Modified CMP polyurethane polishing pad and preparation method thereof
By introducing single-terminated hydroxyl polydimethylsiloxane and dynamic disulfide bond extender into the polyurethane polishing pad, a self-healing polishing pad is formed, which solves the problems of insufficient durability and lubrication of traditional polishing pads and achieves efficient and stable polishing performance.
Patent Information
- Application Number
- CN202511937558.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-02-24
AI Technical Summary
Traditional polyurethane polishing pads have shortcomings in improving durability and interfacial lubrication, resulting in structural collapse and high friction coefficient under long-term high pressure. They cannot simultaneously meet the requirements of high material removal rate, ultra-smooth surface and stability.
By introducing single-hydroxyl-terminated polydimethylsiloxane and chain extenders containing dynamic disulfide bonds, a self-healing polyurethane prepolymer is formed. Combined with mechanical foaming, it forms a polishing pad and a permanent lubricating layer, synergistically improving polishing performance.
The polishing pad achieves high material removal rate, ultra-smooth surface and long life, significantly improving the manufacturing yield and production efficiency of high-end chips and reducing costs.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polyurethane polishing pad technology, and in particular to a modified CMP polyurethane polishing pad and its preparation method. Background Technology
[0002] As a core consumable in the CMP process, polyurethane polishing pads directly determine the polishing rate, surface quality, and product yield of wafers. An ideal CMP polishing pad must simultaneously meet multiple stringent requirements: first, it must have a high material removal rate to ensure production efficiency; second, it must be able to achieve a scratch-free, low-roughness, ultra-smooth surface to meet the requirements of nanoscale processes; and finally, it must possess excellent structural stability and fatigue resistance to maintain long lifespan and stable polishing performance, thereby reducing production costs.
[0003] Traditional polyurethane networks incorporate dynamic covalent bonds, such as disulfide bonds, to leverage their reversible fracture and recombination properties, thereby endowing the material with self-healing capabilities and improving its durability. On the other hand, some studies have attempted to add lubricating components such as organosilicon to reduce friction during polishing and minimize surface defects. However, these improvements are mostly single-point optimizations. Simply introducing dynamic disulfide bonds, while potentially extending lifespan, often fails to address interfacial lubrication issues and may even lead to internal material defects due to compatibility problems. Conversely, simply adding lubricants may result in performance instability due to small molecule migration and precipitation, and cannot solve the problem of permanent structural collapse of the polishing pad under long-term high pressure.
[0004] In view of the above problems, this invention proposes a modified CMP polyurethane polishing pad and its preparation method. By introducing a single-hydroxyl-terminated polydimethylsiloxane for modification, its hydrophobic and lubricating organosilicon segments can spontaneously migrate to the surface of the polishing pad and accumulate during and after polymerization, forming an inherent and permanent lubricating layer. This significantly reduces the dynamic friction coefficient between the polishing pad and the wafer surface, achieving a high material removal rate while obtaining an ultra-smooth polished surface, thus significantly improving the manufacturing yield of high-end chips. Summary of the Invention
[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a modified CMP polyurethane polishing pad and its preparation method.
[0006] The objective of this invention can be achieved through the following technical solutions: A modified CMP polyurethane polishing pad and its preparation method, characterized in that it comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 15-35 parts curing agent, 0.1-5 parts foaming agent, 0.5-5 parts surfactant, and 1-30 parts hollow filler; The polyurethane prepolymer is prepared by reacting the following components: 100 parts of a polyol mixture, wherein the polyol mixture comprises polyether polyol and polyester polyol in a weight ratio of (60~80):(20~40), 15~50 parts of diisocyanate, 0.5~10 parts of monohydroxyl-terminated polydimethylsiloxane, and 0.5-5 parts of a dihydroxy chain extender containing dynamic disulfide bonds.
[0007] Preferably, the dihydroxy chain extender containing dynamic disulfide bonds is 2,2'-dithiodiethanol, and the relative molecular mass of the single-hydroxyl-terminated polydimethylsiloxane is 1000~5000.
[0008] Preferably, the polyether-type polyol is polytetramethylene ether diol, and the polyester-type polyol is at least one of polyethylene adipate diol or polycaprolactone diol.
[0009] Preferably, the diisocyanate is at least one of toluene diisocyanate or diphenylmethane diisocyanate, and the curing agent is an aromatic diamine curing agent.
[0010] Preferably, the hollow filler is any one of hollow glass microspheres, polymer microspheres, or hollow ceramic microspheres.
