Self-adaptive texture CMP (Chemical Mechanical Polishing) pad capable of efficiently removing and preparation method

Abstract

The invention discloses a self-adaptive texture CMP polishing pad with efficient removal and a preparation method, and belongs to the technical field of CMP polishing pads. The CMP polishing pad comprises a workpiece polishing layer, an elastic buffer layer and a base body supporting layer, the elastic buffer layer is arranged on the base body supporting layer, the workpiece polishing layer is arranged on the elastic buffer layer, and the workpiece polishing layer is arranged on the elastic buffer layer. The workpiece polishing layer is used for efficiently conveying polishing liquid and removing waste. The problems that when an existing CMP polishing pad is used, self-adaptive adjustment cannot be conducted according to the irregularity of the surface of a workpiece, waste generated in the polishing process cannot be effectively removed, and the uniformity and high efficiency of the polishing process cannot be fully guaranteed are solved. The elastic buffer layer is prepared from a polyurethane foam material, pressure self-adaptive buffer can be provided during dynamic compression, self-adaptive adjustment can be carried out according to irregularity of the surface of a workpiece, waste generated in the polishing process can be effectively removed, and uniformity and high efficiency of the polishing process can be fully guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of CMP polishing pads, and particularly to an adaptive texture CMP polishing pad for efficient removal and a preparation method thereof. Background Art

[0002] Chemical mechanical polishing (CMP) is a micro-nano processing technology that combines mechanical grinding and chemical oxidation to remove the surface material of a workpiece to be processed, so as to obtain a smooth surface to achieve ultra-precision non-damaging surface processing, and is mainly used for the processing of ultra-precision surfaces.

[0003] Chinese Patent with Publication No. CN102484058B discloses a CMP polishing pad and a manufacturing method thereof. The CMP polishing pad is manufactured by the following method: dispersing a light-absorbing material in or on the surface of the polishing pad and using the light-absorbing material to absorb a laser beam to form holes, wherein the diameter of the holes is determined by the wavelength of the laser beam. The holes formed by the light-absorbing material dispersed in or on the surface of the CMP polishing pad absorbing the laser beam, and various wavelengths of laser beams can be effectively absorbed according to the type of the light-absorbing material, so that holes with a desired diameter can be formed in the CMP polishing pad, thereby enabling the manufacture of a CMP polishing pad with excellent polishing characteristics at low cost. However, this patent has the following defects:

[0004] In the existing technology, when the CMP polishing pad is in use, it cannot be adaptively adjusted according to the irregularity of the workpiece surface, and cannot effectively remove the waste generated during the polishing process, and cannot fully ensure the uniformity and efficiency of the polishing process. Summary of the Invention

[0005] The purpose of the present invention is to provide an adaptive texture CMP polishing pad for efficient removal and a preparation method thereof, which can be adaptively adjusted according to the irregularity of the workpiece surface, can effectively remove the waste generated during the polishing process, and can fully ensure the uniformity and efficiency of the polishing process, and solves the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] An adaptive texture CMP polishing pad for efficient removal, comprising a workpiece polishing layer, an elastic buffer layer and a matrix support layer. The elastic buffer layer is arranged on the matrix support layer, and the workpiece polishing layer is arranged on the elastic buffer layer. The workpiece polishing layer is used for efficiently transporting the polishing liquid and removing waste.

[0008] Preferably, spiral polishing blocks and grid polishing blocks are arranged on the workpiece polishing layer. The spiral polishing blocks are located in the middle of the workpiece polishing layer, and the grid polishing blocks are located on the periphery of the workpiece polishing layer.

[0009] Preferably, a first polishing liquid flow channel for the flow of polishing liquid during CMP polishing is formed between the spiral polishing blocks, and a second polishing liquid flow channel for the flow of polishing liquid during CMP polishing is formed between the grid polishing blocks, wherein the second polishing liquid flow channel is larger than the first polishing liquid flow channel.

[0010] Preferably, a first micro-channel for removing waste during CMP polishing is further formed between the spiral polishing blocks, and a second micro-channel for removing waste during CMP polishing is further formed between the grid polishing blocks, wherein the number of the second micro-channels is more than that of the first micro-channels.

[0011] Preferably, the workpiece polishing layer is made of polyurethane material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form a workpiece polishing layer that meets the dimensional requirements.

[0012] Preferably, the elastic buffer layer is made of polyurethane foam material. Among them, air holes are formed in the elastic buffer layer, the porosity is 30-60%, and the pore diameter is 80-100 μm.

[0013] Preferably, the matrix support layer is made of polyester material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form a matrix support layer that meets the dimensional requirements.

