Photolithographically ordered microconsolidated abrasive polishing pad and method of making same

Abstract

The present application relates to a kind of photolithography ordered micro consolidation abrasive polishing pad and its preparation method.Compared with prior art, the present application is according to the surface to be photolithography of substrate photolithography pattern, so that multiple micro grinding column is ordered distribution and forms on abrasive base according to preset distribution arrangement mode, the distribution shape, direction position of micro grinding column on abrasive base remains unchanged, can present regular distribution and uniform distribution, and can adjust the distribution and size of micro grinding column according to photolithography pattern to meet different polishing needs, again by filling body composite filling between the micro grinding column of substrate, to keep the stability of micro grinding column, the polishing pad of the present application can be applied to micro level, to meet the demand of 5nm below process, that is, by photolithography to form micro grinding column to replace traditional abrasive particle, improve the chemical stability of polishing pad when polishing, increase removal rate, reduce surface roughness, improve the polishing effect of polishing pad to polishing product.

Description

Technical Field

[0001] This invention relates to the field of wafer grinding and polishing technology in semiconductors, and in particular to a photolithographically ordered microstructured abrasive polishing pad and its preparation method. Background Technology

[0002] In the fields of semiconductors, optical components, and precision machining, surface planarization technology is a core factor determining device performance. For the past few decades, chemical mechanical polishing (CMP) has been the mainstream process for wafer planarization in the semiconductor industry, with its core consumables primarily consisting of polishing pads and abrasive slurries. The polishing pad serves both as a carrier for the chemical etching abrasive slurry and as the core material for physical removal.

[0003] In recent years, as integrated circuit manufacturing nodes have moved below 3nm, the demand for defect control on wafer surfaces has become increasingly stringent. Traditional polishing techniques have gradually become ineffective due to thermal damage and material residue issues. Meanwhile, for processes below 5nm, new materials such as ruthenium and molybdenum place higher demands on the chemical stability of polishing pads.

[0004] Traditional polishing pads are made by mixing and curing polyurethane prepolymer and abrasive particles. However, from a microscopic perspective, the shape and orientation of the abrasive particles are irregularly distributed, and the abrasive particles may even agglomerate. Polishing pads can easily scratch wafers and other polishing products during polishing. Moreover, polishing pads have poor chemical stability during polishing, resulting in poor polishing effect on the polished products and affecting the quality of the polished products. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art by providing a photolithographically ordered microstructured abrasive polishing pad and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] According to the present invention, a photolithographically ordered micro-solidified abrasive polishing pad includes a substrate and a filler. The substrate is a silicon dioxide substrate, a cerium dioxide substrate, or an aluminum oxide substrate. The substrate includes an abrasive base and a plurality of micro-grinding pillars. The micro-grinding pillars are fixedly formed on the abrasive base by photolithography of the surface to be photolithographically lithographically lithographically lithographically lithographically distributed on the abrasive base according to a photolithographic pattern, so that the plurality of micro-grinding pillars form an ordered distribution at the microscopic level, and the size of the micro-grinding pillars is controllable to prevent passivation of the solidified abrasive and to meet the requirements of surface defects and chemical stability of materials for polished products in processes below 5nm. The filler is polyurethane, and the filler is composite-filled between the micro-grinding pillars on the abrasive base.

