Preparation method of polishing pad for chemical polishing and grinding machine table

Abstract

The invention provides a preparation method of a polishing pad for a chemical polishing and grinding machine table, which comprises the following steps: (1) providing a grinding base layer, and sequentially carrying out mechanical stripping and window manufacturing on the grinding base layer to obtain a grinding layer; (2) providing a supporting substrate, and after the supporting substrate is attached to the grinding layer, sequentially carrying out heating, pressing and shaping; and (3) the surface of the side, away from the supporting substrate, of the grinding layer is subjected to grooving treatment, and the polishing pad is obtained. The contact area of the polishing pad and the wafer edge can be increased, and the grinding rate of the wafer edge is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical polishing, and relates to a method for preparing a polishing pad used for a chemical polishing grinding machine. Background Art

[0002] During the chemical mechanical polishing process, a retaining ring is used to vacuum absorb the wafer, and under a certain pressure, the wafer is placed in close contact with the surface of the polishing pad in a downward manner. The flatness of the edge of the wafer after grinding is the result of the coupling effect of the pressure of the retaining ring, the basic physical properties of the polishing pad, and the morphology and distribution of the surface grooves. During the semiconductor wafer grinding process, the deposited materials on the excess and non-flat parts of the silicon wafer surface can be effectively removed through the mutual rotation between the wafer and the polishing pad. If there is a height difference or a curved structure on the wafer surface, or the pressure on the edge of the wafer is greater than that on the center, it is easy to cause inconsistent grinding rates in different areas.

[0003] During use, the existing polishing pad cannot effectively contact the edge of the wafer, resulting in a lower edge grinding rate and less removal at the edge of the wafer than in the middle of the wafer. In addition, it is easy to cause problems such as scratches and defects on the product surface, thereby affecting the product yield. At present, the edge grinding rate is generally improved by adjusting the pressure parameters of the retaining ring on the chemical polishing machine, but it cannot completely guarantee that the edge removal rate is consistent with the internal, nor can it avoid problems such as scratches and defects on the product. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a polishing pad for a chemical polishing grinding machine, which increases the contact area between the polishing pad and the edge of the wafer by reducing the hardness of the grinding layer, thereby solving the problem of low polishing rate of the wafer edge.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing a polishing pad for a chemical polishing grinding machine, the preparation method comprising:

[0007] (I) providing a grinding base layer, and sequentially performing mechanical stripping and window fabrication on the grinding base layer to obtain a grinding layer;

[0008] (II) providing a supporting substrate, laminating the supporting substrate and the polishing layer, and then heating, pressing and shaping the supporting substrate;

[0009] (III) Then, a groove is cut on the surface of the grinding layer away from the supporting substrate to obtain a polishing pad.

[0010] The present invention reduces the hardness of the grinding layer by making windows and forming grooves on the grinding layer, thereby increasing the contact area between the polishing pad and the edge of the wafer, ensuring the uniformity of the grinding degree of the wafer surface and edge, improving the flatness of the wafer edge, and further improving the finished product yield.

[0011] As a preferred technical solution of the present invention, the mechanical peeling strength is >350g / cm.

[0012] Preferably, the material of the grinding base layer includes polyurethane.

[0013] Preferably, the mechanical peeling time is 3 to 10 minutes, for example, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] Preferably, the material of the grinding base layer includes polyurethane.

[0015] As a preferred technical solution of the present invention, after the mechanical stripping, the compression rate of the grinding base layer is 2% to 6%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the hardness of the grinding base layer after the mechanical stripping is 57-63SHA, for example, it can be 57SHA, 58SHA, 59SHA, 60SHA, 61SHA, 62SHA or 63SHA, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the flatness of the grinding base layer after the mechanical stripping is less than 0.01 mm.

[0018] As a preferred technical solution of the present invention, the window production includes: using a cutting device to form at least one detection window on the surface of the grinding base layer.

[0019] Preferably, the detection window is circular or rectangular in shape.

[0020] Preferably, the maximum linear length of the orthographic projection of the detection window on the plane where the grinding base layer is located is 0.6 to 1.2 cm, for example, it can be 0.6 cm, 0.8 cm, 0.9 cm, 1 cm, 1.1 cm or 1.2 cm, but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0021] As a preferred technical solution of the present invention, the temperature of the heating and pressing is 85-125°C, for example, it can be 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C or 125°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the heating and pressing pressure is 3 to 6 bar, for example, 3 bar, 3.5 bar, 4 bar, 4.5 bar, 5 bar, 5.5 bar or 6 bar, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] As a preferred technical solution of the present invention, the shaping includes: using a cutting device to perform cutting processing so that the outer dimensions of the support substrate and the grinding layer match the dimensions of the chemical polishing grinding machine.