[0014] According to another aspect of the present invention, a preparation method of an adaptive texture CMP polishing pad with high removal efficiency is further provided, which is used to prepare the adaptive texture CMP polishing pad with high removal efficiency as described above, including:

[0015] Using polyurethane material as raw material, after being stirred, mixed, plasticized and compacted by an extruder, a pre-product of a certain shape is extruded. The pre-product is repeatedly extruded and extended by a calender to form an extended product. The extended product is processed to form a first polishing liquid flow channel and a second polishing liquid flow channel for the flow of polishing liquid during CMP polishing, and a first micro-channel and a second micro-channel for removing waste during CMP polishing are formed to form spiral polishing blocks and grid polishing blocks, thereby preparing a workpiece polishing layer;

[0016] The prepared workpiece polishing layer is bonded to the elastic buffer layer, and the elastic buffer layer is bonded to the matrix support layer, and a CMP polishing pad is formed after lamination.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The present invention polishes a workpiece through a spiral polishing block and a grid polishing block. When polishing the workpiece, polishing liquid is transmitted through a first polishing liquid flow channel and a second polishing liquid flow channel, and the polishing liquid flows in the first polishing liquid flow channel and the second polishing liquid flow channel. At the same time, waste generated during polishing is efficiently removed through a first micro-channel and a second micro-channel. Moreover, a polyurethane foam material is used to prepare an elastic buffer layer, which has good elasticity, durability and chemical stability, and can provide pressure adaptive buffering during dynamic compression, enabling the CMP polishing pad to adapt to the polishing of different workpiece surfaces, being adaptable to adjustment according to the irregularity of the workpiece surface, effectively removing waste generated during the polishing process, and fully ensuring the uniformity and high efficiency of the polishing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a structural diagram of an adaptive texture CMP polishing pad with efficient removal of the present invention;

[0020] Figure 2 is an exploded view of an adaptive texture CMP polishing pad with efficient removal of the present invention;

[0021] Figure 3 is a structural diagram of a workpiece polishing layer of the present invention;

[0022] Figure 4 is a partially enlarged view of a workpiece polishing layer of the present invention;

[0023] Figure 5 is a structural diagram of an elastic buffer layer of the present invention.

[0024] In the figure: 1, workpiece polishing layer; 11, spiral polishing block; 111, first polishing liquid flow channel; 112, first micro-channel; 12, grid polishing block; 121, second polishing liquid flow channel; 122, second micro-channel; 2, elastic buffer layer; 21, air hole; 3, matrix support layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] To solve the problems that the existing CMP polishing pads cannot be adaptively adjusted according to the irregularity of the workpiece surface during use, cannot effectively remove the waste generated during the polishing process, and cannot fully ensure the uniformity and high efficiency of the polishing process, please refer to Figures 1 - 5 , the following technical solutions are provided in this embodiment:

[0027] Example 1

[0028] An adaptive texture CMP polishing pad for efficient removal, comprising a workpiece polishing layer 1, an elastic buffer layer 2 and a matrix support layer 3. The elastic buffer layer 2 is arranged on the matrix support layer 3, and the workpiece polishing layer 1 is arranged on the elastic buffer layer 2. The workpiece polishing layer 1 is used for efficiently transporting polishing liquid and removing waste.

[0029] In this embodiment, spiral polishing blocks 11 and grid polishing blocks 12 are arranged on the workpiece polishing layer 1. The spiral polishing blocks 11 are located in the middle of the workpiece polishing layer 1, and the grid polishing blocks 12 are located on the periphery of the workpiece polishing layer 1. The workpiece is polished by the spiral polishing blocks 11 and the grid polishing blocks 12.

[0030] In this embodiment, a first polishing liquid flow channel 111 for the flow of polishing liquid during CMP polishing is formed between the spiral polishing blocks 11, and a second polishing liquid flow channel 121 for the flow of polishing liquid during CMP polishing is formed between the grid polishing blocks 12. Among them, the second polishing liquid flow channel 121 is larger than the first polishing liquid flow channel 111. During workpiece polishing, the polishing liquid is transported through the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121, and the polishing liquid flows in the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121.

[0031] In this embodiment, a first micro-channel 112 for removing waste during CMP polishing is further formed between the spiral polishing blocks 11, and a second micro-channel 122 for removing waste during CMP polishing is further formed between the grid polishing blocks 12. Among them, the number of the second micro-channels 122 is more than that of the first micro-channels 112. During workpiece polishing, the waste generated during polishing is efficiently removed through the first micro-channel 112 and the second micro-channel 122.

[0032] It should be noted that after adding the polishing liquid onto the workpiece polishing layer 1, the workpiece is polished by the spiral polishing blocks 11 and the grid polishing blocks 12. During workpiece polishing, the polishing liquid is transported through the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121, and the polishing liquid flows in the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121. At the same time, the waste generated during polishing is efficiently removed through the first micro-channel 112 and the second micro-channel 122.

