Multilayer material and abrasive material used by same, and use thereof

Abstract

A multilayer material and an abrasive material used by same, and the use thereof. The abrasive material is a foamed sheet of a polyester elastomer, and the loss factor of the abrasive material at any temperature within the range of 25-85ºC is smaller than 0.1. As the polyester elastomer is used in the abrasive material, the multilayer material using the abrasive material is ensured to have a very good elastic recovery rate and a stable substrate planarization rate.

Description

Multilayer materials and abrasive materials and applications thereof

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on July 31, 2023, with application number 202310962535.6 and application name “Multi-layer materials, abrasive materials used therefor and applications thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of multilayer materials, and in particular to a multilayer material and a grinding material used therein and applications thereof. Background Art

[0003] Multilayer materials are a crucial auxiliary material used in substrate surface planarization. They store and transport the planarization working fluid, working together with the working fluid to achieve the desired planarization. Multilayer materials typically consist of a stacked base layer, an adhesive layer, and a porous abrasive layer. The abrasive layer, which comes into contact with the substrate being treated, is the core functional layer that influences the planarization results.

[0004] In currently commercially available or reported multilayer materials, the polishing layer is typically a porous polyurethane elastomer. However, the elastic modulus of existing polyurethane elastomers varies significantly within the operating range of multilayer materials, resulting in unstable substrate planarization rates and even pore blockage, leading to premature end-of-life. With the advancement of planarization technology and the demand for planarization of diverse substrates, new elastomer materials are needed for multilayer materials that can ensure a stable planarization rate.

[0005] Summary of the Invention

[0006] In view of this, embodiments of the present application provide a polishing layer material that can be used for multi-layer materials to solve the problem of unstable planarization rate of the existing multi-layer materials on the substrate.

[0007] In a first aspect of an embodiment of the present application, there is provided an abrasive material for surface treatment of a substrate. The abrasive material is a foamed sheet of a polyester elastomer, and the loss factor of the abrasive material at any temperature within the range of 25-85°C is less than 0.1.

[0008] This application uses a foamed sheet of polyester elastomer as a grinding material for substrate surface treatment, and controls the loss factor of the grinding material to be less than 0.1 within the temperature range of the flattened substrate, indicating that it has low internal heat generation and high elastic recovery rate, which can ensure that the flattening rate of the multilayer material using the grinding material is stable and has a long service life.

[0009] In the embodiment of the present application, the elastic recovery rate of the abrasive material is above 90%, which indicates that the external force mainly causes elastic deformation of the abrasive material, the internal heat generation is small, and the service life of the abrasive material is long.

[0010] In the embodiment of the present application, the abrasive material has an elastic recovery rate of more than 90% after undergoing 50,000 compression fatigue tests with a deformation of 20%, which better reflects the superior compression resilience of the polyester elastomer foam sheet provided in the present application.

[0011] In the embodiment of the present application, the relative standard deviation of the thickness of the same foam sheet does not exceed 10%, which reflects that the thickness of the polyester elastomer foam sheet at different locations is highly uniform, thereby ensuring high consistency in the degree of grinding at different locations of the substrate.

[0012] In an embodiment of the present application, the polyester elastomer includes a polyester hard segment and a polyether soft segment, wherein the polyester hard segment is selected from one or more of polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate; and the polyether soft segment includes one or more of a polytetramethylene glycol segment, a polyoxypropylene glycol segment, and a polyoxyethylene glycol segment.

[0013] In an embodiment of the present application, the abrasive material is obtained by subjecting a shaped sheet containing the polyester elastomer to vacuum heat treatment and then to supercritical foaming. The vacuum heat treatment of the shaped sheet containing the polyester elastomer prior to supercritical foaming can relieve stress and improve or eliminate structural defects, thereby achieving a foamed sheet with higher thickness uniformity and improved compression resilience.

[0014] A second aspect of an embodiment of the present application provides a multilayer material, which includes a base layer, an adhesive layer and a grinding layer stacked in sequence, wherein the grinding layer includes the grinding material described in the first aspect of the embodiment of the present application.

[0015] The multilayer material used for the flat substrate is introduced with the above-mentioned polishing layer material with good performance, which can ensure that the multilayer material generates less internal heat under the action of external force, the polishing rate of the substrate is stable, the flattening effect of the substrate after processing in different batches is similar, and the service life of the multilayer material is long.

[0016] A third aspect of the embodiments of the present application provides a substrate surface treatment device, which includes the multilayer material described in the second aspect of the embodiments of the present application.

[0017] In some embodiments of the present application, the substrate surface treatment device includes a work platform and a grinding head suspended above the work platform, the surface of the work platform is provided with the multi-layer material, or the multi-layer material is installed on the grinding head.

