Polishing pad and polishing system

Abstract

The embodiment of the invention provides a polishing pad and a polishing system, and relates to the field of polishing, the polishing pad comprises a grinding layer used for making contact with a wafer, the grinding layer, an upper conductive adhesive layer, a conductive cloth layer, a lower conductive adhesive layer and a conductive release paper layer are sequentially stacked and connected in the gravity direction, and the conductive release paper layer is further connected with a machine table. The conductive cloth layer is used for enhancing the conductivity between the upper conductive adhesive layer and the lower conductive adhesive layer, and the conductive release paper layer is peelable. During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are used for forming a conductive path, and polishing liquid is subjected to electrochemical reaction on the grinding layer. Therefore, the oxidation-reduction reaction in the polishing solution is enhanced, and the polishing solution can maintain stable chemical reaction activity in a long-time polishing process. Moreover, the polishing liquid is only left in the grinding layer, so that the damage of the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer caused by electrochemical corrosion is avoided, and the service life of the polishing pad is prolonged.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of polishing, and in particular to a polishing pad and a polishing system. Background Art

[0002] In semiconductor manufacturing, chemical mechanical polishing (CMP) is a key process for achieving global wafer planarization. Traditional CMP technology relies on the flow of a polishing slurry between the wafer and the polishing pad. Through the synergistic effect of chemically corrosive components (such as oxides) in the slurry and mechanical abrasion, it achieves high-precision material removal and surface planarization.

[0003] However, in the actual production process, with the extension of polishing time or the influence of special polishing environment, the chemical activity of the polishing liquid will gradually decrease, resulting in a decrease in the overall efficiency of CMP, affecting the polishing rate and surface quality.

[0004] To improve the efficiency of the CMP process, the industry usually optimizes the polishing liquid formula or adjusts the process parameters. However, these methods often have limitations, and it is difficult for the polishing liquid to maintain stable chemical reaction activity during the long polishing process. Summary of the Invention

[0005] In view of the above problems, the embodiments of the present application provide a polishing pad and a polishing system, which overcome or at least partially solve the problem that the above-mentioned existing polishing liquid is difficult to maintain stable chemical reaction activity during a long polishing process.

[0006] In a first aspect of an embodiment of the present application, a polishing pad is provided, comprising: a grinding layer, an upper conductive adhesive layer, a conductive cloth layer, a lower conductive adhesive layer, and a conductive release paper layer. The grinding layer is used to contact the wafer, and the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer are stacked and connected in sequence along the direction of gravity, and the conductive release paper layer is also connected to the machine. The conductive cloth layer is used to enhance the conductivity between the upper conductive adhesive layer and the lower conductive adhesive layer, and the conductive release paper layer is removable. During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer.

[0007] In this embodiment, by providing a grinding layer, an upper conductive adhesive layer, a conductive cloth layer, a lower conductive adhesive layer, and a conductive release paper layer, during polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer form a conductive path. The polishing liquid undergoes an electrochemical reaction in the grinding layer, thereby enhancing the redox reaction in the polishing liquid and increasing the activity of the oxidant. This allows the polishing liquid to maintain stable chemical reactivity during long-term polishing. Furthermore, the conductive cloth layer enhances the conductivity between the upper conductive adhesive layer and the lower conductive adhesive layer. The upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer all have good conductivity. Therefore, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer can form a conductive path without the need for perforation. The polishing liquid remains only in the grinding layer, preventing damage to the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer due to electrochemical corrosion, thereby increasing the service life of the polishing pad. Furthermore, the removable conductive release paper layer facilitates replacement of the polishing pad.

[0008] In one alternative embodiment, the polishing layer comprises a polyurethane material and a conductive additive, wherein the polyurethane material is a foamed open-cell polyurethane or a microsphere closed-cell polyurethane. During polishing, the polishing layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer form a conductive path. The polishing liquid undergoes an electrochemical reaction on the surface of the polishing layer away from the upper conductive adhesive layer.

[0009] In an optional manner, the mass fraction of the conductive additive is 0.1%-25%.

[0010] In one alternative embodiment, the polishing layer comprises a non-woven polyurethane composite material produced by a needle-punching process to provide gaps in the polishing layer. During polishing, the polishing layer, the upper conductive adhesive layer, the conductive fabric layer, the lower conductive adhesive layer, and the conductive release paper layer form a conductive path. The polishing liquid undergoes an electrochemical reaction on the surface of the polishing layer away from the upper conductive adhesive layer and within the gaps.