[0008] Compared with existing technologies, the substrate of this invention uses a pure abrasive substrate such as a silicon dioxide substrate, a cerium dioxide substrate, or an aluminum oxide substrate. The substrate's surface to be photolithographically lithographic is lithographically patterned, and multiple micro-grinding pillars are orderly distributed and formed on the abrasive base in a preset distribution pattern at the microscopic level. At the microscopic level, the micro-grinding pillars replace traditional abrasive particles. The distribution shape, orientation, and position of the micro-grinding pillars on the abrasive base remain unchanged, exhibiting a regular and uniform distribution. Furthermore, the distribution and size of the micro-grinding pillars can be adjusted according to the photolithographic pattern to meet different polishing requirements. A polyurethane filler is then used to fill the spaces between the micro-grinding pillars on the substrate to maintain their stability, making the polishing pad of this invention suitable for various applications. At the microscopic level, to meet the needs of processes below 5nm, micro-grinding pillars are formed by photolithography to replace traditional abrasive particles. At the microscopic level, multiple abrasive pillars are formed in an orderly distribution with controllable particle size, solving the problems of agglomeration and random distribution of traditional abrasives in polishing applications. It can also effectively solve the passivation problem of bonded abrasive polishing pads during use, meeting the requirements of surface defects and chemical stability of polished products in processes below 5nm. It improves the chemical stability of the polishing pad during polishing, increases the removal rate, solves the self-passivation problem of traditional bonded abrasive polishing pads, reduces surface roughness, meets the requirements for defect control of polished products, improves the polishing effect of the polishing pad on the polished products, and thus improves the quality of polished products.

[0009] Preferably, the size of the micro-grinding column is in the micrometer and / or nanometer range.

[0010] Preferably, the micro-grinding column is a circular column with a photolithographic diameter of 0.01um to 500um, and / or a polygonal column with a photolithographic side length of 0.01um to 500um.

[0011] Preferably, the filler is formed by casting polyurethane prepolymer between the micro-grinding columns on the abrasive base and then vulcanizing it to maintain the strength of the micro-grinding columns.

[0012] Compared with the prior art, the present invention prevents the polyurethane prepolymer from detaching and prevents the micro-grinding columns from breaking by casting polyurethane prepolymer between the micro-grinding columns on the abrasive base and then vulcanizing it to form a filler, thus maintaining the strength of the micro-grinding columns.

[0013] Preferably, the polyurethane prepolymer is cast under negative pressure, and the negative pressure is maintained for 1 min to 30 min.

[0014] Compared with the prior art, the present invention uses negative pressure to cast polyurethane prepolymer between the micro-grinding columns on the abrasive base, maintains negative pressure for a preset time, and vulcanizes to form a filler, further preventing the polyurethane prepolymer from coming out, preventing the micro-grinding columns from breaking, and maintaining the strength of the micro-grinding columns.

[0015] Preferably, the substrate is made of quartz, the diameter of the substrate is 2mm to 830mm, and the thickness of the substrate is 1mm to 3mm.

[0016] The present invention also provides a method for preparing a photolithographically ordered microstructured abrasive polishing pad, used to prepare any of the above-described photolithographically ordered microstructured abrasive polishing pads, comprising: applying photoresist to the photolithographic surface of a substrate; performing photolithography on the substrate coated with photoresist according to a photolithographic pattern to divide the substrate into an abrasive base and a plurality of micro-grinding pillars, the plurality of micro-grinding pillars being orderly distributed and formed on the abrasive base; removing the photoresist from the photolithographically lithographically formed substrate; and filling the spaces between the micro-grinding pillars on the abrasive base with a filler composite to form a photolithographically ordered microstructured abrasive polishing pad.

[0017] Preferably, the filler composite is filled between the micro-grinding pillars on the abrasive base, including: selecting a polyurethane prepolymer and a curing agent to cast the substrate after removing the photoresist, and curing the cast substrate at a temperature of 80°C to 200°C for 1 hour to 36 hours.

[0018] The polyurethane prepolymer contains 3% to 12% isocyanate groups, the vulcanizing agent is a diamine crosslinking agent, and the casting conditions are negative pressure casting in a vacuum casting mold, maintaining the negative pressure state for 1 to 30 minutes.

[0019] Preferably, applying photoresist to the photolithographic surface of the substrate includes: pre-cleaning the substrate with a cleaning solvent to remove surface impurities, drying the cleaned substrate, and irradiating it under a UV lamp with a wavelength of 230nm~390nm for 1min~60min after drying; diluting positive or negative photoresist to a concentration of 1%~80% and applying it to the substrate; and drying the substrate coated with photoresist at a temperature of 20℃~200℃ for 1min~60min.

