A quick rebound chemical mechanical polishing pad and its preparation method and application

Abstract

The present application provides a kind of quick rebound chemical mechanical polishing pad and its preparation method and application, the polishing layer thickness of the chemical mechanical polishing pad is 0.3-2mm, the compression rate is not higher than 25%, and the quick rebound rate is more than 80%.The polishing layer of the quick rebound chemical mechanical polishing pad uses solution method to synthesize polyurethane resin by the way of adding isocyanate and chain extender in stages, is prepared into coating slurry, is uniformly coated on the support layer with a certain thickness, and is immediately immersed in coagulation bath to be cured and formed.The chemical mechanical polishing pad prepared by the present application has quick rebound capacity, enhances the storage / release process of polishing liquid in the polishing pad during polishing process, and improves the polishing speed.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, specifically to a chemical mechanical polishing pad with rapid rebound capability, its preparation method, and its application. Background Technology

[0002] Chemical mechanical polishing (CMP) combines the abrasive action of nanoscale particles with the chemical etching effect of a polishing slurry to planarize the surface of a workpiece on a polishing pad. CMP is widely used in the planarization process of semiconductor wafers and is an indispensable processing step in the production of wafers used to manufacture electronic components.

[0003] Chemical mechanical polishing (CMP) pads, as key consumables in the CMP process, utilize their unique porous structure to transport polishing fluid and remove waste generated during polishing. Among CMP pads, soft polyurethane microporous polishing pads are typically used for finishing or final polishing to achieve a low defect rate in the polished material.

[0004] To ensure polishing speed, high flatness of the workpiece, and low surface defects, the selection of polishing pad resin is crucial. For example, patent CN111349213A, by controlling the content of the resin's mesophase, selects resins that produce polishing pads with a combination of low compressibility, softness, and low surface defects. However, the relationship between the resin mesophase ratio and resin preparation is not clear, making resin selection using this method rather cumbersome. Furthermore, the three basic properties of polishing pads mentioned in the patent do not adequately summarize the polishing capability of the pads; other basic properties also play an important role in the polishing process.

[0005] Therefore, there is a need to develop a polishing pad with rapid rebound properties and to provide a method for obtaining a resin that increases the rapid rebound rate of the polishing layer of the manufactured polishing pad, thereby increasing the polishing rate of the polishing pad. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a chemical mechanical polishing pad with rapid recovery capability, exhibiting a rapid rebound rate exceeding 80%. Because this polishing pad rebounds more quickly, it facilitates faster storage and release of polishing slurry within the pad, thereby improving the polishing rate.

[0007] Another object of the present invention is to provide a method for preparing such a chemical mechanical polishing pad, and in particular a method for preparing a resin used in such a chemical mechanical polishing pad.

[0008] Another object of the present invention is to provide an application of this chemical mechanical polishing pad.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A rapid rebound chemical mechanical polishing pad, wherein the polishing layer thickness of the chemical mechanical polishing pad is 0.3-2 mm, the compression ratio is not higher than 25%, the rebound rate is higher than 70%, and the rapid rebound rate is higher than 80%;

[0011] The ratio of the thickness reduction of the polished layer after applying pressure of 37.43 kPa for 30 seconds to the thickness of the unpressurized polished layer is denoted as the compression ratio.

[0012] Remove the applied pressure and record the thickness recovery 5 seconds and 30 seconds after removing the pressure. The ratio of the thickness recovery 30 seconds after removing the pressure to the thickness reduction of the polished layer under pressure is recorded as the springback rate.

[0013] The ratio of the thickness recovery amount 5 seconds after the pressure is removed to the thickness recovery amount 30 seconds after the pressure is removed is denoted as the rapid rebound rate.

[0014] In a preferred embodiment, the thickness of the polished layer is 0.6-1.2 mm; the compression rate is less than 20%, the springback rate is more than 80%, and the rapid springback rate exceeds 90%.

[0015] In some specific implementations, the Shore A hardness of the polished layer is 5 to 50 degrees, preferably 10 to 30 degrees.