[0018] By using a substrate surface treatment device with the multilayer material, the flattening rate of the substrate surface is stable and the flattening effect is good, scratches are not easily generated on the substrate surface, and the service life of the device is long.

[0019] The present invention also provides a method for preparing an abrasive material, comprising the following steps:

[0020] forming a polyester elastomer into a sheet for foaming;

[0021] The foaming sheet is subjected to vacuum heat treatment and then supercritical foaming to obtain a grinding material; wherein the grinding material is a foamed sheet of polyester elastomer, and the loss factor of the grinding material is less than 0.1 at any temperature within the range of 25-85°C.

[0022] Before the polyester elastomer sheet to be foamed is subjected to supercritical foaming, it is first subjected to vacuum heat treatment, which can squeeze out the original bubbles inside, release the stress, and improve or eliminate various structural defects caused during its molding process, thereby improving the thickness uniformity and bubble size uniformity of the foamed sheet obtained by foaming, while ensuring that the compression rebound resilience becomes better, so that the loss factor of the obtained grinding material can be less than 0.1 at any temperature in the range of 25-85°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1A and FIG1B are two structural schematic diagrams of a multilayer material 100 provided in an embodiment of the present application.

[0024] FIG2 is a schematic structural diagram of a substrate surface treatment device 200 provided in an embodiment of the present application.

[0025] FIG3 is a graph showing the loss factor of the grinding layer samples of Examples 1-2 and Comparative Example 1 at different temperatures provided in the examples of the present application. DETAILED DESCRIPTION

[0026] The technical solution of this application will be described below in conjunction with the drawings in the embodiments of this application.

[0027] Multilayer materials are important auxiliary materials in surface planarization processes that determine the surface treatment quality of substrates to be treated (such as semiconductor substrates, glass, metals, ceramics, optical devices, etc.). Referring to Figures 1A and 1B , a multilayer material 100 for substrate surface treatment provided in an embodiment of the present application includes a base layer 11, an adhesive layer 12, and a porous polishing layer 13, which are sequentially stacked.

[0028] Among them, the surface of the base layer 11 away from the grinding layer 13 is the adsorption surface of the multilayer material 100, which is used to ensure that the multilayer material 100 is attached to the substrate surface treatment device. The surface of the grinding layer 13 away from the base layer 11 is the working surface of the multilayer material 100, which is used to contact the surface to be processed of the substrate, so that the substrate obtains a flat surface under the mechanical action of the multilayer material 100 and the chemical action of the grinding working fluid. During the flattening process of the substrate, the multilayer material will undergo multiple compressions and rebounds. If the compression resilience of the grinding layer 13 is not good, its interior and surface are prone to deformation and collapse of the pore structure, resulting in an unstable flattening rate for the substrate. Therefore, when developing new grinding layer materials that can be used for the multilayer material 100, it is necessary to ensure that the flattening rate of the multilayer material on the substrate is stable.

[0029] An embodiment of the present application provides a material that can be used for the grinding layer 13 in the multilayer material 100. The grinding material is a foamed sheet of polyester elastomer, and the loss factor (denoted as Tanδ(25~85℃)) of the grinding material at any temperature in the range of 25-85℃ is less than 0.1.

[0030] Among them, 25℃ is the common starting working temperature of multilayer materials, and 85℃ is the common maximum working temperature of multilayer materials. The loss factor of the constituent materials of the grinding layer 13 controlled by this application is less than 0.1 within the working temperature range of the multilayer material (25-85℃). This shows that within the above temperature range, it mainly undergoes elastic deformation under the action of external force, with less endogenous heat, high elastic modulus, and low loss modulus E". Therefore, the Tanδ value (=E" / E') is low, and there will be no sudden increase / decrease in the elastic modulus. After the external force is removed, the material can basically return to its initial deformation, with good resilience and low probability of plastic deformation. The probability of its pore structure being blocked / collapsed due to plastic deformation is also low, thereby ensuring that the grinding rate of the grinding material on the substrate is stable during its working process and improving its own service life.

[0031] In some embodiments of the present application, the abrasive material has a loss factor of less than or equal to 0.08, less than or equal to 0.075, less than or equal to 0.06, less than or equal to 0.05, etc. at any temperature within the range of 25-85°C. In this case, the abrasive layer generates less stress and heat during operation of the multilayer material 100, and has better compression resilience, which is more conducive to maintaining a stable planarization effect for the multilayer material 100.

[0032] The loss factor Tanδ of the abrasive material at different temperatures can be obtained based on dynamic mechanical analysis (DMA) testing. Tanδ can be measured according to ISO 6721-4, with a test frequency of 1 Hz and a heating rate of 3°C / min.

