Polishing pad and chemical mechanical polishing equipment

Abstract

The utility model provides a grinding pad and chemical mechanical polishing equipment. The grinding pad comprises a base and a plurality of grinding ribs arranged in the radius direction of the base. Each grinding rib comprises two sub-grinding ribs, the two sub-grinding ribs in any grinding rib are oppositely arranged in a spaced mode and define a grinding liquid storage cavity structure with the base, and the two adjacent sub-grinding ribs in the adjacent grinding ribs are oppositely arranged in a spaced mode and define an impurity storage cavity structure with the base; wafer scraping fins used for making contact with a wafer are arranged at the tops of the sub grinding protruding edges, and the wafer scraping fins are extruded by the wafer to extend towards the impurity entering part of the impurity storage cavity structure so as to push impurities into the impurity storage cavity structure. According to the utility model, hard friction between the wafer and the wafer scraping fins is avoided, the product yield is improved, and impurity particles generated by grinding can be pushed and collected in the impurity storage cavity structure, so that the impurity particles generated by grinding are prevented from being in contact with the wafer, and the wafer is prevented from being scratched due to aggregation of the impurity particles.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a grinding pad and chemical mechanical polishing equipment. Background Art

[0002] With the continuous iteration and upgrading of chip preparation technology, the requirements for chemical mechanical polishing (CMP) are getting higher and higher. Chemical mechanical polishing is a processing technology that combines chemical corrosion and mechanical removal. CMP is an important process in the manufacturing process of semiconductor devices. It is completed by a dedicated grinding machine and is mainly used for flattening and cleaning the surface of the wafer. In the CMP process, a grinding pad and a grinding liquid are required. The grinding pad is attached to the rotating platform of the grinding machine. The grinding head of the grinding machine presses the wafer on the grinding pad, and the grinding liquid is added to the grinding pad. The grinding is carried out in coordination with the rotation of the rotating platform to eliminate the oxide layer or metal layer or other substances on the surface of the wafer.

[0003] During CMP grinding, due to centrifugal force and grinding heat generation, it is easy to reduce the moisture in the wafer and the grinding pad, resulting in hard friction between the wafer and the grinding pad. At the same time, as the number of grinding particles increases, it is easy for the grinding particles to agglomerate, causing the particles to easily scratch the wafer surface, greatly affecting the yield of the chip. Moreover, during the initial grinding, when the wafer and the grinding pad just come into contact, sometimes there is not enough grinding fluid on the grinding pad, resulting in greater friction, which may cause unexpected damage to the wafer.

[0004] Therefore, it is necessary to provide a novel grinding pad and chemical mechanical polishing equipment to solve the above problems existing in the prior art. Utility Model Content

[0005] The utility model aims to provide a grinding pad and chemical mechanical polishing equipment, which can increase the supply of grinding liquid between the wafer and the grinding pad, especially when the wafer is pressed and contacts the grinding pad at the beginning, the grinding liquid stored in the grinding liquid storage chamber structure can flow out to wet the wafer, thereby reducing hard friction and improving the product yield, and can push the impurity particles generated by grinding into the impurity storage chamber structure for collection, so as to avoid the impurity particles generated by grinding from contacting the wafer, and prevent the impurity particles from agglomerating and causing scratches on the wafer.

[0006] To achieve the above-mentioned purpose, the grinding pad of the utility model includes a base and a plurality of grinding ridges arranged along the radial direction of the base; the grinding ridge includes two sub-grinding ridges, two of the sub-grinding ridges in any one of the grinding ridges are arranged with a gap facing each other and are surrounded by the base to form a grinding liquid storage chamber structure, and two of the adjacent sub-grinding ridges in adjacent grinding ridges are arranged with a gap facing each other and are surrounded by the base to form an impurity storage chamber structure; a wafer scraping fin for contacting a wafer is provided on the top of the sub-grinding ridge, and the wafer scraping fin is squeezed by the wafer to extend toward the impurity entry part of the impurity storage chamber structure and push the impurities into the impurity storage chamber structure.