[0016] On the other hand, the aforementioned method for preparing a rapid-rebound chemical mechanical polishing pad includes the following steps:

[0017] a) Polyurethane resin was prepared by adding isocyanate and chain extender in stages using a solution method;

[0018] b) Dissolve the polyurethane resin and additives in a solvent to prepare a coating slurry;

[0019] c) Apply the coating slurry evenly to the support layer at a certain thickness;

[0020] d) Immediately immerse in a coagulation bath to solidify and form a polished layer;

[0021] e) The polishing layer after washing and drying is sanded and then grooved and laminated with a buffer layer, an adhesive backing layer and a release layer to obtain a chemical mechanical polishing pad.

[0022] In some specific implementation schemes, step a) is as follows:

[0023] i) First stage: Polyol, chain extender, solvent and isocyanate are added to the reactor under nitrogen atmosphere and stirred to react;

[0024] ii) Second stage: Add chain extender and isocyanate again, and continue stirring the reaction;

[0025] iii) Third stage: Continue adding isocyanate and continue stirring the reaction;

[0026] iv) Termination of reaction: After the reaction is complete, a terminator is added to terminate the reaction and polyurethane resin is obtained.

[0027] In some specific implementations, the second stage of step ii) is repeated two or more times to perform repeated feeding and reaction.

[0028] In some specific embodiments, step i) involves adding polyol, chain extender, solvent, and isocyanate to control the -NCO / -OH molar ratio of the system to be maintained between 0.7 and 0.9; and / or

[0029] The chain extender added in step ii) is 10-40% of the mass of the chain extender added in step i); the added isocyanate is used to control the -NCO / -OH molar ratio in the reaction system to be maintained at 0.7-0.9; and / or

[0030] In step iii), isocyanate is added again to bring the -NCO / -OH molar ratio of the reaction system to 1-1.03.

[0031] In some specific embodiments, the reaction temperature is controlled between 70-85°C, and the reaction ends when the viscosity of the reaction system reaches 170,000-200,000 mPa·s; and / or

[0032] The 100% modulus of the polyurethane resin is 5-10 MPa, preferably 6-8 MPa.

[0033] In some specific embodiments, the polyol is selected from at least one of polyester polyols, polyether polyols, polycarbonate polyols, polyacrylic acid polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, and dimer diols, preferably polyester polyols; and / or

[0034] The chain extender is selected from small molecule diols, triols or polyols, preferably selected from any one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, trimethylolethane, and trimethylolpropane.

[0035] The isocyanate is an aromatic diisocyanate or an aliphatic diisocyanate, preferably selected from at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), phenyl dimethyl diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated phenyl dimethyl diisocyanate (hydrogenated XDI), hexamethylene diisocyanate, and norbornene diisocyanate, preferably MDI;

[0036] The solvent is selected from any one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and methyl ethyl ketone, preferably N,N-dimethylformamide.

[0037] On the other hand, the aforementioned rapid rebound chemical mechanical polishing pad or the rapid rebound chemical mechanical polishing pad prepared by the aforementioned preparation method is used in chemical mechanical polishing.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] The chemical mechanical polishing pad of the present invention has a rapid rebound capability with a rapid rebound rate of over 80%, preferably over 90%. This characteristic enhances the retention / release process of polishing fluid in the polishing pad during the polishing process and improves the polishing speed.

[0040] The preparation method of the present invention uses a solution method to prepare polyurethane resin by adding isocyanate and chain extender in stages, and the polishing layer made therefrom has a rapid rebound capability. Detailed Implementation

[0041] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0042] A method for preparing a chemical mechanical polishing pad with rapid rebound capability includes the following steps:

[0043] a) Polyurethane resin was prepared by adding isocyanate and chain extender in stages using a solution method;

[0044] b) Dissolve the polyurethane resin and additives in a solvent to prepare a coating slurry;

[0045] c) Apply the coating slurry evenly to the support layer at a certain thickness;

[0046] d) Immediately immerse in a coagulation bath to solidify and form a polished layer;

[0047] e) The polishing layer after washing and drying is sanded and then grooved and laminated with a buffer layer, an adhesive backing layer and a release layer to obtain a chemical mechanical polishing pad.

