutting the table-side engaging protrusion along the outer peripheral surface of the polishing table, the outer edge of the polishing pad can be abutted against the pad-side engaging protrusion provided on the upper surface of the insertion member, thereby accurately aligning the center of the polishing pad with the rotation center of the polishing table without the need for visual adjustment, etc. Furthermore, according to the method for attaching a polishing pad of the invention of claim 6, if the platen side engaging protrusion provided on the lower surface of the insertion member is abutted along the outer peripheral surface of the polishing platen, then the outer edge of the polishing pad can be abutted along the pad side engaging protrusion provided on the upper surface of the insertion member, and the center of the polishing pad can be accurately aligned with the center of rotation of the polishing platen without the need for visual adjustment, etc. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a polishing apparatus equipped with a polishing pad; [Figure 2] Cross-sectional view of a polishing pad and a polishing platen [Figure 3] 1 is a perspective view of an attachment jig according to an embodiment of the present invention; [Figure 4] Cross-sectional view explaining the mounting jig [Figure 5] Diagram explaining how to attach the polishing pad [Figure 6] FIG. 10 is a plan view of a mounting jig according to a second embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0008] The illustrated embodiment will now be described. FIG. 1 shows a polishing apparatus 1, which polishes an object 2 to be polished with a polishing pad 3. As shown in FIG. The polishing apparatus 1 includes a polishing platen 4 located on the lower side with a polishing pad 3 attached to its upper surface, a holding platen 5 located on the upper side with an object to be polished 2 held on its lower surface, and a slurry supply means 6 for supplying a slurry S (polishing liquid) between the object to be polished 2 and the polishing pad 3. The object 2 to be polished by the polishing device 1 is an optical material, a silicon wafer, a glass substrate, a semiconductor substrate, or a plate-like object such as glass, metal, or ceramic. As the slurry S supplied by the slurry supply means 6, any suitable conventionally known material can be used depending on the object 2 to be polished and the required polishing accuracy.

[0009] The polishing platen 4 has a cylindrical shape, and a flat mounting surface 4a for mounting the polishing pad 3 on its upper surface is formed, and the platen 4 is rotated by a drive mechanism (not shown). The holding platen 5 also has a cylindrical shape, and the workpiece 2 is held on the underside of the holding platen 5 via a holder not shown, and is rotated by a drive mechanism not shown and can be raised and lowered by a lifting means. With this configuration, when polishing the workpiece 2, the holding platen 5 presses the workpiece 2 against the polishing pad 3 at a set pressure, and in this state the polishing platen 4 and the holding platen 5 are rotated relative to each other, while the slurry supply means 6 supplies slurry S between the workpiece 2 and the polishing pad 3.

[0010] The polishing pad 3 has a disk shape and its diameter is the same as that of the polishing platen 4. As shown in Fig. 2, the polishing pad 3 is composed of a polishing layer 11 having a polishing surface 3a formed on the side of the workpiece 2, and a support layer 12 (cushion layer) located on the side of the polishing platen 4. The polishing layer 11 and the support layer 12 are bonded together by an adhesive or double-sided tape (not shown), and an adhesive layer 13 made of double-sided tape is formed on the underside of the support layer 12 for attachment to the polishing platen 4. Furthermore, concentric grooves 11a are formed on the polishing surface 3a of the polishing pad 3 so as to surround the center (center of rotation) of the polishing pad 3 at equal pitches or at pitches that vary by a certain width in the radial direction. These grooves 11a supply and discharge the slurry S, and the slurry S discharged from the slurry supply means 6 flows into these grooves 11a and is supplied to the entire polishing surface 3a. The grooves formed on the polishing surface 3a are not limited to concentric grooves, and may be lattice-shaped, radial, or have various other patterns as described in Patent Document 1. However, in this embodiment, a greater effect can be obtained if the pattern of the grooves 11a is based on the center of the polishing pad 3.

[0011] Here, it has been found that if the pattern of grooves 11a formed on the polishing surface 3a of the polishing pad 3 is formed based on the center of the polishing pad 3, higher polishing accuracy can be obtained by aligning the center of the polishing pad 3 with the center of rotation of the polishing platen 4 when attaching the polishing pad 3 to the polishing platen 4. For example, it was found that even a 1 mm deviation of the center of the polishing pad 3 from the center of the polishing platen 4 would affect the polishing results. In other words, even if there was no problem with the polishing pad 3 itself, there was a risk that the polishing performance would change depending on the mounting position of the polishing pad 3. Therefore, the present invention provides a mounting jig 21 for a polishing pad 3 that can easily align the center of the polishing table 4 with the center of the polishing pad 3, and a method for mounting the polishing pad 3.

