POLISHING PAD AND MANUFACTURING METHOD OF POLISHING PAD AND POLISHING METHOD

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 112118707, filed on May 19, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND
Field of the Invention

The disclosure relates to a polishing pad, a manufacturing method of the polishing pad, and a polishing method, and in particular, relates to a polishing pad with a detection window, a manufacturing method of the polishing pad, and a polishing method using the polishing pad.

Description of Related Art

In the industrial component manufacturing process, the polishing process is a technology commonly used today to planarize the surface of the object to be polished. In the polishing process, the object is polished by the relative movement between the object itself and the polishing pad, and by selectively providing a slurry between the surface of the object and the polishing pad.

For polishing equipment with an optical detection system, a certain area of the polishing layer of the polishing pad is usually disposed with a detection window. The function thereof is that when the polishing pad is used to polish an object, the user can use the optical detection system of the polishing equipment to detect the polishing condition of the object through the detection window, so as to serve as the end-point detection of the polishing process and ensure the polishing quality.

In some embodiments, the structure of the polishing pad with a detection window is such that the detection window material is directly bonded with the polishing layer material. As shown in FIG. 1, during polishing, relative movement is performed on the polishing surface of a polishing pad P in a rotational manner B or in a rotational manner B plus a left-right and back-forth swinging manner C by a polishing head H carrying an object S. The shear force and normal force generated during the aforementioned process will easily destroy the interface between the polishing layer and the detection window, thereby causing the slurry to leak between the polishing layer and the detection window during polishing, and affecting the polishing quality and the efficiency of the detection window.

Furthermore, the bonding strength between the detection window and the polishing layer is also limited by the material, and as the polishing pad polishes the object more times, the wear amount of the polishing pad increases, and the bonding area between the detection window and the polishing layer becomes smaller and smaller, making it difficult for the interface between the detection window and the polishing layer to withstand the stress of the polishing process.

Therefore, there exists a problem in the current polishing pad in which the interface bonding strength between the detection window and the polishing layer is insufficient, which results in leakage of the slurry, thereby affecting the lifetime of the polishing pad. In view of this, how to improve the bonding strength between the detection window and the polishing layer so that the polishing pad may have a favorable lifetime is currently one of the topics actively studied by those skilled in the art.

SUMMARY

The disclosure provides a polishing pad in which there is improved bonding strength between a detection window and a polishing layer.

A polishing pad of the disclosure includes a polishing layer and at least one detection window. The at least one detection window is located in the polishing layer. The at least one detection window includes a center portion and a cover portion surrounding the center portion. The cover portion is joined to the polishing layer. A ratio of an area of the center portion to an area of the cover portion is between about 0.03 to about 5.00.

A manufacturing method of a polishing pad of the disclosure includes the following steps. A detection window is formed, in which a center portion is pre-disposed in a first mold, and a covering material is filled into the first mold and a first curing process is performed to form a cover portion that covers the center portion. The detection window is pre-disposed in a second mold. A polishing layer material is filled into the second mold and a second curing process is performed to form a polishing layer joined to the cover portion.

A polishing method of the disclosure includes the following steps. A polishing pad is provided, in which the polishing pad is any polishing pad as described above. Pressure is applied to an object to press onto the polishing pad. Relative movement is provided between the object and the polishing pad to perform a polishing process.

Based on the above, in the polishing pad of the disclosure, through a detection window including a center portion and a cover portion surrounding the center portion, the cover portion is joined to the polishing layer, and the ratio of the area of the center portion to the area of the cover portion is between about 0.03 to about 5.00, thereby resulting in improved bonding strength between the detection window and the polishing layer. In addition, the cover portion of the detection window of the polishing pad of the disclosure can be made by selecting a material that has a relatively high degree of bonding with the polishing layer and the center portion of the detection window to overcome the stress problem during polishing, so that there is greater freedom in the selection and matching of the polishing layer material and the center portion material of the detection window to better achieve the polishing quality required by the object.

In order to make the above-mentioned features and advantages of the disclosure clearer and easier to understand, the following embodiments are given and described in details with accompanying drawings as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a conventional polishing system.

FIG. 2A is a schematic top view of a polishing pad according to an embodiment of the disclosure.

FIG. 2B is a schematic cross-sectional view along line A-A′ of FIG. 2A.

FIG. 3 is a schematic cross-sectional view of a polishing pad according to another embodiment of the disclosure.

FIG. 4A to FIG. 4C are schematic cross-sectional views of a side surface of a center portion, a cover portion, or a polishing layer according to some embodiments of the disclosure.

FIG. 5A to FIG. 5D are schematic top views of a detection window according to other embodiments of the disclosure.

FIG. 6A to FIG. 6F are schematic cross-sectional views of a manufacturing process of a polishing pad according to an embodiment of the disclosure.

FIG. 7 is a schematic cross-sectional view of a manufacturing process of a polishing pad according to other embodiments of the disclosure.

FIG. 8 is a flow chart of a polishing method according to an embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

Herein, a range indicated by “one value to another value” is a general representation which avoids enumerating all values in the range in the specification. Therefore, the record of a specific value range, any number within this numerical range and any smaller numerical range bounded by any number within that numerical range is contemplated as if such any number and such smaller numerical ranges were expressly written in the specification.