[0033] In the embodiments of the present application, the abrasive material has an elastic recovery rate exceeding 90%. The polyester elastomer foam sheet has an elastic recovery rate exceeding 90% after being subjected to pressure, indicating that external forces primarily cause elastic deformation and minimal internal heat generation. After the abrasive layer 13 completes surface treatment of the substrate, the sheet can substantially recover to its original shape, thereby ensuring the reusability of the multilayer material 100. This elastic recovery rate can be measured in accordance with the national standard GB / T 20671.2-2006.

[0034] In the embodiments of the present application, the abrasive material exhibited an elastic recovery rate exceeding 90% after undergoing 50,000 compression fatigue tests at a deformation of 20%. This further demonstrates the exceptionally excellent compression resilience of the polyester elastomer foam sheet provided herein, thereby enabling the multilayer material 100 utilizing this abrasive material to maintain similar resilience levels during initial and final use.

[0035] In the embodiment of the present application, the grinding material is a foam sheet, and the thickness relative standard deviation of the same foam sheet does not exceed 10%, and can further be less than or equal to 6%, less than or equal to 5%, etc. The thickness relative standard deviation can be obtained by testing and calculating the thickness of the foam sheet at different positions. in, σ1 is the standard deviation of the thickness measured at multiple different locations of the foam sheet, Represents the average value of the thickness measured at multiple different locations of the foam sheet, D i represents the specific thickness value measured at each different position of the same foam sheet, and n represents the number of different positions selected.

[0036] A low RSD indicates a high degree of thickness uniformity across different locations of the polyester elastomer foam sheet. This ensures consistent polishing across different locations of the substrate surface when the multilayer material is polished, and ensures similar polishing results across different batches of substrates. Furthermore, the polyester elastomer foam sheet, after undergoing the vacuum heat treatment followed by supercritical foaming process described below, exhibits even more uniform thickness and cell size.

[0037] In the embodiment of the present application, the grinding material is a foam sheet, and the ratio of the minimum thickness to the maximum thickness of the same foam sheet is greater than 90%, and can further be greater than 95%. This reflects that the thickness of the foam sheet has little fluctuation and good uniformity.

[0038] In the present application, the above-mentioned grinding material is a foam sheet with a porous structure. In the embodiment of the present application, the average pore size (i.e., average cell diameter) of the grinding material is 5 μm-50 μm. Suitable average pore size is conducive to the rapid delivery of the grinding working fluid, ensures that the processing speed of the multilayer material 100 to the substrate is faster, and reduces the surface defects of the substrate after treatment. In some embodiments, the average pore size of the grinding material is 10 μm-40 μm, for example, specifically 15 μm, 20 μm, 25 μm, 30 μm, 35 μm or 39 μm, etc. Wherein, the average pore size can be measured from the scanning electron microscope (SEM) photo of the grinding material. Specifically, the surface of the grinding material can be magnified to 100 times for SEM observation, and the image is binarized using image processing software Image J to confirm the number of cells, and the average cell diameter is further calculated by the sum of the open area of ​​each cell.

[0039] In the embodiment of the present application, the surface porosity of the grinding material is in the range of 20%-80%. In other words, the porosity of the surface of the grinding layer 13 away from the base layer 11 is controlled in the range of 20%-80%. This is conducive to the multilayer material 100 having a suitable processing rate and good processing effect on the substrate to be processed. If the surface porosity of the grinding layer 13 is too low, its carrying capacity for the working fluid is insufficient, and the processing rate of the substrate will be reduced; if the surface porosity is too high, it is easy to cause the thrown waste to fill the surface pores, affecting the subsequent processing effect. Among them, the above-mentioned surface porosity can be obtained by taking a scanning electron microscope photograph of the working surface of the grinding layer 13 (the magnification can be 100 times) to obtain the ratio of the area occupied by the bubbles on it to the area of ​​the surface.

[0040] In the embodiment of the present application, the density of the grinding material is 0.3-1.0 g / cm 3 The density in this range can reflect to some extent that the grinding layer 13 is light in weight and has a porous structure with appropriate porosity to transport the grinding working fluid, while not being too light in density to affect its mechanical properties. Specifically, the density of the grinding material can be 0.4 g / cm 3 , 0.5g / cm 3 , 0.6g / cm 3 , 0.7g / cm 3 , 0.71g / cm 3 , 0.72g / cm 3 , 0.75g / cm 3 , 0.8g / cm 3 , 0.85g / cm 3 wait.

[0041] In embodiments of the present application, the Shore hardness of the abrasive material is within the range of 15D-60D. A polyester elastomer of appropriate hardness is selected for foaming. The resulting foamed material exhibits good resilience while also possessing an appropriate hardness, enhancing its wear resistance. This ensures a smoothing effect on the substrate surface while also resisting scratching. In some embodiments, the Shore hardness of the abrasive material is 30D-50D, and further can be 31D-40D.

