WO2022202059A1

WO2022202059A1 - Method for manufacturing polishing pad

Info

Publication number: WO2022202059A1
Application number: PCT/JP2022/007227
Authority: WO
Inventors: 佳秀川村; 光紀糸山; 仁志関谷; 哲平立野; 堅一小池; 大和 ▲高▼見沢
Original assignee: 富士紡ホールディングス株式会社
Priority date: 2021-03-24
Filing date: 2022-02-22
Publication date: 2022-09-29
Also published as: TW202245980A

Abstract

Provided is a method for manufacturing a polishing pad that comprises a polishing layer having an endpoint detection window, the method including: a curing step for fixing an endpoint detection window member inside of a die, and curing a curable resin that is in contact with the endpoint detection window member so as to form a resin sheet in which the endpoint detection window member is incorporated; and a slicing step for slicing the resin sheet so as to form the polishing layer. In the curing step, the endpoint detection window member is fixed so as to be suspended from a position fixation jig which is installed on top of the die.

Description

Polishing pad manufacturing method

The present invention relates to a method for manufacturing a polishing pad.

In the semiconductor manufacturing process, chemical mechanical polishing (CMP) is used in the process of flattening after insulating film deposition and forming metal wiring. One of the important techniques required for chemical mechanical polishing is polishing endpoint detection for detecting whether the polishing process has been completed. For example, over-polishing or under-polishing to the target polishing end point directly leads to product defects. Therefore, in chemical mechanical polishing, it is necessary to strictly control the polishing amount by detecting the polishing end point.

Chemical mechanical polishing is a complicated 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. Change. Furthermore, in recent years, the precision and in-plane uniformity of the residual film thickness required in the semiconductor manufacturing process have become more and more severe. Under these circumstances, it is becoming more difficult to detect the polishing end point with sufficient accuracy.

Known major polishing end point detection methods include the optical end point detection method, the torque end point detection method, and the eddy current end point detection method. The end point is detected by irradiating the wafer with light through and monitoring the reflected light.

Patent Documents 1 to 3, for example, are known as methods of manufacturing a polishing pad using such an optical end point detection system. Further, as a method for manufacturing a transparent endpoint detection window, for example, Patent Document 4 is known. Further, as a polishing pad using an optical endpoint detection system, for example, Patent Document 5 is known.

JP 2013-197597 A Japanese Patent Application Laid-Open No. 2013-219276 Japanese Patent Application Laid-Open No. 2001-291686 Japanese Patent Application Laid-Open No. 2004-260156 JP-A-2002-001647

However, in the method described in Patent Document 1, if the liner is deformed by heat during curing, a problem arises in that the window block cannot be vertically fixed to the mold. In addition, since the window block is directly fixed to the liner, it is difficult to reuse and the manufacturing cost is a problem. In addition, the method described in Patent Document 2 may damage the polishing layer and the endpoint detection window, which may lead to a reduction in the strength of the polishing pad and a reduction in optical properties required for endpoint detection. Furthermore, in the method described in Patent Document 3, the alignment notch exists at the edge of the polishing layer, and even if the size of the alignment notch is limited, there is a possibility that the polishing performance may be adversely affected. Further, in the method described in Patent Document 4, the obtained window member is inferior in film thickness evaluation performance unless the surface is smoothed by buffing or the like.

An object of one embodiment of the present invention is to provide a manufacturing method that can more easily manufacture a polishing pad having an endpoint detection window.

One embodiment of the invention is as follows.
[1]
A method for manufacturing a polishing pad comprising a polishing layer with an endpoint detection window, comprising:
a curing step of fixing an endpoint detection window member in a mold and curing a curable resin in a state of contact with the endpoint detection window member to form a resin sheet in which the endpoint detection window member is incorporated; ,
a slicing step of slicing the resin sheet to form a polishing layer;
In the curing step, the end point detection window member is suspended and fixed by a position fixing jig installed above the mold.
A method for manufacturing a polishing pad.
[2]
In the curing step, the mold is filled with a curable resin, and then the end point detection window member is brought into contact with the curable resin to cure the curable resin.
[1] The method for producing a polishing pad according to [1].
[3]
In the curing step, after fixing the end point detection window member in the mold, a curable resin is filled and cured.
[1] The method for producing a polishing pad according to [1].
[4]
The position fixing jig has a first fitting part that fits with the mold upper part, and/or
The mold has a second fitting portion that fits with the position fixing jig,
[1] A method for producing a polishing pad according to any one of [3].
[5]
The position fixing jig has a positioning portion that positions and fixes the end point detection window member,
[1] A method for producing a polishing pad according to any one of [4].
[6]
In the curing step, the end point detection window member is suspended and fixed by being clamped by the clamping part of the position fixing jig installed on the upper part of the mold,
The holding portion detachably holds the end point detection window member,
[1] A method for producing a polishing pad according to any one of [5].
[7]
In the curing step, the end point detection window member is suspended and fixed by being clamped by the clamping part of the position fixing jig installed on the upper part of the mold,
A lower end of the endpoint detection window member when suspended and fixed has a convex shape,
[1] A method for producing a polishing pad according to any one of [6].
[8]
The length L of the portion having the convex shape of the endpoint detection window member is 3.0 to 20 mm.
[7] The method for producing a polishing pad according to [7].
[9]
The ratio (L/S) of the length L of the convex portion of the endpoint detection window member to the horizontal cross-sectional area S of the endpoint detection window member is 0.002 to 0.4. be,
[7] or [8] The method for producing a polishing pad.
[10]
The length L of the portion having the convex shape of the end point detection window member is 0.03 to 0.30 Lw with respect to the total length Lw of the end point detection window member.
[7] A method for producing a polishing pad according to any one of [9].
[11]
further comprising a step of manufacturing the endpoint detection window member,
The manufacturing process is
A first mixing step of mixing polyisocyanate, polyol, and part of a curing agent, which are raw materials for window materials, to prepare a first reaction mixture, and mixing the first reaction mixture with the remainder of the curing agent. , a second mixing step of preparing a second reaction mixture, and a window material curing step of curing the second reaction mixture to obtain the endpoint detection window member,
The curing agent contained in the window material raw material has 3 or more functional groups.
[1] The method for producing a polishing pad according to any one of [10].
[12]
The curing agent contained in the window material raw material contains a low-molecular-weight polyol having a molecular weight of less than 300.
[11] The method for producing a polishing pad according to [11].
[13]
The polyol contained in the window material raw material contains a high-molecular-weight polyol having a molecular weight of 300 or more.
[11] or [12] The method for producing a polishing pad.
[14]
The polyisocyanate contained in the window material raw material contains an alicyclic polyisocyanate and/or an aliphatic polyisocyanate.
[11] A method for producing a polishing pad according to any one of [13].
[15]
a first acquisition step of acquiring position information of an endpoint detection window provided in the opening of the resin sheet;
a first hole forming step of forming a hole in a portion corresponding to the installation position of the end point detection window on the adhesive sheet based on the position information;
a first bonding step in which the end point detection window and the hole are aligned and the resin sheet and the adhesive surface of the adhesive sheet are bonded together;
[1] A method for producing a polishing pad according to any one of [1] to [14].
[16]
The positional information is based on image information obtained by an imaging device, or information obtained by receiving a laser beam that has passed through an end point detection window among the laser beams applied to the resin sheet by a laser receiver. be,
[15] The method for producing a polishing pad according to [15].
[17]
forming the hole smaller than the endpoint detection window in the first hole forming step;
[15] or [16] The method for producing a polishing pad.
[18]
the position information includes information about the center position of the endpoint detection window;
In the first hole forming step, the hole is formed so that the center position of the endpoint detection window and the center position of the hole match.
[15] The method for producing a polishing pad according to any one of [17].
[19]
The pressure-sensitive adhesive sheet is a double-sided tape or a laminate of a double-sided tape and another layer,
[15] The method for producing a polishing pad according to any one of [18].
[20]
When the adhesive sheet is the double-sided tape,
a second acquisition step of acquiring position information of holes formed in the double-sided tape on the resin sheet;
a second hole forming step of forming a hole in a portion corresponding to the installation position of the endpoint detection window on another layer based on the position information;
a second bonding step of aligning the holes in the double-sided tape with the holes in the other layer and bonding the double-sided tape on the resin sheet and the other layer;
[19] The method for producing a polishing pad according to [19].

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.

It is a perspective view which shows one aspect|mode of the member for endpoint detection windows of this embodiment. It is a perspective view which shows another aspect of the member for endpoint detection windows of this embodiment. It is a perspective view which shows another aspect of the member for endpoint detection windows of this embodiment. FIG. 4 is a perspective view showing one mode in which the end point detection window member of the present embodiment is sandwiched between sandwiching portions. FIG. 11 is a perspective view showing another aspect in which the end point detection window member of the present embodiment is sandwiched between sandwiching portions. FIG. 3 is a top view showing one mode in which a mold and a position fixing jig are combined for producing a resin sheet used in the present embodiment. FIG. 4 is a top view showing another mode in which a mold and a position fixing jig are combined for producing a resin sheet used in the present embodiment. FIG. 4 is a top view showing another mode in which a mold and a position fixing jig are combined for producing a resin sheet used in the present embodiment. FIG. 3B is a cross-sectional view showing one aspect of the A-A′ cross section of the mold shown in FIG. 3A before injecting the curable resin. FIG. 3B is a cross-sectional view showing one aspect of the A-A′ cross section of the mold shown in FIG. 3B before the curable resin is injected. FIG. 3B is a cross-sectional view showing one aspect of the A-A′ cross section of the mold shown in FIG. 3A after the curable resin is injected. FIG. 3B is a cross-sectional view showing one aspect of the A-A′ cross section of the mold shown in FIG. 3B after the curable resin is injected. FIG. 4 is a top view showing a resin sheet obtained after a curing step; FIG. 10 is a cross-sectional view of the resin sheet obtained after the curing process, near the end point detection window; 1 is a schematic perspective view of a polishing pad of this embodiment; FIG. FIG. 3 is a schematic cross-sectional view of the end point detection window portion of the polishing pad of the present embodiment; It is a schematic sectional drawing which shows the aspect|mode of the 1st acquisition process, the 1st hole formation process, and the 1st bonding process in the manufacturing method of the polishing pad of this embodiment. It is a schematic sectional drawing which shows one aspect|mode of the 2nd acquisition process, the 2nd hole formation process, and the 2nd bonding process in the manufacturing method of the polishing pad of this embodiment. It is a top view which shows one aspect|mode of the resin sheet of this embodiment. 1 is a schematic diagram showing a film thickness control system installed in CMP; FIG. It is a graph which shows the dispersion|variation in D hardness in each temperature.

Hereinafter, embodiments of the present invention (hereinafter referred to as "present embodiments") will be described in detail with reference to the drawings as necessary, but the present invention is not limited thereto and the gist thereof. Various modifications are possible without departing from the above. In the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. Moreover, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to the illustrated ratios.

1. Method for Manufacturing Polishing Pad In the method for manufacturing a polishing pad according to the present embodiment, an end-point detection window member (hereinafter simply referred to as “window member”) is fixed in a mold, and the polishing pad is in contact with the end-point detection window member. and a slicing step of slicing the resin sheet to form a polishing layer. 1, a method of manufacturing a polishing pad having a polishing layer with an end point detection window by being suspended and fixed by a position fixing jig installed on the upper part of the mold.