[0024] As a preferred technical solution of the present invention, the grooving process includes: using a cutting tool to process a side surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves.

[0025] Preferably, the grinding grooves are evenly distributed on the surface of the grinding layer in a centrally symmetrical manner.

[0026] Preferably, the grinding groove is circular or rectangular in shape.

[0027] Preferably, the depth of the grinding groove is 300-400 μm, for example, it can be 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm or 400 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the spacing between two adjacent grinding grooves is 4 to 8 μm, for example, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm or 8 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In the present invention, due to the presence of the grinding grooves, the grinding rate of the grinding layer is greatly improved. In addition, during the grinding process, when the grinding liquid flows into the grooves, the particulate matter silicon dioxide therein can fully contact with the wafer, and the friction removal effect is enhanced, so that the grinding rate is further improved.

[0030] As a preferred technical solution of the present invention, the preparation method further comprises: cleaning the polishing pad to remove residues on the surface of the polishing pad and in the grinding grooves.

[0031] Preferably, the cleaning process comprises: using high-pressure gas to blow the polishing pad.

[0032] Preferably, the high-pressure gas includes air and / or nitrogen.

[0033] Preferably, the flow rate of the high-pressure gas is 15 to 35 L / min, for example, it can be 15 L / min, 18 L / min, 20 L / min, 23 L / min, 25 L / min, 30 L / min, 32 L / min, 35 L / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] The present invention cleans the surface of the polishing pad and the inside of the grinding groove to blow away internal waste chips, burrs, etc., and can also customize the packaging of the polishing pad to prevent scratches, dust pollution, moisture and other problems on the surface of the polishing pad during transportation.

[0035] As a preferred technical solution of the present invention, the preparation method further comprises: after the mechanical stripping is completed, testing the material thickness, compression rate, roughness and hardness of the grinding base layer.

[0036] Preferably, the preparation method further comprises: after the heating and pressing is completed, detecting whether the supporting base and the grinding layer are deformed, and performing a secondary detection on the material thickness, compression rate, roughness and hardness of the grinding base layer.

[0037] As a preferred technical solution of the present invention, the Shore hardness of the grinding layer is less than 53 SHA.

[0038] Preferably, the thickness ratio of the grinding layer to the supporting base in the polishing pad is 1:(0.4-1), for example, it can be 1:0.4, 1:0.45, 1:0.5, 1:0.6, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the hardness ratio of the grinding layer to the supporting base is 1:(1-1.25), for example, it can be 1:1, 1:1.05, 1:1.1, 1:1.12, 1:1.15, 1:1.18, 1:1.2, 1:1.23 or 1:1.25, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention provides a method for preparing a polishing pad for a chemical polishing grinding machine. By reducing the hardness of the grinding layer and thus reducing the hardness of the overall polishing pad, the hardness of the polishing pad is solved, which solves the problem that during the chemical polishing process of the wafer, the edge of the wafer cannot fully contact with the polishing pad due to the excessively high hardness of the polishing pad, thereby causing a reduction in the polishing rate of the wafer edge. The method also avoids the problem of scratches and defects on the wafer surface caused by the excessively high hardness of the polishing pad, effectively improves the polishing rate, and improves the surface flatness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure is a comparison chart of the polishing rates of wafer chemical polishing using the polishing pads of Example 1, Example 2, Comparative Example 1 and Comparative Example 2. DETAILED DESCRIPTION

[0043] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0044] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0045] In a specific embodiment, the present invention provides a method for preparing a polishing pad for a chemical polishing grinding machine, the preparation method comprising:

[0046] Step 1: providing a grinding base layer, mechanically peeling the grinding base layer, and then using a cutting device to form at least one detection window on the surface of the grinding base layer to obtain a grinding layer.

[0047] Among them, the material of the grinding base layer includes polyurethane; the strength of mechanical peeling is greater than 350g / cm, and the time is 3 to 10min; after mechanical peeling, the compression rate of the grinding base layer is 2% to 6%, the hardness of the grinding base layer is 57 to 63SHA, and the flatness of the grinding base layer is less than 0.01mm; the maximum linear length of the positive projection of the detection window on the plane where the grinding base layer is located is 0.6 to 1.2cm, and the shape is circular or rectangular.