[0012] Figures 3 to 5 are diagrams explaining the above-mentioned mounting jig 21, with Figure 3 being an oblique view of the mounting jig 21, Figure 4 being a cross-sectional view explaining the mounting jig 21, and Figure 5 being a diagram explaining a method of mounting a polishing pad 3 using the mounting jig 21. The mounting jig 21 is composed of a flat insert member 22 having an approximately fan shape, a base plate-side engaging protrusion 24 having an arc shape provided along the outer edge of the insert member 22 and on the underside of the insert member 22, and a pad-side engaging protrusion 23 having an arc shape provided on the upper surface of the insert member 22. The material of the insert member 22 is not particularly limited, but various materials can be used, such as bakelite, paper-epoxy, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, polyamide, acrylic resin, norbornene resin, cycloolefin resin, glass epoxy resin, etc., and it is made of a hard resin such as acrylic with a thickness of about 2 mm, for example. The platen side engaging projections 24 and pad side engaging projections 23 may be molded integrally with the insert member 22, or may be attached by means of adhesive or the like. The angle of the sector of the insert member 22 is arbitrary, but is preferably in the range of about 180° to 90°. If it exceeds 180°, the operation of attaching the polishing pad 3 becomes complicated, and if it is less than 90°, the accuracy of positioning the polishing pad 3 may decrease. It should be noted that the insert member 22 does not need to be arranged to cover the center of the polishing table 4, and the inner peripheral edge of the insert member 22 may be formed, for example, by a concentric arc located a predetermined distance inside the outer peripheral surface of the polishing table 4. Furthermore, on the underside of the insert member 22, weak adhesive double-sided tape 25 having low adhesive strength is provided at predetermined intervals as anti-slip means for preventing slippage between the insert member 22 and the polishing surface plate 4. As the anti-slip means, instead of the weak adhesive double-sided tape 25, it is possible to use a weak adhesive such as a weak adhesive, adhesive tape, sticky tape, rubber sheet, etc., which has low adhesive strength and does not leave marks on the surface plate but does not slip when in close contact. By providing the above-mentioned anti-slip means, it becomes difficult for the insertion member 22 to become misaligned with the polishing platen 4, further reducing the decrease in the accuracy of the positioning of the polishing pad 3. This allows the center of the polishing pad 3 to be accurately aligned with the center of rotation of the polishing platen 4, thereby fully utilizing the polishing performance of the polishing pad 3.

[0013] As shown in Figure 4, the insertion member 22 is placed on the mounting surface 4a of the polishing table 4, and when the polishing pad 3 is placed on the polishing table 4, it is interposed between the polishing table 4 and the polishing pad 3. The outer edge of the insertion member 22 protrudes slightly outward from between the polishing platen 4 and the polishing pad 3, and the platen-side engaging protrusion 24 and the pad-side engaging protrusion 23 are formed above and below this protruding portion. The outer edge of the insert member 22 may protrude further outward than the platen side engaging projection 24 and the pad side engaging projection 23, and this protrusion may be used as a handle for the worker to grip during work.

[0014] In this embodiment, the platen side engagement protrusion 24 is an arc-shaped protrusion with an abutment surface 24a formed on its inner circumference, the abutment surface 24a having the same diameter as the outer peripheral surface of the polishing platen 4, and the abutment surface 24a is formed perpendicular to the insertion member 22. With this configuration, the entire abutment surface 24a of the platen side engagement protrusion 24 can be closely fitted to the outer peripheral surface 4b of the polishing platen 4, and when the abutment surface 24a is closely fitted to the outer peripheral surface 4b of the polishing platen 4, the center of the arc formed by the abutment surface 24 coincides with the center of the polishing platen 4. Similarly, the pad side engagement protrusion 23 is an arc-shaped protrusion with an abutment surface 23a formed on its inner circumference, the abutment surface 23a having the same diameter as the outer peripheral edge of the polishing pad 3, and the abutment surface 23a is also formed perpendicular to the insertion member 22. With this configuration, when the entire contact surface 23a is in close contact with the outer peripheral edge 3b of the polishing pad 3, the center of the arc formed by the contact surface 23a coincides with the center of the polishing pad 3. That is, in this embodiment, the center of the arc constituting the contact surface 24a of the platen-side engaging projection 24 and the center of the arc constituting the contact surface 23a of the pad-side engaging projection 23 are aligned.