[0048] In step a), the staged addition refers to reacting the isocyanate and chain extender in multiple stages, such as two, three, four, or five times. The amount of reactants used in each reaction can be equal or unequal. Specifically, step a) may be as follows: In the first stage, a certain amount of polyol, small molecule chain extender, and diisocyanate are added, controlling the -NCO / -OH molar ratio of the system to be 0.7-0.9, such as 0.7, 0.75, 0.8, 0.85, or 0.9, preferably 0.85-0.9; In the second stage, after reacting for a period of time, such as 1 hour or 2 hours, a certain amount of small molecule chain extender and diisocyanate are added again, controlling the -NCO / -OH molar ratio of the system to be 0.7-0.9, such as 0.7, 0.75, 0.8, 0.85, or 0.9, preferably 0.85-0.9; The second stage is repeated several times. In this invention, the specific number of times the second stage is repeated is not limited, such as once, twice, or three times. There is no particular limitation on the amount of small molecule chain extender added, but it is preferably 10-40% of the mass of the chain extender in step i), such as 20% or 30%. In the third stage, after reacting for a period of time, such as 1 hour or 2 hours, diisocyanate is added until the molar ratio of -NCO / -OH in the system is 1 to 1.03, such as 1, 1.01, 1.02, or 1.03. Solvent is added to make the solid content of the system reach 28-32%, such as 29%, 30%, or 31%. The reaction ends when the viscosity of the system reaches 170,000 to 200,000 mPa·s. Methanol can be added to terminate the reaction, for example, when the viscosity of the system reaches 180,000 mPa·s or 190,000 mPa·s. A terminator is added to terminate the reaction.

[0049] The polyols used may include, for example, polyester polyols, polyether polyols, polycarbonate polyols, polyacrylic acid polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, dimer diols, etc. These polyols can be used alone or in combination of two or more. Polyester polyols are preferred.

[0050] The chain extender may include ethylene glycol, 1,3-propanediol, 1,4-butanediol and other small molecule diols, or trimethylolethane, trimethylolpropane and other ternary or polyols.

[0051] The isocyanate may include toluene diisocyanate (TDI-100; toluene diisocyanate at the 2,4-position, TDI-80; a mixture of toluene diisocyanates at the 2,4-position and 2,6-position, with a mass ratio of 2,4-position / 2,6-position of 80 / 20), diphenylmethane diisocyanate (MDI; which is its 4,4-position, 2,4-position, 2,2-position or a mixture thereof), phenyl dimethyl diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), and other aromatic diisocyanates; or isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated phenyl dimethyl diisocyanate (hydrogenated XDI), and other alicyclic diisocyanates; or hexamethylene diisocyanate, norbornene diisocyanate, and other aliphatic diisocyanates. MDI is preferred.

[0052] In step a) of the present invention, the solvent used in the solution method is selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dimethyl sulfoxide or methyl ethyl ketone and other solvents that can dissolve polyurethane resin, preferably N,N-dimethylformamide.

[0053] The key to this invention lies in the preparation of solvent-based polyurethane resin. The polyurethane resin is then used to formulate a coating slurry. Subsequent processes such as coating, curing, sanding, pressing, and bonding are not particularly limited and can all be implemented with reference to existing technologies.

[0054] For example, in step b) of the present invention, the additives include film-forming aids, foaming control agents, etc. Preferably, the additives are a mixture of film-forming aids and foaming control agents.

[0055] Examples of film-forming aids include hydrophobic surfactants. Examples of hydrophobic surfactants include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, perfluoroalkyl ethylene oxide adducts, glycerol fatty acid esters, propylene glycol fatty acid esters, and dehydrated sorbitan fatty acid esters, as well as anionic surfactants such as alkyl carboxylic acids.

[0056] Examples of foaming control aids include hydrophilic surfactants, such as carboxylates, sulfonates, sulfates, and phosphates.