[0020] The cleaning solvent includes one or more of water, alcohol solvents, ketone solvents, amide solvents, ether solvents, and benzene solvents; the photoresist coating method includes one or more of spin coating, spray coating, atomization coating, roller coating, and immersion coating.

[0021] Preferably, photolithography is performed on a substrate coated with photoresist according to a photolithography pattern, comprising: placing the substrate coated with photoresist onto a photolithography stage; selecting a photolithography wavelength of 200nm to 490nm to perform photolithography on the substrate coated with photoresist according to a photolithography pattern mask; placing the photolithographically ...

[0022] Removing photoresist from the photolithographic substrate includes: immersing the etched substrate in a photoresist remover to remove the photoresist, and drying the photoresist-removed substrate at a temperature of 70°C to 150°C for 5 to 60 minutes. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the photolithographically ordered microstructured abrasive polishing pad of the present invention;

[0024] Figure 2 This is a schematic cross-sectional view of the photolithographically ordered microstructured abrasive polishing pad of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the photolithographically ordered micro-bonded abrasive polishing pad with an equilateral triangular array according to the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the photolithographically ordered micro-bonded abrasive polishing pad with a regular hexagonal array according to the present invention.

[0027] Reference numerals: 1. Substrate; 101. Micro-grinding column; 102. Abrasive base; 2. Filler. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] Through in-depth research and improvement exploration of polishing pads, the applicant also discovered that the conventional abrasive particles of traditional polishing pads are distributed between hundreds of nanometers and tens of micrometers in size, and the particle size exhibits a normal distribution, making it difficult to achieve uniform particles.

[0030] Based on this, the technical solutions provided by the various embodiments of this application will be described below with reference to the accompanying drawings.

[0031] This invention provides a photolithographically ordered microstructured abrasive polishing pad, such as... Figure 1 and Figure 2 As shown, the system includes a substrate 1 and a filler 2. The substrate 1 includes an abrasive base 102 and a plurality of micro-abrasive pillars 101 fixed on the abrasive base 102. The plurality of micro-abrasive pillars 101 are formed on the abrasive base 102 by photolithographically lithographically lithographically distributing the photolithographic surfaces of the substrate 1 according to a photolithographic pattern. The filler 2 is compositely filled between the micro-abrasive pillars 101 on the abrasive base 102. The micro-abrasive pillars 101 can be arranged in a triangular, square, or regular hexagonal array with equal intervals. The array distribution density and / or scratch density of the micro-abrasive pillars 101 are positively correlated with the removal rate of the polished product, so the array distribution shape of the micro-abrasive pillars 101 can be selected. Figure 1 As shown, it is a square array, such as Figure 3 As shown, this is an equilateral triangle array, such as... Figure 4 The diagram shows a regular hexagonal array. The micro-grinding pillars 101 can also be arranged in concentric circles or spirals. The substrate 1 is a silicon dioxide substrate, a cerium dioxide substrate, or an aluminum oxide substrate; the micro-grinding pillars 101 are formed in an ordered distribution at the microscopic level, and the size of the micro-grinding pillars 101 is controllable to prevent passivation of the bonded abrasive and to meet the requirements of surface defects and chemical stability of materials for polished products in processes below 5nm. The filler 2 is polyurethane.

[0032] In one embodiment, the micro-grinding column 101 is a micro-scale grinding column with a micron and / or nano-scale size.

[0033] In one embodiment, the micro-grinding column 101 is a circular column with a photolithographic diameter of 0.01µm to 500µm, and / or a polygonal column with a photolithographic side length of 0.01µm to 500µm. For example, regular polygons include squares and regular hexagons.

[0034] In one embodiment, the filler 2 is formed by casting polyurethane prepolymer between the micro-grinding columns 101 on the abrasive base 102 and then vulcanizing it to prevent the polyurethane prepolymer from coming off, prevent the micro-grinding columns from breaking, and maintain the strength of the micro-grinding columns.