[0011] Preferably, the density of the polishing pad is 0.6-0.95 g / cm³. 3 Its Shore D hardness is 50~70.
[0012] A method for preparing a modified CMP polyurethane polishing pad, characterized by comprising the following steps: S1: Prepolymer synthesis and dual modification: In the presence of a catalyst, a mixture of polyols is reacted with diisocyanate to form a prepolymer. Subsequently, at 55-65℃, a single-hydroxyl-terminated polydimethylsiloxane and a dihydroxy chain extender containing dynamic disulfide bonds are simultaneously added to the system to carry out a simultaneous dual modification reaction, thereby obtaining a modified polyurethane prepolymer. S2: Mixing and foaming: Mix 100 parts of modified polyurethane prepolymer obtained in step S1 with 0.5 to 5 parts of surfactant, 0.1 to 5 parts of foaming agent and 1 to 30 parts of hollow filler, and perform mechanical foaming to form a uniform foam slurry. S3: Curing and molding. The foam slurry obtained in step S2 is mixed with 15-35 parts of curing agent, injected into a mold, and heated for curing, post-curing and maturation to obtain the polishing pad.
[0013] Preferably, in step S1, the polyol mixture is a mixture of polytetramethylene ether diol and polyethylene adipate diol, with a weight ratio of (65~75):(25~35).
[0014] Preferably, in step S2, the foaming agent is nitrogen, and foaming is carried out at a stirring speed of 1500~5000 rpm. In step S3, the equivalent ratio of the curing agent to the isocyanate groups in the prepolymer is 0.9~1.05.
[0015] Compared with existing technologies, the medium-frequency heat treatment process for this support roller has the following advantages: 1. The present invention provides a modified CMP polyurethane polishing pad and its preparation method. By introducing a chain extender containing dynamic disulfide bonds into the main chain, the polishing pad material is endowed with inherent self-healing ability by utilizing the reversible fracture and recombination characteristics of disulfide bonds under external stress. After long-term pressure work, the polishing pad can effectively restore its original structure and hardness, and has extremely strong resistance to permanent compression deformation, which greatly reduces the replacement frequency, improves production efficiency and reduces costs.
[0016] 2. The present invention provides a modified CMP polyurethane polishing pad and its preparation method. By introducing a single-hydroxyl-terminated polydimethylsiloxane for modification, its hydrophobic and lubricating organosilicon segments can spontaneously migrate to the surface of the polishing pad and accumulate during and after polymerization, forming an inherent and permanent lubricating layer. This significantly reduces the dynamic friction coefficient between the polishing pad and the wafer surface, achieving a high material removal rate while obtaining an ultra-smooth polished surface, thus significantly improving the manufacturing yield of high-end chips.
[0017] 3. The modified CMP polyurethane polishing pad and its preparation method provided by the present invention ensure the stability of the macroscopic physical properties of the polishing pad from the bulk structure through dynamic disulfide bonds, while the organosilicon segments ensure the stability of the friction state during the polishing process from the interfacial chemistry. The two work together to ensure the high consistency of the polishing pad's performance throughout its entire life cycle.
[0018] 4. The present invention provides a modified CMP polyurethane polishing pad and its preparation method. Through molecular design, self-healing and surface lubrication are unified in the same polyurethane system. The polishing pad prepared has comprehensive excellent performance with high removal rate, long life and low defects.
[0019] In summary, this invention provides a modified CMP polyurethane polishing pad and its preparation method. Through simultaneous dual modification, a CMP polishing pad with significant improvements in efficiency, quality, lifespan, and stability is created. Detailed Implementation
[0020] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the present invention is not limited to these embodiments. Example 1:
[0021] A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts MOCA curing agent, 1.5 parts foaming agent (deionized water), 2 parts siloxane surfactant, and 15 parts hollow glass microsphere filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 70 parts of polytetramethylene ether glycol (PTMEG), 30 parts of polyethylene adipate glycol (PEA), 35 parts of diisocyanate (MDI), 3 parts of single-hydroxyl-terminated polydimethylsiloxane (molecular weight 2000), and 2 parts of a dihydroxyl chain extender (2,2'-dithiodiethanol) containing dynamic disulfide bonds.
[0022] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer. The system was then cooled to 60℃, and hydroxyl-terminated polydimethylsiloxane and 2,2'-dithiodiethanol were added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain a dual-modified polyurethane prepolymer (with an measured NCO content of approximately 8.5%).