[0048] Furthermore, after the mechanical stripping is completed, the material thickness, compression rate, roughness and hardness of the grinding base layer are tested.

[0049] Step 2: providing a supporting substrate, laminating the supporting substrate and the grinding layer, heating and pressing them, and then cutting them using a cutting device so that the outer dimensions of the supporting substrate and the grinding layer match the dimensions of the chemical polishing grinding machine.

[0050] The temperature of the heating and pressing is 85-125° C., and the pressure is 3-6 bar.

[0051] Furthermore, after the heating and pressing is completed, the support base and the grinding layer are detected to see if they are deformed, and the material thickness, compression rate, roughness and hardness of the grinding base layer are secondarily detected.

[0052] Step 3: Then, a groove is cut on the surface of the grinding layer away from the supporting substrate to obtain a polishing pad.

[0053] The grooving process specifically includes: using a cutting tool to process the surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves. The grinding grooves are evenly distributed on the surface of the grinding layer in a central symmetrical manner, with a depth of 300 to 400 μm, a circular or rectangular shape, and a spacing of 4 to 8 μm between two adjacent grinding grooves.

[0054] Step 4: Use high-pressure gas to blow the polishing pad to clean the polishing pad and remove residues on the surface of the polishing pad and in the grinding grooves.

[0055] The high pressure gas includes air and / or nitrogen, and the flow rate of the high pressure gas is 15 to 35 L / min. The Shore hardness of the grinding layer is less than 53 SHA, the thickness ratio of the grinding layer to the supporting substrate in the polishing pad is 1:(0.4 to 1), and the hardness ratio of the grinding layer to the supporting substrate is 1:(1 to 1.25).

[0056] Example 1

[0057] This embodiment provides a method for preparing a polishing pad for a chemical polishing machine, comprising the following steps:

[0058] (1) providing a grinding base layer, mechanically peeling the grinding base layer, and then using a cutting device to form at least one detection window on the surface of the grinding base layer to obtain a grinding layer;

[0059] The material of the grinding base layer includes polyurethane; the mechanical peeling strength is greater than 350g / cm, and the time is 8min; after mechanical peeling, the compression rate of the grinding base layer is 4.8%, the hardness of the grinding base layer is 61SHA, and the flatness of the grinding base layer is less than 0.01mm; the maximum linear length of the positive projection of the detection window on the plane where the grinding base layer is located is 1cm, and the shape is rectangular;

[0060] (2) After mechanical stripping is completed, the material thickness, compression rate, roughness and hardness of the grinding base layer are tested.

[0061] (3) providing a support substrate, laminating the support substrate and the grinding layer, heating and pressing them, and then cutting them using a cutting device so that the outer dimensions of the support substrate and the grinding layer match the dimensions of the chemical polishing machine, and the heating and pressing temperature is 115° C. and the pressure is 5 bar;

[0062] (4) After the heating and pressing is completed, the support base and the grinding layer are inspected for deformation, and the material thickness, compression rate, roughness and hardness of the grinding base layer are secondarily inspected;

[0063] (5) subsequently, a cutting tool is used to process a surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves to obtain a polishing pad, wherein the grinding grooves are evenly distributed on the surface of the grinding layer in a centrally symmetrical manner, have a depth of 350 μm, are circular in shape, and a distance between two adjacent grinding grooves is 5 μm;

[0064] (6) Use high-pressure gas to purge the polishing pad to clean the polishing pad and remove residues on the polishing pad surface and in the grinding groove. The high-pressure gas uses air with a flow rate of 25L / min.

[0065] In the polishing pad prepared in this embodiment, the thickness ratio of the grinding layer to the supporting substrate is 1:0.5, and the hardness ratio of the grinding layer to the supporting substrate is 1:1.2; the hardness of the polishing pad is 39SHA, the thickness is 2.589mm, and the compression rate is 5.03%.