[0035] In one embodiment, the polyurethane prepolymer is cast under negative pressure, and the negative pressure state is maintained for 1 min to 30 min to further maintain the strength of the micro-level grinding column.

[0036] In one embodiment, the substrate 1 is made of quartz, and the diameter of the substrate 1 is 2mm to 830mm; the thickness of the substrate 1 is 1mm to 3mm.

[0037] This invention utilizes photolithography to prepare bonded abrasives of different shapes and sizes, solving the problem of inhomogeneity in traditional abrasives. It also enables uniform, homogeneous array arrangement, overcoming the random arrangement problem of traditional abrasives. Furthermore, this invention combines the photolithographically prepared bonded abrasives with polyurethane to form a composite material, enabling precise control over abrasive removal rates, surface roughness, and defects.

[0038] This invention also provides a method for preparing a photolithographically ordered microstructured abrasive polishing pad, used to prepare any of the photolithographically ordered microstructured abrasive polishing pads described in the above embodiments, comprising: applying photoresist to the photolithographic surface of a substrate 1; performing photolithography on the substrate 1 coated with photoresist according to the photolithographic pattern to divide the substrate 1 into an abrasive base 102 and a plurality of micro-grinding pillars 101, wherein the plurality of micro-grinding pillars 101 are orderly distributed on the abrasive base 102; removing the photoresist from the photolithographically lithographically formed substrate 1; and filling the spaces between the micro-grinding pillars 101 on the abrasive base 102 with a filler 2 to form a photolithographically ordered microstructured abrasive polishing pad.

[0039] Specifically: Step 1: Select a suitable photoresist and apply it to the quartz substrate.

[0040] The photoresist is coated onto a quartz substrate. Specifically, the substrate, of a specific size and thickness, is pre-cleaned with a solvent to remove surface impurities. Then, the substrate is irradiated under ultraviolet light to alter its surface condition. Next, a suitable photoresist is selected and diluted to a specific concentration, then coated onto the quartz substrate under certain conditions. Finally, the photoresist-coated quartz substrate is dried at a specific temperature for a certain period to remove residual solvent. The dried, photoresist-coated quartz substrate is then stored for later use.

[0041] Step 2: Obtain ordered and consolidated abrasive materials that meet the requirements through photolithography.

[0042] The photolithography development process is specifically implemented as follows: a quartz substrate coated with photoresist is placed on a photolithography machine stage; a specific wavelength is selected; and a photolithography mask with a specific pattern is used to lithographically etch the photoresist-coated quartz substrate. After photolithography, the quartz substrate is placed in a developing solution for a certain period of time for development. After development, it is then placed in an oven at a certain temperature for drying for a certain period of time.

[0043] Step 3: Form the corresponding columnar structure according to the pattern by etching.

[0044] The etching process is specifically implemented by etching the photolithographically etched and developed quartz substrate downwards according to the pattern to form a columnar structure of a specific shape.

[0045] Step 4: Remove the photoresist from the quartz substrate.

[0046] The cleaning step involves immersing the etched quartz substrate in a photoresist remover to remove the photoresist, and then drying it at a certain temperature for a certain period of time before storing it for later use.

[0047] Step 5: Composite polyurethane with bonded abrasive.

[0048] The casting process is specifically implemented by placing the developed quartz substrate into a vacuum casting mold, selecting a suitable polyurethane prepolymer and vulcanizing agent, and performing vacuum casting under certain temperature and conditions.

[0049] Step 6: The vulcanization process is specifically implemented by vulcanizing the cast substrate under certain temperature and time conditions. After vulcanization, the resulting ordered solidified abrasive polishing pad is formed.