[0011] The grinding layer in this embodiment has gaps, and the polishing liquid undergoes electrochemical reaction on the surface of the grinding layer away from the upper conductive adhesive layer and in the gaps, further enhancing the redox reaction in the polishing liquid and increasing the activity of the oxidant.

[0012] In an optional manner, the upper conductive adhesive layer and the lower conductive adhesive layer are conductive double-sided acrylic pressure-sensitive adhesives.

[0013] In an optional embodiment, the conductive fabric layer is aluminum foil.

[0014] In an optional embodiment, the conductive release paper layer is a conductive PET film.

[0015] In an optional manner, a shallow groove is provided on a surface of the grinding layer away from the upper conductive adhesive layer, and the shallow groove is used to discharge debris generated during the polishing process.

[0016] In one optional embodiment, a through-hole is provided on the surface of the grinding layer away from the upper conductive adhesive layer. During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, and the conductive release paper layer form a conductive path, and the polishing liquid undergoes an electrochemical reaction between the surface of the grinding layer away from the upper conductive adhesive layer and the through-hole.

[0017] In this embodiment, the through-holes allow for rapid transfer and storage of polishing liquid within the polishing pad, ensuring a continuous and uniform supply of polishing liquid to the wafer surface. This further enhances the redox reaction within the polishing liquid, thereby increasing the polishing rate. Furthermore, the through-holes and shallow grooves act as a buffer, reducing mechanical impact during polishing and protecting the wafer surface.

[0018] A second aspect of the present invention provides a polishing system comprising a base substrate, a platform, and the polishing pad provided by the first aspect of the present invention. The base substrate is used to absorb wafers, and the base substrate has a positive contact, while the platform has a negative contact.

[0019] During polishing, the positive contact is connected to the positive pole of the power supply, and the negative contact is connected to the negative pole of the power supply. The base substrate moves in the direction close to the grinding layer to make the wafer contact with the grinding layer. The base substrate, wafer, grinding layer, upper conductive adhesive layer, conductive cloth layer, lower conductive adhesive layer, conductive release paper layer and machine are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer.

[0020] The polishing system provided in this embodiment can enhance the redox reaction in the polishing liquid by applying an external electric field, thereby increasing the activity of the oxidant and improving the polishing efficiency. Moreover, the polishing liquid only remains in the grinding layer, avoiding damage to the upper conductive adhesive layer, conductive cloth layer, lower conductive adhesive layer and conductive release paper layer due to electrochemical corrosion, thereby increasing the service life of the polishing pad.

[0021] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A schematic structural diagram of a polishing pad provided in some embodiments of the present application.

[0024] Figure 2 A schematic structural diagram of another polishing pad provided in some embodiments of the present application.

[0025] Figure 3 A polishing system is provided for some embodiments of the present application. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0028] The terms "comprises", "comprising" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover but not exclude other contents. The word "a" or "an" does not exclude the presence of a plurality.

[0029] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In addition, the terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more such features.

[0031] In the description of this application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two (including two).

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, "connected" or "connected" in a mechanical structure can refer to a physical connection. For example, a physical connection can be a fixed connection, such as a fixed connection via a fixing member, such as a screw, bolt, or other fixing member. A physical connection can also be a detachable connection, such as a mutual snap-fit ​​connection. A physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. "Connected" or "connected" in a circuit structure can refer not only to a physical connection but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate element, as long as the circuit is interconnected. It can also refer to internal communication between two elements. A signal connection can refer to a signal connection through a circuit or a signal connection through a media medium, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application.

[0033] Figure 1 A schematic diagram of the structure of a polishing pad provided in some embodiments of the present application, referring to Figure 1 The polishing pad includes: a grinding layer 01, an upper conductive adhesive layer 02, a conductive fabric layer 03, a lower conductive adhesive layer 04, and a conductive release paper layer 05. The grinding layer 01 is used to contact the wafer. The grinding layer 01, upper conductive adhesive layer 02, conductive fabric layer 03, lower conductive adhesive layer 04, and conductive release paper layer 05 are stacked and connected in sequence along the direction of gravity. For example, a hot pressing process can be used to tightly bond the layers under a certain temperature and pressure. The conductive release paper layer 05 is also connected to the machine. The conductive fabric layer 03 is used to enhance the conductivity between the upper conductive adhesive layer 02 and the lower conductive adhesive layer 04. The conductive release paper layer 05 is removable. During polishing, the grinding layer 01, upper conductive adhesive layer 02, conductive fabric layer 03, lower conductive adhesive layer 04, and conductive release paper layer 05 form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer 01.

