Method for manufacturing polishing pad

Abstract

To provide a manufacturing method by which a polishing pad with an end point detection window can be manufactured more easily.SOLUTION: A manufacturing method of a polishing pad having a polishing layer with an end point detection window includes: a curing process of fixing an end point detection window member 10 in a die 20, curing curable resin 30 in a contact state with the end point detection window member 10, and forming a resin sheet with the end point detection window member 10 incorporated; and a slicing process of slicing the resin sheet and forming the polishing layer. In the curing process, the end point detection window member 10 is suspended and fixed by a position fixing tool 21 arranged above the die 20.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a polishing pad. [Background technology]

[0002] In semiconductor manufacturing processes, chemical mechanical polishing (CMP) is used for planarization after insulating film deposition and for forming metal wiring. One of the important technologies required for chemical mechanical polishing is polishing endpoint detection, which detects whether the polishing process is complete. For example, over-polishing or under-polishing relative to the target polishing endpoint directly leads to product defects. Therefore, in chemical mechanical polishing, the amount of polishing must be strictly controlled by polishing endpoint detection.

[0003] Chemical mechanical polishing is a complex process, and the polishing speed (polishing rate) varies depending on the operating conditions of the polishing equipment, the quality of consumables (slurry, polishing pads, dressers, etc.), and variations in conditions over time during the polishing process. Furthermore, in recent years, the precision of remaining film thickness and in-plane uniformity required in semiconductor manufacturing processes have become increasingly strict. For these reasons, detecting the polishing endpoint with sufficient precision has become more difficult.

[0004] The main methods for detecting the polishing endpoint include the optical endpoint detection method, the torque endpoint detection method, and the eddy current endpoint detection method. In the optical endpoint detection method, the endpoint is detected by irradiating the wafer with light through a transparent window member provided on the polishing pad and monitoring the reflected light.

[0005] As an example of a method for manufacturing a polishing pad using such an optical endpoint detection method, Patent Document 1 discloses a method for manufacturing a polishing pad in which a liner is provided on the bottom surface of a mold to fix a window block, and then a curable material is filled into the mold and cured. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-197597 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the method of fixing the window block at the bottom of the mold as in Patent Document 1, if the liner deforms due to heat during curing, the window block cannot be fixed perpendicularly to the mold, which is a problem. Also, because the window block is fixed directly to the liner, it is difficult to reuse, which raises manufacturing costs.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a manufacturing method that can more easily manufacture a polishing pad having an end-point detection window. [Means for solving the problem]

