POLISHING PAD AND POLISHING METHOD

Abstract

A polishing pad is provided. The polishing pad, suitable for a polishing process, includes a polishing layer, an adhesive layer and at least one heat storage material. The polishing layer has a polishing surface and a back surface opposite to each other. The adhesive layer is disposed on the back surface of the polishing layer. A region where the at least one heat storage material is disposed is located above the adhesive layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims the priority benefit of U.S. patent application Ser. No. 15/937,872, filed on Mar. 28, 2018, now pending, which claims the priority benefit of Taiwan application serial no. 106111034, filed on Mar. 31, 2017. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

1. Field of the Invention

This invention is related to a polishing pad and a polishing method, especially related to a polishing pad that the temperature thereof may be decreased during a polishing process and a polishing method using the same polishing pad.

2. Description of Related Art

In the industrial component manufacturing process, a polishing process is a technique that is more commonly used today to planarize the surface of an object being polished. In the polishing process, a polishing fluid is provided between the surface of an object and a polishing pad. The planarization is performed by mechanical friction caused by the relative motion of the object and the polishing pad with each other. The interface between the layers of the polishing pad is usually adhered by using an adhesive layer. However, the temperature of the polishing pad may increase due to the friction generated during the polishing process. Therefore, the adhesive layer is prone to deterioration, deformation or adhesion decay to affect the stability of the polishing process.

Accordingly, there is a need to provide a means for decreasing the temperature of a polishing pad during a polishing process, so that the industry may has a choice to solve the problem above.

SUMMARY

This invention provides a polishing pad and a polishing method to decrease the temperature of a polish pad during a polishing process, so as to avoid the problem that the adhesive layer deteriorates, deforms or decreases in adhesion due to high temperature during the polishing process.

In some embodiments of this invention, the polishing pad is suitable to be used in a polishing process. The polishing pad includes a polishing layer, an adhesive layer, and at least one heat storage material. The polishing layer has a polishing surface and a back surface opposite to each other. The adhesive layer is disposed on the back surface of the polishing layer. A region where the at least one heat storage material is disposed is located above the adhesive layer.

In some other embodiments of this invention, the polishing pad is suitable to be used in a polishing process. The polishing pad includes a polishing layer, a base layer, a first adhesive layer, a second adhesive layer, and at least one heat storage material. The base layer is disposed below the polishing layer. The first adhesive layer is disposed between the polishing layer and the base layer. The second adhesive layer is disposed below the base layer. A region where the at least one heat storage material is disposed is located between the first adhesive layer and the second adhesive layer.

In some other embodiments of this invention, the polishing method is suitable for polishing an object and includes the following steps: providing a polishing pad, wherein the polishing pad is any one of the polishing pads described above; applying a pressure to the object to press the object on the polishing pad; and providing relative motion to the object and the polishing pad to perform the polishing process.

Accordingly, the polishing pad of this invention may reduce the degree of temperature increase of the polishing pad due to mechanical friction when the polishing pad is used to perform a polishing process through the region where the at least one heat storage material is disposed is located above on the adhesive layer or between the first adhesive layer and the second adhesive layer. Thus, the problem that the adhesive layer deteriorates, deforms or decreases in adhesion due to high temperature during the polishing process is avoided.

In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

FIG. 1 is a diagram showing a top view of a polishing pad according to a first embodiment of the invention.

FIG. 2 is a cross-sectional diagram taking along the cross-sectional line I-I′ of FIG. 1.

FIG. 3 is a diagram showing the relationship between time of polishing an object and polishing pad temperature of a polishing pad of the invention and a conventional polishing pad.

FIG. 4 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a second embodiment of the invention.

FIG. 5 is a diagram showing the relationship between temperature and heat flow rate of the two heat storage materials of the invention.

FIG. 6 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a third embodiment of the invention.

FIG. 7 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a fourth embodiment of the invention.

FIG. 8 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a fifth embodiment of the invention.

FIG. 9 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a sixth embodiment of the invention.

FIG. 10 is a process flow diagram showing a polishing method according to an embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a diagram showing a top view of a polishing pad according to a first embodiment of the invention. FIG. 2 is a cross-sectional diagram taking along the cross-sectional line I-I′ of FIG. 1. In detail, the cross-sectional line I-I′ is set along the radius direction. Namely, FIG. 2 is a cross-sectional diagram along the radius direction of the polishing pad in FIG. 1.

Please refer to FIGS. 1 and 2. In this embodiment, a polishing pad 100 includes a polishing track region A and a non-polishing track region B, wherein the polishing track region A is surrounded by the non-polishing track region B. In detail, the polishing pad 100 is suitable to be used in a polishing process for polishing an object. When the polishing pad 100 is used to polish an object, the object is placed in the polishing track region A. In addition, the polishing pad 100 has a rotation center C, and the rotation center C of the polishing pad 100 is utilized as a center for counterclockwise rotation or clockwise rotation. The rotation center C is the central point of the polishing pod 100, for example.

In another aspect, in this embodiment, the polishing pad 100 includes a polishing layer 110, a plurality of grooves G, an adhesive layer 120, and a heat storage material 130. In order to clearly label the polishing track region A and the non-polishing track region B, the grooves G are omitted in FIG. 1.

The polishing layer 110 has a polishing surface PS and a back surface BS opposite to the polishing surface PS. In this embodiment, when the polishing pad 100 is used to polishing an object, the object contacts the polishing surface PS of the polishing layer 110. Moreover, the polishing pad 100 is made from a polymer, such as a polyester, a polyether, a polyurethane, a polycarbonate, a polyacrylate, a polybutadiene, or other polymer base material synthesized from suitable thermosetting resins or thermoplastic resins, for example. However, the invention is not limited thereto.

The grooves G are disposed in the polishing surface PS of the polishing layer 110. In this embodiment, the grooves G have a groove depth D from the bottom Gb thereof to the polishing surface PS. In addition, although the polishing pad 100 has many grooves G along the radius direction, as shown in FIG. 2, but the invention is not limited thereto. As long as the polish pad 100 includes at least one groove G, this is within the scope of the invention. Moreover, the distribution profile of the grooves G may be concentric circles, eccentric circles, ellipses, polygonal rings, spiral rings, irregular rings, parallel linear shapes, radial shapes, radiation arcs, spiral shapes, dots, or XY grids, for example.