[0034] For example, the electrochemical reaction that occurs is Cu-e - →Cu + , Cu + -e - →Cu 2+ , Si-4e - →Si 4+Compared with the conventional addition of oxidants, the oxides produced by electrochemical reactions are more reactive, have fewer side reactions, and are easier to control in terms of release rate. For example, the release rate can be controlled by the size of the applied current density. After the reaction, the surface material of the wafer changes, forming a soft layer that is easy to remove mechanically, thereby better achieving the polishing efficiency. In addition, compared with traditional polishing technology, due to the existence of the interfacial electric field effect, electrochemical reactions can further reduce the reaction energy barrier and even increase the Gibbs free energy of the local reaction, thereby greatly improving the reaction effect.

[0035] In practical applications, the upper conductive adhesive layer 02 and the lower conductive adhesive layer 04 are conductive double-sided acrylic pressure-sensitive adhesives, the conductive cloth layer 03 is aluminum foil, and the conductive release paper layer 05 is a conductive polyethylene terephthalate (PET) film, for example, indium tin oxide conductive PET film.

[0036] In practical applications, the acrylic pressure-sensitive adhesive can be evenly coated on the upper and lower surfaces of the conductive cloth layer 03 through a coating process. After coating, the acrylic pressure-sensitive adhesive is cured through a drying process to have good adhesion properties.

[0037] It should be noted that there is a slight difference in viscosity between the upper conductive adhesive layer 02 and the lower conductive adhesive layer 04 . The upper conductive adhesive layer 02 needs to be connected to the polishing layer 01 and therefore has a stronger viscosity.

[0038] In this embodiment, by providing a grinding layer 01, an upper conductive adhesive layer 02, a conductive cloth layer 03, a lower conductive adhesive layer 04, and a conductive release paper layer 05, during polishing, the grinding layer 01, the upper conductive adhesive layer 02, the conductive cloth layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 can form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer 01. In this way, the redox reaction in the polishing liquid is enhanced, the activity of the oxidant is increased, and the polishing liquid can maintain stable chemical reaction activity during a long polishing process. Furthermore, the conductive fabric layer 03 enhances the conductivity between the upper conductive adhesive layer 02 and the lower conductive adhesive layer 04. The upper conductive adhesive layer 02, the conductive fabric layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 all possess excellent conductivity. Therefore, a conductive path is formed through the upper conductive adhesive layer 02, the conductive fabric layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 without the need for perforations. The polishing fluid remains solely in the abrasive layer 01, preventing damage to the upper conductive adhesive layer 02, the conductive fabric layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 due to electrochemical corrosion, thereby extending the lifespan of the polishing pad. Furthermore, the removable conductive release paper layer 05 facilitates polishing pad replacement.

[0039] In some embodiments, the polishing layer 01 comprises a polyurethane material and a conductive additive. The polyurethane material is either a foamed, open-cell polyurethane or a microsphere-type, closed-cell polyurethane. During polishing, the polishing layer 01, the upper conductive adhesive layer 02, the conductive fabric layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 form a conductive path. The polishing liquid undergoes an electrochemical reaction on the side of the polishing layer 01 facing away from the upper conductive adhesive layer 02.

[0040] In practical applications, the mass fraction of the conductive additive is 0.1%-25%, and the conductive additive can be copper powder, silver powder, nickel powder, aluminum powder, etc.

[0041] It is worth noting that foamed through-cell polyurethane uses water as a component during the polyurethane reaction to achieve foaming during the reaction, improving the overall performance of the polishing pad. Microsphere-type closed-cell polyurethane uses different types of micron-sized microsphere particles added during the reaction process. For example, the microsphere particles have a diameter of 20 nanometers (nm) to 50 nm and a mass fraction of 10% to 20%. The microsphere particles can be one or more of aluminum oxide, silicon dioxide, and barium sulfate. The addition of microsphere particles enhances the hardness and wear resistance of the polishing pad and also synergizes with the chemical reagents in the polishing liquid, promoting chemical reactions and improving polishing efficiency.