[0050] In one embodiment, the filler 2 is compositely filled between the micro-abrasive pillars 101 on the abrasive base 102, including: selecting polyurethane prepolymer and vulcanizing agent to cast the substrate 1 after removing photoresist, and vulcanizing the cast substrate 1 at a temperature of 80°C to 200°C for 1 hour to 36 hours.

[0051] The polyurethane prepolymer contains 3% to 12% isocyanate groups, the vulcanizing agent is a diamine crosslinking agent, and the casting conditions are negative pressure casting in a vacuum casting mold, maintaining the negative pressure state for 1 to 30 minutes.

[0052] Specifically, in the casting process, step 5 involves mixing a polyurethane prepolymer with an NCO content of 3%-12% with a diamine crosslinking agent, pouring the mixture into a mold containing quartz glass, and then maintaining it under a certain negative pressure for 1-30 minutes. The polyurethane prepolymer with an NCO content of 3%-12% is selected for casting, and a diamine crosslinking agent is used. The negative pressure is, for example, -0.9 MPa. NCO stands for isocyanate group.

[0053] In one embodiment, applying photoresist to the photolithographic surface of substrate 1 includes: pre-cleaning substrate 1 with a cleaning solvent to remove surface impurities; drying the cleaned substrate 1; irradiating it under a UV lamp with a wavelength of 230nm~390nm for 1min~60min after drying; diluting positive or negative photoresist to a concentration of 1%~80% and applying it to substrate 1; and drying the substrate 1 coated with photoresist at a temperature of 20℃~200℃ for 1min~60min.

[0054] The cleaning solvent includes one or more of water, alcohol solvents, ketone solvents, amide solvents, ether solvents, and benzene solvents; the photoresist coating method includes one or more of spin coating, spray coating, atomization coating, roller coating, and immersion coating.

[0055] Specifically, the photoresist coating process on substrate 1 involves step 1, where the glass substrate is treated. The selected quartz glass has a diameter of 2mm-830mm and a thickness of 1mm-3mm. It is then ultrasonically cleaned in a solvent, including but not limited to one or more mixed solvents such as water, alcohols, ketones, amides, ethers, and benzenes. The cleaned glass substrate is then dried, and subsequently irradiated under a UV lamp. The UV irradiation wavelength for the quartz substrate surface treatment is 230-390nm, and the irradiation time is 1min-60min, which allows for better photoresist coating on the quartz substrate.

[0056] The photoresist coating process on substrate 1, in step 1, involves selecting a positive or negative photoresist with a concentration of 1%-80% and coating it onto the quartz substrate. The coating method includes, but is not limited to, spin coating, spraying, atomization, roller coating, dipping, or one or more mixed coating methods. After coating, the photoresist-coated quartz substrate is dried at 20℃-200℃ for 1min-60min, and then stored for later use. The photoresist concentration is 1%-80%, and the photoresist type is either negative or positive.

[0057] In one embodiment, photolithography is performed on a substrate 1 coated with photoresist according to a photolithography pattern, including: placing the substrate 1 coated with photoresist onto a photolithography stage, selecting a photolithography wavelength of 200nm~490nm to perform photolithography on the substrate 1 coated with photoresist according to a photolithography pattern mask, placing the photolithographically ...

[0058] Specifically, in the photolithography and development process, step 2 involves photolithography using a photolithography mask pattern with a wavelength of 200nm-490nm and a diameter of 0.01µm-500µm, including but not limited to circles with a side length of 0.01µm-500µm. After photolithography, the mask is immersed in a 0.1%-40% sodium hydroxide developer solution for 5s-120s. Then, it is dried at a temperature of 70℃-200℃ for 30min-300min. The photolithography pattern can be any polygonal pattern with a diameter or side length of 0.01µm-500µm, including but not limited to circles.

[0059] In the etching process, step 3 involves using plasma etching to etch the developed quartz substrate, for example, dry etching.

[0060] Removing photoresist from the photolithographic substrate 1 includes: placing the etched substrate 1 in a photoresist remover to remove the photoresist, and drying the photoresist-removed substrate 1 at a temperature of 70°C to 150°C for 5 min to 60 min.