[0057] When adding film-forming aids as additives, it is preferable to add 0.2 to 10 wt% relative to the solid content of the coating slurry, for example, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. When adding foaming control aids as additives, it is preferable to add 0.2 to 10 wt% relative to the solid content of the coating slurry, for example, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0058] The mass concentration of polyurethane resin in the above-mentioned coating slurry is preferably 15% to 50%, such as 16%, 20%, 25%, 30%, 35%, 40%, 45%, etc., and more preferably 20% to 40%. If the polyurethane resin concentration is within the above range, the coating slurry has appropriate fluidity and can be coated more evenly on the support layer in subsequent coating processes.

[0059] In step c) of this invention, the uniform coating method is not limited; for example, gravure coating, blade coating, tube coating, comma coating, etc., can be used. The thickness of the dried film of the polyurethane resin composition coated or impregnated by the above method is, for example, in the range of 0.5 mm to 5 mm, such as 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc., preferably in the range of 0.5 mm to 3 mm.

[0060] In step d) of the present invention, the coagulation bath is a mixture of N,N-dimethylformamide and water, wherein the mass percentage of N,N-dimethylformamide is 5% to 20%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc., but is not limited thereto, and is preferably 10% to 17%.

[0061] The coagulation bath temperature is 20–50°C, for example, 20°C, 30°C, 40°C, or 50°C, but not limited thereto, preferably 25–35°C; the curing time is 20–40 min, for example, 20 min, 25 min, 30 min, 35 min, or 40 min, but not limited thereto, preferably 30–35 min.

[0062] In step e) of the present invention, the drying temperature is 80-150°C, for example 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, but not limited thereto, preferably 100-120°C; the drying time is 10-50 min, for example 10 min, 20 min, 30 min, 40 min, 50 min, but not limited thereto, preferably 20-40 min.

[0063] The polished layer obtained after the above drying steps is combined with a buffer layer using conventional processes of existing technology, and then an adhesive backing is attached, followed by a release layer to obtain the chemical mechanical polishing pad with rapid rebound capability of the present invention.

[0064] The chemical mechanical polishing pad prepared by the method of the present invention can be applied to the field of chemical mechanical polishing, including but not limited to the chemical mechanical polishing of silicon wafers, SiC, sapphire, etc.

[0065] The present invention will be further explained and illustrated below through more specific embodiments, but these do not constitute any limitation.

[0066] [Example 1]

[0067] Polyurethane resin synthesis: In the first stage, 100 parts by mass of polyester polyol (the reactant of ethylene glycol and adipic acid, with a number average molecular weight of 2000, hereinafter referred to as PEs1), 13 parts by mass of 1,4-butanediol (hereinafter referred to as BG), 441 parts by mass of N,N-dimethylformamide (hereinafter referred to as DMF), and 42 parts by mass of 4,4'-diphenylmethane diisocyanate (hereinafter referred to as MDI) were added to a four-necked flask equipped with a stirrer, thermometer, and nitrogen inlet tube. The mixture was reacted at 80°C for 1 hour with stirring. In the second stage, 4 parts by mass of BG and 9 parts by mass of MDI were added, and the mixture was reacted at 80°C for 2 hours with stirring. The second stage was repeated, with 3 parts by mass of BG and 9 parts by mass of MDI added, and the mixture was reacted at 80°C for 2 hours with stirring. In the third stage, 9 parts by mass of MDI were added, and the mixture was reacted at 80°C for 1 hour with stirring. After the reaction was completed, 1 part by mass of methanol was added and the mixture was stirred at 80°C for 1 hour to terminate the reaction, thereby obtaining polyurethane resin.

[0068] Polishing layer preparation: 100 parts by weight of the above polyurethane resin, 20 parts by weight of DMF, and 2 parts by weight of dehydrated sorbitan monooleate are uniformly dispersed and prepared into a coating slurry. The coating slurry is uniformly coated on the PET film with a coating thickness of 1.70 mm. Then, it is immersed in a coagulation bath with a mass concentration of 15% DMF aqueous solution and cured for 35 min. After washing with water, the polishing layer is peeled off from the PET film and placed in an oven at 100°C to dry for 30 min.

