JP7624858B2 - Method for manufacturing polishing pad - Google Patents

Description

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

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

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

The main methods for detecting the polishing end point are known to be optical end point detection, torque end point detection, and eddy current end point detection. In the optical end point detection method, the end point is detected by irradiating the wafer with light through a transparent window member installed on the polishing pad and monitoring the reflected light.

As a method for manufacturing a polishing pad using such an optical end point detection method, for example, Patent Document 1 discloses a method for manufacturing a laminated polishing pad that includes a process for forming an opening by removing the support layer and the peelable protective member in the portion corresponding to the light transmitting region. In addition, Patent Document 2 discloses providing an alignment notch for aligning the openings with each other in a polishing pad having a transparent sheet in the opening.

JP 2013-219276 A JP 2001-291686 A

The invention of Patent Document 1 is a method of forming an opening after laminating each layer, in which the portion corresponding to the light-transmitting region is protected with a peelable protective member to prevent the portion from being scratched or foreign matter from adhering to the portion. However, in order to remove the peelable protective member after forming the opening, it is necessary to form the opening larger than the peelable protective member. As a result, when forming the opening, the portion where the peelable protective member does not exist is cut, so there is a risk of damaging the polishing layer and the end point detection window, which is a concern as it may lead to a decrease in the strength of the polishing pad and a decrease in the optical characteristics required for end point detection. In addition, in the method of providing an alignment notch as in Patent Document 2, the alignment notch is present at the end of the polishing layer, and even if the size of the alignment notch is limited, there is a risk of adversely affecting the polishing performance.

The present invention was made in consideration of the above problems, and aims to provide a manufacturing method that can more easily manufacture a polishing pad with an end point detection window.

That is, the present invention is as follows.
[1]
a first acquisition step of acquiring position information of an end point detection window provided in an opening of the resin sheet;
a first hole forming step of forming a hole in a portion of the adhesive sheet corresponding to a position where the end point detection window is to be installed based on the position information;
a first bonding step of aligning the end point detection window with the hole and bonding the resin sheet to the adhesive surface of the adhesive sheet;
A method for manufacturing a polishing pad.
[2]
The position information is based on image information obtained by an imaging device, or information obtained by receiving, by a laser receiver, the laser light that is irradiated on the resin sheet and that has passed through an end point detection window.
A method for producing the polishing pad described in [1].
[3]
In the first hole forming step, the hole is formed to be smaller than the end point detection window.
A method for producing a polishing pad according to [1] or [2].
[4]
the position information includes information regarding a center position of the end point detection window,
In the first hole forming step, the hole is formed so that a center position of the end point detection window coincides with a center position of the hole.
A method for producing a polishing pad according to any one of [1] to [3].
[5]
The resin sheet has a plurality of the end point detection windows.
A method for producing a polishing pad according to any one of [1] to [4].
[6]
The pressure-sensitive adhesive sheet is a double-sided tape or a laminate of a double-sided tape and another layer.
A method for producing a polishing pad according to any one of [1] to [5].
[7]
When the pressure-sensitive 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 of the other layer corresponding to the installation position of the endpoint detection window based on the position information;
and a second bonding step of aligning the hole in the double-sided tape with the hole in the other layer, and bonding the double-sided tape on the resin sheet to the other layer.
A method for producing a polishing pad according to [6].

The present invention provides a manufacturing method that can more easily manufacture a polishing pad with an end point detection window.

3A to 3C are schematic cross-sectional views showing an embodiment of a first obtaining step, a first hole forming step, and a first bonding step in the method for manufacturing a polishing pad according to the present embodiment. 3A to 3C are schematic cross-sectional views showing an embodiment of a second obtaining step, a second hole forming step, and a second bonding step in the method for manufacturing a polishing pad according to the present embodiment. FIG. 2 is a top view showing one aspect of the resin sheet of the present embodiment. 1 is a schematic perspective view of a polishing pad according to an embodiment of the present invention. 3 is a schematic cross-sectional view of an end point detection window portion of the polishing pad of the present embodiment. FIG.

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

1. Method for Manufacturing Polishing Pad The method for manufacturing a polishing pad of this embodiment includes a first acquisition step of acquiring position information of an end point detection window provided in an opening of a resin sheet, a first hole formation step of forming a hole in a portion of the adhesive sheet corresponding to the installation position of the end point detection window based on the position information, and a first bonding step of aligning the end point detection window and the hole and bonding the adhesive surface of the resin sheet and the adhesive sheet together.