[0061] Specifically, in the cleaning process, step 4 involves using a photoresist remover to remove the photoresist. After the photoresist is removed, the quartz glass substrate is dried at 70-150℃ for 5-60 minutes.

[0062] This invention, for the first time, uses photolithography to fabricate uniform micro-abrasive pillars 101 at the micrometer or nanometer scale. These pillars can be arranged in a specific pattern on a quartz substrate and ultimately used as bonded abrasives in a polishing pad. The ordered bonded abrasive polishing pad prepared by this invention can effectively solve the passivation problem in conventional bonded abrasive polishing pads during use. The ordered bonded abrasive polishing pad prepared by this invention allows for the design of the shape, size, and arrangement of the bonded abrasives to meet different polishing needs, mainly in terms of increasing removal rate, reducing roughness, and improving defects.

[0063] This invention also provides a method for preparing a polishing pad, comprising the following steps:

[0064] Step 1: A circular quartz substrate with a thickness of 1 mm and a diameter of 2 mm was pre-cleaned using a mixture of ethanol and water (30:70, v / v) to remove surface impurities. Then, the substrate was irradiated under 200 nm ultraviolet light for 1 minute to alter the surface condition. Next, a positive photoresist was selected and diluted to a 1% concentration, then applied to the quartz substrate by spin coating. Finally, the photoresist-coated quartz substrate was dried at 20°C for 1 minute to remove residual solvent. The dried, photoresist-coated quartz substrate was then stored for later use.

[0065] Step 2: Place the photoresist-coated quartz substrate onto the lithography machine stage. Use a 200nm wavelength lithography machine to perform photolithography on the photoresist-coated quartz substrate using a circular pattern with a diameter of 0.01µm. After photolithography, place the quartz substrate in a 1% sodium hydroxide developer solution for 5 seconds. After development, dry it in a 70°C oven for 30 minutes.

[0066] Step 3: The photolithographically etched and developed quartz substrate is etched downwards according to the pattern using plasma etching to form a columnar structure of a specific shape.

[0067] Step 4: Place the etched quartz substrate in a photoresist remover to remove the photoresist, then dry it at 70°C for 5 minutes and store it for later use.

[0068] Step 5: Place the developed quartz substrate into a vacuum casting mold, select a polyurethane prepolymer with an NCO content of 3% and a crosslinking agent 4,4'-methylenebis(2-chloroaniline), perform vacuum casting under a certain negative pressure of -0.9 MPa, and hold for 1 minute.

[0069] Step 6: Vulcanize the cast substrate at 80℃ for 1 hour. After vulcanization, the resulting ordered bonded abrasive polishing pad is formed.

[0070] This invention also discloses a method for preparing a polishing pad, comprising the following steps:

[0071] Step 1: A circular quartz substrate with a thickness of 1.5 mm and a diameter of 450 mm was pre-cleaned using a mixture of acetone and methyl ethyl ether (30:70, v / v) to remove surface impurities. Then, the substrate was irradiated under 300 nm ultraviolet light for 30 min to alter its surface condition. Next, a positive photoresist was selected and diluted to a 50% concentration, then applied to the quartz substrate using a roller coating method. Finally, the photoresist-coated quartz substrate was dried at 130°C for 30 min to remove residual solvent. The dried, photoresist-coated quartz substrate was then stored for later use.

[0072] Step 2: Place the photoresist-coated quartz substrate onto the lithography machine stage. Use a 300nm wavelength lithography machine to perform photolithography on the photoresist-coated quartz substrate using a triangular pattern with a side length of 250µm. After photolithography, place the quartz substrate in a 20% sodium hydroxide developer solution for 60 seconds. After development, place it in a 120℃ oven to dry for 150 minutes.

[0073] Step 3: The photolithographically etched and developed quartz substrate is etched downwards according to the pattern using plasma etching to form a columnar structure of a specific shape.