The term “about” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by those of ordinary skill in the art, considering the measurement in question and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within, for example, ±30%, ±20%, ±15%, ±10%, ±5% of the stated value. Moreover, a relatively acceptable range of deviation or standard deviation may be chosen for the term “about” or “substantially” as used herein based on measurement properties or other properties, instead of applying one standard deviation across all the properties.

It will be understood that when an element such as a layer, film, region or groove is referred to as being “on,” “connected to” or “in contact with” another element, it can be directly on or connected to/in contact with the other element, or intervening elements may also be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly in contact with” another element, there are no intervening elements present.

In the figures, for clarity, the size and thickness of each layer, region, and portion are not shown to actual scale.

FIG. 2A is a schematic top view of a polishing pad according to an embodiment of the disclosure. FIG. 2B is a schematic cross-sectional view along line A-A′ of FIG. 2A.

Please refer to FIG. 2A and FIG. 2B at the same time. A polishing pad 100 includes a polishing layer 102 and a detection window 104. In another embodiment, the polishing pad further includes a base layer, which is configured below the polishing layer 102, as shown in FIG. 3 (the following will be described in details based on FIG. 3).

In the embodiment, the polishing layer 102 is composed of a polymer substrate, for example. The polymer substrate may be polyester, polyether, polyurethane, polycarbonate, polyacrylate, polybutadiene, or other polymer substrates synthesized by suitable thermosetting resin or thermoplastic resin, but the disclosure is not limited thereto. In addition to the polymer substrate, the polishing layer 102 may also include conductive materials, polishing particles, micro-spheres, or soluble additives in the polymer substrate.

In the embodiment, the polishing layer 102 has a polishing surface PS and a back surface BS opposite to the polishing surface PS. Herein, the polishing surface PS of the polishing layer 102 is also called the top surface; the back surface BS of the polishing layer 102 is also called the bottom surface. When the polishing pad 100 is used to perform a polishing process on an object, the object will be in contact with the polishing surface PS of the polishing layer 102. It is worth mentioning that, although not shown in FIG. 2A and FIG. 2B, any person skilled in the art should know that the polishing surface PS includes groove patterns, and the groove patterns can have a variety of different pattern distributions, such as concentric rings, non-centric rings, elliptical rings, wavy rings, irregular rings, multiple straight lines, parallel straight lines, radial straight lines, radial arcs, spirals, polygonal grids, or a combination thereof, but the disclosure is not limited thereto.

The detection window 104 is located in the polishing layer 102. As shown in FIG. 2A and FIG. 2B, the detection window 104 includes a center portion 104a and a cover portion 104b surrounding the center portion 104a. In other words, the detection window 104 includes two portions. From another perspective, as shown in FIG. 2A and FIG. 2B, the center portion 104a and the cover portion 104b are in direct contact.

In addition, as shown in FIG. 2A and FIG. 2B, the cover portion 104b is joined to the polishing layer 102. That is to say, the detection window 104 is fixed to the polishing layer 102 through the cover portion 104b. In other words, the cover portion 104b is joined between the center portion 104a and the polishing layer 102. From another perspective, as shown in FIG. 2B, the bonding interface between the center portion 104a and the cover portion 104b and the bonding interface between the cover portion 104b and the polishing layer 102 are both smooth surfaces. That is, in the embodiment, a side surface S1 of the center portion 104a, an inner side surface S2 and an outer side surface S3 of the cover portion 104b, and an inner side surface S4 of the polishing layer 102 are all smooth surfaces. However, the disclosure is not limited thereto. In other embodiments, each of the side surface S1 of the center portion 104a, the inner side surface S2 and the outer side surface S3 of the cover portion 104b, and the inner side surface S4 of the polishing layer 102 may be a rough surface, such as a spiral surface (shown in FIG. 4A), a corrugated surface (shown in FIG. 4B), or a granular surface (shown in FIG. 4C). That is to say, in the aforementioned embodiments, the bonding interface between the center portion 104a and the cover portion 104b and the bonding interface between the cover portion 104b and the polishing layer 102 may be rough surfaces. It is worth mentioning that by designing each of the side surface S1 of the center portion 104a, the inner side surface S2 and the outer side surface S3 of the cover portion 104b, and the inner side surface S4 of the polishing layer 102 as a rough surface, the contact area between the center portion 104a, the cover portion 104b, and the polishing layer 102 can be increased, thereby increasing the closeness between the three. In another embodiment, the side surface S1 of the center portion 104a and the inner side surface S2 of the cover portion 104b may also be designed as rough surfaces, and the outer side surface S3 of the cover portion 104b and the inner side surface S4 of the polishing layer 102 may be designed as smooth surfaces, thereby increasing the contact area between the center portion 104a and the cover portion 104b to increase the bonding strength between the center portion 104a and the cover portion 104b of the detection window 104.