In this way, by suspending and fixing the window material by the position fixing jig installed on the upper part of the mold, even if the contact part between the window material and the position fixing jig is formed to be wide, the part is not hardened resin. The resin sheet can be molded without touching the Therefore, it is not necessary to remove unnecessary portions from the obtained resin sheet. Moreover, since the window material is attached to the position fixing jig instead of the mold, the mold itself does not need to be processed, and the conventional mold can be used as it is. Furthermore, since the position fixing jig can be used repeatedly, unlike the liner, it does not need to be thrown away.

In addition, by suspending and fixing the window material with a position fixing jig installed on the upper part of the mold, it is possible to finely adjust the embedding position of the window material until the hardening resin hardens. It is also possible to improve the product yield by fine adjustment.

1.1. Window Member Forming Step The method for manufacturing the polishing pad of the present embodiment may further include, before the curing step, a window member forming step of forming a window member having a convex shape at least at one end. The method of forming the window member 10 is not particularly limited, but for example, resin may be injected into a mold (not shown) having a shape corresponding to a convex shape and cured, or a cured product having an arbitrary shape may be cut. It can be produced by molding a convex shape after curing with.

As for the polymerization method of the cured product (window material) in the step of forming the window member, the method for manufacturing the window material described below can be referred to.

1.1.1. Window Material First, a window material is prepared prior to the curing step. As shown in FIGS. 1A to 1C, the window member 10 may be rectangular parallelepiped or columnar.

As shown in FIG. 1A, the rectangular parallelepiped window member 10 has, for example, a columnar portion 11. As shown in FIG. Here, after the curing process, the columnar portion 11 is embedded in the resin sheet (polishing layer 50) and becomes the end point detection window 51. As shown in FIG. Since the columnar portion 11 of the rectangular parallelepiped window member 10 has side surfaces that are easy to hold, it can be more stably fixed to the position fixing jig 30 .

The end face of the columnar portion 11 in the hanging direction may be planar or convex. Since the end face in the hanging direction has a convex shape, the curable resin can easily flow between the end face of the window material 10 and the bottom surface 21 of the mold 20, and the entrainment of air bubbles in the curable resin can be suppressed. can. As a result, it is possible to prevent air portions from appearing as voids (holes) when slicing, and to prevent deterioration of polishing performance due to voids.

As shown in FIGS. 1B and 1C, the columnar window material 10 can have, for example, a columnar portion 11 and a pedestal portion 12 . Here, after the curing process, the columnar portion 11 is embedded in the resin sheet (polishing layer 50) and becomes the end point detection window 51. As shown in FIG. The cross-sectional shape of the columnar portion 11 is not particularly limited, and may be circular or polygonal.

The lower end 10a of the columnar portion 11 in the hanging direction may have a convex shape (Fig. 1B) or may have a planar shape (Fig. 1C).

Also, the pedestal portion 12 may be used differently depending on the method of fixing the window member 10 to the position fixing jig 30 .

For example, when the window member 10 is fixed to the position fixing jig 30 with an adhesive or the like, the pedestal portion 12 is a portion to be fixed to the position fixing jig 30 with an adhesive or the like. good too. Thus, by forming the columnar portion 11 and the pedestal portion 12 into a shape having the columnar portion 11 and the base portion 12 , the columnar portion 11 can be made relatively small within a range necessary for the end point detection window, and the pedestal portion 12 can be brought into close contact with the position fixing jig 30 . can ensure the integrity of the

When the window member 10 is fixed to the position fixing jig 30 by the holding portion 31 of the position fixing jig 30, the holding portion 31 may be displaced toward the pedestal portion 12 when the holding portion 31 holds the columnar portion 11. It may be a part for deterring In this case, the pedestal portion 12 may be configured to be wider than the hole diameter of the holding portion 31 of the position fixing jig 30 . As a result, when the window member 10 is inserted through the holding portion 31 of the position fixing jig 30 from above, it is locked by the pedestal portion 12, and the columnar window member 10 is fixed without falling off. In this way, the columnar window member 10 has a shape having the columnar portion 11 and the pedestal portion 12 , so that the columnar portion 11 is relatively small within the range necessary for the end point detection window, and the columnar portion 11 is dropped by the pedestal portion 12 . can be further suppressed.

By configuring the window material as described above, the tendency of the window material 10 to be displaced or slanted due to the resin injected in the curing process or the resin being cured is suppressed. It is in. In addition, since the columnar portion 11 can be configured to be relatively small within a necessary range as the end point detection window, the effect of embedding the end point detection window on the polishing characteristics of the polishing pad can be further reduced.

The shape of the window material 10 is not limited to that shown in FIGS. 1B and 1C. For example, the columnar window member 10 may have only the columnar portion 11 without the pedestal portion 12 .

Although the window material 10 is not particularly limited, it can be produced, for example, by injecting resin into a mold (not shown) and curing the resin. It is preferable that the side surface of the columnar portion 11 of the window material 10 removed from the mold is treated with sandpaper or treated with a solvent. As a result, if the release agent is attached to the window material 10, the release agent can be removed. When the window material 10 is embedded in the inner wall, the adhesiveness between the resin sheet (polishing layer 50) and the window material 10 (end point detection window 51) tends to be further improved.

1.1.2. Convex shape In the present embodiment, the term “convex shape” means a surface that rises from an end toward an arbitrary portion. For example, in FIG. It has a convex shape with both ends in the axial direction being low and gradually rising toward the central portion in the longitudinal direction. The shape of the convex surface need not be curved as long as it is convex, and any shape that is convex toward the center can be selected.

In the "convex shape" of the present embodiment, the highest portion may be flat, but the area S1 of the highest portion is preferably 0 to 50 area%, more preferably 0 to 40 area%, still more preferably 0 to 30 area%, even more preferably 0 to 20 area%, still more preferably 0 to 10 area% %. Since the ratio of the area S1 to the cross-sectional area S is 50 area % or less, the curable resin easily flows between the lower surface of the window member 10 and the bottom surface 21 of the mold 20, and the curable resin does not involve air bubbles. is easily suppressed, and trapped air bubbles can be easily released.

The fact that the ratio of the area S1 to the cross-sectional area S is 50 area % or less means that the "convex shape" in the present embodiment does not include the case where the lower end of the window material is simply chamfered. But also.

Further, the length L of the convex portion of the window member 10 is preferably 3.0 to 20 mm, more preferably 3.0 to 15 mm, and even more preferably 3.0 to 10 mm. The longer the length L, the greater the difference between the lowest part and the highest part of the convex shape, which tends to suppress entrainment of air bubbles in the curable resin and facilitate release of entrained air bubbles. On the other hand, the shorter the length L, the shorter the portion that cannot be used as a polishing pad and is discarded.

The ratio (L/S) between the length L of the convex portion of the window member 10 and the horizontal cross-sectional area S of the window member 10 is preferably 0.002 to 0.4, more preferably It is 0.005 to 0.35, more preferably 0.010 to 0.30. The larger the ratio (L/S), the greater the difference between the lowest part and the highest part of the convex shape, the tendency that the curable resin tends to suppress the entrainment of air bubbles, and the entrained air bubbles tend to escape. It is in. On the other hand, the smaller the ratio (L/S), the shorter the portion that cannot be used as a polishing pad and is discarded.

The length L of the convex portion of the window member 10 is preferably 0.03 to 0.30 Lw, more preferably 0.03 to 0.25 Lw, relative to the total length Lw of the window member 10, More preferably 0.03 to 0.20 Lw. The larger the length L, the greater the difference between the lowest part and the highest part of the convex shape, which tends to suppress entrainment of air bubbles in the curable resin and facilitate release of entrained air bubbles. On the other hand, the smaller the length L, the shorter the portion that cannot be used as a polishing pad and is discarded.

1.2. Curing Step The curing step is a step of fixing the window member in the mold and curing the curable resin in contact with the window member to form a resin sheet incorporating the window member.

1.2.1. Position Fixing Jig In the curing process, the window member 10 is suspended and fixed by a position fixing jig 30 installed above the mold 20 . 3A to 3C show top views of a mold 20 for producing a resin sheet. 3A to 3C, the position fixing jig 30 is installed above the mold 20, and the window member 10 is fixed vertically downward from the position fixing jig 30. In FIG. Note that FIG. 3B is a top view of the mold 20 and shows a mode in which the window material 10 is fixed below the position fixing jig 30 with an adhesive. showing.

4A and 4B are shown in order to explain the positional relationship between the mold 20, the position fixing jig 30 and the window material 10 in more detail. FIGS. 4A and 4B are cross-sectional views taken along line A-A' in FIGS. 3A and 3B before the curable resin is injected into the mold 20. FIG. As can be seen from FIGS. 3A and 3B and FIGS. 4A and 4B, the mold 20 is a flat mold for forming a resin sheet, and the position fixing jig 30 is a concave portion of the mold 20. is fixed in contact with the side wall 22 so as to cover the .

The portion of the position fixing jig 30 that contacts the mold 20 may have an uneven shape (first fitting portion) that can be fitted to the upper portion of the mold 20 . Further, the portion of the mold 20 that contacts the position fixing jig 30 may also have an uneven shape (second fitting portion) that can be fitted with the position fixing jig 30 . This facilitates the positioning of the position fixing jig 30 when installing the position fixing jig 30 in the mold 20, and tends to suppress deviation of the embedding position of the window material 10 for each curing process. be.

Furthermore, the window member 10 is suspended and fixed to the lower side of the position fixing jig 30, and the columnar portion 11 faces downward in the vertical direction. At this time, the window member 10 may be fixed to the position fixing jig 30 by the pedestal portion 12 . Any adhesive, double-sided tape, or the like can be used for this fixation.

Furthermore, the position fixing jig 30 may have a positioning portion for positioning and fixing the window material 10 . Here, the positioning portion may have an uneven shape formed at a place where the position fixing jig 30 and the pedestal portion 12 are in contact with each other so that the position fixing jig 30 and the pedestal portion 12 can be fitted. As a result, it tends to be possible to suppress displacement of the embedding position of the window member 10 for each curing step.

For example, when the window material 10 is fixed to the bottom surface of the mold 20, it is difficult to change the number and position of the window material 10 after filling the mold with a curable resin. On the other hand, when the window material 10 is suspended and fixed as in the present embodiment, the position of the window material 10 is changed even after the curable resin is filled into the mold 20 but before it is cured. or change the number of window materials 10 .

In addition, there is no need to modify the mold itself such as the bottom of the mold 20 to fix the window member 10, and the mold 20 is similar to that used for manufacturing a polishing pad without an endpoint detection window. It is also possible to use the object as it is.

Although the material of the position fixing jig 30 is not particularly limited, it may be a heat-resistant material that does not deform even with the heat of the hardening process. Examples include aluminum alloy and stainless steel.

1.2.3. Holding Part The position fixing jig 30 preferably has a holding part 31 . The holding part 31 can hold a part of the window member 10 and suspend and fix it. By holding the side surface of the window member 10 with such a holding portion 31, the window member 10 can be vertically suspended and fixed. becomes less likely to occur. Therefore, if the window material 10 is fixed obliquely rather than straight and vertically, it may not function as an endpoint detection window, or may be caused by the flow of the curable material, or by the expansion or contraction of the curable material during curing. , the window material 10 is suppressed from being pushed and causing positional deviation or the like.