[0074] Step 4: Place the etched quartz substrate in a photoresist remover to remove the photoresist, then dry it at 100°C for 30 minutes and store it for later use.

[0075] Step 5: Place the developed quartz substrate into a vacuum casting mold, select a polyurethane prepolymer with an NCO content of 8% and a crosslinking agent 4,4'-methylenebis(2-chloroaniline), perform vacuum casting under a negative pressure of -0.9 MPa, and maintain for 15 minutes.

[0076] Step 6: The cast substrate is vulcanized at 150℃ for 18 hours. After vulcanization, the ordered bonded abrasive polishing pad is obtained.

[0077] This invention also discloses a method for preparing a polishing pad, comprising the following steps:

[0078] Step 1: A circular quartz substrate with a thickness of 3 mm and a diameter of 830 mm was pre-cleaned using a mixed solution of toluene and N,N-dimethylformamide (30:70, v / v) to remove surface impurities. Then, the substrate was irradiated under 390 nm ultraviolet light for 60 min to alter its surface condition. Subsequently, a negative photoresist was selected and diluted to 80% concentration, then applied to the quartz substrate via spraying. Finally, the photoresist-coated quartz substrate was dried at 200°C for 60 min to remove residual solvent. The dried, photoresist-coated quartz substrate was then stored for later use.

[0079] Step 2: Place the photoresist-coated quartz substrate onto the lithography machine stage and perform photolithography on the substrate using a 390nm wavelength lithography machine, creating a pentagonal pattern with a side length of 500µm. After photolithography, place the quartz substrate in a 40% sodium hydroxide developer for 120 seconds, and then dry it in a 200°C oven for 300 minutes.

[0080] Step 3: After photolithography and development, the quartz substrate is etched downwards according to the pattern using plasma etching to form a columnar structure of a specific shape.

[0081] Step 4: Place the etched quartz substrate in a photoresist remover to remove the photoresist, then dry it at 150°C for 60 minutes and store it for later use.

[0082] Step 5: Place the developed quartz substrate into a vacuum casting mold, select a polyurethane prepolymer with an NCO content of 12% and a crosslinking agent 4,4'-methylenebis(2-chloroaniline), perform vacuum casting under a negative pressure of -0.9 MPa, and maintain for 30 minutes.

[0083] Step 6: The cast substrate is vulcanized at 200℃ for 36 hours. After vulcanization, it becomes an ordered bonded abrasive polishing pad.

[0084] This invention belongs to the field of semiconductor polishing pads and aims to solve the problems of agglomeration and random distribution of abrasive particles in traditional polishing pads during polishing applications. First, the shape and arrangement of the bonded abrasive particles are designed using photolithography. Second, polyurethane elastomer is fully filled into the bonded abrasive matrix with a specific shape and arrangement using vacuum casting. Finally, the formed ordered bonded abrasive polishing pad undergoes surface treatment to obtain an ordered and uniformly distributed bonded abrasive polishing pad, which can significantly improve the abrasive material removal rate and surface roughness.

[0085] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A photolithographically ordered microstructured abrasive polishing pad, characterized in that, The device includes a substrate and a filler. The substrate is a silicon dioxide substrate, a cerium dioxide substrate, or an aluminum oxide substrate. The substrate includes an abrasive base and multiple micro-grinding pillars. The micro-grinding pillars are fixedly formed on the abrasive base by photolithography of the surface to be photolithographically etched on the substrate. The multiple micro-grinding pillars are orderly distributed on the abrasive base according to the photolithographic pattern, so that the multiple micro-grinding pillars form an orderly distribution at the micro level, and the size of the micro-grinding pillars is controllable to prevent passivation of the solidified abrasive and to meet the surface defects and chemical stability requirements of polished products for processes below 5nm. The filler is polyurethane, which is composite-filled between the micro-grinding pillars on the abrasive base to form a composite polishing pad. The polished product is a wafer.