The adhesive layer 120 is disposed on the back surface BS of the polishing layer 110. Namely, in this embodiment, the adhesive layer 120 is attached on the back surface BS of the polishing layer 110. Furthermore, the adhesive layer 120 includes, but not limited to, a carrier-free adhesive or a double-sided adhesive. The material of the adhesive layer 120 is an acrylic-based adhesive, a silicone-based adhesive, a rubber-based adhesive, an epoxy-based adhesive, or a urethane-based adhesive, for example. However, the invention is not limited thereto.

The heat storage material 130 is disposed in a heat storage region H. In this embodiment, the heat storage region H is disposed above the adhesive layer 120 and does not contact the bottom Gb of the grooves G. As described above, the grooves G have a groove depth D. The distance between the top edge Ht of the heat storage region H and the polishing surface PS is larger than D. Additionally, the distance between the top edge Ht and the polishing surface PS may be optionally smaller or equal to 1.5D, so that the region where the heat storage material 130 is disposed is larger to effectively decrease the temperature of the polishing pad 100. From another point of view, the top edge Ht of the heat storage region H does not contact or overlap with the bottom Gb of the grooves G.

In this embodiment, the heat storage material 130 is dispersed in the material of the polishing layer 110. Namely, the heat storage material 130 is distributed in a portion of the polishing layer 110. The method of forming the polishing layer 110 includes a step of mixing the heat storage material 130 and the material of the polishing layer 110. Specifically, the heat storage material 130 is distributed in the polishing layer 110 below a position having a distance larger than D from the polishing surface PS. A part of the polishing layer 110 that includes the heat storage material 130 and a part of the polishing layer 110 that does not include the heat storage material 130 are combined and formed by the perfusion method, for example. In another point of view, the heat storage region H is disposed in a portion of the polishing layer 110.

A cover layer 140 may be optionally formed to cover the heat storage material 130. In detail, the material of the cover layer 140 does not chemically react with the material of the polishing layer 110 or the heat storage material 130. More specifically, the material of the cover layer 140 may be an organic material comprising a phenolic resin, a urea-formaldehyde resin, polystyrene or a polyamide, for example. However, the invention is not limiter thereto.

Additionally, the heat storage material 130 includes an inorganic heat storage material, an organic heat storage material, or a combination thereof. In detail, the inorganic includes, but is not limited to, a hydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heat storage material includes, but is not limited to, a polyol, a fatty alcohol, a fatty acid, or an alkane. The polyol may be trimethylolpropane (C₆H₁₄O₃, TMP), for example. The fatty alcohol may be tetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid (CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkane may be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆), n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 130 undergoes an endothermic reaction at a certain temperature or in a certain temperature range to absorb heat from surroundings, and thus the purpose of lowering the surrounding temperature is achieved. In this embodiment, the heat storage material 130 undergoes an endothermic reaction at a certain temperature within a range from the lowest temperature Tmin to the highest temperature Tmax of the polishing pad 100 during a polishing process. Namely, the heat storage material 130 inevitably undergoes an endothermic reaction during the polishing process. Since the polishing pad 100 includes the heat storage material 130, the heat generated by mechanical friction may be absorbed by the heat storage material 130 to reduce the temperature increase degree of the polishing pad 100 during the polishing process, and thereby the purpose of effectively reducing the temperature of the polishing pad 100 is achieved. FIG. 3 is a diagram showing the relationship between time of polishing an object and polishing pad temperature of a polishing pad of the invention and a conventional polishing pad. From FIG. 3, it may be known that the polishing pad of the invention has a lower temperature during the period of the polishing process, comparing with a conventional polishing pad.

In detail, the lowest temperature Tmin may be the temperature of water at room temperature (about 25° C.-35° C.) or the temperature of cooled water (such as below 10° C.). This is because the minimum temperature Tmin is the surface temperature of the polishing pad 100 at the time when the cleaning process is performed on the polishing pad 100 in the machine idle state or the cleaning process is performed before the next object entering the polishing pad 100. The cleaning process mentioned above may use water at room temperature or water after cooling. The highest temperature Tmax of the polishing pad varies depending on the polishing process. For example, the highest temperature of the polishing pad is about 65° C. in an oxide polishing process; the highest temperature of the polishing pad is about 55° C. in a copper polishing process; and the highest temperature of the polishing pad is about 80° C. in a tungsten polishing process. Besides, the certain temperature may be a fixed temperature or a temperature range.

Further, the physical state or the molecular structure of the heat storage material 130 may be changed after the endothermic reaction. In one embodiment, the molecular arrangement of the heat storage material 130 after the endothermic reaction is looser than the molecular arrangement of the heat storage material 130 before the endothermic reaction. In other words, the molecular arrangement of the heat storage material 130 before the endothermic reaction is closer than the molecular arrangement of the heat storage material 130 after the endothermic reaction. In an alternative embodiment, the heat storage material 130 undergoes a phase transition from a first solid state to a second solid state during the endothermic reaction, and the molecular arrangements of the first solid state and the second solid state are different. For example, the crystal arrangements of the first solid state and the second solid state are different.

It is worth noting that the polishing pad 100 includes the heat storage material 130, as described above, so that the temperature of the polishing pad 100 may be decreased during the period of a polishing process. Thereby, since the heat storage region H where the heat storage material 130 is disposed is above the adhesive layer 120, the adhesive layer 120 disposed under the heat storage region H does not have the problem of deterioration, deformation or adhesion degradation due to high temperature during the polishing process, so as to maintain the stability of the polishing process.

In this embodiment, the heat storage region H where the heat storage material 130 is disposed is not in contact with the bottom Gb of the grooves G, so that the contact between an object and the heat storage material 130 may be avoided, thereby preventing scratches and negative impact on the polishing quality when the polishing process is performed on the object using the polishing pad 100.