Further, by using the clamping part 31, it is not necessary to use fixing means such as an adhesive, and the attachment and detachment of the window material 10 is facilitated. For example, when an adhesive or the like is used, if the adhesive strength is weak, there is a concern that misalignment or falling off may occur. 10 becomes difficult to remove. On the other hand, when the clamping portion 31 is used, the window member 10 can be clamped from at least one direction, and the clamping force can be weakened to facilitate attachment and detachment. Furthermore, when an adhesive is used, processing such as flattening the bonding surface of the window material 10 by scraping it with sandpaper or the like is required, but such a treatment is not required when the clamping portion 31 is used. Become.

Furthermore, when the window material is fixed to the bottom surface of the mold with an adhesive or the like, the position cannot be adjusted once fixed. Until the hardening resin is hardened, the clamping portion can be loosened to finely adjust the embedding position of the window material.

Since the endpoint detection window usually has no polishing capability, the size of the window placed in the polishing pad should be as small as possible to accurately deliver the transmitted light to the detector portion of the polishing apparatus through the small endpoint detection window. For this purpose, it is necessary to place the windows at exactly the same location on both polishing pads. Therefore, by enabling fine adjustment as described above, it is also possible to improve the non-defective product rate. Further, after the curable resin is cured, the clamping portion is loosened and the window material is removed from the clamping portion, thereby separating the position fixing jig and the obtained resin sheet.

The clamping portion 31 is not particularly limited as long as it clamps and fixes the window member 10 as described above, and may have one or more members that clamp the window member 10. Further, the clamping force may be reduced. It may have an adjusting section 32 for adjustment. Among these, from the viewpoint of ease of attachment and detachment, the holding portion 31 configured to hold the window material 10 by simply fitting is preferable, and from the point of being able to adjust the fixing strength, the holding portion 31 having the adjustment portion 32 is preferred. preferable.

For example, such an adjusting portion 32 may be a screw or a spring that tightens a plurality of members (holding portion 31) that hold the window material 10 therebetween as shown in FIG. 2A. In FIG. 2A, the clamping part 31 made up of two members is connected via an adjusting part 32 (screw), and the adjusting part 32 can adjust the distance between the clamping part 31 made up of the two members. there is As a result, the adjusting portion 32 tightens the clamping portions 31 so that the distance between the clamping portions 31 is shortened, thereby pressing the side surfaces of the window member 10 and adjusting the clamping force.

Further, the adjustment part 32 may be, for example, a screw or a spring that tightens the window member 10 together with the clamping part 31 as shown in FIG. 2B. In FIG. 2B, the bottom portion of the adjusting portion 32 (screw) penetrating from the side surface of the clamping portion 31 presses the side surface of the window member 10, thereby pressing the inner wall of the clamping portion 31 and the bottom portion of the adjusting portion 32 (screw). The clamping force is adjusted.

The forms of the holding part 31 and the adjusting part 32 are not limited to the above, and can have any structure as long as they are configured to increase or decrease the holding force.

The position fixing jig 30 may have a through-hole 33 through which the window member 10 is inserted, and at this time, the holding portion 31 may hold the window member 10 inserted through the through-hole 33 . By inserting the window member 10 into the through-hole 33 provided in advance in the position fixing jig 30 and holding it therebetween, it is possible to easily perform positioning according to the through-hole 33 .

3A and 3B show a top view of the mold 20 for making the resin sheet, and FIGS. 4A and 4B show the A− in FIGS. A' shows a cross-sectional view. A mold 20 shown in FIGS. 3A and 4A includes a position fixing jig 30 that fixes the window member 10 shown in FIG. 1B by an adjusting portion 32 shown in FIG. 2B.

As shown in FIGS. 4A and 5A, the position fixing jig 30 is installed on top of the mold 20, and the window member 10 is held by the holding portion 31 of the position fixing jig 30, thereby vertically downward. Suspended and fixed.

The shape of the mold 20 is not particularly limited. can be a type. A position fixing jig 30 is fixed in contact with the side wall 22 so as to cover the upper portion of the mold 20 .

1.2.3. Curable Resin In the curing step, the window member 10 is fixed in the mold 20 as described above, and the curable resin 40 is cured while in contact with the window member 10 to form the window member 10 (end point detection window 51). to form a resin sheet (polishing layer 50) in which is incorporated.

FIG. 4A shows a cross-sectional view of A-A' in FIG. 3A. In this cross-sectional view, the window member 10 is fixed to the position fixing jig 30 by the holding portion 31 (see FIG. 2A). Further, FIG. 5A shows a cross-sectional view of a state in which the curable resin is injected into the mold 20 in FIG. 4A.

FIG. 4B shows a cross-sectional view along A-A' in FIG. 3B. In this cross-sectional view, the window material 10 is fixed to the position fixing jig 30 with an adhesive. Further, FIG. 5B shows a cross-sectional view of a state in which the curable resin is injected into the mold 20 in FIG. 4B.

The curing process is not particularly limited as long as it cures the curable resin 40 in contact with the window material 10 . For example, after fixing the window member 10 to the mold 20 as shown in FIGS. 5A and 5B, the mold 20 may be filled with the curable resin 40 and the curable resin 40 may be cured. Alternatively, the mold 20 may be filled with the curable resin 40, the window material 10 may be brought into contact with the curable resin 40, and then the curable resin 40 may be cured.

Also, in FIG. 5B, only the columnar portion 11 is in contact with the curable resin 40 , but the pedestal portion 12 may be in contact with the curable resin 40 .

The curable resin is not particularly limited, but examples include polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins. You may use these individually by 1 type or in combination of 2 or more types. Such a polyurethane resin can be synthesized from polyisocyanate and polyol.

1.3. Slicing Step The slicing step is a step of slicing the resin sheet to form a polishing layer. 6 and 7 show a top view and a cross-sectional view of the resin sheet (polishing layer 50) obtained by removing it from the mold 20 and removing the pedestal portion 12 after the curing process. As shown in FIGS. 6 and 7, the resin sheet has a window material embedded therein.

The slicing method is not particularly limited, but for example, a method of cutting a resin sheet as shown in FIGS. Moreover, as shown in FIG. 8, a rectangular polishing pad may be cut into a circular shape. The temperature for slicing is preferably 80.degree. C. to 100.degree. This tends to further improve flatness.

1.4. Dressing Treatment If necessary, the polished surface of the resin sheet obtained may be dressed. The temperature in the dressing treatment is preferably 85°C to 95°C. This tends to further improve flatness.

1.5. Groove Forming Step The method of manufacturing the polishing pad of the present embodiment may optionally include a groove forming step of performing groove processing on the polishing surface of the polishing layer (see FIG. 9). Note that it is preferable not to perform grooving on the exposed portion of the window material, as this interferes with the detection of the optical end point.

1.6. Lamination step The method for producing the polishing pad of the present embodiment may optionally include a lamination step of laminating a base material layer and/or a cushion layer on the surface of the polishing layer opposite to the polishing surface. good. The stacking process may be performed before or after the dressing process and the groove forming process. That is, the stacking process, the dressing process, and the groove forming process can be performed in any order.

For the lamination process, known means such as simply laminating each layer may be used. In the following, a description will be given of a lamination process in which the positional deviation of the window material can be suppressed and the position of the window material can be easily adjusted.

The lamination step for the above purpose includes a first acquisition step of acquiring position information of the end point detection window provided in the opening of the resin sheet, and a portion corresponding to the installation position of the end point detection window on the adhesive sheet based on the position information. a first hole forming step of forming a hole; and a first bonding step of bonding the resin sheet and the adhesive surface of the adhesive sheet together by aligning the end point detection window with the hole.

Further, the lamination step of this aspect further includes a second acquisition step of acquiring position information of holes formed in the double-sided tape on the resin sheet when the adhesive sheet is a double-sided tape, and based on the position information, A second hole forming step of forming a hole in a portion corresponding to the installation position of the end point detection window on another layer, and aligning the hole in the double-sided tape with the hole in the other layer, and a second bonding step of bonding the tape and another layer. In addition, a cushion layer is mentioned as "another layer" here.

Each step will be described in detail below with reference to FIGS. 10 and 11, which are schematic cross-sectional views of each step.

1.6.1. Cutting step The stacking step of this embodiment may include a cutting step for trimming the outer shape of the resin sheet in which the end point detection window 51 is embedded (hereinafter referred to as “polishing layer 50”) before the first obtaining step. good. In the cutting process, a center position O that is equidistant from each of the end point detection windows 51 is specified from the positions of the end point detection windows 51, and the polishing layer 50 is cut into a predetermined square shape centering on that position. You can cut it.

Thereby, it is possible to obtain the polishing layer 50 having a standardized outer shape based on the center position O specified by the end point detection window 51 . By providing the polishing layer 50 having a fixed shape in this manner to each step described later, each step can be performed with higher accuracy.

It should be noted that the polishing layer 50 provided after the first obtaining step is formed into a square shape as shown in FIG. It may be one before punching. Among these, a rectangular shape is preferable in carrying out subsequent steps related to alignment, such as regulating the orientation of the polishing layer 50 during transportation. When each step is performed with the polishing layer 50 in a square state, in the final step after each step, the polishing pad is obtained by further punching into a circular shape based on the center position O specified by the end point detection window 51. can be

1.6.2. First Acquisition Step The first acquisition step is a step of acquiring position information of the endpoint detection window 51 provided in the opening of the polishing layer 50 . The resin sheet may have multiple endpoint detection windows.

In FIG. 10, the first manufacturing apparatus 100 acquires the position information of the transport mechanism 110 such as a belt conveyor that transports the polishing layer 50 having the end point detection window 51 and the end point detection window 51 provided at the opening of the polishing layer 50. a roller 141 for sending out an adhesive sheet 61 with a release sheet 62 attached thereto; a hole forming device 130 for forming openings in the sent adhesive sheet 61; The polishing layer 50 and the adhesive sheet 61 are bonded together while aligning the roller 142 for peeling the sheet 62, the hole of the adhesive sheet 61 from which the release sheet 62 has been peeled, and the end point detection window 51 of the polishing layer 50. - 特許庁A roller 143 is provided.

Here, the conveying mechanism 110, the imaging device 120, the hole forming device 130, and the

rollers

141, 142, 143 may be connected by wire or wirelessly to a control unit (not shown) that controls them. The control unit can be configured as an information processing device such as a personal computer. Driving control of the conveying mechanism 110, imaging device 120, hole forming device 130, and

rollers

141, 142, 143, and transmission of information can be performed via this controller.

A method of acquiring the positional information of the end point detection window 51 is not particularly limited, but for example, image information captured when the polishing layer 50 conveyed in the direction of arrow F by the conveying mechanism 110 passes directly below the imaging device 120 is used. can be obtained. At this time, the transport mechanism 110 may be driven so that the polishing layer 50 is temporarily stopped immediately below the imaging device 120 for imaging.

The method for extracting the position information of the end point detection window 51 from the image information acquired in this way is not particularly limited. A method of specifying the window 51 and specifying its contour; and a method of specifying the end point detection window 51 by image processing such as edge detection from image information and specifying its contour.

Also, instead of the imaging device 120, a laser receiver may be used. For example, the position of the end-point detection window 51 may be specified based on the information obtained by receiving the laser light that has passed through the end-point detection window 51 out of the laser beams applied to the polishing layer 50 by a laser receiver. good.