[0042] In the present application, the polyester elastomer is a linear block copolymer containing a polyester hard segment and a polyether soft segment, combining the excellent elasticity of rubber with the easy processability of thermoplastics, and having adjustable hardness and softness. The polyester elastomer can be prepared by reacting dimethyl terephthalate with a small molecule diol (such as ethylene glycol, propylene glycol, butanediol, etc.) and a polyether polyol through an ester exchange reaction and a polycondensation reaction. The polyester hard segment of the polyester elastomer has repeating units derived from the ester exchange-polycondensation reaction product of dimethyl terephthalate and a small molecule diol, and the polyether soft segment has repeating units derived from the ester exchange-polycondensation reaction product of dimethyl terephthalate and a polyether polyol.

[0043] In the embodiment of the present application, the polyester hard segment of the polyester elastomer may include one or more of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polypropylene terephthalate (PTT), but is not limited thereto. The polyether soft segment of the polyester elastomer may include one or more of polytetramethylene ether glycol (PTMEG) segments, polyoxypropylene glycol (PPG) segments, and polyethylene glycol (PEG) segments, but is not limited thereto.

[0044] In an embodiment of the present application, the abrasive material is obtained by subjecting a polyester elastomer-containing formed sheet to vacuum heat treatment and then to supercritical foaming. The polyester elastomer-containing formed sheet is subjected to vacuum heat treatment prior to supercritical foaming to release stress and improve or eliminate structural defects, thereby achieving a foamed sheet with higher thickness uniformity and improved compression resilience.

[0045] The present application also provides a method for preparing the above-mentioned abrasive material. Specifically, the method for preparing the abrasive material may include the following steps:

[0046] forming the polyester elastomer into a sheet to be foamed;

[0047] The sheet to be foamed is subjected to vacuum heat treatment and then supercritical foaming to obtain a grinding material; wherein the grinding material is a foamed sheet of polyester elastomer, and the loss factor of the grinding material is less than 0.1 at any temperature within the range of 25-85°C.

[0048] Among them, before the foam sheet is subjected to supercritical foaming, it is first subjected to vacuum heat treatment, which can squeeze out the original bubbles inside, release the stress, and improve or eliminate various tissue defects caused during its molding process, thereby improving the thickness uniformity and bubble size uniformity of the foam sheet obtained by foaming, while ensuring that the compression rebound resilience becomes better, and the loss factor at any temperature in the range of 25-85°C can be less than 0.1.

[0049] In the embodiment of the present application, the processing temperature of the vacuum heat treatment is between T m -20℃ to T m ℃, the treatment time is 1-10 hours; among which, T m represents the melting point of the polyester elastomer.

[0050] Among them, the vacuum condition is conducive to the removal of bubbles in the foamed sheet; between T m -20℃ to T m ℃, can cause the sheet to be foamed to undergo an appropriate degree of micro-melting without changing the overall structural configuration, so that various tissue defects therein are improved or eliminated, and the unevenness of the surface is improved. At the same time, after the vacuum condition is removed, it is not easy to introduce new bubbles. In addition, sufficient vacuum heat treatment time can ensure that the above-mentioned various improvement effects are fully presented. In some embodiments, the treatment temperature of the vacuum heat treatment is in the range of 120-150 ℃, for example, specifically 125, 130, 135, 140 or 145 ℃. Furthermore, the vacuum degree during the vacuum heat treatment is less than 0.08 MPa.

[0051] In the embodiments of the present application, the molding methods for forming the polyester elastomer material into the sheet to be foamed include, but are not limited to, one or more of extrusion molding, hot pressing molding, and injection molding. Using a sheet-like molded article for foaming ensures that the resulting foamed material is also a sheet, with a high degree of conformity between the two shapes, differing only in thickness, density, and other factors.

[0052] Supercritical foaming is a physical foaming molding technology that uses a supercritical fluid as a foaming agent and foams at a certain foaming pressure and temperature. "Supercritical fluid" refers to a special state in which a substance is in a temperature and pressure above its supercritical point. In this state, the fluid has both gas and liquid properties, for example, its viscosity and diffusion coefficient are similar to those of a gas, and its density and solvation capacity are similar to those of a liquid. In the embodiment of the present application, the supercritical fluid used can be selected from one or more of supercritical nitrogen (N2) and supercritical carbon dioxide (CO2).