In the embodiment, the ratio of the area of the center portion 104a to the area of the cover portion 104b is between about 0.03 to about 5.00. Specifically, if the ratio of the area of the center portion 104a to the area of the cover portion 104b is less than about 0.03, it means that the area of the cover portion 104b is much larger than the area of the center portion 104a. In this way, due to the area of the cover portion 104b being excessively large, the reduction of the polishing area on the polishing surface PS will easily cause the object (object to be polished) to be simultaneously polished into the polishing area on the polishing surface PS and the area on a top surface TSb of the cover portion 104b during polishing. Or even more so, during polishing, the object is mainly polished to the area on the top surface TSb of the cover portion 104 instead of the polishing area on the polishing surface PS that is mainly used to polish the object, which in turn affects the polishing performance. For example, the planarity of the object may not be as favorable as expected, the object may generate surface dishing, or the object may be prone to defects. If the ratio of the area of the center portion 104a to the area of the cover portion 104b is greater than about 5.00, it means that the area of the cover portion 104b is less than ⅕ of the area of the center portion 104a. In this way, since the area of the cover portion 104b is excessively small, that is, a width d of the cover portion 104b is very small, the interface bonding force between the center portion 104a and the cover portion 104b and the cover portion 104b and the polishing layer 102 may be difficult to resist the lateral shear force and positive (gravity direction) pressure exerted on the polishing pad by the polishing head carrying the object due to the excessively small width d such that the interface may detach or break. It is worth mentioning that by designing the ratio of the area of the center portion 104a to the area of the cover portion 104b within a range between about 0.03 to about 5.00, the interface bonding force between the detection window 104 and the polishing layer 102 may be improved.

In the embodiment, as shown in FIG. 2B, the center portion 104a has a top surface TSa

and a bottom surface USa that are opposite to each other. The top surface TSa of the center portion 104a is adjacent to the polishing surface PS of the polishing layer 102, and the bottom surface USa of the center portion 104a is also adjacent to the back surface BS of the polishing layer 102. In other words, the top surface TSa and the bottom surface USa of the center portion 104a are coplanar with the top surface (i.e., the polishing surface PS) and the bottom surface (i.e., the back surface BS) of the polishing layer 102 respectively. On the other hand, as shown in FIG. 2B, the cover portion 104b has a top surface TSb and a bottom surface USb that are opposite to each other. The top surface TSb of the cover portion 104b is adjacent to the polishing surface PS of the polishing layer 102, and the bottom surface USb of the cover portion 104b is also adjacent to the back surface BS of the polishing layer 102. In other words, the top surface TSb and the bottom surface USb of the cover portion 104b are coplanar with the top surface (i.e., the polishing surface PS) and the bottom surface (i.e., the back surface BS) of the polishing layer 102 respectively. From another perspective, in the embodiment shown in FIG. 2B, the top surface TSa of the center portion 104a, the top surface TSb of the cover portion 104b, and the top surface of the polishing layer 102 (i.e., the polishing surface PS) are all coplanar; and the bottom surface USa of the center portion 104a, the bottom surface USb of the cover portion 104b, and the bottom surface (i.e., the backside BS) of the polishing layer 102 are all coplanar.

In the embodiment, the center portion 104a may be composed of any material known to those skilled in the art that can be used as a detection window of a polishing pad. For example, the material of the center portion 104a of the detection window 104 may be a transparent polymer, such as thermosetting plastic or thermoplastic plastic. From another perspective, in the embodiment, the material of the center portion 104a is translucent under visible light. In detail, for light with a wavelength between 380 nm and 780 nm, the light transmittance of the center portion 104a is at least 40%. In this way, when using the polishing pad 100 to polish an object, the user can use the optical detection system to detect the polishing condition of the object through the center portion 104a of the detection window 104, so as to serve as the end-point detection of the polishing process and ensure the polishing quality.

In the embodiment, the cover portion 104b may include polyester, polyether, polyurethane, polycarbonate, polyacrylate, or polybutadiene., or other polymer substrates synthesized by suitable thermosetting resin or thermoplastic resin. In the embodiment, the material of the cover portion 104b is different from the material of the center portion 104a. Specifically, in an embodiment, the material of the center portion 104a is translucent under visible light, while the material of the cover portion 104b is not translucent under visible light. In another embodiment, the hardness of the cover portion 104b and the center portion 104a is different, and the ratio of the hardness of the center portion 104a to the hardness of the cover portion 104b is not greater than about 1.8. Specifically, if the ratio of the hardness of the center portion 104a to the hardness of the cover portion 104b is greater than about 1.8, the hardness difference between the center portion 104a and the cover portion 104b will be too large, causing the cover portion 104b to be easily squeezed by the center portion 104a during polishing and in turn destroying the interface between the center portion 104a and the cover portion 104b, thereby affecting the lifetime of the polishing pad. It is worth mentioning that by designing the ratio of the hardness of the center portion 104a to the hardness of the cover portion 104b to be within a range of not greater than about 1.8, in addition to improving the interface bonding force between the detection window 104 and the polishing layer 102, it also prevents the wear amount of the center portion 104a and the cover portion 104b from being too different during polishing to affect the polishing quality of the object, the detection quality of the detection window 104, or the lifetime of the polishing pad.