[0007] The chemical mechanical polishing equipment of the utility model comprises the grinding pad, and the grinding pad is adhered to the rotating platform of the grinding machine.

[0008] The beneficial effects of the grinding pad and the chemical mechanical polishing equipment including the grinding pad of the utility model are as follows: the grinding ridge includes two sub-grinding ridges, and the two sub-grinding ridges in any one of the grinding ridges are arranged with a gap facing each other and surrounded by the base to form a grinding liquid storage chamber structure, so that the supply of grinding liquid between the wafer and the grinding pad can be increased, especially when the wafer is pressed and contacts the grinding pad at the beginning, the grinding liquid stored in the grinding liquid storage chamber structure can flow out to wet the wafer, thereby avoiding hard friction between the wafer and the wafer scraping fin, thereby improving the product yield; by adjacent grinding Two adjacent sub-grinding ridges in the ridge are arranged with their backs to the gap and are arranged together with the base to form an impurity storage chamber structure. A wafer scraper fin for contacting the wafer is provided on the top of the sub-grinding ridge, and the wafer scraper fin is squeezed by the wafer to extend toward the impurity entry part of the impurity storage chamber structure and push the impurities into the impurity storage chamber structure, so that not only grinding can be achieved by contacting the wafer with the wafer scraper fin, but also impurity particles generated by grinding can be pushed into and collected in the impurity storage chamber structure, so as to avoid contact between the impurity particles generated by grinding and the wafer, and prevent the impurity particles from agglomerating and scratching the wafer.

[0009] Preferably, the grinding liquid storage chamber structure includes a first liquid outlet and a liquid storage chamber, and the first liquid outlet is lower than the wafer scraping fin, so that a recessed portion recessed toward the base is formed between two of the sub-grinding ridges in any of the grinding ridges, and the recessed portion is connected to the liquid storage chamber through the first liquid outlet. The beneficial effect is that when the wafer squeezes the wafer scraping fin, there is still a gap between the grinding liquid storage chamber structure and the wafer due to the recessed portion, so that the grinding liquid in the grinding liquid storage chamber structure can be sprayed out smoothly.

[0010] Preferably, the first end of the wafer scraping fin close to the impurity storage chamber structure is higher than the second end of the wafer scraping fin close to the grinding liquid storage chamber structure. The beneficial effect is that the first end of the wafer scraping fin is preferentially contacted with the wafer to grind the wafer, which is conducive to pushing the generated impurities into the adjacent impurity storage chamber structure.

[0011] Preferably, the impurity storage cavity structure includes an impurity storage cavity, and the maximum width of the impurity entry portion is smaller than the maximum width of the impurity storage cavity. The beneficial effect is that it is not only conducive to the storage of abrasive particles, but also makes the impurities fall to the bottom of the impurity storage cavity after entering the impurity entry portion, so that the abrasive particles can be kept away from the wafer, and the abrasive particles are prevented from agglomerating and causing scratches on the wafer.

[0012] Preferably, the grinding liquid storage cavity structure further includes a first liquid inlet and a first liquid outlet respectively connected to the liquid storage cavity, the first liquid inlet is arranged near the center of the base, the first liquid outlet is arranged near the edge of the base, and the cross-sectional area of ​​the first liquid inlet is larger than the cross-sectional area of ​​the first liquid outlet. Its beneficial effect is that the first liquid inlet is arranged to facilitate the replenishment of the grinding liquid, the first liquid outlet is arranged to facilitate the cleaning of the liquid storage cavity, and the cross-sectional area of ​​the first liquid inlet is larger than the cross-sectional area of ​​the first liquid outlet, so as to avoid the grinding liquid from not directly flowing out from the first liquid outlet after entering from the first liquid inlet, but to make more grinding liquid flow out from the first liquid outlet to wet the wafer.