In addition, the manufacturing method of the polishing pad of this embodiment may further include, when the adhesive sheet is a double-sided tape, a second acquisition step of acquiring position information of a hole formed in the double-sided tape on the resin sheet, a second hole formation step of forming a hole in a portion of the other layer corresponding to the installation position of the end point detection window based on the position information, and a second bonding step of aligning the hole in the double-sided tape with the hole in the other layer and bonding the double-sided tape on the resin sheet to the other layer. Note that the "other layer" here may be a cushion layer.

Each step is explained in detail below using Figures 1 and 2, which are schematic cross-sectional views of each step.

The method for manufacturing a polishing pad may include a cutting step for adjusting the outer shape of the resin sheet 11 having the embedded end point detection windows 12 before the first obtaining step. In the cutting step, a center position O that is equidistant from each of the end point detection windows 12 may be specified based on the positions of the multiple end point detection windows 12, and the resin sheet 11 may be cut into a predetermined square shape with the center at that position.

This makes it possible to obtain a resin sheet 11 having a standardized outer shape based on the center position O identified by the end point detection window 12. Then, by subjecting the resin sheet 11 with such a fixed shape to each process described below, each process can be performed with greater precision.

The resin sheet 11 provided to the first acquisition process and thereafter may be one after it has been punched into a circle, or may be one before it has been punched into a circle in a rectangular shape as shown in FIG. 3, which shows a top view of one embodiment of the resin sheet 11. Of these, a rectangular shape is preferable when carrying out each of the subsequent alignment processes, such as regulating the orientation of the resin sheet 11 during transport. When carrying out each process with the resin sheet 11 in a rectangular state, in the final stage after each process, the polishing pad may be obtained by further punching into a circle based on the center position O identified by the end point detection window 12.

1.2 First Acquisition Step The first acquisition step is a step of acquiring position information of the end point detection window 12 provided in the opening of the resin sheet 11. The resin sheet may have a plurality of end point detection windows.

In FIG. 1, the first manufacturing apparatus 100 includes a conveying mechanism 110 such as a belt conveyor that conveys a resin sheet 11 having an end point detection window 12, an imaging device 120 that acquires position information of the end point detection window 12 provided in the opening of the resin sheet 11, a roller 141 that feeds out an adhesive sheet 21 with a release sheet 22 attached, a hole forming device 130 that forms an opening in the fed adhesive sheet 21, a roller 142 that peels off the release sheet 22 from the adhesive sheet 21 with the hole formed therein, and a roller 143 that bonds the resin sheet 11 and the adhesive sheet 21 together while aligning the hole in the adhesive sheet 21 from which the release sheet 22 has been peeled off with the end point detection window 12 of the resin sheet 11.

Here, the transport mechanism 110, the imaging device 120, the hole forming device 130, and the rollers 141, 142, and 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. Drive control of the transport mechanism 110, the imaging device 120, the hole forming device 130, and the rollers 141, 142, and 143, and information transmission can be performed via this control unit.

The method of acquiring the position information of the end point detection window 12 is not particularly limited, but for example, it can be acquired from image information captured when the resin sheet 11 transported in the direction of arrow F by the transport mechanism 110 passes directly below the imaging device 120. At this time, the transport mechanism 110 may be driven so that the resin sheet 11 pauses directly below the imaging device 120 for imaging.

The method for extracting the position information of the end point detection window 12 from the image information thus obtained is not particularly limited, but examples include a method of identifying the end point detection window 12 based on differences in the color shades of the resin sheet 11 and the end point detection window 12 in the image information and identifying its contour; and a method of identifying the end point detection window 12 from the image information by image processing such as edge detection and identifying its contour.

In addition, a laser receiver may be used instead of the imaging device 120. For example, the position of the end point detection window 12 may be identified based on information obtained by receiving the laser light that is irradiated on the resin sheet 11 and that has passed through the end point detection window 12 using the laser receiver.

At this time, the conveying mechanism 110 may be driven to temporarily suspend the resin sheet 11 directly below the laser oscillator and laser receiver, and the laser oscillator and laser receiver may scan the resin sheet 11. Alternatively, the laser oscillator and laser receiver may be fixed midway along the conveying mechanism 110, and the conveying mechanism 110 may be kept moving at a constant speed, causing the laser oscillator and laser receiver to scan the resin sheet 11 relative to each other, thereby determining the position of the end point detection window 12.