[0042] Figure 2 A schematic diagram of another polishing pad provided in some embodiments of the present application, see Figure 2 In some embodiments, shallow grooves 011 are provided on the side of the polishing layer 01 away from the upper conductive adhesive layer 02. These grooves 011 are used to remove debris generated during the polishing process, reducing scratches and defects on the wafer surface. They also guide the polishing slurry, ensuring a more even distribution of the polishing slurry on the polishing layer 01. The width of the shallow grooves 011 can be between 50 micrometers (μm) and 100 μm, and the depth can be between 30 μm and 60 μm. The shallow grooves 011 can be rectangular and evenly distributed on the side of the polishing layer 01 away from the upper conductive adhesive layer 02.

[0043] In some embodiments, reference Figure 2 A through-hole 012 is provided on the surface of the grinding layer 01 facing away from the upper conductive adhesive layer 02. During polishing, the grinding layer 01, the upper conductive adhesive layer 02, the conductive cloth layer 03, the lower conductive adhesive layer 04, and the conductive release paper layer 05 form a conductive path. The polishing liquid undergoes an electrochemical reaction between the surface of the grinding layer 01 facing away from the upper conductive adhesive layer 02 and the through-hole 012.

[0044] The through holes 012 can be circular or rectangular, and can be evenly distributed on the surface of the grinding layer 01 away from the upper conductive adhesive layer 02. The aperture range of the through holes 012 can be 0.5 mm.

[0045] ~5.0mm, the hole ratio can be 0~30%, that is, the total area of ​​the through holes 012 does not exceed 30% of the total area of ​​the surface of the grinding layer 01 away from the upper conductive adhesive layer 02.

[0046] In some embodiments, the through hole 012 and the shallow groove 011 may be designed to be disconnected, so as to further reduce the rigidity of the polishing pad and prevent the through hole 012 from affecting the processing of the shallow groove 011 .

[0047] In this embodiment, the provision of through-holes 012 allows for rapid transfer and storage of polishing liquid within the polishing pad, enabling a continuous and uniform supply of polishing liquid to the wafer surface. This further enhances the redox reaction in the polishing liquid, thereby increasing the polishing rate. Furthermore, the design of through-holes 012 and shallow grooves 011 reduces the rigidity of the polishing pad, increases the contact area with the wafer surface, and provides more uniform contact and consistent pressure distribution, reducing the potential for uneven wear and achieving a higher wafer surface flatness, thereby improving the yield rate of chip manufacturing.

[0048] In some embodiments, polishing layer 01 comprises a non-woven polyurethane composite material produced by a needle-punching process, resulting in gaps within polishing layer 01. During polishing, polishing layer 01, upper conductive adhesive layer 02, conductive fabric layer 03, lower conductive adhesive layer 04, and conductive release paper layer 05 form a conductive path. The polishing liquid undergoes an electrochemical reaction on the surface of polishing layer 01 facing away from upper conductive adhesive layer 02 and within the gaps.

[0049] In practical applications, the non-woven fabric material can be first prepared by needle punching, then immersed in a polyurethane solution for second-stage preparation, and then subjected to aging treatment. After a grooving process, a grinding layer 01 with shallow grooves 011 is prepared, and the polishing pad is polished and cleaned to remove impurities and burrs on the surface.

[0050] The grinding layer 01 in this embodiment has a gap, and the polishing liquid undergoes an electrochemical reaction on the surface of the grinding layer 01 away from the upper conductive adhesive layer 02 and in the gap, further enhancing the redox reaction in the polishing liquid and increasing the activity of the oxidant.

[0051] This application takes polishing silicon wafers as an example. The experimental silicon wafers are fixed on a polishing machine, and different polishing pad products are used to polish the silicon wafers. Sample 1 is a traditional polyurethane polishing pad, sample 2 is a polishing pad provided by this application, and sample 3 is another polishing pad provided by this application. The grinding layer 01 of sample 2 and sample 3 includes polyurethane material and conductive additives. The difference between sample 2 and sample 3 is that the pore size and pore ratio of sample 3 are both larger than those of sample 2.

[0052] Assume that the polishing equipment is set to a current density of 100 mA / cm2. 2), the polishing time was 30 minutes, and the rotation speed of the polishing table was adjusted to 300 revolutions per minute to ensure good contact between the silicon wafer and each polishing pad. The final comparison of the polishing effects between different samples is shown in Table 1 below.

[0053] Table 1: Comparison of polishing effects between different samples

[0054]

[0055] As can be seen from the table above, compared to traditional polyurethane polishing pads, the polishing effect of the polishing pad provided by this application has been greatly improved. For example, the wafer removal rate and roughness have been greatly improved. Moreover, compared with traditional polyurethane polishing pads, Sample 2 provided by this application can process more wafers and has a longer lifespan. A comparison of Samples 2 and 3 provided by this application shows that the larger the pore size, the greater the pore ratio, and the higher the removal rate.