At this time, the conveying mechanism 110 may be driven so as to temporarily stop the polishing layer 50 immediately below the laser oscillator and the laser receiver, and the laser oscillator and the laser receiver may be scanned with respect to the polishing layer 50, or By fixing the laser oscillator and the laser receiver in the middle of the transport mechanism 110 and continuing to move the transport mechanism 110 at a constant speed, the laser oscillator and the laser receiver relatively scan the polishing layer 50. The position of the endpoint detection window 51 may be specified.

Further, the control unit may calculate the center position of the end point detection window 51 based on the information regarding the contour of the end point detection window 51 obtained from the image information. The positional information such as the outline and center position of the end point detection window 51 acquired in this manner may be transmitted to the hole forming device 130 via the control unit.

1.6.3. First Hole Forming Step The first hole forming step is a step of forming a hole in a portion corresponding to the installation position of the endpoint detection window on the adhesive sheet based on the positional information. Here, the adhesive sheet may be a double-sided tape, or may be a laminate of a double-sided tape and another layer such as a cushion layer.

Specifically, the control unit drives and controls the roller 141 to send out the adhesive sheet 61 , transmits the positional information of the end point detection window 51 to the hole forming device 130 , and detects the end point detection window on the sent adhesive sheet 61 . A hole is formed by the hole forming device 130 in a portion corresponding to the installation position of the . The rollers 141 may be paused while the perforations are being performed by the perforator 130 .

At this time, the hole forming device 130 may form a hole smaller than the end point detection window 51 . More specifically, the control unit transmits positional information including information on the contour of the end point detection window 51 and its center position to the hole forming device 130, and the hole forming device 130 forms a hole smaller than the contour. , can be formed while aligning so that the center position of the end point detection window 51 and the center position of the hole to be formed match.

As a result, the adhesive sheet 61 having a hole smaller than the end point detection window 51 can be attached to the polishing layer 50 while aligning the center position of the formed hole with the center position of the end point detection window 51 . can. Thus, by making the hole of the adhesive sheet 61 bonded together smaller than the endpoint detection window 51 , the endpoint detection window 51 can be supported from the back side of the polishing layer 50 by the adhesive sheet 61 . Therefore, the durability of the resulting polishing pad can be further improved.

1.6.4. First Bonding Step The first bonding step is a step of aligning the endpoint detection window and the hole and bonding the resin sheet and the adhesive surface of the adhesive sheet together. The adhesive sheet after bonding may be cut according to the size of the resin sheet.

Specifically, the control unit drives and controls the roller 141 to further feed out the perforated adhesive sheet 61 , and drives and controls the roller 142 to release the mold release bonded to the adhesive surface of the adhesive sheet 61 . The sheet 62 is wound. At the same time, the controller drives the conveying mechanism 110 to further feed the polishing layer 50 in the direction of the arrow F, align the end point detection window 51 with the hole, and adhere the polishing layer 50 and the adhesive sheet 61 to each other. Glue the surface together.

At this time, the controller can drive and control the roller 143 and the transport mechanism 110 while calculating the positional relationship between the adhesive sheet 61 sent by the roller 141 and the polishing layer 50 transported by the transport mechanism 110 . Further, in the drive control, based on the information on the center position of the hole formed in the adhesive sheet 61 and the information on the center position of the end point detection window 51 of the polishing layer 50, polishing is performed so that these center positions overlap each other. The moving distance of the layer 50 and the adhesive sheet 61 may be controlled to adhere them together.

As a result, the end point detection window 51 and the holes formed in the adhesive sheet 61 can be stuck together in a state where they overlap concentrically. Therefore, for example, as shown in FIGS. 8 and 9, when the hole formed in the adhesive sheet 61 is smaller than the endpoint detection window 51, the endpoint detection window 51 can be supported from the back side of the polishing layer 50 by the adhesive sheet 61. can. Therefore, the durability of the resulting polishing pad can be further improved.

1.6.5. Second Acquisition Step The second acquisition step is a step of acquiring the positional information of the holes of the double-sided tape laminated onto the polishing layer 50 in the first lamination step.

In FIG. 11, the second manufacturing apparatus 200 includes a transport mechanism 210 that transports the polishing layer 50, an imaging device 220 that acquires the positional information of the holes of the double-sided tape, a roller 241 that transports the other layer 71, and a The hole forming device 230 for forming openings in the other layer 71 and the polishing layer 50 and the other layer 71 are aligned while aligning the holes of the other layer 71 with the holes of the double-sided tape of the polishing layer 50 . and a roller 242 for bonding.

Here, the conveying mechanism 210, the imaging device 220, the hole forming device 230, and the

rollers

241 and 242 may be connected by wire or wirelessly to a second control section (not shown) that controls them. The second control unit can be configured as an information processing device such as a personal computer. Driving control of the conveying mechanism 210, imaging device 220, hole forming device 230, and

rollers

241 and 242, and transmission of information can be performed via this second control section.

The method for acquiring the positional information of the holes of the double-sided tape bonded onto the polishing layer 50 is not particularly limited. method.

1.6.6. Second Hole Forming Step The second hole forming step is a step of forming a hole in a portion corresponding to the installation position of the endpoint detection window on another layer based on the position information acquired in the second acquiring step. Here, the other layer may be a cushion layer, or may be a cushion layer laminated with double-sided tape.

Specifically, the control unit drives and controls the roller 241 to send out the other layer 71, and transmits the positional information of the holes of the double-sided tape to the hole forming device 230, and Holes are formed by the hole forming device 230 in portions corresponding to the installation positions of the double-sided tape. The rollers 241 may be paused while the perforations are being performed by the perforator 230 .

1.6.7. Second Bonding Step The second bonding step is a step of aligning the holes in the double-sided tape with the holes in the other layer and bonding the double-sided tape on the resin sheet to the other layer. Other layers after bonding may be cut according to the size of the resin sheet.

Specifically, the second control unit drives and controls the roller 242 to further send out the perforated adhesive sheet 61, drives the conveying mechanism 210 to further send out the polishing layer 50 in the direction of arrow F, The adhesive surface (adhesive sheet 61) of the polishing layer 50 and the other layer 71 are bonded together by aligning the holes in the double-sided tape with the holes in the other layer.

Also at this time, based on the information on the center position of the hole formed in the other layer 71 and the information on the center position of the hole of the double-sided tape of the polishing layer 50, the transport mechanism is arranged so that these center positions overlap each other. 210 and roller 242 may be driven and controlled. As a result, the holes formed in the other layer 71 and the holes of the double-sided tape of the polishing layer 50 can be laminated in a state where they overlap concentrically, so that the durability of the resulting polishing pad can be further improved. .

In addition, the polishing layer 50 to which the other layer 71 is attached as described above can be punched into a circular shape in the subsequent steps and used as a polishing pad.

2. Method for Manufacturing End Point Detection Window Member The window material is not particularly limited as long as it is a method for obtaining a transparent window material by curing a window material raw material. Among them, Mode I for the purpose of removing air bubbles efficiently in a shorter time and Mode II for the purpose of improving the uniformity of physical properties of the resulting window material will be described below. In addition, you may use these aspects in combination, respectively.

2.1. Aspect I
Aspect I is a rotational movement step in which a container containing the prepared window material is rotated at 100 to 800 rpm while revolving on a predetermined circumference at 200 to 1600 rpm, and the window material after the rotational movement is cured. and a window material curing step of obtaining a window material.

It is desirable that the endpoint detection window is non-foaming and evenly mixed so as not to adversely affect the optical transparency. This is because if there is bubbling, the attenuation of the reflected light increases due to light scattering, which lowers the polishing end point detection accuracy and the film thickness measurement accuracy. This is because there is a portion that advances, and an end-point detection window with non-uniform crosslink density is formed.

On the other hand, in Mode I, the window material raw material containing no air bubbles and uniformly mixed can be obtained by going through the rotational movement step as described above. As a result, it is possible to manufacture an endpoint detection window with excellent polishing endpoint detection accuracy and film thickness measurement accuracy.

In addition, non-foaming and uniform mixing can be achieved in a shorter period of time by going through the rotational movement process. As a result, it becomes possible to use even a highly reactive window material, which could not be used until now in consideration of the time required for defoaming, etc., as the window material for the endpoint detection window. Also, until now, since the reactivity is different, only the slow-reacting components are mixed first, and then the highly reactive components are added. As for the raw material for the window material, it is possible to prepare the raw material for the window material at the same time, and to perform stirring and defoaming.

2.1.1. Preheating Step The method of manufacturing the endpoint detection window member may include a preheating step of individually heating each component contained in the window material in advance. When mixing is started, each component contained in the raw material for the window material may react and generate heat. Therefore, by individually preheating each component contained in the window material in advance and then mixing them as the window material, the processing temperature tends to be stabilized in the rotation process. This tends to promote degassing and improve mixing uniformity.

Although the preheating temperature is not particularly limited, for example, it is preferably 50 to 130°C, more preferably 60 to 125°C, and even more preferably 70 to 120°C. When the preheating temperature is within the above range, the degassing is further promoted, and the uniformity of mixing tends to be further improved.

2.1.2. Rotational Motion Step The rotational motion step is a step of revolving on a predetermined circle at 200 to 1600 rpm while rotating the container containing the blended window material raw material at 100 to 800 rpm. By going through this rotary movement process, there is no need for stirring with a stirring blade, and stirring and defoaming can be performed in the same process. As a result, since no stirring blade is used, unnecessary air bubbles are less likely to occur, and the process can be simplified.

The rotation speed is 100-800 rpm, preferably 200-700 rpm, more preferably 300-600 rpm. When the rotation speed is within the above range, the uniformity of mixing tends to be further improved.

The revolution speed is 200-1600 rpm, preferably 400-1400 rpm, more preferably 600-1200 rpm. When the revolution speed is within the above range, degassing tends to be promoted more.

The inclination of the axis of rotation and the axis of revolution in the rotational motion process is preferably 20 to 70°, more preferably 30 to 60°, and even more preferably 35 to 55°. When the inclination is within the above range, a three-dimensional swirling flow is generated in the raw material for the window material in the container, which tends to promote degassing and improve uniformity of mixing.

The rotary motion step is preferably performed under reduced pressure, more preferably 0.1 to 0.9 atm or less, and even more preferably 0.2 to 0.8 atm or less. Degassing tends to be promoted more by performing the rotary movement process under reduced pressure. Further, by performing the rotational movement process at 0.1 atm or more, there is a tendency that unintended volatilization of the components can be suppressed.

The processing time of the rotational motion step is preferably 1 to 10 minutes, more preferably 2 to 8 minutes, and even more preferably 3 to 6 minutes. If the treatment time is shorter than the above range, mixing will be insufficient and a uniform window material raw material will not be obtained. As the reaction of the raw materials progresses, the viscosity increases, and it tends to be difficult to take out the window material raw materials from the container. When the surface of the endpoint detection window is flush with the polishing surface, polishing is likely to be adversely affected unless the endpoint detection window is made of a window material with a short curing time (high reactivity). A window material having a long hardening time is less likely to be worn, and the produced polishing pad having the end point detection window may have a protruded window portion during polishing, which may adversely affect polishing such as scratches. On the other hand, the window material raw material having a short curing time is moderately hard and brittle, and as the polishing layer wears, the end-point detection window is also worn, preventing the end-point detection window alone from protruding. Therefore, it is preferable that the treatment time is within the above range.