Furthermore, the control unit may calculate the center position of the end point detection window 12 based on information about the contour of the end point detection window 12 thus obtained from the image information. The position information, such as the contour and center position of the end point detection window 12 thus obtained, may be transmitted to the hole forming device 130 via the control unit.

1.3. First hole forming process The first hole forming process is a process of forming a hole in a portion of the adhesive sheet corresponding to the installation position of the end point detection window based on the position information. Here, the adhesive sheet may be a double-sided tape or a laminate of the double-sided tape and another layer such as a cushion layer.

Specifically, the control unit controls the drive of the roller 141 to feed out the adhesive sheet 21, and transmits the position information of the end point detection window 12 to the hole forming device 130, and the hole forming device 130 forms a hole in the part of the fed adhesive sheet 21 that corresponds to the installation position of the end point detection window. When the hole forming device 130 forms a hole, the roller 141 may be temporarily stopped.

At this time, the hole forming device 130 may form a hole smaller than the end point detection window 12. More specifically, the control unit transmits position information including information about the contour of the end point detection window 12 and its center position to the hole forming device 130, and the hole forming device 130 can form a hole smaller than the contour while aligning the center position of the end point detection window 12 so that it coincides with the center position of the hole to be formed.

This allows the adhesive sheet 21, in which a hole smaller than the end point detection window 12 is formed, to be attached to the resin sheet 11 while aligning the center position of the formed hole with the center position of the end point detection window 12. In this way, by making the hole in the adhesive sheet 21 to be attached smaller than the end point detection window 12, the end point detection window 12 can be supported from the back side of the resin sheet 11 by the adhesive sheet 21. This further improves the durability of the resulting polishing pad.

The first bonding step is a step of bonding the adhesive surface of the adhesive sheet to the resin sheet by aligning the end point detection window with the hole. The adhesive sheet after bonding may be cut to fit the size of the resin sheet.

Specifically, the control unit drives and controls roller 141 to further feed adhesive sheet 21 with holes formed therein, and drives and controls roller 142 to wind up the release sheet that has been attached to the adhesive surface of adhesive sheet 21. At the same time, the control unit drives conveying mechanism 110 to further feed resin sheet 11 in the direction of arrow F, aligns end point detection window 12 with the holes, and attaches resin sheet 11 to the adhesive surface of adhesive sheet 21.

At this time, the control unit can drive and control the rollers 143 and the transport mechanism 110 while calculating the positional relationship between the adhesive sheet 21 sent out by the rollers 141 and the resin sheet 11 transported by the transport mechanism 110. Furthermore, in the drive control, the moving distance of the resin sheet 11 and the adhesive sheet 21 can be controlled based on information on the center position of the hole formed in the adhesive sheet 21 and information on the center position of the end point detection window 12 of the resin sheet 11 so that these center positions overlap, and the resin sheet 11 and the adhesive sheet 21 are bonded together.

This allows the end point detection window 12 and the hole formed in the adhesive sheet 21 to be attached in a state where they overlap concentrically. Therefore, for example, as shown in FIG. 5, which shows a cross-sectional view of the periphery of the end point detection window 12, if the hole formed in the adhesive sheet 21 is smaller than the end point detection window 12, the end point detection window 12 can be supported from the back side of the resin sheet 11 by the adhesive sheet 21. This further improves the durability of the resulting polishing pad.

1.5. Second Obtaining Step The second obtaining step is a step of obtaining position information of holes in the double-sided tape that has been attached to the resin sheet 11 in the first attaching step.

In FIG. 2, the second manufacturing apparatus 200 includes a conveying mechanism 210 that conveys the resin sheet 11, an imaging device 220 that acquires positional information of holes in the double-sided tape, a roller 241 that feeds out the other layer 31, a hole forming device 230 that forms openings in the fed out other layer 31, and a roller 242 that bonds the resin sheet 11 and the other layer 31 together while aligning the holes in the other layer 31 with the holes in the double-sided tape of the resin sheet 11.

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

The method for acquiring the position information of the holes in the double-sided tape attached to the resin sheet 11 is not particularly limited, but examples include the method using an imaging device or the method using a laser receiver described in the first acquisition process above.

The second hole forming step is a step of forming a hole in a portion of the other layer corresponding to the installation position of the end point detection window based on the position information acquired in the second acquisition step. Here, the other layer may be a cushion layer or a cushion layer to which double-sided tape is attached.