[0056] Another embodiment of the present application provides a polishing system, Figure 3 A polishing system is provided for some embodiments of the present application. Figure 3 The polishing system includes a base substrate 31, a platform 32, and the polishing pad provided by the first aspect of the embodiment of the present application. The base substrate 31 is used to absorb the wafer 33. The base substrate 31 has a positive contact 311, and the platform 32 has a negative contact 322.

[0057] During polishing, the positive contact is connected to the positive pole of the power supply, and the negative contact is connected to the negative pole of the power supply. The base substrate 31 moves in the direction close to the polishing layer 01 to make the wafer 33 contact the polishing layer 01. The base substrate 31, wafer 33, polishing layer 01, upper conductive adhesive layer 02, conductive cloth layer 03, lower conductive adhesive layer 04, conductive release paper layer 05 and machine 32 are used to form a conductive path. The polishing slurry undergoes an electrochemical reaction in the polishing layer 01. Figure 3 The polishing liquid barrel 34 continuously delivers polishing liquid slurry to the grinding layer 01.

[0058] The polishing system provided in this embodiment can enhance the redox reaction in the polishing liquid by applying an external electric field, thereby increasing the activity of the oxidant and improving the polishing efficiency. Moreover, the polishing liquid only remains in the grinding layer 01, avoiding damage to the upper conductive adhesive layer 02, the conductive cloth layer 03, the lower conductive adhesive layer 04 and the conductive release paper layer 05 due to electrochemical corrosion, thereby increasing the service life of the polishing pad.

[0059] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0060] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A polishing pad, characterized in that: The polishing pad comprises: an abrasive layer, an upper conductive adhesive layer, a conductive cloth layer, a lower conductive adhesive layer and a conductive release paper layer; The grinding layer is used to contact the wafer, and the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are stacked and connected in sequence along the direction of gravity, and the conductive release paper layer is also connected to the machine; The conductive fabric layer is used to enhance the conductivity between the upper conductive adhesive layer and the lower conductive adhesive layer, and the conductive release paper layer is removable; During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer.

2. The polishing pad according to claim 1, wherein The grinding layer comprises a polyurethane material and a conductive additive, wherein the polyurethane material is a foamed through-hole polyurethane or a microsphere closed-cell polyurethane; During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction on the surface of the grinding layer away from the upper conductive adhesive layer.

3. The polishing pad according to claim 2, wherein The mass fraction of the conductive additive is 0.1%-25%.

4. The polishing pad according to claim 1, wherein The grinding layer comprises a non-woven polyurethane composite material, and the non-woven polyurethane composite material is prepared by a needle punching method so that the grinding layer has gaps; During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction on the surface of the grinding layer away from the upper conductive adhesive layer and in the gap.

5. The polishing pad according to claim 1, wherein The upper conductive adhesive layer and the lower conductive adhesive layer are conductive double-sided acrylic pressure-sensitive adhesives.

6. The polishing pad according to claim 1, wherein The conductive cloth layer is aluminum foil.

7. The polishing pad according to claim 1, wherein The conductive release paper layer is a conductive PET film.

8. The polishing pad according to claim 2, wherein A shallow groove is provided on a surface of the grinding layer on one side away from the upper conductive adhesive layer, and the shallow groove is used to discharge debris generated during the polishing process.

9. The polishing pad according to claim 2, wherein A through hole is provided on a surface of the grinding layer away from the upper conductive adhesive layer; During polishing, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer and the conductive release paper layer are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction on the surface of the grinding layer away from the upper conductive adhesive layer and in the through hole.

10. A polishing system, characterized in that: The polishing system comprises a base substrate, a machine table and a polishing pad according to any one of claims 1 to 9; The base substrate is used to absorb the wafer, the base substrate is provided with a positive contact, and the machine is provided with a negative contact; During polishing, the positive contact is connected to the positive pole of the power supply, the negative contact is connected to the negative pole of the power supply, and the base substrate moves in a direction close to the grinding layer to make the wafer contact the grinding layer. The base substrate, the wafer, the grinding layer, the upper conductive adhesive layer, the conductive cloth layer, the lower conductive adhesive layer, the conductive release paper layer and the machine are used to form a conductive path, and the polishing liquid undergoes an electrochemical reaction in the grinding layer.

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