The temperature of the rotational motion step is preferably 50-130°C, more preferably 60-125°C, and even more preferably 70-120°C. When the temperature is 50° C. or higher, the viscosity tends to be relatively low and the degassing tends to be promoted more. When the temperature is 130° C. or lower, the reaction rate of the window material raw materials does not become too high, and the mixing uniformity tends to be further improved.

2.1.3. Window Material Curing Step The window material curing step is a step of obtaining the window material by curing the window material raw material after the rotational movement. This window material curing step is not particularly limited, but for example, the window material is provided by pouring the window material material after rotational movement into the hollowed out portion of the polishing layer and allowing the curing reaction to proceed in the hollowed out portion. A mode of obtaining a polishing layer; and a mode of obtaining a window material by curing a window material raw material in a mold.

In addition, in the mode of obtaining the window material by curing the window material raw material in the mold, a curable resin that constitutes the polishing layer is then cast around the obtained window material, and cured to constitute the polishing layer. A mode of obtaining a polishing layer provided with a window material by curing a curable resin; a mode of obtaining a polishing layer provided with a window material by slicing the obtained window material as necessary and inserting it into a polishing layer provided with an opening. may be included.

2.1.4. Window material raw material The window material raw material for obtaining the window material is not particularly limited as long as it is a transparent member that can function as a window when cured. Ethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin and the like can be mentioned. Among these, polyurethane resin is preferable.

The window material raw material preferably contains polyisocyanate, polyol, and curing agent. A polyurethane resin can be synthesized from such a window material.

2.1.4.1. Polyisocyanate Polyisocyanate is not particularly limited, but includes, for example, alicyclic polyisocyanate, aliphatic polyisocyanate, and aromatic polyisocyanate. Polyisocyanate may be used individually by 1 type, or may use 2 or more types together. Among these, the polyurethane resin preferably contains an alicyclic isocyanate and/or an aliphatic isocyanate. This tends to further improve the transparency.

Although the alicyclic polyisocyanate is not particularly limited, for example, 4,4′-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI), cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate , isophorone diisocyanate, and the like.

Examples of aliphatic polyisocyanates include, but are not limited to, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), tetramethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, and trimethylene. diisocyanate, trimethylhexamethylene diisocyanate, and the like.

Examples of aromatic polyisocyanates include, but are not limited to, phenylene diisocyanate, 2,6-tolylene diisocyanate (2,6-TDI), 2,4-tolylene diisocyanate (2,4-TDI), and xylylene diisocyanate. , naphthalene diisocyanate, and diphenylmethane-4,4′-diisocyanate (MDI).

The number of isocyanates in the polyisocyanate is preferably 2-4, more preferably 2-3, and still more preferably 2.

2.1.4.2. High Molecular Weight Polyol As used herein, a high molecular weight polyol is a polyol having a molecular weight of 300 or higher. Examples of such high-molecular-weight polyols include, but are not limited to, polyether polyols, polyester polyols, polycarbonate polyols, polyether polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomers. modified polyols; The high-molecular-weight polyols may be used singly or in combination of two or more.

Among these, polyether polyol is preferred, and polytetramethylene ether glycol is more preferred. Use of such a high-molecular-weight polyol tends to further improve transparency.

The number of hydroxyl groups possessed by the polyol is preferably 2-4, more preferably 2-3, still more preferably 2.

The content of polyether polyol in the window material raw material is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, relative to the total amount of polyol. When the polyether polyol content is within the above range, the transparency tends to be further improved.

2.1.4.3. Curing Agent Although the curing agent is not particularly limited, examples thereof include low-molecular-weight polyols and polyamines having a molecular weight of less than 300.

Examples of low-molecular-weight polyols include, but are not limited to, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4- butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclode low molecular weight polyols having two hydroxyl groups such as candimethanol and 1,4-cyclohexanedimethanol; and low molecular weight polyols having three or more hydroxyl groups such as glycerin, hexanetriol, trimethylolpropane, isocyanuric acid and erythritol. Low-molecular-weight polyols may be used singly or in combination of two or more.

Among these, low-molecular-weight polyols having 3 or more hydroxyl groups are preferred, and glycerin is more preferred. Use of such a low-molecular-weight polyol tends to further improve transparency.

The polyamine is not particularly limited, but for example, aliphatic polyamines such as ethylenediamine, propylenediamine and hexamethylenediamine; alicyclic polyamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; '-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4-methyl-2,6-bis(methylthio)-1,3-benzenediamine, 2-methyl-4,6-bis(methylthio)-1, aromatic polyamines such as 3-benzenediamine and 2,2-bis(3-amino-4-hydroxyphenyl)propane;

Among these, aromatic polyamines are preferred, and 3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) is more preferred.

The content of the curing agent in the window material raw material is preferably 40 to 90 mol%, more preferably 50 to 80 mol%, still more preferably 60 to 70 mol%, relative to the total amount of the polyol and the curing agent. . When the content of the curing agent is within the above range, hardness or durability suitable for the endpoint detection window tends to be obtained.

2.2. Aspect II
The method for producing a window material of Embodiment II includes a first mixing step of mixing a polyisocyanate, a polyol, and a portion of a curing agent to prepare a first reaction mixture; and a window material curing step of curing the second reaction mixture to obtain a window material, wherein the curing agent has three or more functional groups have.

In the one-shot method, in which all of the window material raw materials are put in at the same time and reacted, the polymerization reaction progresses from the most reactive component first, so when viewed from a microscopic point of view, the cross-linked portion becomes dense. , a portion where cross-linking is sparse is likely to occur, and physical properties of the obtained window material may vary. Such variations in physical properties may make it difficult to stabilize the surface shape of the end-point detection window during slicing, destabilize polishing performance, and cause variations in end-point detection accuracy.

In addition, in the prepolymer method, since the reaction is progressing between the curing agent and the prepolymer, compared to the one-shot method, the reaction is easier to control, and there is an advantage that a window material with stable physical properties can be obtained. A prepolymer is prepared by reacting a polyol with an excess amount of polyisocyanate in advance, then taken out and mixed with a prepolymer and a chain extender (curing agent) in a container separate from the container in which the prepolymer was prepared. Therefore, compared with the one-shot method, there is a problem that the work becomes more complicated.

In contrast, in mode II, in the first mixing step, the polyisocyanate, the polyol, and a portion of the curing agent are mixed to synthesize a pseudo-prepolymer, and in the second mixing step, the remaining curing agent is added to allow chain extension of the quasi-prepolymer to proceed. As a result, the curing agent and the pseudo-prepolymer are reacted in the second mixing step, so that the physical properties of the window material can be easily stabilized in the same manner as in the prepolymer method. Further, by performing the first mixing step and the second mixing step in one batch, the second mixing step can be started only by adding a chain extender (curing agent) without taking out the pseudo prepolymer after the first mixing step. Allow the reaction to proceed. Therefore, the complexity of the work surface in the prepolymer method can be omitted, and a window material having uniform physical properties can be obtained more easily.

2.2.1. First Mixing Step The first mixing step is the step of mixing the polyisocyanate, the polyol, and a portion of the curing agent to form a first reaction mixture. The mixing method is not particularly limited as long as it is mixed by a conventionally known method, but it is preferable to mix using a rotation-revolution mixer. Moreover, mixing is preferably performed under reduced pressure and/or with centrifugal force applied. As a result, air bubbles generated during mixing can be easily removed, and air bubbles can be prevented from entering the obtained window material.

The first reaction mixture (pseudo-prepolymer) obtained by this first mixing step is a compound obtained by reacting one or more functional groups of the curing agent with the isocyanate groups of the polyisocyanate, one or more hydroxyl groups of the polyol and the polyisocyanate. Compounds reacted with isocyanate groups, or compounds obtained by further reacting isocyanate groups of these compounds with functional groups of curing agents or hydroxyl groups of polyols may be included.

Since the first reaction mixture obtained in this manner lacks the curing agent, the terminal of each compound rather has an isocyanate group, which is close to the prepolymer in the prepolymer method. . More specifically, in the prepolymer method, a compound obtained by reacting the hydroxyl groups of the polyol with the isocyanate groups of the polyisocyanate is produced as a prepolymer, whereas in the quasi-prepolymer method of Mode II, one of the curing agents Compounds obtained by reacting the above functional groups with isocyanate groups of polyisocyanate, compounds obtained by reacting one or more hydroxyl groups of polyol with isocyanate groups of polyisocyanate, or isocyanate groups possessed by these compounds, and further functional groups of curing agents or polyols. A compound etc. is produced by reaction of the hydroxyl group of Compounds in this state are referred to as quasi-prepolymers in Embodiment II.

The mixing temperature in the first mixing step is preferably 40-80°C, more preferably 40-70°C, still more preferably 40-60°C. Also, the mixing time in the first mixing step is preferably 5 to 30 minutes, more preferably 7 to 25 minutes, still more preferably 10 to 20 minutes. By performing mixing under the above conditions, the reaction rate of each component can be controlled, and the resulting window material tends to have more uniform physical properties.

2.2.1.1. Polyisocyanate Polyisocyanate is not particularly limited, but includes, for example, alicyclic polyisocyanate, aliphatic polyisocyanate, and aromatic polyisocyanate. Polyisocyanate may be used individually by 1 type, or may use 2 or more types together. Among these, it preferably contains alicyclic polyisocyanate and/or aliphatic polyisocyanate, and more preferably contains alicyclic polyisocyanate. As a result, the dynamic viscoelastic properties and the D hardness can be easily adjusted within the above range, and the transparency tends to be further improved.

Examples of the alicyclic polyisocyanate, aliphatic polyisocyanate, and aromatic polyisocyanate include those exemplified in Mode I above.

2.2.1.2. Low Molecular Weight Diols and High Molecular Weight Polyols As used herein, low molecular weight diols are diols with a molecular weight of less than 300. Moreover, in this specification, a high molecular weight polyol is a polyol having a molecular weight of 300 or more. Each of the low-molecular-weight diol and the high-molecular-weight polyol may be used alone or in combination of two or more. Among these, it is preferable to contain a high-molecular-weight polyol. As a result, the physical properties of the resulting window material tend to be more uniform.

Examples of low-molecular-weight diols include, but are not limited to, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4- butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclode Kandimethanol, 1,4-cyclohexanedimethanol and the like can be mentioned.

Examples of high-molecular-weight polyols include those exemplified in Mode I above. Among these, it is preferable to contain a polyether polyol. As a result, the physical properties of the resulting window material tend to be more uniform.

The amount of isocyanate groups in polyisocyanate and the amount of hydroxyl groups in polyol are defined as follows. The hydroxyl group content of the polyol in this definition is preferably 0.20 to 0.50, more preferably 0.25 to 0.40, and still more preferably 0.30, relative to the isocyanate group content of the polyisocyanate. ~0.35.