2. The photolithographically ordered microstructured abrasive polishing pad according to claim 1, characterized in that, The dimensions of the micro-grinding column are in the micrometer or nanometer range.

3. The photolithographically ordered microstructured abrasive polishing pad according to claim 1, characterized in that, The micro-grinding column is a circular column with a photolithographic diameter of 0.01um to 500um, or a polygonal column with a photolithographic side length of 0.01um to 500um.

4. The photolithographically ordered microstructured abrasive polishing pad according to claim 1, characterized in that, The filler is formed by casting polyurethane prepolymer between the micro-grinding columns on the abrasive base and then vulcanizing it to maintain the strength of the micro-grinding columns.

5. The photolithographically ordered microstructured abrasive polishing pad according to claim 4, characterized in that, The polyurethane prepolymer is cast under negative pressure, and the negative pressure is maintained for 1 min to 30 min.

6. The photolithographically ordered microstructured abrasive polishing pad according to any one of claims 1 to 5, characterized in that, The diameter of the substrate is 2mm to 830mm; the thickness of the substrate is 1mm to 3mm.

7. A method for preparing a photolithographically ordered microstructured abrasive polishing pad, characterized in that, The preparation of the photolithographically ordered micro-solidified abrasive polishing pad according to any one of claims 1 to 6 includes: applying photoresist to the photolithographic surface of a substrate; performing photolithography on the substrate coated with photoresist according to the photolithographic pattern to divide the substrate into an abrasive base and a plurality of micro-grinding pillars, wherein the plurality of micro-grinding pillars are orderly distributed on the abrasive base; removing the photoresist from the photolithographically ...

8. The method for preparing a photolithographically ordered microstructured abrasive polishing pad according to claim 7, characterized in that, The filler composite is filled between the micro-grinding pillars on the abrasive base, including: selecting polyurethane prepolymer and vulcanizing agent to cast the substrate after removing photoresist, and vulcanizing the cast substrate at a temperature of 80℃~200℃ for 1h~36h. The polyurethane prepolymer contains 3% to 12% isocyanate groups, the vulcanizing agent is a diamine crosslinking agent, and the casting conditions are negative pressure casting in a vacuum casting mold, maintaining the negative pressure state for 1 to 30 minutes.

9. The method for preparing a photolithographically ordered microstructured abrasive polishing pad according to claim 7, characterized in that, Applying photoresist to the photolithographic surface of a substrate includes: pre-cleaning the substrate with a cleaning solvent to remove surface impurities; drying the cleaned substrate; irradiating the substrate under a UV lamp with a wavelength of 230nm~390nm for 1min~60min after drying; diluting positive or negative photoresist to a concentration of 1%~80% and applying it to the substrate; and drying the substrate coated with photoresist at a temperature of 20℃~200℃ for 1min~60min. The cleaning solvent includes one or more of water, alcohol solvents, ketone solvents, amide solvents, ether solvents, and benzene solvents; the photoresist coating method includes one or more of spin coating, spray coating, atomization coating, roller coating, and immersion coating.

10. The method for preparing a photolithographically ordered microstructured abrasive polishing pad according to claim 7, characterized in that, Photolithography is performed on a substrate coated with photoresist according to a photolithography pattern, including: placing the substrate coated with photoresist onto a photolithography stage; selecting a photolithography wavelength of 200nm~490nm to perform photolithography on the substrate coated with photoresist according to a photolithography pattern mask; placing the photolithographically patterned substrate in a developing solution for 5s~120s; drying the developed substrate at a temperature of 70℃~200℃ for 30min~300min; and using dry plasma etching to form micro-polishing pillars on the developed and dried substrate according to the photolithography pattern; wherein the developing solution is sodium hydroxide with a concentration of 0.1%~40%. Removing photoresist from the photolithographic substrate includes: immersing the etched substrate in a photoresist remover to remove the photoresist, and drying the photoresist-removed substrate at a temperature of 70°C to 150°C for 5 to 60 minutes.

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