[0023] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 3000 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0024] S3: Curing and molding. The foam slurry is rapidly mixed with 25 parts of MOCA curing agent preheated to 120°C (equivalent ratio NCO:NH2=1:1), injected into a mold at 100°C, heated and cured at 100°C for 2 hours, then post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad. Example 2:
[0025] A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 15 parts TDA-80 curing agent, 0.1 parts foaming agent (deionized water), 0.5 parts siloxane surfactant, and 15 parts polymer microsphere hollow filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 60 parts of PTMEG, 40 parts of polycaprolactone diol (PCL), 15 parts of diisocyanate (TDI), 0.5 parts of hydroxyl-terminated polydimethylsiloxane (molecular weight 1000), and 0.5 parts of 2,2'-dithiodiethanol.
[0026] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PCL were dehydrated under vacuum at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and TDI and a small amount of catalyst were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer (NCO content measured to be approximately 4.0%). The system was then cooled to 55℃, and hydroxyl-terminated polydimethylsiloxane and 2,2'-dithiodiethanol were added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain a dual-modified polyurethane prepolymer.
[0027] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 1500 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0028] S3: Curing and molding. The foam slurry is quickly mixed with 15 parts of TDA-80 curing agent preheated to 120°C, injected into a mold at 100°C, and cured at 100°C for 2 hours. Then it is post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad. Example 3:
[0029] A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts DETDA curing agent, 5 parts foaming agent (deionized water), 5 parts siloxane surfactant, 30 parts hollow glass microsphere filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 80 parts of PTMEG, 20 parts of PEA, 50 parts of diisocyanate (MDI), 10 parts of single-hydroxyl-terminated polydimethylsiloxane (molecular weight 5000), and 5 parts of 2,2'-dithiodiethanol.
[0030] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer. The system was then cooled to 65℃, and hydroxyl-terminated polydimethylsiloxane and 2,2'-dithiodiethanol were added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain a dual-modified polyurethane prepolymer (NCO content of 8.5%).
[0031] S2: Mixing and foaming. Mix 100 parts of the modified prepolymer (maintained at 5-10 MPa pressure), surfactant, and hollow filler, while simultaneously injecting 2 parts of nitrogen into the system to dissolve it in the prepolymer. Then, mechanically stir at 4000 rpm for 3 minutes under normal pressure to release the dissolved nitrogen and form a uniform and fine foam slurry.
[0032] S3: Curing and molding. The foam slurry is quickly mixed with 25 parts of curing agent preheated to 120°C and injected into a mold at 100°C. It is then heated and cured at 100°C for 2 hours, followed by post-curing at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad. Example 4:
[0033] A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts MOCA curing agent, 2 parts foaming agent (nitrogen), 2 parts siloxane surfactant, 20 parts hollow filler (1:1 mixture of hollow glass microspheres and polymer microspheres): The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 65 parts of PTMEG, 35 parts of PEA, 40 parts of diisocyanate (MDI), 5 parts of hydroxyl-terminated polydimethylsiloxane (molecular weight 3000), and 3 parts of 2,2'-dithiodiethanol.
[0034] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer. The system was then cooled to 60℃, and hydroxyl-terminated polydimethylsiloxane and 2,2'-dithiodiethanol were added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain a dual-modified polyurethane prepolymer (NCO content of 8.5%).
[0035] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 4000 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0036] S3: Curing and molding. The foam slurry is rapidly mixed with 25 parts of MOCA curing agent preheated to 120°C (equivalent ratio NCO:NH2=1:1), injected into a mold at 100°C, heated and cured at 100°C for 2 hours, then post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad.
[0037] Comparative Example 1: A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts MOCA curing agent, 1.5 parts foaming agent (deionized water), 2 parts siloxane surfactant, and 15 parts hollow glass microsphere filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 70 parts of polytetramethylene ether glycol (PTMEG), 30 parts of polyethylene adipate glycol (PEA), 35 parts of diisocyanate (MDI), and 3 parts of hydroxyl-terminated polydimethylsiloxane (molecular weight 2000).
[0038] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer. The system was then cooled to 60℃, and hydroxyl-terminated polydimethylsiloxane was added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain a modified polyurethane prepolymer (NCO content 8.5%).
[0039] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 3000 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0040] S3: Curing and molding. The foam slurry is rapidly mixed with 25 parts of MOCA curing agent preheated to 120°C (equivalent ratio NCO:NH2=1:1), injected into a mold at 100°C, heated and cured at 100°C for 2 hours, then post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad.