[0069] After the above drying steps, a polishing layer is obtained. Using existing steps, grooves are pressed into the polishing layer and combined with a buffer layer. Then, an adhesive backing is applied, and a release layer is attached to obtain a microporous polyurethane polishing pad.

[0070] [Example 2]

[0071] Polyurethane resin synthesis: In the first stage, 100 parts by mass of polyester polyol (the reactant of butanediol and adipic acid, number average molecular weight 2000, hereinafter referred to as PEs2), 10 parts by mass of BG, 406 parts by mass of DMF, and 35 parts by mass of MDI were added to a four-necked flask equipped with a stirrer, thermometer, and nitrogen inlet tube. The reaction was carried out at 80°C for 1 hour with stirring. In the second stage, 3 parts by mass of BG and 7 parts by mass of MDI were added, and the reaction was continued at 80°C for 2 hours with stirring. The second stage was repeated, with the addition of 3 parts by mass of BG and 8 parts by mass of MDI, and the reaction was continued at 80°C for 2 hours with stirring. In the third stage, 8 parts by mass of MDI were added, and the reaction was continued at 80°C for 1 hour with stirring. After the reaction was completed, 1 part by mass of methanol was added and the reaction was terminated by stirring at 80°C for 1 hour, thus obtaining polyurethane resin.

[0072] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0073] [Example 3]

[0074] Polyurethane resin synthesis: In the first stage, 50 parts by mass of PEs1, 50 parts by mass of PEs2, 8 parts by mass of ethylene glycol (EG), 441 parts by mass of DMF, and 40 parts by mass of MDI were added to a four-necked flask equipped with a stirrer, thermometer, and nitrogen inlet tube. The mixture was reacted at 80°C for 1 hour with stirring. In the second stage, 2 parts by mass of EG and 7 parts by mass of MDI were added, and the reaction was continued at 80°C for 2 hours with stirring. In the third stage, 7 parts by mass of MDI were added, and the reaction was continued at 80°C for 1 hour with stirring. After the reaction was completed, 1 part by mass of methanol was added, and the reaction was terminated by stirring at 80°C for 1 hour, thus obtaining polyurethane resin.

[0075] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0076] [Comparative Example 1]

[0077] Polyurethane resin synthesis: The types of reactants and the total amount and ratio of reactants used in the polyurethane resin synthesis process of this comparative example are exactly the same as those in Example 1. The only difference is that Example 1 used a stepwise addition method, while this comparative example uses a one-pot method to add all reactants at once. After stirring at 80°C for 6 hours, 1 part by mass of methanol was added after the reaction was completed, and the mixture was stirred at 80°C for 1 hour to terminate the reaction and obtain polyurethane resin.

[0078] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0079] [Comparative Example 2]

[0080] Polyurethane resin synthesis: The types of reactants and the total amount and ratio of reactants used in the polyurethane resin synthesis process of this comparative example are exactly the same as those in Example 2. The only difference is that Example 2 used a stepwise addition method, while this comparative example uses a one-pot method to add all reactants at once. After stirring at 80°C for 6 hours, 1 part by mass of methanol is added after the reaction is completed, and the mixture is stirred at 80°C for 1 hour to terminate the reaction and obtain polyurethane resin.

[0081] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0082] [Comparative Example 3]

[0083] Polyurethane resin synthesis: The types of reactants and the total amount and ratio of reactants used in the polyurethane resin synthesis process of this comparative example are exactly the same as those in Example 3. The only difference is that Example 3 used a stepwise addition method, while this comparative example uses a one-pot method to add all reactants at once. After stirring at 80°C for 6 hours, 1 part by mass of methanol is added after the reaction is completed, and the mixture is stirred at 80°C for 1 hour to terminate the reaction and obtain polyurethane resin.

[0084] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0085] [Comparative Example 4]

[0086] The commercially available Huada Chemical HDW-3050 (100% modulus 5 MPa) was used instead of the polyurethane resin synthesized in Example 1.