Specifically, the control unit controls the drive of the roller 241 to send out the other layer 31, and transmits position information of the holes in the double-sided tape to the hole forming device 230, and the hole forming device 230 forms holes in the parts of the other layer 31 that correspond to the installation positions of the double-sided tape. When the hole forming device 230 is performing hole formation, the roller 241 may be temporarily stopped.

1.7. Second bonding step The second bonding step is a step of bonding the double-sided tape on the resin sheet to the other layer by aligning the holes in the double-sided tape with the holes in the other layer. The other layer after bonding may be cut to fit the size of the resin sheet.

Specifically, the second control unit drives and controls the roller 242 to further feed the adhesive sheet 21 with the holes formed therein, and drives the conveying mechanism 210 to further feed the resin sheet 11 in the direction of the arrow F, aligning the holes in the double-sided tape with the holes in the other layer, and bonding the adhesive surface of the resin sheet 11 (adhesive sheet 21) to the other layer 31.

Even in this case, the transport mechanism 210 and the roller 242 may be driven and controlled based on information on the center position of the hole formed in the other layer 31 and information on the center position of the hole in the double-sided tape of the resin sheet 11 so that these center positions overlap. This allows the holes formed in the other layer 31 and the holes in the double-sided tape of the resin sheet 11 to be bonded together in a state where they overlap concentrically, thereby further improving the durability of the resulting polishing pad.

In addition, the resin sheet 11 to which the other layer 31 is bonded as described above can be punched into a circular shape in a subsequent process and used as a polishing pad.

2. Polishing Pad A schematic perspective view of the polishing pad of this embodiment is shown in Fig. 4. As shown in Fig. 4, the polishing pad 10 of this embodiment has a polishing layer made of a resin sheet 11 and a plurality of end point detection windows 12, and may have another layer 31 such as a cushion layer 13 on the side opposite to the polishing surface 11a, as necessary.

Figure 5 shows a cross-sectional view of the periphery of the end point detection window 12 in Figure 4. As shown in Figure 5, an adhesive layer 14 (adhesive sheet 21) may be provided between the polishing layer (resin sheet 11) and the cushion layer 13 (other layer 31), and an adhesive layer 15 may be provided on the surface of the cushion layer 13 (other layer 31). The polishing surface 11a of the polishing pad of this embodiment may be flat, or may be uneven with grooves 16 formed therein, as shown in Figure 5.

The polishing pad manufacturing method of the present invention has industrial applicability as a method for efficiently manufacturing polishing pads that can be suitably used in optical endpoint detection methods.

10... polishing pad, 11... resin sheet, 11a... polishing surface, 12... end point detection window, 13... cushion layer, 14, 15... adhesive layer, 16... groove, 21... adhesive sheet, 22... release sheet, 31... other layers, 100... first manufacturing device, 110... conveying mechanism, 120... imaging device, 130... hole forming device, 141, 142, 143... roller, 200... second manufacturing device, 210... conveying mechanism, 220... imaging device, 230... hole forming device, 241, 242... roller

Claims (7)

a first acquisition step of acquiring position information of an end point detection window provided in an opening of the resin sheet;
a first hole forming step of forming a hole in a portion of the adhesive sheet corresponding to a position where the end point detection window is to be installed based on the position information;
a first bonding step of aligning the end point detection window with the hole and bonding the resin sheet to the adhesive surface of the adhesive sheet;
A method for manufacturing a polishing pad. The position information is based on image information obtained by an imaging device, or information obtained by receiving, by a laser receiver, the laser light that is irradiated on the resin sheet and that has passed through an end point detection window.
A method for producing the polishing pad according to claim 1 . In the first hole forming step, the hole is formed to be smaller than the end point detection window.
The method for producing the polishing pad according to claim 1 or 2. the position information includes information regarding a center position of the end point detection window,
In the first hole forming step, the hole is formed so that a center position of the end point detection window coincides with a center position of the hole.
The method for producing a polishing pad according to any one of claims 1 to 3. The resin sheet has a plurality of the end point detection windows.
The method for producing the polishing pad according to any one of claims 1 to 4. The pressure-sensitive adhesive sheet is a double-sided tape or a laminate of a double-sided tape and another layer.
The method for producing a polishing pad according to any one of claims 1 to 5. When the pressure-sensitive 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 of the other layer corresponding to the installation position of the endpoint detection window based on the position information;
and a second bonding step of aligning the hole in the double-sided tape with the hole in the other layer, and bonding the double-sided tape on the resin sheet to the other layer.
The method for producing the polishing pad according to claim 6 .