Isocyanate group weight of polyisocyanate = number of isocyanate groups per molecule of polyisocyanate x parts by mass of polyisocyanate/molecular weight of polyisocyanate (1)
Hydroxyl group content of polyol = number of hydroxyl groups per polyol molecule x parts by mass of polyol/molecular weight of polyol (2)

2.2.1.3. Curing Agent The curing agent in Embodiment I and the curing agent in Embodiment II partially overlap.

The curing agent in Mode II has 3 or more functional groups in one molecule. Examples of functional groups include, but are not limited to, hydroxyl groups and primary amino groups. In addition, "the curing agent has 3 or more functional groups" may mean that the total number of hydroxyl groups and primary amino groups is 3 or more. The curing agent forms cross-linking points by reacting with the polyisocyanate.

Examples of such curing agents include, but are not limited to, polyamines and polyols having 3 or more functional groups. Curing agents may be used singly or in combination of two or more.

The polyamine is not particularly limited as long as it is a substance having 3 or more amino groups, and examples thereof include a trifunctional triamine compound, a tetrafunctional or higher polyamine compound, and the like.

Although the polyol having 3 or more hydroxyl groups is not particularly limited, for example, a low-molecular-weight polyol is preferable, and glycerin is more preferable. Examples of such low-molecular-weight polyols include, but are not limited to, glycerin, hexanetriol, trimethylolpropane, isocyanuric acid, erythritol, and the like. By using such a curing agent, aggregation of the first reaction mixture can be controlled, and the physical properties of the window material can be stabilized while using a simple production method in terms of production work.

In the first mixing step, part of the total amount of curing agent used in the first mixing step and the second mixing step is used. The amount of the curing agent used in the first mixing step is preferably when the sum of the amount a of the curing agent used in the first mixing step and the amount b of the curing agent used in the second mixing step is 100% by mass. , the amount a used is 10 to 90% by mass, more preferably 20 to 80% by mass, still more preferably 30 to 70% by mass, and even more preferably 40 to 60% by mass. When the amount a used is within the above range, the resulting window material tends to have more uniform physical properties.

The number of functional groups possessed by the curing agent is preferably 3-5, more preferably 3-4, still more preferably 3. The molecular weight of the curing agent is preferably less than 500, more preferably less than 300, even more preferably less than 100.

When the isocyanate group amount of the polyisocyanate and the functional group amount of the curing agent are defined as follows, the functional group amount of the curing agent used in the first mixing step is preferably relative to the isocyanate group amount of the polyisocyanate. is 0.20 to 0.50, more preferably 0.25 to 0.40, still more preferably 0.30 to 0.35.

Isocyanate group weight of polyisocyanate = number of isocyanate groups per molecule of polyisocyanate x parts by mass of polyisocyanate/molecular weight of polyisocyanate (1)
Amount of functional groups in curing agent=number of functional groups per molecule of curing agent×parts by mass of curing agent/molecular weight of curing agent (3)

Further, when the isocyanate group amount of the polyisocyanate and the functional group amount of the curing agent are defined as described above, the functional group amount of the curing agent used in the first mixing step and the second mixing step is the same as the isocyanate group amount of the polyisocyanate. The amount is preferably 0.40 to 1.0, more preferably 0.50 to 0.80, still more preferably 0.60 to 0.70.

2.2.2. Second Mixing Step The second mixing step is the step of mixing the first reaction mixture with the remainder of the curing agent to form a second reaction mixture. The mixing method is not particularly limited as long as it is mixed by a conventionally known method, but it is preferable to mix using a rotation-revolution mixer. Moreover, mixing is preferably performed under reduced pressure and/or with centrifugal force applied. As a result, air bubbles generated during mixing can be easily removed, and air bubbles can be prevented from entering the obtained window material.

Through this second mixing step, the reaction between the isocyanate groups of the pseudo-prepolymer produced in the first mixing step and the functional groups of the newly added remaining curing agent proceeds. As a result, the polymerization reaction can proceed in a controlled manner as compared with the one-shot method, and a polyurethane having more uniform physical properties can be produced. During this reaction, a reaction between a functional group such as a hydroxyl group of the pseudo-prepolymer and an isocyanate group of the pseudo-prepolymer may proceed.

The mixing temperature in the second mixing step is preferably 40-80°C, more preferably 40-70°C, still more preferably 40-60°C. Further, the mixing time in the second mixing step is preferably 10 seconds to 5 minutes, more preferably 30 seconds to 4 minutes, still more preferably 60 seconds to 3 minutes. By performing mixing under the above conditions, the reaction rate of each component can be controlled, and the resulting window material tends to have more uniform physical properties.

2.2.2.1. Curing Agent The curing agent may be the same type as the curing agent used in the first mixing step, or may be different, but it is preferable to use the same type of curing agent. This makes it possible to make the physical properties of the obtained window material more uniform while using a simple manufacturing method in terms of manufacturing work.

As described above, when the isocyanate group amount of the polyisocyanate and the functional group amount of the curing agent are defined, the functional group amount of the curing agent used in the second mixing step is preferably relative to the isocyanate group amount of the polyisocyanate. is 0.20 to 0.50, more preferably 0.25 to 0.40, still more preferably 0.30 to 0.35.

2.2.3. Window Material Curing Step The window material curing step is a step of obtaining a window material by curing the window material raw material after stirring the second reaction mixture. This window material curing step is not particularly limited, but for example, the window material is provided by pouring the window material material after rotational movement into the hollowed out portion of the polishing layer and allowing the curing reaction to proceed in the hollowed out portion. A mode of obtaining a polishing layer; and a mode of obtaining a window material by curing a window material raw material in a mold.

The window material curing process may be performed in multiple stages of pre-curing and post-curing.

The curing temperature in precuring is preferably 70 to 170°C, more preferably 90 to 150°C, still more preferably 110 to 130°C. The curing time in precuring is preferably 5 to 180 minutes, more preferably 10 to 120 minutes, still more preferably 15 to 60 minutes.

The curing temperature in post curing is preferably 70 to 170°C, more preferably 90 to 150°C, still more preferably 110 to 130°C. The curing time in post-curing is preferably 1 to 18 hours, more preferably 2 to 12 hours, still more preferably 4 to 8 hours.

3. Polishing Pad The polishing pad of the present embodiment has a polishing layer and an endpoint detection window provided in the opening of the polishing layer. FIG. 8 shows a schematic perspective view of the polishing pad of this embodiment. As shown in FIG. 8, the polishing pad 1 of this embodiment has a polishing layer 50 and an end point detection window 51, and optionally a cushion layer 52 on the side opposite to the polishing surface 50a. You may have

FIG. 9 shows a cross-sectional view around the end point detection window 51 in FIG. As shown in FIG. 9, an adhesive layer 53 may be provided between the polishing layer 50 and the cushion layer 52, and an adhesive layer 53 may be provided on the surface of the cushion layer 52 for attachment to the table of the polishing apparatus. A layer 54 may be provided.

The polishing surface 50a of the polishing pad of the present embodiment may be flat or uneven with grooves 55 formed therein, as shown in FIG. The grooves 55 may be formed with a plurality of grooves having various shapes such as concentric circles, grids, and radial grooves singly or in combination.

3.1. Endpoint Detection Window The endpoint detection window may be produced by the manufacturing method disclosed herein. The endpoint detection window is a transparent member provided in the opening of the polishing layer, and serves as a transmission path for light from the film thickness detection sensor in optical endpoint detection. In this embodiment, the endpoint detection window is circular, but the endpoint detection window may be circular, square, rectangular, polygonal, elliptical, or any other shape, if desired.

It should be noted that the endpoint detection window of the present embodiment preferably has polyisocyanate, high-molecular-weight polyol, and low-molecular-weight polyol having 3 or more hydroxyl groups as structural units.

In addition, the standard deviation of the D hardness (D _W20 to D _W80 ) at 20° C. to 80° C. at the center and both ends (upper end and lower end) of the endpoint detection window is preferably 1.5 or less, more preferably. is 0.2 to 1.4, more preferably 0.3 to 1.2, still more preferably 0.4 to 1.0.

3.2. Polishing Layer The polishing layer of the present embodiment is not particularly limited, but for example, a polyurethane sheet can be used. This polyurethane sheet has an opening in which the endpoint detection window is embedded. Although the position of the opening is not particularly limited, it is preferably provided at a position in the radial direction corresponding to the film thickness detection sensor installed on the table of the polishing apparatus. Although the number of openings is not particularly limited, a plurality of openings are provided at similar radial positions so that the windows pass over the film thickness detection sensor multiple times when the polishing pad attached to the table rotates once. is preferred.

The form of the polyurethane sheet is not particularly limited, but examples thereof include a foamed resin article, a non-foamed resin article, and a resin-impregnated base material in which a fiber base material is impregnated with polyurethane.

Here, the resin foam molding refers to a foam that does not have a fiber base material and is composed of a predetermined resin. The foam shape is not particularly limited, but examples thereof include spherical cells, substantially spherical cells, tear-shaped cells, and open cells in which each cell is partially connected.

In addition, a non-foamed resin molded body refers to a non-foamed body that does not have a fiber base material and is composed of a predetermined resin. A non-foamed body refers to a body that does not have air bubbles as described above. In the first embodiment, non-foamed molded articles of resin include those obtained by applying a curable composition to a base material such as a film and then curing the same. More specifically, the resin cured product formed by a labia coater method, a small diameter gravure coater method, a reverse roll coater method, a transfer roll coater method, a kiss coater method, a die coater method, a screen printing method, a spray coating method, etc. Included in non-foamed molded products.

Furthermore, a resin-impregnated base material refers to a material obtained by impregnating a fiber base material with a resin. Here, the fiber base material is not particularly limited, and examples thereof include woven fabrics, nonwoven fabrics, and knitted fabrics.

4. Method for producing a polished object The method for producing a polished object according to the present embodiment includes a polishing step of polishing an object to be polished using the above-described polishing pad in the presence of a polishing slurry to obtain a polished object; and an endpoint detection step of performing endpoint detection by an optical endpoint detection method.

4.1. Polishing process The polishing process may be primary lapping polishing (rough lapping), secondary lapping (finish lapping), primary polishing (rough polishing), or secondary polishing (finish polishing). ), or may also serve as polishing. Here, "lapping" refers to polishing at a relatively high rate using coarse abrasive grains, and "polishing" refers to increasing the surface quality at a relatively low rate using fine abrasive grains. Say to polish for.

Among these, the polishing pad of the present embodiment is preferably used for chemical mechanical polishing (CMP). The method for producing a polished object of this embodiment will be described below using chemical mechanical polishing as an example, but the method for producing a polished object of this embodiment is not limited to the following.

The object to be polished is not particularly limited, but for example, materials such as semiconductor devices and electronic components, particularly Si substrates (silicon wafers), SiC (silicon carbide) substrates, GaAs (gallium arsenide) substrates, glass, hard disks and LCDs. Thin substrates (objects to be polished) such as substrates for (liquid crystal displays) can be mentioned. In particular, semiconductor devices having metal wiring such as W (tungsten) and Cu (copper) are mentioned.

A conventionally known method can be used as the polishing method, and is not particularly limited. For example, first, an object to be polished held on a holding surface plate arranged to face the polishing pad is pressed against the polishing surface, and the polishing pad and/or the holding surface plate are rotated while slurry is supplied from the outside. Let The polishing pad and the holding platen may rotate in the same direction or in opposite directions at different rotational speeds. Further, the object to be polished may be polished while moving (rotating) inside the frame during the polishing process.