[0087] The preparation of the polishing layer and subsequent steps are exactly the same as in Example 1.

[0088] [Method for determining 100% modulus]

[0089] In the examples and comparative examples, all polyurethane resins were mixed with 20 parts by weight of DMF to obtain a compound solution. This compound solution was coated onto a PET film with a coating thickness of 0.02 mm to achieve a film thickness of approximately 30 μm after drying. The film was then dried at 120°C for 5 minutes to produce a film. Next, the resulting film was cut into strips at least 25 mm wide and 35 mm long. The 100% modulus (MPa) was measured using a tensile testing machine at a tensile speed of 100 mm / min. The tensile testing machine used in this invention was a PARAM XLW(PC) type intelligent electronic testing machine.

[0090] [Method for evaluating the hardness of polished layers]

[0091] For all polished layers obtained in the above embodiments and comparative examples, tests were conducted using a TECLOCK GS-719H Shore A hardness tester, following the same test method described in GB / T 2411-2008 (or ISO 868:2003) for Shore A hardness testers.

[0092] [Evaluation Methods for Polished Layer Compression Ratio, Springback Ratio, and Rapid Springback Ratio]

[0093] For all polished layers obtained in the above embodiments and comparative examples, a SCHOPPER type thickness measuring instrument was used. With a pressure surface of 1 cm, the thickness t0 was measured after applying an initial load of 3.74 kPa for 30 s, and then the thickness t1 was measured after applying a final pressure of 37.43 kPa for 30 s. The compression rate (%) was calculated as 100 × (t0 - t1) / t0. After removing the applied pressure, the thicknesses t2 and t3 were recorded after removing the pressure for 5 s and 30 s, respectively. The recovery rate (%) was calculated as 100 × (t3 - t1) / (t0 - t1); the rapid recovery rate (%) was calculated as 100 × (t2 - t1) / (t3 - t1).

[0094] The test results of the polished layer compression rate, springback rate, and rapid springback rate are shown in Table 1.

[0095] Table 1. Test results of polished layer compression rate, springback rate, and rapid springback rate

[0096]

[0097] As can be seen from the data in Table 1, the polishing layers made from the resins of each embodiment synthesized by the stepwise feeding method have a significantly higher rapid rebound rate than the polishing layers of each comparative embodiment synthesized by the one-pot method.

[0098] [Polishing Test]

[0099] Polishing experiments were conducted using an E460 CMP testing machine, ANJI AEP U3061A polishing slurry, a polishing pad with a diameter of 609 mm, and a copper target with a diameter of 75 mm.

[0100] The polishing parameters are as follows: polishing pressure 1.5psi, polishing speed 50-60rpm, polishing fluid flow rate 300mL / min, and polishing time 60s.

[0101] The film thickness was measured using an AMBioS XP-300 profilometer, and the average value of nine points was taken. The copper target removal rate was determined based on the difference before and after CMP. and non-uniformity % (NU%).

[0102] The results of the removal rate and non-uniformity tests are shown in Table 2.

[0103] Table 2. Results of Removal Rate and Non-uniformity Tests

[0104]

[0105] As can be seen from the test results in Table 2, the polishing pad prepared by the polishing layer of the present invention can improve the polishing rate of the polishing material.

[0106] Although the present invention has been described in detail through the preferred embodiments described above, it should be understood that the above description should not be considered as a limitation of the present invention. Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A method for preparing a rapid-rebound chemical mechanical polishing pad, characterized in that, Includes the following steps: a) Polyurethane resin was prepared by adding isocyanate and chain extender in stages using a solution method; b) Dissolve the polyurethane resin and additives in a solvent to prepare a coating slurry; c) Apply the coating slurry evenly to the support layer at a certain thickness; d) Immediately immerse in a coagulation bath to solidify and form a polished layer; e) The polishing layer after washing and drying is sanded and grooved and then bonded with a buffer layer, an adhesive backing layer and a release layer to obtain a chemical mechanical polishing pad. Step a) is: i) First stage: Polyol, chain extender, solvent and isocyanate are added to the reactor under nitrogen atmosphere and stirred to react; ii) Second stage: Add chain extender and isocyanate again, and continue stirring the reaction; iii) Third stage: Continue adding isocyanate and continue stirring the reaction; iv) Termination of reaction: After the reaction is complete, a terminator is added to terminate the reaction and polyurethane resin is obtained.