From another point of view, in an embodiment, the material of the cover portion 104b is the same as the material of the polishing layer 102, that is, the cover portion 104b and the polishing layer 102 include the same polymer substrate, and the aforementioned polymer substrate may include polyester, polyether, polyurethane, polycarbonate, polyacrylate, polybutadiene, or other polymer substrates synthesized by suitable thermosetting resin or thermoplastic resin. It should be noted here that although the cover portion 104b and the polishing layer 102 are made of the same polymer substrate, the cover portion 104b and the polishing layer 102 can be selectively made to have the same or different physical properties (such as hardness, density, or compressibility) by adjusting the process conditions (such as injection volume, gas pressure, reaction temperature, mold design, etc., but not limited thereto). Specifically, in an embodiment, polyurethane is selected as the polymer substrate of the cover portion 104b and the polishing layer 102, and the cover portion 104b and the polishing layer 102 are manufactured by an injection molding method. By allowing the cover portion 104b and the polishing layer 102 to have different process conditions (such as injection volume, gas pressure, reaction temperature, mold design, etc., but not limited thereto), the manufactured cover portion 104b and the polishing layer 102 can be made to have different hardness, density. or compressibility. In other words, by adjusting the process conditions of the cover portion 104b and the polishing layer 102 (such as injection volume, gas pressure, reaction temperature, mold design, etc., but not limited thereto), the cover portion 104b and the polishing layer 102 can be made to have predetermined physical properties (such as hardness, density, or compressibility). It is worth mentioning that the cover portion 104b and the polishing layer 102 have a same material, so the material properties of the cover portion 104b and the material properties of the polishing layer 102 have a more favorable material compatibility, thereby effectively improving the interface bonding force between the cover portion 104b and the polishing layer 102.

In another embodiment, the material of the cover portion 104b is different from the material of the polishing layer 102. It should be noted here that although the cover portion 104b and the polishing layer 102 are made of different polymer substrates, in addition to the selection of different polymer substrates so that the cover portion 104b and the polishing layer 102 can have a more favorable material compatibility, the cover portion 104b and the polishing layer 102 can also be selectively made to have similar physical properties (such as hardness, density, or compressibility) by adjusting the process conditions (such as injection volume, gas pressure, reaction temperature, mold design, etc., but not limited thereto), so that there is a more favorable material compatibility between the cover portion 104b and the polishing layer 102, thereby effectively improving the interface bonding force between the cover portion 104b and the polishing layer 102. It is worth mentioning that the cover portion 104b and the polishing layer 102 made of different materials can be made to have similar physical properties (such as hardness, density, or compressibility) by adjusting the process conditions (such as injection volume, gas pressure, reaction temperature, mold design, etc., but not limited thereto), so that there is greater freedom in selecting materials for the cover portion 104b and the polishing layer 102.

In the embodiment, the outer contours of the center portion 104a and the cover portion 104b can be designed into various shapes according to actual requirements, such as a circular shape, an elliptical shape, a spindle shape, or a raindrop shape. That is to say, the shapes of the outer contours of the center portion 104a and the cover portion 104b may be irregular shapes or regular geometric shapes. As shown in FIG. 2A, the shapes of the outer contours of the center portion 104a and the cover portion 104b are both spindle shapes. That is to say, in the embodiment, the outer contour of the center portion 104a and the outer contour of the cover portion 104b have the same shape and are both irregular shapes. However, the disclosure is not limited thereto. In another embodiment, the outer contour of the center portion 104a and the outer contour of the cover portion 104b have the same shape and are both regular geometric shapes. For example, as shown in FIG. 5A, the shapes of the outer contours of the center portion 104a and the cover portion 104b are both circular shapes. In yet another embodiment, the outer contour of the center portion 104a and the outer contour of the cover portion 104b have different shapes. For example, as shown in FIG. 5B, the shape of the outer contour of the center portion 104a is a circular shape, and the shape of the outer contour of the cover portion 104b is a spindle shape; as shown in FIG. 5C, the shape of the outer contour of the center portion 104a is a raindrop shape, and the shape of the outer contour of the cover portion 104b is a circular shape; and as shown in FIG. 5D, the shape of the outer contour of the center portion 104a is a raindrop shape, and the shape of the outer contour of the cover portion 104b is a spindle shape, but it is not intended to limit the disclosure.

In addition, although the number of the detection window 104 shown in FIG. 2A and FIG. 2B is one, the disclosure is not limited thereto. In other embodiments, the number of the detection window 104 may also be two, three, or more according to actual requirements. That is to say, as long as at least one detection window 104 is disposed in the polishing layer 102, it falls within the scope of the disclosure.

In another embodiment, the polishing pad may further include a base layer configured below the polishing layer. Specifically, as shown in FIG. 3, a polishing pad 100′ includes a polishing layer 102 and a base layer 106. The base layer 106 is located below the polishing layer 102. In detail, the main function of the base layer 106 is to pad the polishing layer 102 and to be fixed on the polishing platen (not shown). As shown in FIG. 3, the base layer 106 is also located below the cover portion 104b of the detection window 104. Specifically, as shown in FIG. 3, an inner side surface S5 of the base layer 106 is substantially aligned with the inner side surface S2 of the cover portion 104b. That is to say, the cover portion 104b completely overlaps the base layer 106. However, the disclosure is not limited thereto. In another embodiment, when the bonding interface between the cover portion 104b and the polishing layer 102 overlaps with the base layer 106, the inner side surface S5 of the base layer 106 and the inner side surface S2 of the cover portion 104b are not aligned (for example, there may be a gap between the inner side surface S2 and the inner side surface S5). In addition, in the embodiment, the base layer 106 can be bonded together with the cover portion 104b and the polishing layer 102 through an adhesive layer (not shown). In addition, in the embodiment, the main material of the base layer 106 is, for example, polyurethane, polyethylene, polypropylene, a copolymer of polyethylene and ethylene vinyl acetate, or a copolymer of polypropylene and ethylene vinyl acetate, or any material currently known that can be used for the base layer of the polishing pad.