Depending on the object to be polished, polishing conditions, etc., the slurry may contain water, chemical components such as oxidizing agents represented by hydrogen peroxide, additives, abrasive grains (abrasive particles; for example, SiC, SiO ₂ , Al ₂ O ₃ , CeO ₂ ) and the like.

4.2. End Point Detection Step The method for manufacturing a polished workpiece according to the present embodiment has an end point detection step of detecting the end point by an optical end point detection method in the polishing step. Specifically, a conventionally known method can be used as the end point detection method by the optical end point detection method.

FIG. 13 shows a schematic diagram of the endpoint detection method of the optical endpoint detection method. This schematic diagram shows a chemical mechanical polishing process in which a wafer W held by a top ring 90 is pressed onto a polishing pad 1 affixed on a table 91 while slurry 92 is flowing therethrough, and the uneven film on the surface of the wafer W is scraped and flattened. . The polishing apparatus 94 has a film thickness detection sensor 93 mounted on the table 91 for monitoring the film thickness in order to detect a predetermined film thickness at the end point and finish the process with high accuracy at the same time as the planarization. The film thickness detection sensor 93 can detect the polishing end point by, for example, irradiating the polishing surface of the wafer W with light and measuring and analyzing the spectral intensity characteristics of the reflected light.

More specifically, the film thickness detection sensor 93 causes light to enter the surface of the wafer W through the end point detection window 51, and the light reflected by the film on the wafer W (wafer surface) and the film on the wafer W are detected. A film thickness change can be detected by detecting the strength of the reflection intensity caused by the phase difference with respect to the light reflected at the interface between the wafer and the substrate.

5. Aspects Based on the above disclosure, the following aspects are further recognized as the present invention.

5.1. Aspect A
Aspect A is, inter alia, an aspect aimed at providing a manufacturing method capable of more easily manufacturing a polishing pad having an endpoint detection window. Its configuration is as follows.

[1]
A method for manufacturing a polishing pad comprising a polishing layer with an endpoint detection window, comprising:
a curing step of fixing the end-point detection window member in the mold and curing the curable resin in a state of contact with the end-point detection window member to form a resin sheet in which the end-point detection window member is incorporated;
a slicing step of slicing the resin sheet to form a polishing layer;
In the curing step, the end point detection window member is suspended and fixed by a position fixing jig installed above the mold.
A method for manufacturing a polishing pad.
[2]
In the curing step, the mold is filled with a curable resin, and then the end point detection window member is brought into contact with the curable resin to cure the curable resin.
[1] The method for producing a polishing pad according to [1].
[3]
In the curing step, after fixing the end point detection window member in the mold, a curable resin is filled and cured.
[1] The method for producing a polishing pad according to [1].
[4]
The endpoint detection window member has a columnar portion that serves as an endpoint detection window, and a pedestal portion for fixing the endpoint detection window member to the position fixing jig.
[1] A method for producing a polishing pad according to any one of [3].
[5]
The position fixing jig has a first fitting part that fits with the upper part of the mold,
[1] A method for producing a polishing pad according to any one of [4].
[6]
The mold has a second fitting portion that fits with the position fixing jig,
[1] A method for producing a polishing pad according to any one of [5].
[7]
The position fixing jig has a positioning portion that positions and fixes the end point detection window member,
[1] A method for producing a polishing pad according to any one of [6].
[8]
a groove forming step of performing groove processing on the polishing surface of the polishing layer;
Grooving is not performed on the exposed portion of the end point detection window member before the groove forming step.
[1] A method for producing a polishing pad according to any one of [7].
[9]
A lamination step of laminating a base material layer and/or a cushion layer on the surface of the polishing layer opposite to the polishing surface,
[1] A method for producing a polishing pad according to any one of [8].

5.2. Aspect B
Aspect B aims to provide a method of manufacturing a polishing pad that can easily adjust the position of the end-point detection window member while suppressing the positional deviation of the end-point detection window member. It is a mode. Its configuration is as follows.

[1]
A method for manufacturing a polishing pad comprising a polishing layer with an endpoint detection window, comprising:
a curing step of fixing an endpoint detection window member in a mold and curing a curable resin in a state of contact with the endpoint detection window member to form a resin sheet in which the endpoint detection window member is incorporated; ,
a slicing step of slicing the resin sheet to form a polishing layer;
In the curing step, the end point detection window member is held by a holding portion of a position fixing jig installed on the upper portion of the mold, thereby being suspended and fixed.
A method for manufacturing a polishing pad.
[2]
In the curing step, the mold is filled with a curable resin, and then the end point detection window member is brought into contact with the curable resin to cure the curable resin.
[1] The method for producing a polishing pad according to [1].
[3]
In the curing step, after fixing the end point detection window member in the mold, a curable resin is filled and cured.
[1] The method for producing a polishing pad according to [1].
[4]
The position fixing jig has a through hole through which the end point detection window member is inserted,
The holding portion holds the end point detection window member inserted through the through hole.
[1] A method for producing a polishing pad according to any one of [3].
[5]
The holding portion detachably holds the end point detection window member,
[1] A method for producing a polishing pad according to any one of [4].
[6]
The position fixing jig has a first fitting part that fits with the upper part of the mold,
[1] A method for producing a polishing pad according to any one of [5].
[7]
The mold has a second fitting portion that fits with the position fixing jig,
[1] A method for producing a polishing pad according to any one of [6].
[8]
a groove forming step of performing groove processing on the polishing surface of the polishing layer;
Grooving is not performed on the exposed portion of the end point detection window member before the groove forming step.
[1] A method for producing a polishing pad according to any one of [7].
[9]
A lamination step of laminating a base material layer and/or a cushion layer on the surface of the polishing layer opposite to the polishing surface,
[1] A method for producing a polishing pad according to any one of [8].

5.3. Aspect C
Aspect C aims to provide a method for manufacturing a polishing pad in which air bubbles are less likely to occur when the curable resin is cured while in contact with the end-point detection window member suspended from the mold and fixed. It is a mode. Its configuration is as follows.

[1]
A method for manufacturing a polishing pad comprising a polishing layer with an endpoint detection window, comprising:
a curing step of fixing an endpoint detection window member in a mold and curing a curable resin in a state of contact with the endpoint detection window member to form a resin sheet in which the endpoint detection window member is incorporated; ,
a slicing step of slicing the resin sheet to form a polishing 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 lower end of the endpoint detection window member when suspended and fixed has a convex shape,
A method for manufacturing a polishing pad.
[2]
In the curing step, the mold is filled with a curable resin, and then the end point detection window member is brought into contact with the curable resin to cure the curable resin.
[1] The method for producing a polishing pad according to [1].
[3]
In the curing step, after fixing the end point detection window member in the mold, a curable resin is filled and cured.
[1] The method for producing a polishing pad according to [1].
[4]
further comprising a window member forming step of forming the endpoint detection window member having at least one end with the convex shape;
[1] A method for producing a polishing pad according to any one of [3].
[5]
The length L of the portion having the convex shape of the endpoint detection window member is 3.0 to 20 mm.
[1] A method for producing a polishing pad according to any one of [4].
[6]
The ratio (L/S) of the length L of the convex portion of the endpoint detection window member to the horizontal cross-sectional area S of the endpoint detection window member is 0.002 to 0.4. be,
[1] A method for producing a polishing pad according to any one of [5].
[7]
The length L of the portion having the convex shape of the end point detection window member is 0.03 to 0.30 Lw with respect to the total length Lw of the end point detection window member.
[1] A method for producing a polishing pad according to any one of [6].
[8]
The position fixing jig has a first fitting part that fits with the upper part of the mold,
[1] A method for producing a polishing pad according to any one of [7].
[9]
The mold has a second fitting portion that fits with the position fixing jig,
[1] A method for producing a polishing pad according to any one of [8].
[10]
The position fixing jig has a positioning portion that positions and fixes the end point detection window member,
[1] A method for producing a polishing pad according to any one of [9].
[11]
a groove forming step of performing groove processing on the polishing surface of the polishing layer;
Grooving is not performed on the exposed portion of the end point detection window member before the groove forming step.
[1] The method for producing a polishing pad according to any one of [10].
[12]
A lamination step of laminating a base material layer and/or a cushion layer on the surface of the polishing layer opposite to the polishing surface,
[1] A method for producing a polishing pad according to any one of [11].

5.4. Aspect D
Aspect D is an aspect aimed at providing a method of manufacturing a polishing pad that can efficiently remove air bubbles in a shorter time. Its configuration is as follows.

[1]
A method for manufacturing a polishing pad having an endpoint detection window, comprising:
a rotational motion step of revolving on a predetermined circumference at 200 to 1600 rpm while rotating the container containing the prepared window material raw material at 100 to 800 rpm;
a window material curing step for obtaining an endpoint detection window member by curing the window material raw material after the rotational movement;
A method for manufacturing a polishing pad.
[2]
performing the rotational movement step under reduced pressure;
[1] The method for producing a polishing pad according to [1].
[3]
The processing time of the rotational motion step is 1 to 10 minutes,
A method for producing a polishing pad according to [1] or [2].
[4]
The temperature of the rotational motion step is 50 to 130°C,
[1] A method for producing a polishing pad according to any one of [3].
[5]
The inclination of the axis of rotation and the axis of revolution in the rotational motion step is 20 to 70°.
[1] A method for producing a polishing pad according to any one of [4].
[6]
The window material raw material contains a polyisocyanate, a polyol, and a curing agent,
[1] A method for producing a polishing pad according to any one of [5].
[7]
a groove forming step of performing groove processing on the polishing surface of the polishing layer provided with the end point detection window member;
[1] A method for producing a polishing pad according to any one of [6].
[8]
a lamination step of laminating a base material layer and/or a cushion layer on the surface opposite to the polishing surface of the polishing layer provided with the end point detection window member;
[1] A method for producing a polishing pad according to any one of [7].

5.5. Aspect E
Aspect E is, inter alia, an aspect aimed at providing a manufacturing method that can more easily obtain an endpoint detection window material having uniform physical properties. Its configuration is as follows.

[1]
A method for manufacturing an endpoint detection window material in a polishing pad with an endpoint detection window, comprising:
a first mixing step of mixing the polyisocyanate, the polyol and a portion of the curing agent to form a first reaction mixture;
a second mixing step of mixing the first reaction mixture with the remainder of the curing agent to form a second reaction mixture;
a window material curing step of curing the second reaction mixture to obtain the endpoint detection window material;
the curing agent has 3 or more functional groups;
A method for manufacturing an endpoint detection window material.
[2]
When the sum of the amount a of the curing agent used in the first mixing step and the amount b of the curing agent used in the second mixing step is 100% by mass,
The amount a used is 10 to 90% by mass,
[1] The method for manufacturing the endpoint detection window material described above.
[3]
the curing agent comprises a low molecular weight polyol having a molecular weight of less than 300;
[1] or [2] manufacturing method of the endpoint detection window material.
[4]
The polyol contains a high molecular weight polyol having a molecular weight of 300 or more,
[1] A method for manufacturing an endpoint detection window material according to any one of [3].
[5]
The polyisocyanate comprises an alicyclic polyisocyanate and/or an aliphatic polyisocyanate,
[1] to [4] A method for manufacturing an endpoint detection window material according to any one of items.
[6]
An endpoint detection window material in a polishing pad with an endpoint detection window,
The standard deviation of the D hardness (D _W20 to D _W80 ) at 20° C. to 80° C. of the center and both ends of the endpoint detection window material is 1.5 or less.
Endpoint detection window material.
[7]
The endpoint detection window material according to [6];
a polishing layer comprising the endpoint detection window material;
polishing pad.