[0015] Hereinafter, a method for attaching the polishing pad 3 to the polishing platen 4 using the above-mentioned attachment jig 21 will be described with reference to FIG. FIG. 5( a ) shows the process of setting the attachment jig 21 on the polishing platen 4 . First, the mounting jig 21 is placed on the mounting surface 4 a of the polishing surface plate 4 using the weak adhesive double-sided tape 25 provided on the lower surface of the insertion member 22 of the mounting jig 21 . At this time, the insert member 22 is placed on the attachment surface 4 a so that the entire abutment surface 24 a of the platen-side engagement projection 24 of the attachment jig 21 abuts against the outer peripheral surface 4 b of the polishing platen 4 . By performing this operation, the center of the polishing platen 4 and the center of the arc formed by the contact surface 24a of the platen-side engaging projection 24 are aligned.

[0016] FIG. 5(b) shows the operation of positioning the polishing pad 3 using the mounting jig 21. The worker places the polishing pad 3 on the polishing platen 4. As a result, the insert member 22 is interposed between the polishing pad 3 and the polishing platen 4. At this time, the release paper 14 is not removed from the adhesive layer 13 of the polishing pad 3, and by moving the polishing pad 3 above the polishing table 4 and the insertion member 22, the outer peripheral edge 3b is brought into contact with the entire abutment surface 23a of the pad side engagement protrusion 23. At this time, the attachment jig 21 is positioned relative to the polishing platen 4 by the weak adhesive double-sided tape 25, so that the attachment jig 21 does not move even if the polishing pad 3 is moved. By performing this operation, the center of the arc formed by the contact surface 23 a of the pad-side engaging projection 23 and the center of the outer circumferential edge 3 b of the polishing pad 3 are aligned. As a result, the center of the polishing pad positioned by the mounting jig 21 coincides with the center of the polishing platen 4 .

[0017] FIG. 5( c ) shows the process of fixing a part of the polishing pad 3 to the polishing platen 4 . While keeping the outer peripheral edge 3b of the polishing pad 3 in contact with the contact surface 23a of the pad side engagement protrusion 23, the worker removes a portion of the release paper 14 from the adhesive layer 13 of the polishing pad 3, and adheres the exposed adhesive layer 13 to the mounting surface 4a. At this time, it is desirable that the release paper 14 to be peeled off is the portion where the mounting jig 21 is not located, and is the portion facing the portion where the mounting jig 21 is located. It is also desirable to remove as much of the release paper 14 as possible so that the polishing pad 3 does not shift when the entire polishing pad 3 is subsequently attached to the polishing platen 4 .

[0018] FIG. 5( d ) shows the process of attaching the entire polishing pad 3 to the polishing platen 4 . The worker first removes the mounting jig 21 from between the polishing platen 4 and the polishing pad 3, and then gradually removes all of the release paper 14 from the adhesive layer 13 of the polishing pad 3 while adhering the entire adhesive layer 13 of the polishing pad 3 to the mounting surface 4a, thereby completing the mounting of the polishing pad 3.

[0019] According to the method of attaching the polishing pad 3 to the polishing table 4 using the above-mentioned mounting jig 21, the mounting jig 21 is positioned on the polishing table 4 in advance, and then the polishing pad 3 is positioned using the mounting jig 21 in that state, thereby aligning the center of the polishing table 4 with the center of the polishing pad 3. In this case, the operator does not need to visually determine positioning, since the platen side engagement protrusion 24 is simply brought into contact with the outer peripheral surface 4b of the polishing platen 4 and the pad side engagement protrusion 23 is brought into contact with the outer peripheral edge 3b of the polishing pad 3. Furthermore, once positioned, by removing the release paper 14 from the adhesive layer 13 and adhering it to the mounting surface 4a, the polishing pad 3 can be attached to the polishing table 4 while the center of the polishing table 4 and the center of the polishing pad 3 are aligned, and as described above, the polishing pad 3 can be used to polish the workpiece 2 with high polishing precision.

[0020] FIG. 6 shows a plan view of the mounting jig 21 according to the second embodiment as viewed from the polishing platen 4 side. The insert member 22 has a fan shape similar to that of the first embodiment, and a plurality of platen-side engaging protrusions 24, each having a substantially square shape in plan view, are aligned along the outer periphery of the insert member 22. The inner end face of each platen side engaging protrusion 24 is the contact portion with the polishing platen 4, and is formed along an arc of the same diameter as the abutment surface 24a of the platen side engaging protrusion 24 having an arc shape in the first embodiment described above. Here, the method of forming the above protrusions is to form an arc-shaped protrusion as in the first embodiment, and then cut the arc-shaped protrusion or adhere multiple base plate side engagement protrusions 24 to it. In the mounting jig 21 having the above configuration, the inner peripheral end faces of the platen side engaging projections 24 are brought into contact with the polishing platen 4, so that the mounting jig 21 can be accurately positioned relative to the polishing platen 4. The shape of the platen side engagement protrusion 24 is not limited to the approximately square shape described above, but may be, for example, triangular or circular, and the contact portions of each protrusion and the polishing platen 4 may contact each other by point contact or line contact with the polishing platen 4 rather than by surface contact. Similarly to the platen-side engaging protrusions 24, the pad-side engaging protrusions 23 can also be configured by a plurality of protrusions formed along the outer periphery 3b of the polishing pad 3.