It is worth mentioning that in the embodiment, by designing the ratio of the area of the center portion 104a to the area of the cover portion 104b to be between about 0.03 and about 5.00, and by allowing the bonding interface between the cover portion 104b and the center portion 104a to overlap the base layer 106, the interface bonding force between the detection window 104 and the polishing layer 102 may be effectively improved, so that when the polishing pad 100′ is used to polish the object, the bonding interface between the cover portion 104b and the polishing layer 102 will not cause delamination due to withstanding the applied downward pressure, which will cause polishing leakage to the delamination point of the polishing pad and affect the lifetime of the polishing pad. As a result, in the polishing pad 100′, the interface bonding force between the detection window 104 and the polishing layer 102 is improved.

In order to confirm that the detection window 104 and the polishing layer 102 proposed by the disclosure have improved interface bonding force, an actual interface bonding force test was performed. In the experimental test, the test methods and Sample settings used are as follows, and the test results are listed in Table 1-1 and Table 1-2.

Bonding force test method: ASTM D412 standard test method was used to measure the bonding force between the detection window and the polishing layer.

Sample 1 to Sample 4: Samples 1 to 4 were all single-layer polishing pads with detection windows (that is, polishing pads that did not include base layers). Sample 1 was configured with a conventional detection window, while Samples 2 to 4 were configured with detection windows including a center portion and a cover portion of the disclosure, and the differences between the detection windows configured in Samples 2 to 4 were in the ratio of the area of the center portion to the area of the cover portion.

Sample 5 to Sample 8: Samples 5 to 8 were all double-layer polishing pads with detection

windows (that is, polishing pads that included polishing layers and base layers). Sample 5 was configured with a conventional detection window, while Samples 6 to 8 were configured with detection windows including a center portion and a cover portion of the disclosure, and the differences between the detection windows configured in Samples 6 to 8 were in the ratio of the area of the center portion to the area of the cover portion.

TABLE 1-1

Sample 1
Sample 2
Sample 3
Sample 4

Ratio of area of
N/A
0.04
1.05
4.54

center portion

to area of

cover portion

Bonding force
93.6
130.6
128.2
101.5

(kgf/mm²)

TABLE 1-2

Sample 5
Sample 6
Sample 7
Sample 8

Ratio of area of
N/A
0.04
1.05
4.54

center portion

to area of

cover portion

Bonding force
79.9
136.7
118.0
84.9

(kgf/mm²)

It can be seen from the contents of the above Table 1-1 that the bonding force between the conventional detection window and the polishing layer of Sample 1 is 93.6 kgf/mm², and the bonding forces between the detection window of the disclosure and the polishing layer of Samples 2 to 4 are respectively 130.6 kgf/mm², 128.2 kgf/mm², and 101.5 kgf/mm². Samples 2 to 4 have different bonding forces because they have different area ratios of the center portion and the cover portion. It can be seen that compared with the polishing pad of Sample 1, the polishing pads of Samples 2 to 4 have a more favorable bonding force between the detection window and the polishing layer. The same experimental results can also be known from the above Table 1-2. Specifically, the bonding force between the conventional detection window and the polishing layer of Sample 5 is 79.9 kgf/mm², and the bonding force between the detection window of the disclosure and the polishing layer of Samples 6 to 8 are respectively 136.7 kgf/mm², 118.0 kgf/mm², and 84.9 kgf/mm². Samples 6 to 8 have different bonding forces because they have different area ratios of the center portion and the cover portion. It can be seen that compared with the polishing pad of Sample 5, the polishing pads of Samples 6 to 8 have a more favorable bonding force between the detection window and the polishing layer. The results in the above Table 1-1 and Table 1-2 show that whether the polishing pad is a single-layer polishing pad or a double-layer polishing pad composed of a polishing layer and a base layer, the interface bonding force between the detection window and the polishing layer can be improved by replacing the conventional detection window with the detection window of the disclosure. In other words, by including a detection window structure composed of a center portion and a cover portion, and with the ratio of the area of the center portion to the area of the cover portion designed to be within a range of about 0.03 to about 5.00, it can indeed improve the interface bonding force between the detection window and the polishing layer in the polishing pad.

Table 2 below describes the bonding force between the center portion and the cover

portion of the detection window measured according to the ASTM D412 standard test method using polishing pad samples with different ratios of the hardness of the center portion to the hardness of the cover portion.

Samples 9 to 13 in Table 2 were all single-layer polishing pads with the detection window of the disclosure, and Samples 9 to 13 were formed with different ratios of the hardness of the center portion to the hardness of the cover portion.