[0013] Preferably, the impurity storage cavity structure further includes a second liquid inlet and a second liquid outlet respectively connected to the impurity storage cavity, the second liquid inlet is arranged near the center of the base, and the second liquid outlet is arranged near the edge of the base. Its beneficial effect is that after the grinding liquid drips from above the center of the base, it enters the impurity storage cavity from the second liquid inlet, so that the grinding liquid drives the impurities to be thrown out through the second liquid outlet under the action of centrifugal force, thereby improving the removal efficiency of impurities in the impurity storage cavity, and timely removing impurities in the impurity storage cavity can effectively prevent the agglomeration of grinding particles from causing wafer scratches.

[0014] Preferably, the sub-grinding ridge further includes an inclined portion and an arc portion, one end of the inclined portion is connected to the second end of the wafer scraping fin, and the inclined portions of two sub-grinding ridges in the grinding ridge are arranged oppositely to form the recessed portion; one end of the arc portion is connected to the first end of the wafer scraping fin, and the other end of the arc portion is connected to the base, and the arc portions of two adjacent sub-grinding ridges in adjacent grinding ridges are arranged oppositely to form the impurity storage cavity of the impurity storage cavity structure. Its beneficial effect is that it enables the recessed portion and the impurity storage cavity to be formed.

[0015] Preferably, the grinding ridge is in a heart-shaped structure or a Y-shaped structure, which has the beneficial effect of enabling the formation of the recessed portion and the impurity storage cavity.

[0016] Preferably, a plurality of the grinding ridges are radially arranged on the base with the center of the base as the center, and the lengths of adjacent grinding ridges are different. The beneficial effect is that more grinding ridges can be arranged while fully utilizing the space of the base.

[0017] Preferably, the grinding ridge is made of a soft material. The beneficial effect thereof is that the wafer scraping fin is squeezed by the wafer and extends toward the impurity entry portion of the impurity storage cavity structure.

[0018] Preferably, the base and the grinding ridge are an integrally formed structure, or the base and the grinding ridge are a detachable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic top view of a polishing pad according to an embodiment of the present utility model;

[0020] Figure 2 for Figure 1 A schematic cross-sectional view of the polishing pad shown along the axial direction;

[0021] Figure 3 for Figure 1 Schematic diagram of the use of the polishing pad shown;

[0022] Figure 4 It is a structural schematic diagram of the chemical mechanical polishing equipment of an embodiment of the utility model. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the utility model belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0024] In order to overcome the problems existing in the prior art, the embodiments of the utility model provide a grinding pad and a chemical mechanical polishing device, which can increase the supply of grinding liquid between the wafer and the grinding pad, especially when the wafer is pressed and contacts the grinding pad at the beginning, the grinding liquid stored in the grinding liquid storage chamber structure can flow out to wet the wafer, thereby reducing hard friction and improving product yield. In addition, the impurity particles generated by grinding can be pushed into the impurity storage chamber structure for collection, so as to avoid the impurity particles generated by grinding from contacting the wafer, and prevent the impurity particles from agglomerating and causing scratches on the wafer.

[0025] Figure 1 A schematic top view of a polishing pad according to an embodiment of the present utility model; Figure 2 for Figure 1 A schematic cross-sectional view of the polishing pad shown along the axial direction; Figure 3 for Figure 1 Schematic diagram of the use of the polishing pad shown.