2. The preparation method according to claim 1, characterized in that, The second stage of step ii) is repeated two or more times, involving repeated feeding and reaction.

3. The preparation method according to claim 1, characterized in that, In step i), the addition of polyol, chain extender, solvent, and isocyanate controls the -NCO / -OH molar ratio of the system to be maintained between 0.7 and 0.9; and / or The chain extender added in step ii) is 10-40% of the mass of the chain extender added in step i); the added isocyanate is used to control the -NCO / -OH molar ratio in the reaction system to be maintained at 0.7-0.9; and / or In step iii), isocyanate is added again to bring the -NCO / -OH molar ratio of the reaction system to 1-1.

03.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The reaction temperature is controlled between 70-85 degrees Celsius, and the reaction ends when the viscosity of the reaction system reaches 170,000-200,000 mPa·s; and / or The 100% modulus of the polyurethane resin is 5-10 MPa.

5. The preparation method according to claim 4, characterized in that, The 100% modulus of the polyurethane resin is 6-8 MPa.

6. The preparation method according to any one of claims 1 to 3, characterized in that, The polyol is selected from at least one of polyester polyols, polyether polyols, polycarbonate polyols, polyacrylic acid polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, and dimer diols; and / or The chain extender is selected from small molecule diols, triols, or polyols; and / or The isocyanate is an aromatic diisocyanate or an aliphatic diisocyanate; and / or The solvent is selected from any one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and methyl ethyl ketone.

7. The preparation method according to claim 6, characterized in that, The polyol is a polyester polyol; and / or The chain extender is selected from any one of ethylene glycol, 1,3-propanediol, 1,4-butanediol, trimethylolethane, and trimethylolpropane; and / or The isocyanate is selected from at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), phenyl dimethyl diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated phenyl dimethyl diisocyanate (hydrogenated XDI), hexamethylene diisocyanate, and norbornene diisocyanate; and / or The solvent is N,N-dimethylformamide.

8. The preparation method according to claim 7, characterized in that, The isocyanate is MDI.

9. The rapid-rebound chemical mechanical polishing pad prepared by the method according to any one of claims 1 to 8, characterized in that, The chemical mechanical polishing pad has a polishing layer thickness of 0.3~2mm, a compression ratio of no more than 25%, a resilience of more than 70%, and a rapid rebound rate of more than 80%. The ratio of the thickness reduction of the polished layer after applying pressure of 37.43 kPa for 30 seconds to the thickness of the unpressurized polished layer is denoted as the compression ratio. Remove the applied pressure and record the thickness recovery 5 seconds and 30 seconds after removing the pressure. The ratio of the thickness recovery 30 seconds after removing the pressure to the thickness reduction of the polished layer under pressure is recorded as the springback rate. The ratio of the thickness recovery amount 5 seconds after the pressure is removed to the thickness recovery amount 30 seconds after the pressure is removed is denoted as the rapid rebound rate.

10. The chemical mechanical polishing pad according to claim 9, characterized in that, The thickness of the polished layer is 0.6-1.2 mm; the compression rate is below 20%, the springback rate is above 80%, and the rapid springback rate exceeds 90%.

11. The chemical mechanical polishing pad according to claim 9 or 10, characterized in that, The Shore A hardness of the polished layer is 5 to 50 degrees.

12. The chemical mechanical polishing pad according to claim 11, characterized in that, The Shore A hardness of the polished layer is 10~30 degrees.

13. The application of the rapid rebound chemical mechanical polishing pad prepared by the preparation method according to any one of claims 1 to 8 or the rapid rebound chemical mechanical polishing pad according to any one of claims 9 to 12 in chemical mechanical polishing.

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