In the embodiment shown in FIG. 2, although the heat storage region H where the heat storage material 130 is disposed does not contact with the bottom Gb of the grooves G, but the invention is not limited thereto. The option of the distance between the top edge Ht of the heat storage region H and the polishing surface PS may depend on the abrasion degree of the polishing layer 110 when the polishing pad 100 is used. In other embodiments, the distance from the top edge Ht of the heat storage region H to the polishing surface PS may be D/2, 2D/3, 3D/4, 4D/5, or D to avoid the contact between an object and the heat storage material 130, thereby preventing scratches and negative impact on the polishing quality. Moreover, in some other embodiments, the object may not be easily scratched, or the heat storage material 130 that does not easily scratch the object is selected. Then, it may choose to distribute the heat storage material 130 over the entire polishing layer 110 of the polishing pad 100.

Moreover, in this embodiment, the polishing pad 100 may include the cover layer 140 covering the heat storage material 130, but the invention is not limited thereto. In some other embodiments, in the case where the material of the polishing layer 110 mixed with the heat storage material 130 may seal the heat storage material 130 therein, the polishing pad 100 may not include the cover layer 140.

In the first embodiment, the polishing pad 100 includes the heat storage material 130 disposed within the polishing track region A and the non-polishing track region B, but the invention is not limited thereto. Comparing with the non-polishing track region B, the polishing track region A usually has a higher temperature. Therefore, the heat storage material 130 may be disposed within the polishing track region A only to achieve the purpose of more evenly lowering the temperature of the polishing pad 100 during the polishing process. In other embodiments, the polishing pad may include different heat storage material respectively disposed within the polishing track region A and the non-polishing track region B. The details will be described below with reference to FIG. 4.

FIG. 4 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a second embodiment of the invention. Reference may be made to FIG. 1 for a top view diagram of a polishing pad 200 of FIG. 4. The cross-sectional position of FIG. 4 may refer to the position of the line I-I′ in FIG. 1. Please refer to FIGS. 2 and 4 at the same time, the polishing pad 200 in FIG. 4 is similar to the polishing pad 100 in FIG. 2. Therefore, the same or similar elements are represented by the same or similar numerals, and the related descriptions thereof may refer to the descriptions above and are thus omitted here. In addition, a polishing layer 210 and an adhesive layer 220 are the same or similar to the corresponding ones in the first embodiment, and the related descriptions are thus omitted here. The difference between the two embodiments will be described below.

Please refer to FIG. 4. In this embodiment, the polishing pad 200 includes a first heat storage material 230a and a second heat storage material 230b, and both of the first heat storage material 230a and the second heat storage material 230b are disposed in the heat storage region H. From another point of view, the first heat storage material 230a is disposed within the polishing track region A, and the second heat storage material 230b is disposed within the non-polishing track region B, in this embodiment. Namely, different heat storage materials are disposed within the different regions of the polishing pad 200 in this embodiment.

Further, both of the first heat storage material 230a and the second heat storage material 230b are dispersed in the material of the polishing layer 210. That is, the first heat storage material 230a and the second heat storage material 230b are distributed in the polishing layer 210. The method of forming the polishing layer 210 includes respectively forming the structural portions corresponding to the polishing track region A and the non-polishing track region B. The method of forming the structural portion corresponding to the polishing track region A includes a step of mixing the first heat storage material 230a and the material of the polishing layer 210, for example. The method of forming the structural portion corresponding to the non-polishing track region B includes a step of mixing the second heat storage material 230b and the material of the polishing layer 210, for example. The first heat storage material 230a and the second heat storage material 230b are distributed in the polishing layer 210 below a position with a distance greater than D from the polishing surface PS. In an embodiment, the method of forming the polishing layer 210 may include bonding to combine the two structural portions after respectively forming the structural portions corresponding to the polishing track region A and the non-polishing track region B. The two structural portions are joined by an adhesive or thermal fusion, for example. In another embodiment, the method of forming the polishing layer 210 includes forming the structural portion corresponding to the polishing track region A by perfusion method and then forming the structural portion corresponding to the polishing track region B by perfusion method. In this case, the structural portion corresponding to the non-polishing track region B and the formed structural portion corresponding to the polishing track region A are connected and integrated. A part of the polishing layer 210 that includes the first heat storage material 230a and the second heat storage material 230b and a part of the polishing layer 210 that does not include the first heat storage material 230a and the second heat storage material 230b are combined and formed by the perfusion method, for example. From another point of view, the heat storage region H is disposed in a portion of the polishing layer 210.

Moreover, a cover layer 240 may be optionally formed to cover the first heat storage material 230a and the second heat storage material 230b. The property and material of the cover layer 240 are the same as those of the cover layer 140 and thus are omitted here.

Additionally, the first heat storage material 230a and the second heat storage material 230b respectively include an inorganic heat storage material, an organic heat storage material, or a combination thereof. In detail, the inorganic includes, but is not limited to, a hydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heat storage material includes, but is not limited to, a polyol, a fatty alcohol, a fatty acid, or an alkane. The polyol may be trimethylolpropane (TMP, C₆H₁₄O₃), for example. The fatty alcohol may be tetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid (CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkane may be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆), n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the first heat storage material 230a and the second heat storage material 230b undergo an endothermic reaction at different certain temperatures or in different temperature ranges to absorb heat from surroundings, and thus the purpose of lowering the surrounding temperature is achieved. In this embodiment, the first heat storage material 230a and the second heat storage material 230b undergo an endothermic reaction at different temperatures within a range from the lowest temperature Tmin to the highest temperature Tmax of the polishing pad 200 during a polishing process. Namely, both of the first heat storage material 230a and the second heat storage material 230b undergo an endothermic reaction during the polishing process. As shown in FIG. 5, the first heat storage material 230a and the second heat storage material 230b undergo an endothermic reaction at different temperatures between the lowest temperature Tmin and the highest temperature Tmax. Since the polishing pad 200 includes the first heat storage material 230a and the second heat storage material 230b, the heat generated by mechanical friction may be absorbed by the first heat storage material 230a and the second heat storage material 230b to reduce the temperature increase degree of the polishing pad 200 during the polishing process, and thereby the purpose of effectively reducing the temperature of the polishing pad 200 is achieved. Besides, the certain temperature may be a fixed temperature or a temperature range.