[0026] In some embodiments of the present invention, reference Figures 1 to 3 The grinding pad 100 includes a base 1 and a plurality of grinding ridges 2 arranged along the radial direction of the base 1; the grinding ridge 2 includes two sub-grinding ridges 21, two of the sub-grinding ridges 21 in any of the grinding ridges 2 are arranged with a gap facing each other and are surrounded by the base 1 to form a grinding liquid storage chamber structure 3, and two of the adjacent sub-grinding ridges 21 arranged adjacent to each other in the adjacent grinding ridges 2 are arranged with a gap facing each other and are surrounded by the base 1 to form an impurity storage chamber structure 4; a wafer scraping fin 21 is provided on the top of the sub-grinding ridge 21 for contacting the wafer 200, and the wafer scraping fin 211 is squeezed by the wafer 200 to extend toward the impurity entry part 41 of the impurity storage chamber structure 4 and push the impurities 300 into the impurity storage chamber structure 4 (because the wafer scraping fin 211 is squeezed by the wafer 200 and faces the impurity storage chamber structure 4, so no matter whether the wafer rotates clockwise or counterclockwise relative to the wafer scraping fin 211, it is easy to push the impurities 300 into the impurity storage chamber structure 4).

[0027] Specifically, the grinding ridge 2 includes two sub-grinding ridges 21, and the two sub-grinding ridges 21 in any one of the grinding ridges 2 are arranged with a gap facing each other and are surrounded by the base 1 to form a grinding liquid storage chamber structure 3, so that the supply of grinding liquid between the wafer 200 and the grinding pad 100 can be increased, especially when the wafer 200 is pressed and contacts the grinding pad 100 at the beginning, the grinding liquid stored in the grinding liquid storage chamber structure 3 can flow out to wet the wafer 200, thereby avoiding hard friction between the wafer 200 and the wafer scraping fin 211, and improving the product yield; by the two sub-grinding ridges 21 adjacent to each other in the adjacent grinding ridges 2, A back-to-back gap is set and the impurity storage chamber structure 4 is formed together with the base 1. A wafer scraping fin 211 for contacting the wafer is provided on the top of the sub-grinding ridge 21, and the wafer scraping fin 211 is squeezed by the wafer 200 and extends toward the impurity entry part 41 of the impurity storage chamber structure 4 and pushes the impurities 300 into the impurity storage chamber structure 4, so that not only can grinding be achieved through the contact between the wafer scraping fin 211 and the wafer 200, but also the impurity particles generated by grinding can be pushed into and collected in the impurity storage chamber structure 4, so as to avoid the impurity particles generated by grinding from contacting the wafer 200, and prevent the impurity particles from agglomerating and causing scratches to the wafer 200.

[0028] In some embodiments of the present invention, reference Figure 3 The grinding ridge 2 includes a first grinding ridge 201 and a second grinding ridge 202 that are adjacent to each other. The first grinding ridge 201 includes two sub-grinding ridges 21, namely a first sub-grinding ridge 2011 and a second sub-grinding ridge 2012. The second grinding ridge 202 includes two sub-grinding ridges 21, namely a third sub-grinding ridge 2021 and a fourth sub-grinding ridge 2022. The third sub-grinding ridge 2021 is adjacent to the second sub-grinding ridge 2012. The first sub-grinding ridge 2011 and the second sub-grinding ridge 2012 are arranged with a gap facing each other and are surrounded by the base 1 to form a grinding liquid storage cavity structure 3. The third sub-grinding ridge 2021 and the fourth sub-grinding ridge 2022 are arranged with a gap facing each other and are surrounded by the base 1 to form a grinding liquid storage cavity structure 3. The second sub-grinding ridge 2012 and the third sub-grinding ridge 2021 are arranged with a gap facing each other and are surrounded by the base 1 to form an impurity storage cavity structure 4.

[0029] In some embodiments of the present invention, reference Figure 2 and Figure 3The grinding liquid storage chamber structure 3 includes a first liquid outlet 31 and a liquid storage chamber 32, and the first liquid outlet 31 is lower than the wafer scraping fin 211, so that a recessed portion 22 recessed toward the base 1 is formed between the two sub-grinding ridges 21 in any of the grinding ridges 2. That is, the recessed portion 22 is located above the grinding liquid storage chamber structure 3, and the recessed portion 22 is connected to the liquid storage chamber 32 through the first liquid outlet 31. Even when the wafer 200 squeezes the wafer scraping fin 211, there is still a gap between the grinding liquid storage chamber structure 3 and the wafer 200 because of the recessed portion 22, so that the grinding liquid in the grinding liquid storage chamber structure 3 can be sprayed out smoothly, that is, the recessed portion 22 can prevent the wafer 200 from squeezing the wafer scraping fin 211 and blocking the first liquid outlet 31.