[0009] That is, the present invention is as follows. [1] A method for manufacturing a polishing pad having a polishing layer with an endpoint detection window, comprising: a curing step of fixing an end point detection window member in a mold and curing the curable resin in contact with the end point detection window member to form a resin sheet incorporating the end point detection window member; a slicing step of slicing the resin sheet to form an abrasive layer, In the curing step, the end point detection window member is suspended and fixed by a position fixing jig installed on the upper part of the mold. A method for manufacturing a polishing pad. [2] In the curing step, after filling the mold with a curable resin, the end-point detection window member is brought into contact with the curable resin to cure the curable resin. A method for manufacturing the polishing pad described in [1]. [3] In the curing step, the end point detection window member is fixed in the mold, and then a curable resin is filled in the mold and cured. A method for manufacturing the polishing pad described in [1]. [4] The end point detection window member has a columnar portion that serves as the end point detection window, and a base portion for fixing the end point detection window member to the position fixing jig. A method for producing the polishing pad according to any one of [1] to [3]. [5] The position fixing jig has a first fitting portion that fits with the upper part of the mold. A method for producing the polishing pad according to any one of [1] to [4]. [6] The mold has a second fitting portion that fits with the position fixing jig. A method for producing a polishing pad according to any one of [1] to [5]. [7] The position fixing jig has a positioning portion that positions and fixes the end point detection window member. A method for producing a polishing pad according to any one of [1] to [6]. [8] a groove forming step of forming grooves on the polishing surface of the polishing layer, No groove processing is performed on the exposed portion of the end point detection window member before the groove forming step. A method for producing the polishing pad according to any one of [1] to [7]. [9] a lamination step of laminating a base layer and / or a cushion layer on the surface of the polishing layer opposite to the polishing surface, A method for producing a polishing pad according to any one of [1] to [8]. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a manufacturing method that can more easily manufacture a polishing pad having an end point detection window. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view showing one aspect of a member for an end-point detection window according to the present embodiment. [Figure 2]FIG. 2 is a top view showing one embodiment of a mold for producing a resin sheet used in the present embodiment. [Figure 3] 3 is a cross-sectional view showing the AA' cross section of the mold shown in FIG. 2 before the hardening resin is poured into the mold. FIG. [Figure 4] 3 is a cross-sectional view showing the AA' cross section of the mold shown in FIG. 2 after a curable resin has been poured into it. FIG. [Figure 5] FIG. 3 is a top view showing the resin sheet obtained after the curing process. [Figure 6] 10 is a cross-sectional view of the resin sheet obtained after the curing process, near the end point detection window. FIG. [Figure 7] 1 is a schematic perspective view of a polishing pad according to an embodiment of the present invention. [Figure 8] 3 is a schematic cross-sectional view of an end point detection window portion of the polishing pad of the present embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as necessary, but the present invention is not limited to this, and various modifications are possible without departing from the spirit of the present invention. In the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0013] 1. Manufacturing method of polishing pad The method for manufacturing a polishing pad of this embodiment includes a curing process in which an end point detection window member is fixed in a mold and a curable resin is cured while in contact with the end point detection window member to form a resin sheet incorporating the end point detection window member, and a slicing process in which the resin sheet is sliced ​​to form a polishing layer.In the curing process, the end point detection window member is hung and fixed by a position fixing jig installed on the top of the mold, thereby manufacturing a polishing pad having a polishing layer with an end point detection window.

[0014] In this way, by suspending and fixing the end point detection window member by a position fixing jig installed above the mold, even if the contact portion between the end point detection window member and the position fixing jig is molded to be wide, the resin sheet can be molded without that portion coming into contact with the curable resin. Therefore, there is no need to remove unnecessary portions from the obtained resin sheet. Furthermore, because the end point detection window member is attached to the position fixing jig rather than the mold, there is no need to process the mold itself, and conventional molds can be used as is. Furthermore, the position fixing jig can be used multiple times, so it does not need to be disposable like a liner.

[0015] Furthermore, by hanging and fixing the component for the end point detection window using a position fixing jig installed on the top of the mold, the embedding position of the component for the end point detection window can be fine-tuned until the curable resin hardens, and such fine adjustments can also improve product yield.

[0016] 1.1.Curing process The curing process is a process in which a component for an end point detection window is fixed in a mold, and the curable resin is cured while in contact with the component for an end point detection window to form a resin sheet incorporating the component for an end point detection window.

[0017] 1.1.1.End-point detection window component First, prior to the curing step, an endpoint detection window member 10 is prepared. As shown in FIG. 1, the endpoint detection window member 10 can have, for example, a pillar portion 11 and a base portion 12. Here, after the curing step, the pillar portion 11 is embedded in a resin sheet 40 to form an endpoint detection window 41. The base portion 12 serves as a part for fixing the endpoint detection window member 10 to a position fixing jig 21.

[0018] By forming the end point detection window member 10 in this shape with the pillar-shaped portion 11 and the base portion 12, the pillar-shaped portion 11 can be made relatively small within the range required for the end point detection window, while the base portion 12 ensures close contact with the position fixing jig 21. This tends to prevent the end point detection window member 10 from being displaced or tilted due to the resin injected during the curing process or the resin being cured. Furthermore, because the pillar-shaped portion 11 can be made relatively small within the range required for the end point detection window, the impact of embedding the end point detection window on the polishing characteristics of the polishing pad can be further reduced.

[0019] The shape of the end-point detection window member 10 is not limited to that shown in FIG. 1, and it may have only the columnar portion 11.