[0066] Example 2

[0067] This embodiment provides a method for preparing a polishing pad for a chemical polishing machine, comprising the following steps:

[0068] (1) providing a grinding base layer, mechanically peeling the grinding base layer, and then using a cutting device to form at least one detection window on the surface of the grinding base layer to obtain a grinding layer;

[0069] The material of the grinding base layer includes polyurethane; the mechanical peeling strength is greater than 350g / cm, and the time is 5min; after mechanical peeling, the compression rate of the grinding base layer is 2%, the hardness of the grinding base layer is 58SHA, and the flatness of the grinding base layer is less than 0.01mm; the maximum linear length of the positive projection of the detection window on the plane where the grinding base layer is located is 0.8cm, and the shape is circular;

[0070] (2) After mechanical stripping is completed, the material thickness, compression rate, roughness and hardness of the grinding base layer are tested.

[0071] (3) providing a supporting substrate, laminating the supporting substrate and the grinding layer, heating and pressing them, and then cutting them using a cutting device so that the outer dimensions of the supporting substrate and the grinding layer match the dimensions of the chemical polishing machine, and the heating and pressing temperature is 90° C. and the pressure is 4 bar;

[0072] (4) After the heating and pressing is completed, the support base and the grinding layer are inspected for deformation, and the material thickness, compression rate, roughness and hardness of the grinding base layer are secondarily inspected;

[0073] (5) Then, a cutting tool is used to process the surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves to obtain a polishing pad. The grinding grooves are evenly distributed on the surface of the grinding layer in a centrally symmetrical manner, with a depth of 400 μm. The shape of the grinding grooves is rectangular, and the distance between two adjacent grinding grooves is 6 μm.

[0074] (6): Use high-pressure gas to purge the polishing pad to clean the polishing pad and remove residues on the polishing pad surface and in the grinding groove. The high-pressure gas uses nitrogen with a flow rate of 30L / min.

[0075] In the polishing pad prepared in this embodiment, the thickness ratio of the grinding layer to the supporting substrate is 1:0.6, and the hardness ratio of the grinding layer to the supporting substrate is 1:1.1; the hardness of the polishing pad is 52SHA, the thickness is 2.607mm, and the compression rate is 2.05%.

[0076] Example 3

[0077] This embodiment provides a method for preparing a polishing pad for a chemical polishing machine, comprising the following steps:

[0078] (1) providing a grinding base layer, mechanically peeling the grinding base layer, and then using a cutting device to form at least one detection window on the surface of the grinding base layer to obtain a grinding layer;

[0079] The material of the grinding base layer includes polyurethane; the mechanical peeling strength is greater than 350g / cm, and the time is 10min; after mechanical peeling, the compression rate of the grinding base layer is 3.2%, the hardness of the grinding base layer is 56SHA, and the flatness of the grinding base layer is less than 0.01mm; the maximum linear length of the positive projection of the detection window on the plane where the grinding base layer is located is 1.2cm, and the shape is rectangular;

[0080] (2) After mechanical stripping is completed, the material thickness, compression rate, roughness and hardness of the grinding base layer are tested.

[0081] (3) providing a support substrate, laminating the support substrate and the grinding layer, heating and pressing them, and then cutting them using a cutting device so that the outer dimensions of the support substrate and the grinding layer match the dimensions of the chemical polishing machine, and the heating and pressing temperature is 100° C. and the pressure is 5 bar;

[0082] (4) After the heating and pressing is completed, the support base and the grinding layer are inspected for deformation, and the material thickness, compression rate, roughness and hardness of the grinding base layer are secondarily inspected;

[0083] (5) Then, a cutting tool is used to process the surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves to obtain a polishing pad. The grinding grooves are evenly distributed on the surface of the grinding layer in a centrally symmetrical manner, with a depth of 300 μm. The shape of the grinding grooves is rectangular, and the distance between two adjacent grinding grooves is 4 μm.

[0084] (6): Use high-pressure gas to purge the polishing pad to clean the polishing pad and remove residues on the polishing pad surface and in the grinding groove. The high-pressure gas uses a mixture of air and nitrogen with a flow rate of 18L / min.

[0085] In the polishing pad prepared in this embodiment, the thickness ratio of the grinding layer to the supporting substrate is 1:1, and the hardness ratio of the grinding layer to the supporting substrate is 1:1.2; the hardness of the polishing pad is 52SHA, the thickness is 2.834mm, and the compression rate is 3.54%.

[0086] Comparative Example 1

[0087] This comparative example provides a method for preparing a polishing pad for a chemical polishing grinding machine. The difference from Example 1 is that in step (5), the grinding layer is not grooved, and the remaining preparation steps, materials and process parameters are the same as those in Example 1.