Furthermore, the inventor found that different areas of a polishing pad may have different temperatures when the polishing pad is used to perform a polishing process on an object. That is, the polishing pad has a temperature gradient or a non-uniform temperature profile. In view of this, the first heat storage material 230a and the second heat storage material 230b which undergo an endothermic reaction at different certain temperatures are respectively disposed within the polishing track region A and the non-polishing track region B of the polishing pad 200, and thereby, the temperature decrease degree of the polishing pad 200 in the polishing process may be more uniform. In one embodiment, the temperature of the polishing track region A is higher than the temperature of the non-polishing track region B when the polishing pad 200 is used in a polishing process. Thereby, the temperature decrease degree of the polishing pad 200 may be more uniform through the polishing pad 200 including the first heat storage material 230a and the second heat storage material 230b having property shown in FIG. 5, wherein a endothermic reaction temperature of the first heat storage material 230a is lower than a endothermic reaction temperature of the second heat storage material 230b, or a heat absorption (i.e. an area of the endothermic peak of the first heat storage material 230a shown in FIG. 5) of the first heat storage material 230a is larger than a heat absorption (i.e. an area of the endothermic peak of the second heat storage material 230b shown in FIG. 5) of the second heat storage material 230b.

Moreover, in this embodiment, the physical state or the molecular structure of the first heat storage material 230a may be changed and the physical state or the molecular structure of the second heat storage material 230b may be changed after the endothermic reaction. This property is the same as the property of the heat storage material 130 in the first embodiment. Since the related description has been described in detail in the first embodiment, and thus is omitted here.

It is worth noting that, in this embodiment, the polishing pad 200 includes the first heat storage material 230a and the second heat storage material 230b, so that the temperature of the polishing pad 200 may be evenly decreased in the polishing process. Thereby, since the heat storage region H where the first heat storage material 230a and the second heat storage material 230b are disposed is above the adhesive layer 220, the adhesive layer 220 disposed under the heat storage region H does not have the problem of deterioration, deformation or adhesion degradation due to high temperature during the polishing process, so as to maintain the stability of the polishing process.

In this embodiment, the heat storage region H where the first heat storage material 230a and the second heat storage material 230b are disposed is not in contact with the bottom Gb of the grooves G, so that the contact between an object and the first heat storage material 230a and the second heat storage material 230b may be avoided, thereby preventing scratches and negative impact on the polishing quality when the polishing process is performed on the object using the polishing pad 200.

In the embodiment shown in FIG. 4, although the heat storage region H where the first heat storage material 230a and the second heat storage material 230b are disposed does not contact with the bottom Gb of the grooves G, but the invention is not limited thereto. The option of the distance between the top edge Ht of the heat storage region H and the polishing surface PS may depend on the abrasion degree of the polishing layer 210 when the polishing pad 200 is used. In other embodiments, the distance from the top edge Ht of the heat storage region H to the polishing surface PS may be D/2, 2D/3, 3D/4, 4D/5, or D to avoid the contact between an object and the first heat storage material 230a and the second heat storage material 230b, thereby preventing scratches and negative impact on the polishing quality. Moreover, in some other embodiments, the object may not be easily scratched, or the first heat storage material 230a and the second heat storage material 230b that does not easily scratch the object are selected. Then, it may choose to distribute the first heat storage material 230a and the second heat storage material 230b over the entire polishing layer 210 of the polishing pad 200.

Moreover, in this embodiment, the polishing pad 200 may include the cover layer 240 covering the first heat storage material 230a and a second heat storage material 230b, but the invention is not limited thereto. In some other embodiments, in the case where the material of the polishing layer 210 mixed with the first heat storage material 230a and a second heat storage material 230b may seal the first heat storage material 230a and a second heat storage material 230b therein, the polishing pad 200 may not include the cover layer 240.

In the first embodiment, the heat storage material 130 is dispersed in the material of the polishing layer 110 in the corresponding heat storage region H, but the invention is not limited thereto. In other embodiments, the heat storage material may also be in the form of an interface layer formed in the heat storage region H in the polishing pad. The details will be described below with reference to FIG. 6.

FIG. 6 is a cross-sectional diagram along illustrating a polishing pad along a radius direction according to a third embodiment of the invention. Reference may be made to FIG. 1 for a top view diagram of a polishing pad 300 of FIG. 6. The cross-sectional position of FIG. 6 may refer to the position of the line I-I′ in FIG. 1. Please refer to FIGS. 2 and 6 at the same time, the polishing pad 300 in FIG. 6 is similar to the polishing pad 100 in FIG. 2. Therefore, the same or similar elements are represented by the same or similar numerals, and the related descriptions thereof may refer to the descriptions above and are thus omitted here. In addition, a polishing layer 310 and an adhesive layer 320 are the same or similar to the corresponding ones in the first embodiment, and the related descriptions are thus omitted here. The difference between the two embodiments will be described below.

Please refer to FIG. 6. In this embodiment, a heat storage material 330 is disposed in the heat storage region H. In detail, the heat storage material 330 in the heat storage region H forms an interface layer 350. Namely, the heat storage region H covers the entire interface layer 350 formed by the heat storage material 330. In this embodiment, the interface layer 350 is disposed above the adhesive layer 320. In this embodiment, the interface layer 350 is disposed between the adhesive layer 320 and the polishing layer 310. Besides, as described above, since the heat storage region H does not contact with the bottom Gb of the grooves G, the interface layer 350 which is disposed in the heat storage region H also does not contact with the bottom Gb of the grooves G.

In one embodiment, the interface layer 350 and the polishing layer 310 are made by using the same mold, for example. In detail, the method of forming the interface layer 350 and the polishing layer 310 includes using perfusion method to inject the heat storage material 330 into a mold to form the interface layer 350, and then using perfusion method to inject the material of the polishing layer 310 into the mold having the formed interface layer 350 therein. However, the invention is not limited to the above method of forming the interface layer 350 and the polishing layer 310. The invention also may choose another method to complete the structure of the interface layer 350 and the polishing layer 310.

Moreover, a cover layer 340 may be optionally formed to cover the heat storage material 330. The property and material of the cover layer 340 are the same as those of the cover layer 140 and thus are omitted here.