[0033] In this embodiment, the workpiece polishing layer 1 is made of polyurethane material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form the workpiece polishing layer 1 that meets the dimensional requirements.

[0034] It should be noted that the workpiece polishing layer 1 prepared from polyurethane material has excellent elasticity and wear resistance, and can better polish the workpiece.

[0035] In this embodiment, the substrate support layer 3 is made of polyester material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form the substrate support layer 3 that meets the dimensional requirements.

[0036] It should be noted that the substrate support layer 3 prepared from polyester material can play a good supporting role.

[0037] In order to better show the preparation process of the self-adaptive texture CMP polishing pad with high removal efficiency, this embodiment now provides a preparation method of the self-adaptive texture CMP polishing pad with high removal efficiency for preparing the self-adaptive texture CMP polishing pad with high removal efficiency as described above, including:

[0038] Using polyurethane material as the raw material, after being stirred, mixed, plasticized and compacted by an extruder, a pre-product of a certain shape is extruded. The pre-product is repeatedly extruded and extended by a calender to form an extended product. The extended product is processed to open a first polishing liquid flow channel 111 and a second polishing liquid flow channel 121 for the flow of polishing liquid during CMP polishing, and a first micro-channel 112 and a second micro-channel 122 for removing waste during CMP polishing are opened to form a spiral polishing block 11 and a grid polishing block 12, thereby preparing the workpiece polishing layer 1; the prepared workpiece polishing layer 1 is bonded to the elastic buffer layer 2, and the elastic buffer layer 2 is bonded to the substrate support layer 3, and a CMP polishing pad is formed after lamination.

[0039] Embodiment 2

[0040] The difference from Embodiment 1 is that the elastic buffer layer 2 is made of polyurethane foam material. Among them, air holes 21 are opened on the elastic buffer layer 2, the porosity is 30-60%, and the pore diameter is 80-100 μm.

[0041] It should be noted that using polyurethane foam material to prepare the elastic buffer layer 2 has good elasticity, durability and chemical stability. It can provide pressure self-adaptive buffering during dynamic compression, enabling the CMP polishing pad to adapt to the polishing of different workpiece surfaces and can be self-adaptively adjusted according to the irregularity of the workpiece surface.

[0042] Comparative Example

[0043] The difference from Embodiment 1 is that the CMP polishing pad includes a workpiece polishing layer (1) and a substrate support layer (3). The workpiece polishing layer (1) is arranged on the substrate support layer (3), and the workpiece polishing layer (1) is used for polishing the workpiece.

[0044] The waste removal rate, surface flatness and removal uniformity of the CMP polishing pads prepared in Embodiments 1-2 and the comparative example are tested.

[0045] Among them, the operation process of the waste removal rate test is as follows: Select the polishing pad, polishing liquid, and wafer material to be tested, determine the experimental conditions such as polishing pressure, speed, and temperature, fix the wafer on the polishing machine, perform the polishing operation using the polishing pad, and record the polishing time and the amount of polishing liquid used simultaneously. During the polishing process, evaluate the waste removal effect by analyzing the changes on the surface of the polishing pad and the wafer surface. During or after the polishing process, collect the waste remaining on the polishing liquid and the wafer surface, and use tools such as spectroscopic analysis and particle counters to detect the types and concentrations of the waste. Calculate the waste removal rate by comparing the changes in the amount of waste before and after polishing.

[0046] Among them, the operation process of the surface flatness test is as follows: Reflect the light beam onto the surface of the polishing pad through an interferometer, analyze the distribution of the light beam interference fringes, and thus calculate the surface height change to determine the surface flatness situation.

[0047] Among them, the operation process of the removal uniformity test is as follows: Calculate the removal thickness and uniformity by measuring the thickness change of the wafer before and after polishing.

[0048] The performance test results of the CMP polishing pad are shown in Table 1:

[0049] Table 1: Performance Test Results of CMP Polishing Pad

[0050]

[0051]

[0052] It can be seen from this that compared with Example 1, the waste removal rate of Example 2 has little difference, but the surface flatness and removal uniformity are significantly better than those of Example 1. Since the elastic buffer layer 2 in Example 2 is made of polyurethane foam material, and there are air holes 21 on the elastic buffer layer 2, the porosity is 30 - 60%, and the pore diameter is 80 - 100 μm. It can provide pressure self-adaptive buffering during dynamic compression, enabling the CMP polishing pad to adapt to the polishing of different workpiece surfaces and significantly improving the self-adaptive adjustment performance of the CMP polishing pad.