[0041] Comparative Example 2: A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts MOCA curing agent, 1.5 parts foaming agent (deionized water), 2 parts siloxane surfactant, and 15 parts hollow glass microsphere filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 73 parts of polytetramethylene ether glycol (PTMEG) (70+3), 30 parts of polyethylene adipate glycol (PEA), 35 parts of diisocyanate (MDI), polydimethylsiloxane without single-terminated hydroxyl groups, and 2 parts of a dihydroxy chain extender (2,2'-dithiodiethanol) containing dynamic disulfide bonds.
[0042] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer Synthesis and Dual Modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated prepolymer. The system was then cooled to 60℃, and PTMEG and 2,2'-dithiodiethanol were added simultaneously. The reaction was maintained at this temperature for 1.5 hours to obtain the modified polyurethane prepolymer.
[0043] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 3000 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0044] S3: Curing and molding. The foam slurry is rapidly mixed with 25 parts of MOCA curing agent preheated to 120°C (equivalent ratio NCO:NH2=1:1), injected into a mold at 100°C, heated and cured at 100°C for 2 hours, then post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad.
[0045] Comparative Example 3: A modified CMP polyurethane polishing pad comprises the following raw materials in parts by weight: 100 parts polyurethane prepolymer, 25 parts MOCA curing agent, 1.5 parts foaming agent (deionized water), 2 parts siloxane surfactant, and 15 parts hollow glass microsphere filler: The polyurethane prepolymer composition includes: 100 parts of a polyol mixture, including 73 parts of PTMEG, 30 parts of PEA, and 35 parts of diisocyanate (MDI).
[0046] A method for preparing a modified CMP polyurethane polishing pad includes the following steps: S1: Prepolymer synthesis and dual modification: In a reactor, PTMEG and PEA were vacuum dehydrated at 110℃ and -0.095MPa for 2 hours. The temperature was then lowered to 80℃, and MDI and a small amount of catalyst (dibutyltin dilaurate, accounting for 0.05% of the total prepolymer mass) were added. The reaction was carried out under nitrogen protection for 3 hours to obtain an NCO-terminated ordinary polyurethane prepolymer (NCO content approximately 8.5%).
[0047] S2: Mixing and foaming: Mix the above 100 parts of modified prepolymer, surfactant, foaming agent and hollow glass microspheres, and mechanically foam at a stirring speed of 3000 rpm for 3 minutes to form a uniform and delicate foam slurry.
[0048] S3: Curing and molding. The foam slurry is rapidly mixed with 25 parts of MOCA curing agent preheated to 120°C (equivalent ratio NCO:NH2=1:1), injected into a mold at 100°C, heated and cured at 100°C for 2 hours, then post-cured at 110°C for 4 hours, and finally cured at room temperature for 48 hours to obtain the finished polishing pad.
[0049] Table 1 Performance data results of the examples and comparative samples
[0050] As shown in Table 1, Comparative Example 1, lacking dynamic disulfide bonds, suffered permanent structural collapse due to the inability of the polymer network to effectively reconstruct under pressure. In contrast, the reversible exchange of disulfide bonds in Example 1 continuously dissipates energy and repairs damage, maintaining the pad's elasticity like a "self-healing skeleton." Example 1's lifespan was nearly three times longer than Comparative Example 1, directly demonstrating its self-healing capability under long-term operating conditions. The pad in Comparative Example 1 hardened due to permanent deformation, resulting in decreased porosity, hindered polishing fluid transport, and reduced material removal rate, ultimately leading to failure. The results indicate that dynamic disulfide bonds are the core of the polishing pad's long-term operation, primarily addressing its fatigue resistance and structural stability. Comparative Example 2, lacking surface lubrication, experienced high friction and heat generation during polishing, easily generating microscopic tears and scratches, leading to a sharp deterioration in wafer surface quality. The comparison of the dynamic friction coefficients between Example 1 and Comparative Example 2, showing a difference of more than three times, directly confirms that organosilicon plays an excellent lubricating role at the polishing interface, transforming "sliding friction" into a gentler "shear friction." The results show that organosilicon modification is the key to obtaining ultra-high surface quality, and it mainly solves the problem of wafer surface damage during the polishing process.