[0053] Among them, the supercritical foaming process may include:

[0054] 1) placing the sheet to be foamed after vacuum heat treatment in a foaming cavity, and heating the foaming cavity to a preset foaming temperature;

[0055] 2) introducing a supercritical fluid into the foaming cavity, causing the pressure in the foaming cavity to reach a preset foaming pressure, and maintaining the preset foaming temperature and preset foaming pressure for a period of time so that the supercritical fluid reaches a dissolution equilibrium in the sheet to be foamed;

[0056] 3) Relieving the pressure of the foaming cavity to foam the sheet to be foamed to obtain a foamed sheet.

[0057] In step 1), the preset temperature can be set based on the melting points of the supercritical fluid and polyester elastomer used. The preset temperature should be higher than the critical temperature of the supercritical fluid and the glass transition temperature (Tg) of the polyester elastomer to maintain the fluid in a supercritical state and ensure that the sheet to be foamed has a suitable melt strength for foaming. Accordingly, in step 2), when the supercritical fluid is introduced into the foaming cavity, the preset foaming pressure reached within the foaming cavity should be higher than the critical pressure of the supercritical fluid to maintain the fluid in a supercritical state, facilitate diffusion into the sheet to be foamed, and achieve a high solubility therein. In some embodiments, when the supercritical fluid is supercritical CO2 and / or N2, the preset foaming pressure can be in the range of 10-20 MPa, for example, specifically 10, 12, 15 or 18 MPa, etc., and can further be 10-15 MPa; the preset foaming temperature can be in the range of 120-160°C, for example, specifically 125, 130, 135, 140, 150, 155, 158°C, etc.

[0058] In step 2), the preset foaming temperature and preset foaming pressure are maintained for a period of time (this holding time can be called "saturation time"), so that the supercritical fluid can fully diffuse into the sheet to be foamed and reach a dissolution equilibrium therein. Afterwards, the pressure relief in step 3) can cause a pressure difference between the pressure inside the sheet to be foamed and the pressure of the external environment, resulting in the supercritical fluid dissolved in the sheet to be foamed being in a thermodynamically unstable state, generating a large number of bubble nuclei in the sheet to be foamed, and the continuous growth of the bubble nuclei can obtain a foamed molded body with a bubble structure. Among them, the above-mentioned "pressure relief" generally refers to reducing the pressure in the foaming cavity to below its critical point pressure, for example, reducing it to atmospheric pressure (i.e., normal pressure).

[0059] In some embodiments of the present application, the holding time in step 2) can be 30-90 minutes, for example, 40 minutes, 45 minutes, 60 minutes, 80 minutes, or 90 minutes. In step 3), the foaming cavity is depressurized at a rate greater than or equal to 20 MPa / s to reduce the pressure in the foaming cavity to atmospheric pressure. Specific depressurization rates can be 25 MPa / s, 28 MPa / s, 30 MPa / s, 35 MPa / s, etc.

[0060] In some embodiments of the present application, after the supercritical foaming, the preparation method may further include performing a hot press treatment. Hot press treatment can improve the surface flatness of the foamed sheet and reduce warping. The hot press treatment temperature may be between Tg - 30°C and Tg + 30°C; Tg represents the glass transition temperature of the foamed sheet, i.e., the glass transition temperature of the polyester elastomer.

[0061] The preparation method of the above-mentioned grinding material in this application is simple to operate and suitable for industrial mass production. The obtained grinding material is a foamed sheet of polyester elastomer, which has a high elastic recovery rate and high uniformity of thickness and pore size. It is particularly suitable for use in multi-layer materials for flattening substrates, so that the grinding rate of the multi-layer material on the substrate is stable, and has broad market application prospects.

[0062] The present application also provides a multilayer material including a grinding layer, wherein the grinding layer is a foamed material of the polyester elastomer. For the physical properties of the grinding layer material, please refer to the description above.

[0063] In an embodiment of the present application, as shown in FIG1A above, the multilayer material 100 may include a base layer 11, an adhesive layer 12, and the aforementioned polishing layer 13 stacked in sequence. In some embodiments, as shown in FIG1B , the multilayer material 100 further includes a backing layer 14, which is located on the side of the base layer 11 facing away from the polishing layer 13.

[0064] The base layer 11 primarily supports and cushions the grinding layer 13, ensuring pressure balance across the grinding layer 13 during operation of the multilayer material 100. The surface of the base layer 11 facing away from the grinding layer 13 serves as the adsorption surface of the multilayer material 100, ensuring that the multilayer material 100 adheres to a substrate surface treatment device, such as a work platform. The presence of an adhesive layer 14 on the side of the base layer 11 facing away from the grinding layer 13 further helps ensure a more stable adhesion of the multilayer material 100 to the substrate surface treatment device. The adhesive layer 12 primarily serves to ensure a good connection between the base layer 11 and the grinding layer 13, reducing the probability of interlayer separation during operation of the multilayer material 100. The adhesive layer 12 can specifically be a solvent-free adhesive. The surface of the grinding layer 13 facing away from the base layer 11 serves as the working surface of the multilayer material 100, contacting the surface of the substrate to be processed, thereby achieving a flat surface under the mechanical action of the multilayer material 100 and the chemical action of the grinding fluid.