[0020] The endpoint detection window member 10 can be produced, for example, by injecting resin into a mold (not shown) and hardening it, without any particular limitation. After the endpoint detection window member 10 is removed from the mold, the side surfaces of the columnar portions 11 are preferably treated with sandpaper or a solvent. This makes it possible to remove any release agent adhering to the endpoint detection window member 10. Furthermore, by roughening the side surfaces with sandpaper, when the endpoint detection window member 10 is embedded in the resin sheet 40, the adhesion between the resin sheet 40 and the endpoint detection window member 10 (endpoint detection window 41) tends to be improved.

[0021] 1.1.2. Positioning fixture In the curing process, the endpoint detection window member 10 is suspended and fixed by a position fixing jig 21 installed on the top of the mold 20. Fig. 2 shows a top view of the mold 20 for producing a resin sheet. In Fig. 2, the position fixing jig 21 is installed on the top of the mold 20, and the endpoint detection window member 10 is fixed facing vertically downward from the position fixing jig 21. Note that, because Fig. 2 is a top view of the mold 20, the fixing location of the endpoint detection window member 10 is indicated by a dashed line.

[0022] FIG. 3 is shown to explain in more detail the positional relationship between the mold 20, the position fixing jig 21, and the endpoint detection window member 10. FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 2 before the curable resin is poured into the mold 20. As can be seen from FIGS. 2 and 3, the mold 20 is a flat mold for forming a resin sheet, and the position fixing jig 21 is fixed in contact with the side wall 22 of the mold 20 so as to cover the recessed portion of the mold 20.

[0023] The location of the position fixing jig 21 that comes into contact with the mold 20 may have an uneven shape (first fitting portion) that can fit with the upper part of the mold 20. Furthermore, the location of the mold 20 that comes into contact with the position fixing jig 21 may also have an uneven shape (second fitting portion) that can fit with the position fixing jig 21. This makes it easier to position the position fixing jig 21 when installing it on the mold 20, and tends to prevent the embedded position of the endpoint detection window member 10 from shifting during each curing process.

[0024] Furthermore, the end point detection window member 10 is suspended and fixed below the position fixing jig 21, with the columnar portion 11 facing vertically downward. In this case, the end point detection window member 10 may be fixed to the position fixing jig 21 by the pedestal portion 12. Any adhesive, double-sided tape, or the like can be used for this fixation.

[0025] Furthermore, the position fixing jig 21 may have a positioning portion that positions and fixes the end point detection window member 10. Here, the positioning portion can have an uneven shape that is formed at a location where the position fixing jig 21 and the pedestal portion 12 come into contact with each other and allows the position fixing jig 21 and the pedestal portion 12 to fit together. This tends to prevent the embedded position of the end point detection window member 10 from shifting during each curing process.

[0026] Furthermore, by hanging the end point detection window member 10 from the position fixing jig 21, it is easier to change the number and positions of the end point detection window member 10 compared to, for example, fixing the end point detection window member 10 to the bottom surface of the mold 20. Furthermore, there is no need to make any changes to the mold 20 itself in order to fix the end point detection window member 10, and a conventional mold 20 can be used as is.

[0027] 1.1.3.Curing resin In the curing step, the endpoint detection window member 10 is fixed in the mold 20 as described above, and the curable resin 30 is cured while in contact with the endpoint detection window member 10 to form a resin sheet 40 incorporating the endpoint detection window member 10 (endpoint detection window 41). Figure 4 shows a cross-sectional view taken along line A-A' in Figure 2 after the curable resin has been injected into the mold 20.

[0028] In this embodiment, there are no particular limitations on the manner in which the curable resin 30 is cured while in contact with the end point detection window member 10. As shown in Figure 3, the end point detection window member 10 may be fixed to the mold 20, and then the mold 20 may be filled with the curable resin 30 and the curable resin 30 may be cured. Alternatively, the mold 20 may be filled with the curable resin 30, and then the position fixing jig 21 to which the end point detection window member 10 is fixed may be fixed to the mold 20, and then the curable resin 30 may be cured.

[0029] In addition, although only the columnar portion 11 is in contact with the hardening resin 30 in FIG. 4, the base portion 12 may also be in contact with the hardening resin 30.

[0030] The curable resin is not particularly limited, but examples thereof include polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins. These may be used alone or in combination of two or more. Such polyurethane resins can be synthesized from polyisocyanate and polyol.