Additionally, the heat storage material 330 includes an inorganic heat storage material, an organic heat storage material, or a combination thereof. In detail, the inorganic includes, but is not limited to, a hydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heat storage material includes, but is not limited to, a polyol, a fatty alcohol, a fatty acid, or an alkane. The polyol may be trimethylolpropane (TMP, C₆H₁₄O₃), for example. The fatty alcohol may be tetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid (CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkane may be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆), n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 330 undergoes an endothermic reaction at a certain temperature or in a certain temperature range to absorb heat from surroundings, and thus the purpose of lowering the surrounding temperature is achieved. In this embodiment, the heat storage material 330 undergoes an endothermic reaction at a certain temperature within a range from the lowest temperature Tmin to the highest temperature Tmax of the polishing pad 300 during a polishing process. Namely, the heat storage material 330 inevitably undergoes an endothermic reaction during the polishing process. Since the polishing pad 300 includes the heat storage material 330, the heat generated by mechanical friction may be absorbed by the heat storage material 330 to reduce the temperature increase degree of the polishing pad 300 during the polishing process, and thereby the purpose of effectively reducing the temperature of the polishing pad 300 is achieved, as shown in FIG. 3. Besides, the certain temperature may be a fixed temperature or a temperature range.

Further, the physical state or the molecular structure of the heat storage material 330 may be changed after the endothermic reaction. This property is the same as the property of the heat storage material 130 in the first embodiment. Since the related description has been described in detail, and thus is omitted here.

It is worth noting that, as described above, in this embodiment, the polishing pad 300 includes the heat storage material 330, so that the temperature of the polishing pad 300 may be decreased in the polishing process. Thereby, since the heat storage region H where the heat storage material 330 is disposed is above the adhesive layer 320, the adhesive layer 320 disposed under the heat storage region H does not have the problem of deterioration, deformation or adhesion decay due to high temperature during the polishing process, so as to maintain the stability of the polishing process.

Moreover, a cover layer 340 may be optionally formed to cover the heat storage material 330, but the invention is not limited thereto. In some other embodiments, the polishing pad 300 may not include the cover layer 340 that cover the heat storage material 330 in a case where the heat storage material 330 does not flow easily to contaminate the polishing layer 310 or the adhesive layer 320 after the endothermic reaction occurs.

Moreover, based on the second and third embodiments, it may be known that the polishing pad 300 of the third embodiment may be designed by using the same concept of the polishing pad 200 of the second embodiment. The heat storage material 330 originally disposed in both of the polishing track region A and the non-polishing track region B may be replaced by different heat storage materials respectively disposed in the polishing track region A and the non-polishing track region B to achieve the purpose of more evenly decrease the temperature of the polishing pad in the polishing process. Incidentally, the polishing track region A usually has a higher temperature than the temperature of the non-polishing track region B. Therefore, the heat storage material 330 may dispose within the polishing track region A only to achieve the purpose of more evenly lowering the temperature of the polishing pad 300 during the polishing process.

FIG. 7 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a fourth embodiment of the invention. Reference may be made to FIG. 1 for a top view diagram of a polishing pad 400 of FIG. 7. The cross-sectional position of FIG. 7 may refer to the position of the line I-I′ in FIG. 1. Please refer to FIGS. 2 and 7 at the same time, the polishing pad 400 in FIG. 7 is similar to the polishing pad 100 in FIG. 2, the difference between the two embodiments is the structure of polishing pad. Therefore, the same or similar elements are represented by the same or similar numerals, and the related descriptions thereof may refer to the descriptions above and are thus omitted here. In addition, a polishing layer 410 is the same or similar to the corresponding one in the first embodiment, and the related descriptions are thus omitted here. The difference between the two embodiments will be described below.

Please refer to FIG. 7. The polishing pad 400 includes a base layer 460 under the polishing layer 410. In detail, in this embodiment, the base layer 460 is suitable for underlaying the polishing layer 410 in the polishing pad 400. The material of the base layer 460 may be a polyurethane, polybutadiene, polyethylene, polypropylene, a copolymer of polyethylene with ethylene vinyl acetate, or a copolymer of polypropylene with ethylene vinyl acetate, for example, but the invention is not limited thereto.

The polishing pad 400 includes a first adhesive layer 420a between the polishing layer 410 and the base layer 460. In detail, in this embodiment, the first adhesive layer 420a is used for adhering the polishing layer 410 to the base layer 460. In addition, the first adhesive layer 420a includes, but is limited to, carrier-free adhesive, double-sided adhesive, hot-melt adhesive, or moisture-hardening adhesive. The material of the first adhesive layer 420a is an acrylic-based adhesive, a silicone-based adhesive, a rubber-based adhesive, an epoxy-based adhesive or a polyurethane-based adhesive, for example. However, the invention is not limited thereto.

The polishing pad 400 includes a second adhesive layer 420b under the base layer 460. In detail, in this embodiment, the second adhesive layer 420b is adhered to the back surface of the base layer 460 away from the first adhesive layer 420a. That is, the base layer 460 is disposed between the first adhesive layer 420a and the second adhesive layer 420b. In addition, the second adhesive layer 420b includes, but is limited to, a carrier-free adhesive or a double-sided adhesive. The material of the second adhesive layer 420b is an acrylic-based adhesive, a silicone-based adhesive, a rubber-based adhesive, an epoxy-based adhesive or a polyurethane-based adhesive, for example. However, the invention is not limited thereto.

The heat storage material 430 is disposed in a heat storage region K. In this embodiment, the heat storage region K is disposed between the first adhesive layer 420a and the second adhesive layer 420b. In detail, in this embodiment, the heat storage region K covers the entire base layer 460. That is, the base layer 460 has a thickness T, and a distance between the top edge Kt and the bottom edge Kb of the heat storage region K is equal to T.

Moreover, in this embodiment, the heat storage material 430 is dispersed in the material of the base layer 460. That is, the heat storage material 430 is distributed in the base layer 460. The method of forming the base layer 460 includes a step of mixing the heat storage material 430 and the material of the base layer 460.