[0065] In the embodiment of the present application, the thickness of the grinding layer 13 used in the multilayer material can be in the range of 0.3-4 mm. Setting the thickness of the polyester elastomer foam sheet within this range ensures that the grinding layer 13 has appropriate hardness and compressibility, fully utilizing the function of flattening the substrate. Specifically, the thickness of the grinding layer 13 can be 0.4 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.2 mm, 3.5 mm, 3.8 mm, etc.

[0066] The present application also provides an embodiment of the present application, wherein the above-mentioned grinding material or the above-mentioned multilayer material is used in substrate surface treatment. The substrate surface treatment is specifically a substrate surface flattening process. The application can specifically be used in a chemical mechanical polishing process.

[0067] The present application also provides a substrate surface treatment device, which includes the multilayer material described above in the present application. The substrate surface treatment device can be used to planarize the surface of a substrate. The substrate surface treatment device can be referred to as a "planarization treatment device" and can be used in a chemical mechanical polishing (CMP) process. The substrate can include, but is not limited to, a wafer, a semiconductor substrate, glass, metal, ceramics, optical devices, and the like.

[0068] Generally, the substrate surface treatment device may include a work platform and a grinding head suspended above the work platform, wherein the multi-layer material is laid on the surface of the work platform or the multi-layer material is mounted on the grinding head. The work platform may be referred to as a "work plate" in some cases.

[0069] Referring to FIG. 2 , some embodiments of the present application provide a substrate surface treatment apparatus 200 comprising a work platform 1, a multilayer material 100 laid on the surface of the work platform 1, a polishing head 2 suspended above the work platform 1, and a working fluid supply unit 4. A substrate 3 to be treated is mounted on the polishing head 2, and its surface to be processed can contact the multilayer material 100, specifically the polishing layer 13 of the multilayer material 100, during polishing. The work platform 1 or the polishing head 2 can rotate clockwise or counterclockwise under the action of electrodes to initiate the treatment / processing process.

[0070] As previously described in this application, the multilayer material 100 can be adhered to the work platform 1, and its grinding layer 13 is away from the work platform 1. The multilayer material 100 can be adhered specifically by a backing layer 14 provided on the side of the base layer 11 away from the grinding layer 13 to prevent the multilayer material 100 from moving arbitrarily during processing. The grinding head 2 is used to carry or clamp the substrate 3 to be processed, and press the substrate 3 to be processed against the multilayer material 100 with a certain pressure, so that the substrate 3 to be processed is located between the grinding head 2 and the multilayer material 100. The working liquid supply unit 4 is used to provide a working liquid, which is generally a chemical solution containing abrasive particles. During the processing of the substrate, the working liquid supply unit 4 can spray the working liquid onto the multilayer material 100. The substrate 3 to be processed reacts chemically with the working liquid, and the surface is flattened under mechanical friction with the multilayer material 100.

[0071] In some embodiments of the present application, the substrate surface treatment device 200 further includes a trimming unit 5. The trimming unit 5 is used to trim the multilayer material 100. During the processing of the substrate, the trimming unit 5 can be pressed against the multilayer material 100 and remove debris and reactants on the surface of the multilayer material 100 when the trimming unit 5 and the multilayer material 100 rub against each other.

[0072] By using the substrate surface treatment device 200 with the multilayer material 100 according to the embodiment of the present application, the surface flattening treatment effect of the substrate 3 to be treated is good, and the device can work for a long time.

[0073] The technical solutions of the embodiments of the present application are further described below with reference to a number of embodiments.

[0074] Example 1

[0075] Preparation of a grinding layer material for a multi-layer material, comprising the following steps:

[0076] Preparation of foaming profiles: 42D hardness thermoplastic polyester elastomer (TPEE) particles (composed of a PTMEG polyether soft segment and a PBT hard segment, with a melt index of 5.6 g / 10 min (190°C-2.16 kg)) were pre-dried in a 90°C oven for 12 hours and then added to the extruder's feeding device. The hopper was protected by nitrogen and the sample was fed by its own weight. The extruder used was a single-screw sheet extruder with barrel temperatures of 215°C, 210°C, and 220°C, a die temperature of 220°C, and an extrusion rate of 0.25 m / min. The TPEE sheet produced by the extruder had a width of 1.4 meters and a thickness of 2 mm. After cooling, the extruded TPEE sheet was cut into 0.8 m x 0.8 m square sheets, cleaned with isopropyl alcohol, and air-dried for use.