[0031] 1.2.Slicing process The slicing step is a step of slicing the resin sheet to form a polishing layer. Figures 5 and 6 show a top view and a cross-sectional view of the resin sheet 40 obtained after the curing step, by removing it from the mold 20 and removing the base portion 12. As shown in Figures 5 and 6, the resin sheet has an endpoint detection window member embedded therein.

[0032] The slicing method is not particularly limited, but an example is a method in which a resin sheet as shown in Figures 5 and 6 is cut in the surface direction to obtain a polishing pad of any thickness. Also, a rectangular polishing pad as shown in Figure 5 may be cut into a circular shape.

[0033] 1.3.Groove formation process The method for manufacturing a polishing pad of this embodiment may optionally include a groove forming step of forming grooves on the polishing surface of the polishing layer (see FIG. 8). Note that it is preferable not to perform groove processing on the exposed portion of the end-point detection window member, as this would interfere with optical end-point detection.

[0034] 1.4.Other processes The method for producing a polishing pad of this embodiment may optionally include a lamination step of laminating a base layer and / or a cushion layer on the surface of the polishing layer opposite the polishing surface.

[0035] Fig. 7 shows a schematic perspective view of the polishing pad of this embodiment, and Fig. 8 shows a cross-sectional view of the periphery of the endpoint detection window 41 in Fig. 7. As shown in Fig. 7, the polishing pad of this embodiment has a resin sheet 40 (polishing layer) and an endpoint detection window 41, and may have a cushion layer 42 on the side opposite to the polishing surface 40a, as necessary.

[0036] 8, an adhesive layer 43 may be provided between the resin sheet 40 (polishing layer) and the cushion layer 42, and an adhesive layer 44 may be provided on the surface of the cushion layer 42. The polishing surface 40a of the polishing pad of this embodiment may be flat, or may be uneven with grooves 45 formed therein, as shown in FIG. [Industrial Applicability]

[0037] The method for producing a polishing pad of the present invention has industrial applicability as an efficient method for producing a polishing pad suitable for an optical endpoint detection method. [Explanation of symbols]

[0038] 10...End point detection window member, 11...Columnar portion, 12...Pedestal portion, 20...Mold, 21...Position fixing jig, 22...Side wall, 30...Hardening resin, 40...Resin sheet, 40a...Polished surface, 41...End point detection window, 42...Cushion layer, 43...Adhesive layer, 44...Adhesive layer, 45...Groove

Claims

1. A method for manufacturing a polishing pad having a polishing layer with an endpoint detection window, comprising: a curing step of fixing an end point detection window member in a mold and curing the curable resin in contact with the end point detection window member to form a resin sheet incorporating the end point detection window member; A slicing step of slicing the resin sheet to form an abrasive layer, In the curing step, the end point detection window member is suspended and fixed by a position fixing jig installed on the upper part of the mold, the end point detection window member has a columnar portion that becomes an end point detection window, and a base portion for fixing the end point detection window member to the position fixing jig, In the slicing step, the pedestal portion is removed. A method for manufacturing a polishing pad.

2. In the curing step, a curable resin is filled into the mold, and then the end point detection window member is brought into contact with the curable resin to cure the curable resin. A method for producing the polishing pad according to claim 1 .

3. In the curing step, the end point detection window member is fixed in the mold, and then a curable resin is filled in the mold and cured. A method for producing the polishing pad according to claim 1 .

4. The position fixing jig has a first fitting portion that fits with the upper part of the mold. The method for producing a polishing pad according to any one of claims 1 to 3.

5. The mold has a second fitting portion that fits with the position fixing jig. The method for producing the polishing pad according to any one of claims 1 to 4.

6. The position fixing jig has a positioning portion that positions and fixes the end point detection window member. The method for producing a polishing pad according to any one of claims 1 to 5.

7. A groove forming step of forming grooves on the polishing surface of the polishing layer, No groove processing is performed on the exposed portion of the end point detection window member prior to the groove forming step. The method for producing the polishing pad according to any one of claims 1 to 6.

8. A lamination step of laminating a base layer and / or a cushion layer on the surface of the polishing layer opposite to the polishing surface, The method for producing the polishing pad according to any one of claims 1 to 7.

Images