[0030] In some embodiments of the present invention, reference Figure 2 and Figure 3 The first end of the wafer scraping fin 211 close to the impurity storage chamber structure 4 is higher than the second end of the wafer scraping fin 211 close to the grinding liquid storage chamber structure 3, so that the first end of the wafer scraping fin 211 preferentially contacts the wafer 200 to grind the wafer 200, which is conducive to pushing the generated impurities into the adjacent impurity storage chamber structure 4.

[0031] In some embodiments of the present invention, reference Figure 2 and Figure 3 The impurity storage cavity structure 4 further includes an impurity storage cavity 42, and the maximum width of the impurity entry portion 41 is smaller than the maximum width of the impurity storage cavity 42. This is not only beneficial to the storage of abrasive particles, but also makes the impurities fall to the bottom of the impurity storage cavity 42 after entering the impurity entry portion 41, so that the abrasive particles can be kept away from the wafer, preventing the abrasive particles from agglomerating and causing scratches on the wafer.

[0032] In the present utility model embodiment, reference Figure 2 , the width is the width along the circumferential direction of the base, that is, Figure 2 A shown indicates the direction.

[0033] In some embodiments of the utility model, the grinding liquid storage cavity structure 3 also includes a first liquid inlet and a first liquid outlet respectively connected to the liquid storage cavity 32, the first liquid inlet is arranged near the center of the base 1, and the first liquid outlet is arranged near the edge of the base 1. The first liquid inlet is arranged to facilitate the replenishment of grinding liquid to ensure that there is enough grinding liquid to wet the wafer, and the first liquid outlet is arranged to facilitate the cleaning of the liquid storage cavity 32. The cross-sectional area of ​​the first liquid inlet is larger than the cross-sectional area of ​​the first liquid outlet, so as to avoid the grinding liquid from not directly flowing out of the first liquid outlet after entering from the first liquid inlet, but to make more grinding liquid flow out from the first liquid outlet to wet the wafer.

[0034] In the embodiment of the present invention, the cross-sectional area is the cross-sectional area along the axial direction, and the axial direction is the direction perpendicular to the radial direction of the base. Figure 2 The direction shown is perpendicular to the direction in which A points.

[0035] In some embodiments of the utility model, the impurity storage cavity structure further includes a second liquid inlet and a second liquid outlet respectively connected to the impurity storage cavity, the second liquid inlet is arranged near the center of the base, and the second liquid outlet is arranged near the edge of the base. After the grinding liquid drips from above the center of the base, it enters the impurity storage cavity from the second liquid inlet, so that the grinding liquid drives the impurities to be thrown out through the second liquid outlet under the action of centrifugal force, thereby improving the removal efficiency of impurities in the impurity storage cavity, and timely removing impurities in the impurity storage cavity can effectively prevent the agglomeration of grinding particles from causing wafer scratches.

[0036] In some embodiments of the present invention, reference Figure 2 and Figure 3The sub-grinding ridge 21 also includes an inclined portion 212 and an arc-shaped portion 213, one end of the inclined portion 212 is connected to the second end portion of the wafer scraping fin 211, and the inclined portions 212 of the two sub-grinding ridges 21 in the grinding ridge 2 are relatively arranged to form the recessed portion 22, so that when the wafer 200 squeezes the wafer scraping fin 211, there is still a gap between the grinding liquid storage chamber structure 3 and the wafer 200 due to the recessed portion 22, so that the grinding liquid in the grinding liquid storage chamber structure 3 can be sprayed out smoothly. One end of the arc portion 213 is connected to the first end portion of the wafer scraping fin 211, and the other end of the arc portion 213 is connected to the base 1, and the arc portions 213 of the two adjacent sub-grinding ridges 21 in the adjacent grinding ridges 2 are relatively arranged to form the impurity storage cavity 42 of the impurity storage cavity structure 4, which is not only conducive to the storage of grinding particles, but also makes the impurities fall to the bottom of the impurity storage cavity 42 after entering the impurity entry portion 41, so that the grinding particles can stay away from the wafer 200, preventing the grinding particles from agglomerating and scratching the wafer 200.