[0077] The TPEE square sheet prepared above was placed in a vacuum oven and annealed at 132°C for 5 hours. The heating function of the vacuum oven was then turned off and the sheet was naturally cooled to 30°C. The sheet was then removed and placed in a supercritical foaming kettle. Supercritical CO2 was introduced as a physical foaming agent to increase the pressure in the foaming kettle to a foaming pressure of 10 MPa and a temperature of 135°C. This foaming temperature and pressure were maintained for 1.5 hours to achieve impregnation saturation. The foaming kettle was then depressurized at a rate of 28 MPa / s to obtain a TPEE foam sheet with a microporous structure.

[0078] The density of the TPEE foam sheet was measured to be 0.67 g / cm 3 , the average cell diameter is 35μm, and the hardness is 31D. The standard deviation of the thickness measured at different locations of the same TPEE foamed sheet is 6%.

[0079] Example 2

[0080] A preparation method for a grinding layer material for a multilayer material, which differs from Example 1 in that: when preparing the foaming profile, TPEE particles with a hardness of 60D are used as a raw material; the TPEE particles are composed of a PTMEG polyether soft segment and a PBT hard segment, and have a melt index of 5.1 g / 10 min (190°C-2.16 kg); the vacuum heat treatment temperature before supercritical foaming is 145°C; the supercritical foaming pressure is 12 MPa, the foaming temperature is 125°C, and the pressure relief rate is 30 MPa / s.

[0081] The density of the TPEE foam sheet prepared in Example 2 was measured to be 0.71 g / cm 3 The average cell diameter is 38 μm and the hardness is 37 D. The standard deviation of the thickness measured at different locations of the same TPEE foamed sheet is 4%.

[0082] Example 3

[0083] A preparation method for a grinding layer material for a multilayer material, which differs from Example 2 in that the foaming agent used in supercritical foaming is supercritical N2, the foaming pressure is 10 MPa, the foaming temperature is 157°C, the time for maintaining the foaming pressure and temperature is 1.5 hours, and the pressure relief rate is 30 MPa / s.

[0084] The density of the TPEE foam sheet prepared in Example 3 was measured to be 0.67 g / cm 3 , the average cell diameter is 26μm, and the hardness is 39D. The standard deviation of the thickness measured at different locations of the same TPEE foamed sheet is 2%.

[0085] In order to highlight the beneficial effects of the technical solution of the present application, the following comparative examples 1-2 are provided.

[0086] Comparative Example 1

[0087] Preparation of a grinding layer material for a multi-layer material, comprising the following steps:

[0088] (1) 58 parts by weight of TDI (toluene diisocyanate, wherein the content of 2,4-toluene diisocyanate is 80 wt %, the content of 2,6-toluene diisocyanate is 20 wt %, and the NCO content in TDI is ≥48.0 wt %) and 100 parts by weight of PTMEG□650 (polytetramethylene glycol having a molecular weight of 650, a functionality of 2, and a hydroxyl value of 166.2-179.5 mgKOH / g) are reacted at 80° C. to obtain an NCO-terminated prepolymer, wherein the mass percentage of unreacted NCO groups in the prepolymer is 9.81 wt %.

[0089] (2) The NCO-terminated prepolymer was heated to 80° C. and vacuum degassed for 2 hours at a vacuum degree of 0.095 MPa to remove the gas and small molecular compounds in the prepolymer; then 2.4 parts by weight of a porogen (specifically, hollow polymer microspheres with a particle size D50 of 25 μm) was uniformly dispersed in 100 parts by weight of the above-mentioned vacuum-degassed prepolymer by stirring, and vacuum degassed again at a vacuum degree of 0.095 MPa for 30 minutes to obtain a first mixture. 29.1 parts by weight of a diamine curing agent (specifically MOCA (3,3'-dichloro-4,4'-diphenylmethanediamine, with an amine value of 7.4-7.6 mmol / g)) was added to the first mixture and shear-mixed at high speed. The resulting second mixture was poured into a cylindrical mold. The mold containing the material was pre-baked in an 80°C oven for 30 minutes, and then the oven temperature was raised to 104°C within 30 minutes and cured for 16 hours. After curing was completed, the oven heating function was turned off and the temperature was automatically cooled to room temperature. The sample taken out of the mold was a porous polyurethane elastomer, which could be used as a grinding layer for a multilayer material.

[0090] The density of the porous polyurethane elastomer prepared in Comparative Example 1 is 0.68 g / cm 3 , hardness is 40D.