TABLE 2

Sample 9
Sample 10
Sample 11
Sample 12
Sample 13

Ratio of
0.85
0.88
1.00
1.81
2.01

hardness

of center

portion

to hardness

of cover

portion

Bonding
217.7
207.3
93.6
87.6
87.8

force

(kgf/mm²)

It can be seen from the contents of Table 2 above that the ratio of the hardness of the center portion to the hardness of the cover portion of the detection window of Sample 9 is 0.85. The measured bonding force between the center portion and the cover portion of the detection window can be as high as 217.7 kgf/mm², and as the ratio of the hardness of the center portion to the hardness of the cover portion of the detection window changes to 0.88, 1.00, 1.81, and 2.01 of Samples 10 to 13, the measured bonding forces between the center portion and the cover portion of the detection window are reduced to 207.3 kgf/mm², 93.6 kgf/mm², 87.6 kgf/mm², and 87.8 kgf/mm². It can be seen from this that as the ratio of the hardness of the center portion to the hardness of the cover portion of the detection window increases, the bonding force between the center portion and the cover portion of the detection window decreases. From another point of view, a trend diagram is plotted by using the horizontal axis as the ratio of the hardness of the center portion to the hardness of the cover portion of the detection window and by using the vertical axis as the bonding force between the center portion and the cover portion of the detection window. It can be found that when the ratio of the hardness of the center portion to the hardness of the cover portion exceeds 1.8, the value of the bonding force converges and approaches a constant value. This result shows that by designing the ratio of the hardness of the center portion to the hardness of the cover portion to be within a range of not greater than about 1.8, the bonding force between the center portion and the cover portion can be effectively improved. Further, when the ratio of the hardness of the center portion to the hardness of the cover portion is designed to be within a range of not greater than about 1.8, by designing the ratio of the area of the center portion to the area of the cover portion to be within a range of between about 0.03 and about 5.00, the interface bonding force between the detection window and the polishing layer can be improved (as shown in the aforementioned Table 1-1 and Table 1-2).

In addition, the manufacturing method of the polishing pad 100 will be described below with reference to FIG. 6A to FIG. 6F. It should be noted that although the polishing pad 100 in the above embodiments is described by taking the manufacturing method as described below as an example, the manufacturing method of the polishing pad 100 of the disclosure is not limited thereto, and the materials, thicknesses, or functions of the same or similar components in the polishing pad 100 are described in details above and are not be repeated here. FIG. 6A to FIG. 6F are schematic cross-sectional views of a manufacturing process of a polishing pad according to an embodiment of the disclosure.

First, the center portion 104a of the detection window 104 is formed. The center portion 104a has a predetermined outer contour shape. The outer contour shape can be an irregular shape or a regular geometric shape. The outer contour shape can be, for example, as shown in FIG. 5A to FIG. 5D. There are two methods for forming the center portion 104a with a predetermined outer contour shape. The first method is to manufacture a predetermined outer contour shape (such as a spindle shape) on the mold in advance. After the curing process, a center portion 104a having a predetermined outer contour shape (e.g., a spindle shape) can be obtained. The second method is not to manufacture a predetermined outer contour shape (such as a spindle shape) on the mold. After the curing process, a light-transmitting material layer having a conventional outer contour shape (such as a rectangle shape) is obtained, and then the light-transmitting material layer is processed (e.g., machined) to form the center portion 104a having a predetermined outer contour shape (e.g., a spindle shape). In the embodiment, the first manufacturing method is used for explanation. As shown in FIG. 6A, the center portion 104a having a predetermined outer contour shape is directly formed by using a mold 10. The detailed steps are as follows. The mold 10 is provided. The mold 10 has a mold cavity 12 for receiving molding materials. In the embodiment, the shape and size of the mold cavity 12 are related to the shape and size of the outer contour of the center portion 104a to be formed subsequently. That is, as shown in FIG. 2A, the shape of the mold cavity 12 is a spindle shape. In addition, in order to enable those skilled in the art to clearly understand the disclosure, in the following drawings, only part of the mold 10 is shown, that is, the upper cover structure of the mold 10 is omitted. Next, the light-transmitting material is filled into the mold cavity 12 of the mold 10, and a curing process is performed to form the center portion 104a in the mold 10. In the embodiment, the method of filling the light-transmitting material into the mold cavity 12 of the mold 10 includes an injection method. In the embodiment, the curing process for curing the light-transmitting material includes an illuminating process, a heating process, a pressurizing process, or a resting process. In detail, the curing process includes, for example, illuminating or heating to cause a polymerization reaction of the light-transmitting material so as to achieve curing; or, for example, carrying out a natural polymerization reaction of the reactants in the light-transmitting material so as to achieve curing; or, for example, pressurizing the light-transmitting material to cause a polymerization reaction of the light-transmitting material so as to achieve curing. Finally, the mold 10 is removed to obtain the center portion 104a having a predetermined outer contour shape. In the embodiment, the light-transmitting material used to form the center portion 104a is light-transmissive under visible light.