[0037] In some embodiments of the present invention, the inclined portion 212 , the wafer scraping fin 211 and the arc portion 213 are connected in sequence, and the inclined portion 212 and the arc portion 213 are arranged with a gap or in close contact.

[0038] In some specific embodiments of the present invention, the inclined portion 212 and the arc-shaped portion 213 are provided with a gap, so that the upper portion of the sub-grinding ridge 21 close to the wafer scraping fin 211 is a hollow structure.

[0039] In some other specific embodiments of the present invention, the inclined portion 212 is fitted with the arc portion 213 , so that the upper portion of the sub-grinding ridge 21 close to the wafer scraping fin 211 is a solid structure.

[0040] In some embodiments of the present invention, the grinding ridge is in a heart-shaped structure or a Y-shaped structure, so that the recessed portion and the impurity storage cavity can be formed.

[0041] In some embodiments of the present invention, reference Figure 1 A plurality of the grinding ridges 2 are radially arranged on the base 1 with the center of the base 1 as the center, and the lengths of adjacent grinding ridges 2 are different.

[0042] In some specific embodiments of the present invention, one end of the grinding ridge close to the edge of the base is located on the same circumference of the base, and the other end of the grinding ridge is at a different distance from the center of the base.

[0043] In an embodiment of the present invention, the length is the length along the radius direction of the base.

[0044] In some specific embodiments of the present utility model, reference Figure 1 The grinding ridge 2 includes a first grinding ridge 201, a second grinding ridge 202 and a third grinding ridge 203 which are sequentially arranged along the circumference of the base. The length of the first grinding ridge 201 is greater than the length of the third grinding ridge 203, and the length of the third grinding ridge 203 is greater than the length of the second grinding ridge 202.

[0045] In some embodiments of the utility model, the grinding ridge is made of a soft material, so that the wafer scraping fin is squeezed by the wafer and extends toward the impurity entrance portion of the impurity storage cavity structure. Specifically, the maximum distance that the wafer scraping fin is squeezed by the wafer and extends toward the impurity entrance portion of the impurity storage cavity structure is less than 1 / 2 of the width of the impurity entrance portion to avoid blocking the impurity entrance portion.

[0046] In some embodiments of the present invention, the base and the grinding ridge are an integrally formed structure.

[0047] In other embodiments of the present invention, the base and the grinding ridge are detachable structures.

[0048] In some embodiments of the present invention, the base is a circular structure.

[0049] In some embodiments of the present invention, the method for using the polishing pad comprises the following steps:

[0050] S1, the grinding liquid stored in the grinding liquid storage chamber structure in advance;

[0051] S2, placing the wafer on the grinding ridge, the grinding head of the grinding machine presses the wafer on the grinding pad, when the wafer is under pressure and contacts the grinding ridge, the grinding liquid in the grinding liquid storage chamber structure is sprayed out to soak the wafer and the wafer scraping fin, so as to avoid hard friction between the wafer and the wafer scraping fin;

[0052] S3. During grinding, the wafer scraping fins are squeezed by the wafer and extend toward the impurity entry portion of the impurity storage chamber structure. When the wafer rotates relative to the grinding pad, the wafer scraping fins scrape the generated impurities into the impurity storage chamber structure, and then the grinding fluid drives the impurities to be thrown outward under the action of centrifugal force.

[0053] In some embodiments of the present invention, the chemical mechanical polishing equipment includes the polishing pad, and the polishing pad is adhered to the rotating platform of the polishing machine.