[0051] In Comparative Example 1, under long-term pressure, the pore structure gradually collapses and cannot recover, causing continuous changes in the contact area and pressure between the polishing pad and the wafer. This results in a decreasing and unstable material removal rate. In Comparative Example 2, high friction not only directly causes scratches but may also lead to uneven wear on the polishing pad surface and the generation of more debris. This debris interferes with the polishing process, causing the material removal rate to fluctuate around a mean. In Example 1, dynamic disulfide bonds ensure the long-term stability of the pad's macroscopic and microscopic structure, providing a solid physical basis for consistent polishing. Organosilicon ensures frictional stability and low damage at the polishing interface, avoiding process fluctuations caused by surface deterioration. The combination of these two elements simultaneously locks in the stability of the polishing process from both bulk and interfacial dimensions, achieving efficient and stable polishing.
[0052] In summary, the dynamic disulfide bonds in the synchronously dual-modified CMP polyurethane polishing pad provide an ultra-long service life and fatigue resistance, while the organosilicon provides ultra-low surface damage and interfacial friction. The synergistic effect of the two ensures consistent performance and unifies the three performance goals of high efficiency, long service life and low damage that are traditionally difficult to achieve simultaneously.
[0053] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.
Claims
1. A modified CMP polyurethane polishing pad, characterized in that, The following raw materials are included by weight: 100 parts polyurethane prepolymer, 15-35 parts curing agent, 0.1-5 parts foaming agent, 0.5-5 parts surfactant, and 1-30 parts hollow filler; The polyurethane prepolymer is prepared by reacting the following components: 100 parts of a polyol mixture, wherein the polyol mixture comprises polyether polyol and polyester polyol in a weight ratio of (60~80):(20~40), 15~50 parts of diisocyanate, 0.5~10 parts of monohydroxyl-terminated polydimethylsiloxane, and 0.5-5 parts of a dihydroxy chain extender containing dynamic disulfide bonds.
2. The modified CMP polyurethane polishing pad as described in claim 1, characterized in that, The dihydroxy chain extender containing dynamic disulfide bonds is 2,2'-dithiodiethanol, and the relative molecular mass of the single-hydroxyl-terminated polydimethylsiloxane is 1000~5000.
3. The modified CMP polyurethane polishing pad as described in claim 2, characterized in that, The polyether-type polyol is polytetramethylene ether diol, and the polyester-type polyol is at least one of polyethylene adipate diol or polycaprolactone diol.
4. The modified CMP polyurethane polishing pad as described in claim 1, characterized in that, The diisocyanate is at least one of toluene diisocyanate or diphenylmethane diisocyanate, and the curing agent is an aromatic diamine curing agent.
5. The modified CMP polyurethane polishing pad as described in claim 2, characterized in that, The hollow filler is any one of hollow glass microspheres, polymer microspheres, or hollow ceramic microspheres.
6. The modified CMP polyurethane polishing pad as described in claim 1, characterized in that, The density of the polishing pad is 0.6-0.95 g / cm³. 3 Its Shore D hardness is 50~70.
7. A method for preparing a modified CMP polyurethane polishing pad, characterized in that, Includes the following steps: S1: Prepolymer synthesis and dual modification: In the presence of a catalyst, a mixture of polyols is reacted with diisocyanate to form a prepolymer. Subsequently, at 55-65℃, a single-hydroxyl-terminated polydimethylsiloxane and a dihydroxy chain extender containing dynamic disulfide bonds are simultaneously added to the system to carry out a simultaneous dual modification reaction, thereby obtaining a modified polyurethane prepolymer. S2: Mixing and foaming: Mix 100 parts of modified polyurethane prepolymer obtained in step S1 with 0.5 to 5 parts of surfactant, 0.1 to 5 parts of foaming agent and 1 to 30 parts of hollow filler, and perform mechanical foaming to form a uniform foam slurry. S3: Curing and molding: Mix the foam slurry obtained in step S2 with 15-35 parts of curing agent, inject it into the mold, and perform heating curing, post-curing and aging to obtain the polishing pad.
8. The method for preparing a modified CMP polyurethane polishing pad as described in claim 7, characterized in that, In step S1, the polyol mixture is a mixture of polytetramethylene ether diol and polyethylene adipate diol, with a weight ratio of (65~75):(25~35).
9. The method for preparing a modified CMP polyurethane polishing pad as described in claim 7, characterized in that, In step S2, the foaming agent is nitrogen, and foaming is carried out at a stirring speed of 1500~5000 rpm. In step S3, the equivalent ratio of the curing agent to the isocyanate groups in the prepolymer is 0.9~1.05.