Moreover, a cover layer 440 may be optionally formed to cover the heat storage material 430. The property and material of the cover layer 440 are the same as those of the cover layer 140 and thus are omitted here.

Additionally, the heat storage material 430 includes an inorganic heat storage material, an organic heat storage material, or a combination thereof. In detail, the inorganic includes, but is not limited to, a hydrate of a salt, such as CH₃COONa.3H₂O or CaCl₂.6H₂O. The organic heat storage material includes, but is not limited to, a polyol, a fatty alcohol, a fatty acid, or an alkane. The polyol may be trimethylolpropane (TMP, C₆H₁₄O₃), for example. The fatty alcohol may be tetradecanol (C₁₄H₃₀O), for example. The fatty acid may be lauric acid (CH₃(CH₂)₁₀COOH), capric acid (CH₃(CH₂)₈COOH), for example. The alkane may be n-eicosane (C₂₀H₄₂), n-heneicosane (C₂₁H₄₄), n-docosane (C₂₂H₄₆), n-tricosane (C₂₃H₄₈), or n-tetracosane (C₂₄H₅₀).

It is worth mentioning that the heat storage material 430 undergoes an endothermic reaction at a certain temperature or in a certain temperature range to absorb heat from surroundings, and thus the purpose of lowering the surrounding temperature is achieved. In this embodiment, the heat storage material 430 undergoes an endothermic reaction at a certain temperature within a range from the lowest temperature Tmin to the highest temperature Tmax of the polishing pad 400 during a polishing process. Namely, the heat storage material 430 inevitably undergoes an endothermic reaction during the polishing process. Since the polishing pad 400 includes the heat storage material 430, the heat generated by mechanical friction may be absorbed by the heat storage material 430 to reduce the temperature increase degree of the polishing pad 400 during the polishing process, and thereby the purpose of effectively reducing the temperature of the polishing pad 400 is achieved, as shown in FIG. 3. Besides, the certain temperature may be a fixed temperature or a temperature range.

Further, the physical state or the molecular structure of the heat storage material 430 may be changed after the endothermic reaction. This property is the same as the property of the heat storage material 130 in the first embodiment. Since the related description has been described in detail, and thus is omitted here.

It is worth noting that, as described above, in this embodiment, the polishing pad 400 includes the heat storage material 430, so that the temperature of the polishing pad 400 may be decreased in the polishing process. Thereby, since the heat dispose region K where the heat storage material 430 is disposed is between the first adhesive layer 420a and the second adhesive layer 420b, the first adhesive layer 420a and the second adhesive layer 420b disposed on two sides of the heat storage region K do not have the problem of deterioration, deformation or adhesion decay due to high temperature during the polishing process, so as to maintain the stability of the polishing process.

Furthermore, the polishing pad 400 includes the cover layer 440 covering the heat storage material 430, but the invention is not limited thereto. In other embodiments, in the case where the material of the base layer 460 mixed with the heat storage material 430 may seal the heat storage material 430 therein, the polishing pad 400 may not include the cover layer 440.

From the first to fourth embodiments, it may be known that the polishing pad 400 of the fourth embodiment may be designed in the same concept as the polishing pads 100˜300 of the first to third embodiments. A heat storage region where a heat storage material is disposed is formed above the first adhesive layer 420a.

From the second and fourth embodiments, it may be known that the polishing pad 400 of the fourth embodiment may adopt the same conceptual design as the polishing pad 200 of the second embodiment. The heat storage material 430 originally disposed in both of the polishing track region A and the non-polishing track region B may be replaced by different heat storage materials respectively disposed in the polishing track region A and the non-polishing track region B to achieve the purpose of more evenly decrease the temperature of the polishing pad 400 in the polishing process. Incidentally, the temperature of the polishing track region A is usually higher than the temperature of the non-polishing track region B. Therefore, the heat storage material 430 may dispose within the polishing track region A only to achieve the purpose of more evenly lowering the temperature of the polishing pad 400 during the polishing process.

In the fourth embodiment above, the heat storage region K covers the entire base layer 460, but the invention is not limited thereto. The inventor found that each adhesive layer has a different adhesive strength depending on the choice of materials for each adhesive layer. The adhesive layers also have relatively different resistance to the heat generated during the polishing process. Therefore, the heat storage region K does not necessarily need to cover the entire base layer 460. In view of this, in other embodiments, the heat storage area K may also be located in part of the base layer. The details will be described below with reference to FIGS. 8 and 9.

FIG. 8 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a fifth embodiment of the invention. Reference may be made to FIG. 1 for a top view diagram of a polishing pad 500 of FIG. 8. The cross-sectional position of FIG. 8 may refer to the position of the line I-I′ in FIG. 1. Please refer to FIGS. 7 and 8 at the same time, the polishing pad 500 in FIG. 8 is similar to the polishing pad 400 in FIG. 7. Therefore, the same or similar elements are represented by the same or similar numerals, and the related descriptions thereof may refer to the descriptions above and are thus omitted here. In addition, a polishing layer 510, a first adhesive layer 520a, a second adhesive layer 520b, a heat storage material 530, and a cover layer 540 are the same or similar to the corresponding ones in the fourth embodiment, and the related descriptions are thus omitted here. The difference between the two embodiments will be described below.

Please refer to FIG. 8. In this embodiment, a heat storage region L where the heat storage material 530 is disposed is located between the first adhesive layer 520a and the second adhesive layer 520b. In detail, the heat storage region L is located in a portion of the base layer 560 adjacent to the first adhesive layer 520a. That is, in this embodiment, the heat storage region L is located below the first adhesive layer 520a. From another point of view, in this embodiment, the base layer 560 has a thickness T, and a distance between the top edge Lt and the bottom edge Lb of the heat storage area L is T/3 to less than T.

Additionally, in this embodiment, the method of forming the base layer 560 includes a step of mixing the heat storage material 530 and the material of the base layer 560. A part of the base layer 560 that includes the heat storage material 530 and a part of the base layer 560 that does not include the heat storage material 530 are combined and formed by the perfusion method, for example.