Next, after the center portion 104a having a predetermined outer contour shape is formed, the cover portion 104b having a predetermined outer contour shape is formed to obtain the detection window 104. The outer contour shape of the cover portion 104b can be as shown in FIG. 5A to FIG. 5D. Please refer to FIG. 6B and FIG. 6C at the same time for the description of the method of directly forming the cover portion 104b having a predetermined outer contour shape by using a mold 20. The detailed steps are as follows. As shown in FIG. 6B, the mold 20 is provided. The mold 20 has a mold cavity 22 for receiving molding materials. In the embodiment, the shape and size of the mold cavity 22 are related to the shape and size of the outer contour of the cover portion 104b to be formed subsequently. That is, as shown in FIG. 2A, the shape of the mold cavity 22 is a spindle shape. Specifically, as shown in FIG. 2A, the outer contour of the center portion 104a and the outer contour of the cover portion 104b have the same shape, so the outer contour of the mold 20 and the outer contour of the mold 10 can be the same. However, as mentioned above, the shape of the outer contour of the center portion 104a and the shape of the outer contour of the cover portion 104b may be different from each other. Therefore, in this case, the outer contour of the mold 20 and the outer contour of the mold 10 may be different. In addition, in order to enable those skilled in the art to clearly understand the disclosure, in the following drawings, only part of the mold 20 is shown, that is, the upper cover structure of the mold 20 is omitted. Afterwards, please continue to refer to FIG. 6B. The center portion 104a is configured at a specific position in the mold cavity 22 of the mold 20. Specifically, as shown in FIG. 6B, the center portion 104a is spaced apart from the inner side edge of the mold 20 by a distance. In the embodiment, as shown in FIG. 6B, the thickness of the center portion 104a is equivalent to the depth of the mold cavity 22. In addition, the center portion 104a can be fixed at a specific position of the mold 20 by pressing the mold 20 and the upper cover structure or by gluing.

Then, please refer to FIG. 6B and FIG. 6C at the same time. The covering material is filled into the mold cavity 22 of the mold 20 to surround the center portion 104a in the mold 20.

In the embodiment, the method of filling the covering material into the mold cavity 22 of the mold 20 includes an injection method. Then, a curing process is performed to cure the covering material, so as to form the cover portion 104b covering the center portion 104a in the mold 20. In the embodiment, the side surface S1 of the center portion 104a is connected with the inner side surface S2 of the cover portion 104b. In the embodiment, the curing process for curing the covering material includes an illuminating process, a heating process, a pressurizing process, or a resting process. In detail, the curing process includes, for example, illuminating or heating to cause a polymerization reaction of the covering material so as to achieve curing; or, for example, carrying out a natural polymerization reaction of the reactants in the covering material so as to achieve curing; or, for example, pressurizing the covering material to cause a polymerization reaction of the light-transmitting material so as to achieve curing. Finally, the mold 20 is removed to obtain the center portion 104a and the cover portion 104b having predetermined outer contour shapes. However, the disclosure is not limited thereto. In another embodiment, the method of forming the cover portion 104b having a predetermined outer contour shape can be divided into two steps. The first step is to first use a mold to obtain a covering material layer with a conventional shape (such as a rectangle shape), where the shape and size of the mold cavity 22 of the mold 20 used in the step in unrelated to the predetermined shape and size of the outer contour of the cover portion 104b to be formed subsequently. In the embodiment, after the curing process of curing the covering material is performed to form the covering material layer, a second step is performed to process the covering material layer (for example, through a mechanical process) to remove part of the covering material layer to form the cover portion 104b having a predetermined shape (e.g., a spindle shape). In the embodiment, the covering material used to form the cover portion 104b is different from the light-transmitting material used to form the center portion 104a. In the embodiment, as mentioned above, the predetermined shape is an irregular shape or a regular geometric shape.

Next, after the detection window 104 is formed, the polishing layer 102 joined to the cover portion 104b of the detection window 104 is formed. Please refer to FIG. 6D and FIG. 6E at the same time. The polishing layer 102 is formed by using a mold 30. The detailed steps are as follows. As shown in FIG. 6D, the mold 30 is provided. The mold 30 has a mold cavity 32 for receiving molding materials. In the embodiment, the shape and size of the mold cavity 32 are related to the shape and size of the polishing layer 102 to be formed subsequently. That is, as shown in FIG. 2A, the shape of the mold cavity 32 is a circular shape. In addition, in order to enable those skilled in the art to clearly understand the disclosure, in the following drawings, only part of the mold 30 is shown, that is, the upper cover structure of the mold 30 is omitted. Afterwards, please continue to refer to FIG. 6D. The detection window 104 is configured at a specific position in the mold cavity 32 of the mold 30. The specific position corresponds to the position of the optical detection system. In the embodiment, as shown in FIG. 6D, the thickness of the detection window 104 is equivalent to the depth of the mold cavity 32. In addition, the detection window 104 can be fixed at a specific position of the mold 30 by pressing the mold 30 and the upper cover structure or by gluing.

Then, please refer to FIG. 6D and FIG. 6E at the same time. The polishing layer material is filled into the mold cavity 32 of the mold 30 to surround the detection window 104 in the mold 30. In the embodiment, the method of filling the polishing layer material into the mold cavity 32 of the mold 30 includes an injection method. Then, a curing process is performed to cure the polishing layer material to form the polishing layer 102 in the mold 30. In the embodiment, the outer side surface S3 of the cover portion 104b is connected with the inner side surface S4 of the polishing layer 102. In the embodiment, the curing process used to cure the polishing layer material includes an illuminating process, a heating process, a pressurizing process, or a resting process. In detail, the curing process includes, for example, illuminating or heating to cause a polymerization reaction of the polishing layer material so as to achieve curing; or, for example, carrying out a natural polymerization reaction of the reactants in the polishing layer material so as to achieve curing; or, for example, pressurizing the polishing layer material to cause a polymerization reaction of the light-transmitting material so as to achieve curing. In an embodiment, the covering material used to form the cover portion 104b is the same as the polishing layer material used to form the polishing layer 102. In another embodiment, the covering material used to form the cover portion 104b is different from the polishing layer material used to form the polishing layer 102.