[0088] The polishing pad prepared in this comparative example has a hardness of 53SHA, a thickness of 1.62 mm, and a compression rate of 3.5%.

[0089] Comparative Example 2

[0090] This comparative example provides a method for preparing a polishing pad for a chemical polishing grinding machine. The difference from Example 2 is that in step (5), the grinding layer is not grooved, and the remaining preparation steps, materials and process parameters are the same as those in Example 2.

[0091] The polishing pad prepared in this comparative example has a hardness of 62SHA, a thickness of 1.63 mm, and a compression rate of 1.25%.

[0092] The present invention uses the polishing pads prepared in Examples 1-2 and Comparative Examples 1-2 to chemically polish wafers. After polishing, 49 test points are selected on the wafer surface to detect the grinding rate. The results are as follows: Figure 1 As shown. It is not difficult to see that, compared with Comparative Examples 1 and 2, when the polishing pads of Example 1 and Example 2 are used, the grinding rate of the wafer edge is effectively improved. From the perspective of raw materials, the present invention uses a low-hardness grinding layer and adjusts the hardness of the overall polishing pad, thereby solving the problems of low grinding rate at the wafer edge and scratches and defects on the wafer surface, thereby greatly improving the yield of finished products.

[0093] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a polishing pad for a chemical polishing grinding machine, characterized in that: The preparation method comprises: (I) providing a grinding base layer, and sequentially performing mechanical stripping and window fabrication on the grinding base layer to obtain a grinding layer; (II) providing a supporting substrate, laminating the supporting substrate and the polishing layer, and then heating, pressing and shaping the supporting substrate; (III) Then, a groove is cut on the surface of the grinding layer away from the supporting substrate to obtain a polishing pad.

2. The preparation method according to claim 1, characterized in that: The mechanical peeling strength is >350g / cm; Preferably, the mechanical peeling time is 3 to 10 minutes; Preferably, the material of the grinding base layer includes polyurethane.

3. The preparation method according to claim 1 or 2, characterized in that: After the mechanical stripping, the compression rate of the grinding base layer is 2% to 6%; Preferably, the hardness of the grinding base layer after the mechanical stripping is 57-63 SHA; Preferably, the flatness of the grinding base layer after the mechanical stripping is less than 0.01 mm.

4. The preparation method according to any one of claims 1 to 3, characterized in that The window production comprises: using a cutting device to form at least one detection window on the surface of the grinding base layer; Preferably, the shape of the detection window is circular or rectangular; Preferably, the maximum linear length of the orthographic projection of the detection window on the plane where the grinding base layer is located is 0.6-1.2 cm.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The temperature of the heating and pressing is 85-125°C; Preferably, the heating and pressing pressure is 3 to 6 bar.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The shaping includes: performing cutting processing by using a cutting device so that the outer dimensions of the support substrate and the grinding layer match the dimensions of the chemical polishing grinding machine.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The grooving process comprises: using a cutting tool to process a surface of the grinding layer away from the supporting substrate to form a plurality of grinding grooves; Preferably, the grinding grooves are evenly distributed on the surface of the grinding layer in a centrally symmetrical manner; Preferably, the grinding groove is circular or rectangular in shape; Preferably, the depth of the grinding groove is 300-400 μm; Preferably, the distance between two adjacent grinding grooves is 4-8 μm.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The preparation method further comprises: cleaning the polishing pad to remove residues on the surface of the polishing pad and in the grinding grooves; Preferably, the cleaning treatment comprises: using high-pressure gas to blow the polishing pad; Preferably, the high-pressure gas comprises air and / or nitrogen; Preferably, the flow rate of the high-pressure gas is 15 to 35 L / min.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The preparation method further comprises: after the mechanical stripping is completed, testing the material thickness, compression rate, roughness and hardness of the grinding base layer; Preferably, the preparation method further comprises: after the heating and pressing is completed, detecting whether the supporting base and the grinding layer are deformed, and performing a secondary detection on the material thickness, compression rate, roughness and hardness of the grinding base layer.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The Shore hardness of the grinding layer is less than 53 SHA; Preferably, the thickness ratio of the grinding layer to the supporting substrate in the polishing pad is 1:(0.4-1); Preferably, the hardness ratio of the grinding layer to the supporting substrate is 1:(1-1.25).

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