It should be noted that, in this embodiment, since the heat storage material 530 is bound to undergo an endothermic reaction during the polishing process, the polishing pad 500 includes the heat storage material 530, such that heat generated by mechanical friction may be absorbed by the heat storage material 530 in the polishing process. Whereby the degree of temperature increase caused by the mechanical friction of the polishing pad 500 is reduced to achieve the purpose of effectively lowering the temperature of the polishing pad 500, as shown in FIG. 3. As a result, the heat storage region L where the heat storage material 530 is disposed is located in a portion of the base layer 560 adjacent to the first adhesive layer 520a, so that the first adhesive layer 520a disposed above the heat storage area L does not have a problem of deterioration, deformation or adhesion decay due to high temperature during the polishing process so as to maintain the stability of the polishing process.

Moreover, in this embodiment, the polishing pad 500 includes the cover layer 540 covering the heat storage material 530, but the invention is not limited thereto. In other embodiments, in the case where the material of the base layer 560 mixed with the heat storage material 530 may seal the heat storage material 530 therein, the polishing pad 500 may not include the cover layer 540.

From the first to third, and fifth embodiments, it may be known that the polishing pad 500 of the fifth embodiment may be designed in the same concept as the polishing pads 100˜300 of the first to third embodiments. A heat storage region where a heat storage material is disposed is formed above the first adhesive layer 520a.

From the second and fifth embodiments, it may be known that the polishing pad 500 of the fifth embodiment may also adopt the same conceptual design as the polishing pad 200 of the second embodiment. The heat storage material 530 originally disposed in both of the polishing track region A and the non-polishing track region B may be replaced by different heat storage materials respectively disposed in the polishing track region A and the non-polishing track region B to achieve the purpose of more evenly decrease the temperature of the polishing pad 500 in the polishing process. Incidentally, the temperature of the polishing track region A is usually higher than the temperature of the non-polishing track region B. Therefore, the heat storage material 530 may dispose within the polishing track region A only to achieve the purpose of more evenly lowering the temperature of the polishing pad 500 during the polishing process.

From the third and fifth embodiments, it may be known that the polishing pad 500 of the fifth embodiment may also adopt the same conceptual design as the polishing pad 300 of the third embodiment. The heat storage material 530 may be used to form an interface layer between the base layer and the first adhesive layer in the heat storage area L, instead of being dispersed in the material of the base layer 560 within the corresponding heat storage area L in the fifth embodiment, to achieve the same invention effect. Namely, the temperature of the polishing pad 500 may be reduced during the polishing process.

FIG. 9 is a cross-sectional diagram illustrating a polishing pad along a radius direction according to a sixth embodiment of the invention. Reference may be made to FIG. 1 for a top view diagram of a polishing pad 600 of FIG. 9. The cross-sectional position of FIG. 9 may refer to the position of the line I-I′ in FIG. 1. Please refer to FIGS. 8 and 9 at the same time, the polishing pad 600 in FIG. 9 is similar to the polishing pad 500 in FIG. 8. Therefore, the same or similar elements are represented by the same or similar numerals, and the related descriptions thereof may refer to the descriptions above and are thus omitted here. In addition, a polishing layer 610, a first adhesive layer 620a, a second adhesive layer 620b, a heat storage material 630, and a cover layer 640 are the same or similar to the corresponding ones in the fifth embodiment, and the related descriptions are thus omitted here. The difference between the two embodiments will be described below.

Please refer to FIG. 9. In this embodiment, a heat storage region M where the heat storage material 630 is disposed is located between the first adhesive layer 620a and the second adhesive layer 620b. In detail, the heat storage region M is located in a portion of the base layer 660 adjacent to the second adhesive layer 620b. That is, in this embodiment, the heat storage region M is located above the second adhesive layer 620b. From another point of view, in this embodiment, the base layer 660 has a thickness T, and a distance between the top edge Mt and the bottom edge Mb of the heat storage area M is T/3 to less than T.

Additionally, in this embodiment, the method of forming the base layer 660 includes a step of mixing the heat storage material 630 and the material of the base layer 660. A part of the base layer 660 that includes the heat storage material 630 and a part of the base layer 660 that does not include the heat storage material 630 are combined and formed by the perfusion method, for example.

It should be noted that, in this embodiment, since the heat storage material 630 is bound to undergo an endothermic reaction during the polishing process, the polishing pad 600 includes the heat storage material 630, such that heat generated by mechanical friction may be absorbed by the heat storage material 630 in the polishing process. Whereby the degree of temperature increase caused by the mechanical friction of the polishing pad 600 is reduced to achieve the purpose of effectively lowering the temperature of the polishing pad 600, as shown in FIG. 3. As a result, the heat storage region M where the heat storage material 630 is disposed is located in a portion of the base layer 660 adjacent to the second adhesive layer 620b, so that the second adhesive layer 620b disposed under the heat storage region M does not have a problem of deterioration, deformation or adhesion decay due to high temperature during the polishing process so as to maintain the stability of the polishing process.

Moreover, in this embodiment, the polishing pad 600 includes the cover layer 640 covering the heat storage material 630, but the invention is not limited thereto. In other embodiments, in the case where the material of the base layer 660 mixed with the heat storage material 630 may seal the heat storage material 630 therein, the polishing pad 600 may not include the cover layer 640.

From the first to third, and sixth embodiments, it may be known that the polishing pad 600 of the sixth embodiment may be designed in the same concept as the polishing pads 100˜300 of the first to third embodiments. A heat storage region where a heat storage material is disposed is formed above the first adhesive layer 620a.

From the second and sixth embodiments, it may be known that the polishing pad 600 of the sixth embodiment may also adopt the same conceptual design as the polishing pad 200 of the second embodiment. The heat storage material 630 originally disposed in both of the polishing track region A and the non-polishing track region B may be replaced by different heat storage materials respectively disposed in the polishing track region A and the non-polishing track region B to achieve the purpose of more evenly decrease the temperature of the polishing pad 600 in the polishing process. Incidentally, the temperature of the polishing track region A is usually higher than the temperature of the non-polishing track region B. Therefore, the heat storage material 630 may dispose within the polishing track region A only to achieve the purpose of more evenly lowering the temperature of the polishing pad 600 during the polishing process.