Finally, please refer to FIG. 6E and FIG. 6F at the same time. The mold 30 is removed to obtain the polishing pad 100 with the detection window 104. The detection window 104 includes the center portion 104a and the cover portion 104b surrounding the center portion 104a. The cover portion 104b is joined to the polishing layer 102, and the ratio of the area of the center portion 104a to the area of the cover portion 104b of the detection window 104 is between about 0.03 and about 5.00, so that there is improved bonding strength between the detection window 104 and the polishing layer 102.

FIG. 7 is a schematic cross-sectional view of a manufacturing process of a polishing pad according to other embodiments of the disclosure. Please refer to FIG. 7 and FIG. 6F at the same time. The polishing pad 100′ shown in FIG. 7 is similar to the polishing pad 100 shown in FIG. 6F. Therefore, the same or similar components are denoted by the same or similar referential numerals, and descriptions of the same technical contents are omitted. In detail, the main difference between the method of manufacturing the polishing pad 100′ and the method of manufacturing the polishing pad 100 is that in the process of manufacturing the polishing pad 100′, after the polishing layer 102 and the detection window 104 are formed, the base layer 106 is formed below the polishing layer 102 and the cover portion 104b of the detection window 104. In an embodiment, for example, a continuous base layer material is first formed below the polishing layer 102 and the detection window 104, and then part of the base layer material corresponding to the center portion 104a of the detection window 104 is removed to form the base layer 106. In addition, in an embodiment, before the base layer 106 is formed below the polishing layer 102 and the cover portion 104b of the detection window 104, an adhesive layer (not shown) can be selectively formed below the polishing layer 102 and the cover portion 104b of the detection window 104 to bond the base layer 106 to the polishing layer 102 and the cover portion 104b of the detection window 104. The adhesive layer is, for example, a glue layer, which includes (but is not limited to): carrier-free glue, double-sided tape, UV curing glue, hot melt glue, moisture curing glue, or pressure-sensitive adhesive (PSA). The material of the above-mentioned glue layer is, for example, acrylic glue, epoxy resin glue, or polyurethane glue. However, the disclosure is not limited thereto. In other embodiments, the base layer 106 can be directly formed below the polishing layer 102 and the cover portion 104b of the detection window 104 by coating, spraying, stacking, or printing without using an adhesive layer, and at the same time, the process of removing part of the base layer material can be reduced.

FIG. 8 is a flow chart of a polishing method according to an embodiment of the disclosure. This polishing method is adapted to polish objects. Specifically, the polishing method can be applied to the polishing process of manufacturing industrial components, such as components used in the electronics industry, which can include semiconductors, integrated circuits, microelectromechanical, energy conversion, communications, optics, storage disks, displays, etc., and the objects used to manufacture such components may include semiconductor wafers, IIIV wafers, storage element carriers, ceramic substrates, polymer substrates, glass substrates, etc. . . . However, these are not intended to limit the scope of the disclosure.

Please refer to FIG. 8. First, step S10 is performed to provide a polishing pad. In detail, in the embodiment, the polishing pad includes the polishing layer 100 or 100′ in any of the previous embodiments. The relevant descriptions of the polishing pad 100 and the polishing pad 100′ have been described in details above and so are not repeated here.

Next, step S12 is performed to apply pressure to an object, whereby the object is pressed onto the polishing pad and comes into contact with the polishing pad. In detail, as mentioned above, the object is in contact with the polishing surface PS in the polishing layer 102. In addition, the method of applying pressure to the object is, for example, using a carrier capable of holding the object.

Afterwards, step S14 is performed to provide relative movement between the object and the polishing pad, so as to use the polishing pad to perform a polishing process on the object to achieve the purpose of planarizing. Specifically, the method of providing relative movement between the object and the polishing pad is, for example, by rotating the polishing platen to drive the polishing pad fixed on the polishing platen to rotate.

To sum up, in the polishing pad of the disclosure, the detection window includes a center portion and a cover portion surrounding the center portion. The cover portion is joined to the polishing layer, and the ratio of the area of the center portion to the area of the cover portion is between about 0.03 to about 5.00 such that there is improved bonding strength between the detection window and the polishing layer.

In addition, in the polishing pad of the disclosure, the material selection for the cover portion of the detection window can be made by selecting a material that has a relatively high degree of bonding with the polishing layer and the center portion of the detection window to overcome the stress problem during polishing, so that there is greater freedom in the selection and matching of the polishing layer material and the center portion material of the detection window to better achieve the polishing quality required by the object.

Although the disclosure has been described with reference to the embodiments above, the embodiments are not intended to limit the disclosure. Any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the disclosure. Therefore, the scope of the disclosure will be defined in the appended claims.

POLISHING PAD AND MANUFACTURING METHOD OF POLISHING PAD AND POLISHING METHOD

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