[0054] Figure 4 It is a structural schematic diagram of the chemical mechanical polishing equipment of an embodiment of the utility model.

[0055] In some embodiments of the present invention, reference Figure 4 The chemical mechanical polishing equipment also includes a supply pipeline 400 for providing grinding liquid. The liquid outlet of the supply pipeline 400 is arranged at the center of the grinding pad 100, that is, above the center of the circle of the grinding pad 100. After the wafer 200 is placed on the grinding pad 100, the supply pipeline 400 sprays the grinding liquid toward the center of the grinding pad 100.

[0056] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A polishing pad, characterized in that: It comprises a base and a plurality of grinding ridges arranged along the radial direction of the base; The grinding ridge comprises two sub-grinding ridges, two sub-grinding ridges in any one of the grinding ridges are arranged with a gap facing each other and are surrounded by the base to form a grinding liquid storage cavity structure, and two adjacent sub-grinding ridges in adjacent grinding ridges are arranged with a gap facing each other and are surrounded by the base to form an impurity storage cavity structure; A wafer scraping fin for contacting a wafer is disposed on the top of the sub-grinding ridge, and the wafer scraping fin is squeezed by the wafer to extend toward the impurity entry portion of the impurity storage cavity structure and push the impurities into the impurity storage cavity structure.

2. The polishing pad according to claim 1, characterized in that The grinding liquid storage chamber structure includes a first liquid outlet and a liquid storage chamber, and the first liquid outlet is lower than the wafer scraping fin, so that a recessed portion recessed toward the base is formed between two of the sub-grinding ridges in any of the grinding ridges, and the recessed portion is connected to the liquid storage chamber through the first liquid outlet.

3. The polishing pad according to claim 1, characterized in that The first end of the wafer scraping fin close to the impurity storage chamber structure is higher than the second end of the wafer scraping fin close to the grinding liquid storage chamber structure.

4. The polishing pad according to claim 1, characterized in that The impurity storage cavity structure includes an impurity storage cavity body, and the maximum width of the impurity entry portion is smaller than the maximum width of the impurity storage cavity body.

5. The polishing pad according to claim 2, characterized in that: The grinding liquid storage chamber structure also includes a first liquid inlet and a first liquid outlet respectively connected to the liquid storage chamber, the first liquid inlet is arranged near the center of the base, the first liquid outlet is arranged near the edge of the base, and the cross-sectional area of ​​the first liquid inlet is larger than the cross-sectional area of ​​the first liquid outlet.

6. The polishing pad according to claim 4, characterized in that The impurity storage cavity structure further includes a second liquid inlet and a second liquid outlet respectively connected to the impurity storage cavity body, the second liquid inlet is arranged near the center of the base, and the second liquid outlet is arranged near the edge of the base.

7. The polishing pad according to claim 2, characterized in that: The sub-grinding ridge also includes an inclined portion and an arc portion; One end of the inclined portion is connected to the second end of the wafer scraping fin, and the inclined portions of the two sub-grinding ridges in the grinding ridge are arranged opposite to each other to form the recessed portion; One end of the arc-shaped portion is connected to the first end of the wafer scraper fin, and the other end of the arc-shaped portion is connected to the base, and the arc-shaped portions of two adjacent sub-grinding ridges in adjacent grinding ridges are arranged relatively to form an impurity storage cavity of the impurity storage cavity structure.

8. The polishing pad according to claim 1, wherein: The grinding ridge is in a heart-shaped structure or a Y-shaped structure.

9. The polishing pad according to claim 1, characterized in that: A plurality of the grinding ridges are radially arranged on the base with the center of the base as the center, and the lengths of adjacent grinding ridges are different.

10. A chemical mechanical polishing device, characterized in that: The invention comprises a polishing pad as described in any one of claims 1 to 9, wherein the polishing pad is adhered to a rotating platform of a polishing machine.

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