From the third and sixth embodiments, it may be known that the polishing pad 600 of the sixth embodiment may also adopt the same conceptual design as the polishing pad 300 of the third embodiment. The heat storage material 630 may be used to form an interface layer between the base layer and the second adhesive layer in the heat storage region M, instead of being dispersed in the material of the base layer 660 within the corresponding heat storage region M in the sixth embodiment, to achieve the same invention effect. Namely, the temperature of the polishing pad 600 may be reduced during the polishing process.

As described above, depending on the choice of materials for each adhesive layer, the adhesive layers may have different adhesive strength and the adhesive layers may also have different resistance to the heat generated during the polishing process. In view of the above, it should be understood by those of ordinary skilled in the art based on the foregoing fifth and sixth embodiments that the polishing pad of the invention may include two heat storage regions where the heat storage material is disposed and respectively located in a portion of the base layer adjacent to the first adhesive layer and a portion of the base layer adjacent to the second adhesive layer, or include two interface layers respectively located between the base layer and the first adhesive layer as well as between the base layer and the second adhesive layer, at the same time.

FIG. 10 is a process flow diagram showing a polishing method according to an embodiment of the invention. This polishing method is suitably used to polish an object. In detail, the polishing method may be applied to a polishing process for manufacturing an industrial device, such as a device used in the electronic industries including semiconductor devices, integrated circuits, micro-electromechanical devices, energy conversion devices, communication devices, optical devices, disks for storage, and displays etc., and objects used for manufacturing the devices may include semiconductor wafers, Group III-V wafers, carriers of storage devices, ceramic substrates, polymer substrates, and glass substrates, etc. However, the invention is not limited hereto.

Please refer to FIG. 10. First, in step S10, a polishing pad is provided. In detail, in this embodiment, the polishing pad may be any type of polishing pads as described in the foregoing embodiments, e.g., polishing pad 100, 200, 300, 400, 500 or 600. Relevant descriptions of the polishing pads 100, 200, 300, 400, 500 and 600 have been detailed above and thus will not be repeated here.

Next, in step S12, a pressure is applied to an object. Thereby, the object is pressed on the polishing pad and is in contact with the polishing pad. In detail, as previously described, the object is in contact with the polishing surface PS of the polishing layer 110, 210, 310, 410, 510 or 610. In addition, the method of applying pressure to the object is performed by using, for example, a carrier capable of holding the object.

Thereafter, in step S14, relative motion is provided to the object and the polishing pad, so as to perform a polishing process on the object using the polishing pad and achieve the purpose of planarization. In detail, the method for providing relative motion to the object and the polishing pad is, for example, rotating the polishing pad fixed on a platen via rotation of the platen.

Although the invention is disclosed as the embodiments above, the embodiments are not meant to limit the invention. Any person skilled in the art may make slight modifications and variations without departing from the spirit and scope of the invention. Therefore, the protection scope of the invention shall be defined by the claims attached below.

Claims

1. A polishing pad suitable for a polishing process, the polishing pad comprising:

a polishing layer having a polishing surface and a back surface opposite to each other;

an adhesive layer disposed on the back surface of the polishing layer; and

at least one heat storage material, wherein a region where the at least one heat storage material is disposed is located above the adhesive layer.

2. The polishing pad of claim 1, wherein the at least one heat storage material is dispersed in a material of the polishing layer.

3. The polishing pad of claim 1, wherein the at least one heat storage material forms an interface layer in the region where the at least one heat storage material is disposed, and the interface layer is disposed above the adhesive layer.

4. The polishing pad of claim 1, further comprising at least one groove disposed in the polishing surface of the polishing layer, wherein the region where the at least one heat storage material is disposed does not contact a bottom of the at least one groove.

5. The polishing pad of claim 4, wherein the at least one groove has a groove depth D from the bottom of the at least one groove to the polishing surface, and a distance from a top edge of the region where the at least one heat storage material is disposed to the polishing surface is smaller than or equal to 1.5D and larger than D.

6. The polishing pad of claim 1, wherein a lowest temperature of the polishing pad is Tmin and a highest temperature of the polishing pad is Tmax during the polishing process, and the at least one heat storage material undergoes an endothermic reaction at a temperature between the Tmin and the Tmax.

7. The polishing pad of claim 6, wherein a molecular arrangement of the at least one heat storage material after the endothermic reaction is looser than a molecular arrangement of the at least one heat storage material before the endothermic reaction.

8. The polishing pad of claim 6, wherein the at least one heat storage material undergoes a phase transition from a first solid state to a second solid state during the endothermic reaction, and molecular arrangements of the first solid state and the second solid state are different.

9. The polishing pad of claim 1, wherein the at least one heat storage material comprises an inorganic heat storage material, an organic heat storage material, or a combination thereof.

10. The polishing pad of claim 9, wherein the inorganic heat storage material comprises a hydrate of a salt.

11. The polishing pad of claim 9, wherein the organic heat storage material comprises a polyol, a fatty alcohol, a fatty acid, or an alkane.

12. The polishing pad of claim 1, further comprising a cover layer covering the at least one heat storage material.

13. The polishing pad of claim 12, wherein a material of the cover layer does not chemically react with a material of the polishing layer or the at least one heat storage material.

14. The polishing pad of claim 1, further comprising a polishing track region for placing a first heat storage material and a non-polishing track region for placing a second heat storage material, wherein a lowest temperature of the polishing pad is Tmin and a highest temperature of the polishing pad is Tmax during the polishing process, and the first heat storage material and second heat storage material respectively undergo endothermic reactions at different temperatures between the Tmin and the Tmax.

15. The polishing pad of claim 14, wherein a temperature of the endothermic reaction of the first heat storage material is lower than a temperature of the endothermic reaction of the second heat storage material.

16. The polishing pad of claim 14, wherein a heat absorption capacity of the first heat storage material is more than a heat absorption capacity of the second heat storage material.

17. A polishing method suitable for polishing an object, the polishing method comprising:

providing a polishing pad, wherein the polishing pad is the polishing pad according to claim 1;

applying a pressure to the object to press the object on the polishing pad; and

providing relative motion to the object and the polishing pad to perform the polishing process.