[0021] In addition, in the above embodiment, the outer diameter of the polishing pad 3 is the same as the outer diameter of the polishing table 4, and the table side engagement protrusion 24 and the pad side engagement protrusion 23 are formed in the same position, but there are cases where the outer diameter of the polishing pad 3 is different from the outer diameter of the polishing table 4. In this case, a pad side engagement protrusion 23 can be formed on the upper part of the insert member 22 along the outer peripheral edge 3b of the polishing pad 3, and if the polishing pad 3 has a larger diameter than the polishing table 4, the insert member 22 can be made larger to match the polishing pad 3, and a pad side engagement protrusion 24 can be provided on its upper surface. In addition, in order to attach multiple types of polishing pads 3 with different diameters, it is also possible to form steps on the upper surface of the insertion member 22 that increase in height as they approach the outer periphery, and use each step as the pad side engagement protrusion 23.

[0022] Furthermore, in the above embodiment, the polishing pad 3 is attached to the polishing platen 4 using one attachment jig 21, but attachment may be performed using a plurality of attachment jigs 21. [Explanation of symbols]

[0023] 1 Polishing device 2 Object to be polished 3 Polishing pad 3b Outer edge 4 Polishing plate 4a Mounting surface 4b Outer surface 11 Polishing layer 12 Support layer 13 Adhesive layer 14 Release paper 21 Mounting jig 22 Insertion member 23 Pad side engagement protrusion 24 Platen side engagement protrusion 25 Weak adhesive double-sided tape (anti-slip means)

Claims

1. A polishing pad mounting jig for mounting a disc-shaped polishing pad on a cylindrical polishing platen having a circular mounting surface formed on its upper surface, A polishing pad mounting jig comprising: a flat insert member that is placed on the mounting surface of the polishing platen and interposed between the polishing platen and the polishing pad; a platen-side engaging protrusion provided on the underside of the insert member that abuts along the outer peripheral surface of the polishing platen; and a pad-side engaging protrusion provided on the upper surface of the insert member that abuts along the outer peripheral edge of the polishing pad.

2. 2. The polishing pad mounting jig according to claim 1, wherein the insert member has a generally fan-like shape.

3. The polishing pad mounting jig described in claim 1, characterized in that the platen side engagement protrusion is an arc-shaped protrusion with an abutment surface on its inner circumference having the same diameter as the outer peripheral surface of the polishing platen, and the pad side engagement protrusion is an arc-shaped protrusion with an abutment surface on its inner circumference having the same diameter as the outer peripheral edge of the polishing pad.

4. The polishing pad mounting jig described in claim 1, characterized in that the platen side engagement protrusion is composed of a plurality of protrusions formed along the outer peripheral surface of the polishing platen, and the polishing pad side engagement protrusion is composed of a plurality of protrusions formed along the outer peripheral edge of the polishing pad.

5. 2. The polishing pad mounting jig according to claim 1, wherein an anti-slip means is provided on the lower surface of said inserting member to prevent slippage between said inserting member and said polishing surface plate.

6. A method for attaching a disc-shaped polishing pad having an adhesive layer formed on the back surface of a polishing platen having a circular attachment surface on the top surface thereof, the method comprising removing a release paper from the adhesive layer while attaching the pad to the polishing platen, a flat insert member is placed on the mounting surface of the polishing table, and a platen-side engaging protrusion provided on the lower surface of the insert member is brought into contact with the outer peripheral surface of the polishing table; When the polishing pad is placed on the mounting surface of the polishing table, the inserting member is interposed between the polishing pad and the polishing table, and the outer peripheral edge of the polishing pad is brought into contact with the pad-side engaging protrusion provided on the upper surface of the inserting member, removing the release paper from the adhesive layer of the polishing pad in the area where the insert member is not interposed, and adhering the exposed adhesive layer to the mounting surface; A method for attaching a polishing pad, comprising removing the insert member from between the polishing platen and the polishing pad, removing all release paper from the adhesive layer, and adhering the entire adhesive layer of the polishing pad to the attachment surface.

7. A method for attaching a polishing pad as described in claim 6, characterized in that when the flat insert member is placed on the mounting surface of the polishing table, an anti-slip means provided on the underside of the insert member is used to position the insert member so that it does not shift from the polishing table.

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