5.6. Mode F
Aspect F is, inter alia, an aspect aimed at providing a manufacturing method capable of more easily manufacturing a polishing pad having an endpoint detection window. Its configuration is as follows.

[1]
a first acquisition step of acquiring position information of an endpoint detection window provided in the opening of the resin sheet;
a first hole forming step of forming a hole in a portion corresponding to the installation position of the end point detection window on the adhesive sheet based on the position information;
a first bonding step in which the end point detection window and the hole are aligned and the resin sheet and the adhesive surface of the adhesive sheet are bonded together;
A method for manufacturing a polishing pad.
[2]
The positional information is based on image information obtained by an imaging device, or information obtained by receiving a laser beam that has passed through an end point detection window among the laser beams applied to the resin sheet by a laser receiver. be,
[1] The method for producing a polishing pad according to [1].
[3]
forming the hole smaller than the endpoint detection window in the first hole forming step;
A method for producing a polishing pad according to [1] or [2].
[4]
the position information includes information about the center position of the endpoint detection window;
In the first hole forming step, the hole is formed so that the center position of the endpoint detection window and the center position of the hole match.
[1] A method for producing a polishing pad according to any one of [3].
[5]
The resin sheet has a plurality of endpoint detection windows,
[1] A method for producing a polishing pad according to any one of [4].
[6]
The pressure-sensitive adhesive sheet is a double-sided tape or a laminate of a double-sided tape and another layer,
[1] A method for producing a polishing pad according to any one of [5].
[7]
When the adhesive sheet is the double-sided tape,
a second acquisition step of acquiring position information of holes formed in the double-sided tape on the resin sheet;
a second hole forming step of forming a hole in a portion corresponding to the installation position of the endpoint detection window on another layer based on the position information;
a second bonding step of aligning the holes in the double-sided tape with the holes in the other layer and bonding the double-sided tape on the resin sheet and the other layer;
[6] The method for producing a polishing pad according to [6].

The endpoint detection window material will be described in more detail below. The present invention is by no means limited by the following examples.

[Example 1]
(Production of endpoint detection window material)
Poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000, glycerin, and 4,4′-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI) window material raw materials were preheated at 80° C., and the number average 120.9 parts by mass of poly(oxytetramethylene) glycol (PTMG) having a molecular weight of 1000, 7.4 parts by mass of glycerin, 4,4′-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI) 100 parts by mass, A first reaction mixture was obtained by mixing by performing vacuum stirring and defoaming under room temperature conditions for 15 minutes.

After that, 7.4 parts by mass of glycerin was added to the first reaction mixture, and vacuum stirring and defoaming were performed for 1 to 2 minutes at room temperature to obtain a second reaction mixture.

The resulting second reaction mixture was poured into a mold and heated (precured) at 120°C for 30 minutes, after which the cured reaction mixture was removed from the mold and post-cured at 120°C for 6 hours. It was cured to produce a transparent endpoint detection window material.

[Example 2]
An endpoint detection window material was prepared in the same manner as in Example 1, except that the second mixing step was omitted and the entire amount of glycerin as a curing agent was mixed in the first mixing step (one-shot method).

Separately prepared window members were sliced to prepare polyurethane sheets, which were used in the following tests as Examples 1 and 2, respectively.

[Evaluation of variation in physical properties]
D hardness measurement was performed at each temperature in order to confirm variations in hardness change with temperature rise.
The D hardness was measured according to JIS K6253. In the measurement, a metal plate was placed under the end point detection window material, and a D hardness tester manufactured by Teclock was used under the same conditions as the actual polishing process (polishing pad attached to the metal surface plate of the polishing apparatus). It was measured. The sample was prepared by stacking four polyurethane sheets (thickness: about 0.125 cm (1.25 mm)) so that the total thickness would be at least 0.45 cm (4.5 mm).

For Examples 1 and 2, the variation in physical properties was evaluated by performing D hardness measurement at each temperature. If the D hardness varies at each temperature, the surface shape of the endpoint detection window material will not be stable during slicing. The end point cannot be detected accurately. Also, if the surface of the window is convex, it may hit the object to be polished and cause scratches or the like. Based on the above, the standard deviation of heat resistance between samples (1) and (2) of Example 1 and between samples (1) and (2) of Example 2 was evaluated as variation in physical properties, and the results are shown in Table 1 and It is shown in FIG.

From Table 1, the standard deviation of D hardness between samples (1) and (2) of Example 1 is 1.0 or less at 20 ° C. to 80 ° C., whereas samples (1) to ( 2) The standard deviations of D hardness between 20° C., 40° C., and 80° C. are 3.0, 4.0, and 2.0, respectively. It was found that variations in heat resistance can be controlled while using a manufacturing method that is simple in terms of work.

Further, in Examples 1 and 2, the D hardness was measured at each temperature at the top, center, and bottom of a cylindrical window member (length 60 mm) to evaluate the variation in D hardness at each temperature. did. Table 2 shows the results.

From Table 2, the standard deviation of D hardness in Example 1 is 1.5 or less at 20 ° C. to 80 ° C., whereas the standard deviation of D hardness in Example 2 is 1 at 20 ° C. to 80 ° C. 7, 1.9, 1.7 and 1.9, the manufacturing method of the present embodiment can be used to control variations in heat resistance while using a simple manufacturing method in terms of manufacturing work. It turns out that it can be done.

The method for manufacturing a polishing pad of the present invention has industrial applicability as an efficient method for manufacturing a polishing pad suitable for an optical endpoint detection method.

DESCRIPTION OF SYMBOLS 1... Polishing pad 10... End point detection window member 10a... Lower end 11... Columnar part 12... Pedestal part 20... Mold 21... Bottom surface 22... Side wall 30... Position fixing jig 31... Clamping Parts 32... Adjusting part 33... Through hole 40... Curing resin 50... Polishing layer 50a... Polishing surface 51... End point detection window 52... Cushion layer 53... Adhesive layer 54... Adhesive layer 55 Groove 61 Adhesive sheet 62 Release sheet 71 Other layer 90 Top ring 91 Table 92 Slurry 93 Film thickness detection sensor 94 Polishing device 100 First production Apparatus 110 Conveying mechanism 120 Imaging device 130 Hole forming device 141 Roller 142 Roller 143 Roller 200 Second manufacturing device 210 Conveying mechanism 220 Imaging device 230 Hole Forming device 241 Roller 242 Roller L Length of portion having convex shape Lw Total length S Cross-sectional area S1 Area W Wafer

Claims

A method for manufacturing a polishing pad comprising a polishing layer with an endpoint detection window, comprising:
a curing step of fixing an endpoint detection window member in a mold and curing a curable resin in a state of contact with the endpoint detection window member to form a resin sheet in which the endpoint detection window member is incorporated; ,
a slicing step of slicing the resin sheet to form a polishing layer;
In the curing step, the end point detection window member is suspended and fixed by a position fixing jig installed above the mold.
A method for manufacturing a polishing pad.
In the curing step, the mold is filled with a curable resin, and then 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 according to claim 1 .
In the curing step, after fixing the end point detection window member in the mold, a curable resin is filled and cured.
A method for manufacturing the polishing pad according to claim 1 .
The position fixing jig has a first fitting part that fits with the mold upper part, and/or
The mold has a second fitting portion that fits with the position fixing jig,
A method for manufacturing a polishing pad according to any one of claims 1 to 3.
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 claims 1 to 4.
In the curing step, the end point detection window member is suspended and fixed by being clamped by the clamping part of the position fixing jig installed on the upper part of the mold,
The holding portion detachably holds the end point detection window member,
A method for manufacturing a polishing pad according to any one of claims 1 to 5.
In the curing step, the end point detection window member is suspended and fixed by being clamped by the clamping part of the position fixing jig installed on the upper part of the mold,
A lower end of the endpoint detection window member when suspended and fixed has a convex shape,
A method for producing a polishing pad according to any one of claims 1 to 6.
The length L of the portion having the convex shape of the endpoint detection window member is 3.0 to 20 mm.
A method for manufacturing a polishing pad according to claim 7 .
The ratio (L/S) of the length L of the convex portion of the endpoint detection window member to the horizontal cross-sectional area S of the endpoint detection window member is 0.002 to 0.4. be,
A method for manufacturing a polishing pad according to claim 7 or 8.
The length L of the portion having the convex shape of the end point detection window member is 0.03 to 0.30 Lw with respect to the total length Lw of the end point detection window member.
A method for producing a polishing pad according to any one of claims 7 to 9.
further comprising a step of manufacturing the endpoint detection window member,
The manufacturing process is
A first mixing step of mixing polyisocyanate, polyol, and part of a curing agent, which are raw materials for window materials, to prepare a first reaction mixture, and mixing the first reaction mixture with the remainder of the curing agent. , a second mixing step of preparing a second reaction mixture, and a window material curing step of curing the second reaction mixture to obtain the endpoint detection window member,
The curing agent contained in the window material raw material has 3 or more functional groups.
A method for manufacturing a polishing pad according to any one of claims 1 to 10.
The curing agent contained in the window material raw material contains a low-molecular-weight polyol having a molecular weight of less than 300.
A method for manufacturing a polishing pad according to claim 11 .
The polyol contained in the window material raw material contains a high-molecular-weight polyol having a molecular weight of 300 or more.
A method for manufacturing a polishing pad according to claim 11 or 12.
The polyisocyanate contained in the window material raw material contains an alicyclic polyisocyanate and/or an aliphatic polyisocyanate.
A method for manufacturing a polishing pad according to any one of claims 11 to 13.
a first acquisition step of acquiring position information of an endpoint detection window provided in the opening of the resin sheet;
a first hole forming step of forming a hole in a portion corresponding to the installation position of the end point detection window on the adhesive sheet based on the position information;
a first bonding step in which the end point detection window and the hole are aligned and the resin sheet and the adhesive surface of the adhesive sheet are bonded together;
A method for manufacturing a polishing pad according to any one of claims 1 to 14.
The positional information is based on image information obtained by an imaging device, or information obtained by receiving, with a laser receiver, the laser beam that has passed through the end point detection window among the laser beams applied to the resin sheet. is
A method for manufacturing a polishing pad according to claim 15 .
forming the hole smaller than the endpoint detection window in the first hole forming step;
A method for manufacturing a polishing pad according to claim 15 or 16.
the position information includes information about the center position of the endpoint detection window;
In the first hole forming step, the hole is formed so that the center position of the endpoint detection window and the center position of the hole match.
A method for manufacturing a polishing pad according to any one of claims 15 to 17.
The pressure-sensitive adhesive sheet is a double-sided tape or a laminate of a double-sided tape and another layer,
A method for manufacturing a polishing pad according to any one of claims 15 to 18.
When the adhesive sheet is the double-sided tape,
a second acquisition step of acquiring position information of holes formed in the double-sided tape on the resin sheet;
a second hole forming step of forming a hole in a portion corresponding to the installation position of the endpoint detection window on another layer based on the position information;
a second bonding step of aligning the holes in the double-sided tape with the holes in the other layer and bonding the double-sided tape on the resin sheet and the other layer;
A method for manufacturing a polishing pad according to claim 19 .