[0053] It can be seen from this that compared with Example 1, the surface flatness and removal uniformity of the comparative example have little difference, but the waste removal rate decreases. When polishing the workpiece in Example 1, the polishing liquid is transported through the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121, and the polishing liquid flows in the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121. At the same time, the waste generated during polishing is efficiently removed through the first micro-channel 112 and the second micro-channel 122, which can significantly improve the waste removal rate of the CMP polishing pad.

[0054] Therefore, the CMP polishing pad prepared according to Embodiment 2 has the best performance, among which the waste removal rate is the best, reaching 98.25%, and the surface flatness and removal uniformity are good.

[0055] In summary, the workpiece is polished by the spiral polishing block 11 and the grid polishing block 12. When the workpiece is polished, the polishing liquid is transmitted through the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121, and the polishing liquid flows in the first polishing liquid flow channel 111 and the second polishing liquid flow channel 121. At the same time, the waste generated during polishing is efficiently removed through the first microchannel 112 and the second microchannel 122. Moreover, the elastic buffer layer 2 is prepared by using polyurethane foam material, which has good elasticity, durability and chemical stability, and can provide pressure adaptive buffering during dynamic compression, enabling the CMP polishing pad to adapt to the polishing of different workpiece surfaces, and can be adaptively adjusted according to the irregularity of the workpiece surface, effectively removing the waste generated during the polishing process, and fully ensuring the uniformity and efficiency of the polishing process.

[0056] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0057] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adaptive texture CMP polishing pad for efficient removal, characterized in that, It includes a workpiece polishing layer (1), an elastic buffer layer (2) and a substrate support layer (3). The elastic buffer layer (2) is disposed on the substrate support layer (3), and the workpiece polishing layer (1) is disposed on the elastic buffer layer (2). The workpiece polishing layer (1) is used for efficiently transporting polishing liquid and removing waste.

2. The self - adaptive texture CMP polishing pad with efficient removal as described in claim 1, wherein, Spiral polishing blocks (11) and grid polishing blocks (12) are disposed on the workpiece polishing layer (1). The spiral polishing blocks (11) are located in the middle of the workpiece polishing layer (1), and the grid polishing blocks (12) are located on the periphery of the workpiece polishing layer (1).

3. The self - adaptive texture CMP polishing pad for efficient removal according to claim 2, wherein, A first polishing liquid flow channel (111) for the flow of polishing liquid during CMP polishing is formed between the spiral polishing blocks (11), and a second polishing liquid flow channel (121) for the flow of polishing liquid during CMP polishing is formed between the grid polishing blocks (12). Among them, the second polishing liquid flow channel (121) is larger than the first polishing liquid flow channel (111).

4. The adaptive texture CMP polishing pad for efficient removal according to claim 3, wherein A first micro-channel (112) for removing waste during CMP polishing is further formed between the spiral polishing blocks (11), and a second micro-channel (122) for removing waste during CMP polishing is further formed between the grid polishing blocks (12). Among them, the number of the second micro-channels (122) is more than the number of the first micro-channels (112).

5. The adaptive texture CMP polishing pad for efficient removal according to claim 1, wherein The workpiece polishing layer (1) is made of polyurethane material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form a workpiece polishing layer (1) that meets the dimensional requirements.

6. The self-adaptive texture CMP polishing pad with efficient removal as described in claim 1, wherein The elastic buffer layer (2) is made of polyurethane foam material. Among them, air holes (21) are formed on the elastic buffer layer (2), the porosity is 30-60%, and the pore diameter is 80-100 μm.

7. The self - adaptive texture CMP polishing pad with efficient removal as described in claim 1, characterized in that The substrate support layer (3) is made of polyester material. The pre-product is extruded by an extruder, and the pre-product is repeatedly extruded and extended by a calender, and the extended product is processed to form a substrate support layer (3) that meets the dimensional requirements.

8. Method for preparing an adaptive texture CMP polishing pad with high removal efficiency, which is used to prepare the adaptive texture CMP polishing pad with high removal efficiency described in any one of claims 1-7, characterized in that, It includes: Using polyurethane material as raw material, after being stirred, mixed, plasticized and compacted by an extruder, a pre-product of a certain shape is extruded. The pre-product is repeatedly extruded and extended by a calender to form an extended product. The extended product is processed to form a first polishing liquid flow channel (111) and a second polishing liquid flow channel (121) for the flow of polishing liquid during CMP polishing, and a first micro-channel (112) and a second micro-channel (122) for removing waste during CMP polishing are formed to form spiral polishing blocks (11) and grid polishing blocks (12), thereby preparing the workpiece polishing layer (1); The prepared workpiece polishing layer (1) is bonded to the elastic buffer layer (2), and the elastic buffer layer (2) is bonded to the substrate support layer (3), and a CMP polishing pad is formed after lamination.

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