[0091] Comparative Example 2

[0092] A preparation method for a grinding layer material for a multilayer material is disclosed, which differs from Example 1 in that: when preparing the foaming profile, thermoplastic polyurethane (TPU) particles with a hardness of 95A are used as raw materials; no vacuum heat treatment is performed before supercritical foaming; the supercritical foaming pressure is 10 MPa, the foaming temperature is 125°C, the supercritical state is maintained for 3 hours, and the pressure relief rate is 30 MPa / s.

[0093] The density of the TPU foam sheet obtained in Comparative Example 2 was 0.59 g / cm 3 , the average cell diameter is 41 μm, and the hardness is 30D. The standard deviation of the thickness measured at different positions of the same TPU foam sheet is 30%.

[0094] Comparative Example 3

[0095] A method for preparing a grinding layer material for a multilayer material is different from Example 1 in that the TPEE square sheet prepared in Example 1 is not subjected to vacuum heat treatment first, but is directly subjected to supercritical foaming.

[0096] The density of the TPEE foam sheet in Comparative Example 3 was measured to be 0.67 g / cm 3, the average cell diameter is 36μm, and the hardness is 31D. The standard deviation of the thickness measured at different positions of the same TPEE foam sheet is 250%.

[0097] The polishing layer sheets prepared in the above embodiments and comparative examples were subjected to elastic recovery tests and fatigue resistance tests.

[0098] Among them, the elastic recovery rate test includes: taking samples from each grinding layer sheet to obtain a disc sample with a thickness of 2mm and a diameter of 1cm, recording the original thickness as H1, applying a 5kg weight, and then reading it after stabilizing for 60s, recording the thickness of the disc as H2, removing the 5kg weight, and then reading it after stabilizing for 60s, recording the thickness of the disc as H3, then the initial elastic recovery rate of each disc sample = (H3-H2) / (H1-H2)×100%.

[0099] Fatigue test: A 2 mm thick disc specimen was subjected to 50,000 fatigue tests in compression mode with a deformation of 20% and a test frequency of 10 Hz.

[0100] After the fatigue test, a 5kg weight is applied to each disc sample, and the reading is taken after stabilization for 60 seconds. The thickness of the disc is recorded as H4. After the 5kg weight is removed, the reading is taken after stabilization for 60 seconds. The thickness of the disc is recorded as H5. Therefore, after the fatigue test, the elastic recovery rate of each disc sample = (H5-H4) / (H1-H2)×100%.

[0101] Table 1 Elastic recovery rate of each grinding layer sheet before and after fatigue test

[0102] Table 1 summarizes the elastic recovery rates of various polishing layer sheets before and after fatigue testing. As can be seen from Table 1, after 50,000 compression fatigue tests, the TPEE foam sheets of Examples 1-3 maintained excellent elastic recovery rates, virtually unchanged from their initial rates before fatigue testing. In contrast, the elastic recovery rates of the polishing layer sheets of Comparative Examples 1-2 decreased significantly after multiple fatigue tests. This demonstrates the excellent fatigue resistance of the TPEE foam sheets provided herein, enabling the multi-layer polishing pad material prepared therefrom to maintain consistent rebound performance both in the early and later stages of use, resulting in a stable polishing effect.

[0103] DMA tests were also performed on the polishing layer sheets prepared in the above embodiments and comparative examples to obtain their loss factors Tan δ at different temperatures. The relevant results are summarized in the following Table 2 and Figure 3.

[0104] Table 2

[0105] As can be seen from Table 2 and Figure 3, the TPEE foam sheets provided in the Examples of the present application exhibit little variation in their Tanδ values ​​at various temperatures within the range of 25°C-85°C, remaining very low, around 0.05. Accordingly, the lower the endogenous heat of each TPEE foam sheet, the more stable the polishing rate of the multi-layer polishing pad material made therefrom. In contrast, the thermosetting porous polyurethane materials of Comparative Examples 1-2 exhibit significant variations in their Tanδ values ​​at different temperatures. For example, the Tanδ values ​​of Comparative Example 1 within the temperature range of 25-55°C and Comparative Example 2 within the temperature range of 60-85°C are both greater than 0.1, indicating that the materials experience high endogenous heat under external forces, resulting in poor elastic recovery and an inability to maintain good resilience across the entire temperature range of the foam material. This, in turn, hinders their use in multi-layer materials for planarizing substrates to maintain a stable polishing rate.

[0106] Furthermore, the TPEE foam sheet from each embodiment of this application was used as a polishing layer to produce a multilayer material for flattening a substrate. As shown in Figure 1B, the multilayer material includes a base layer 11, an adhesive layer 12, and a 2mm thick polishing layer 13, stacked in sequence. Base layer 11 is specifically a 1mm thick foamed buffer layer with a compression ratio of 25%. A 0.1mm thick adhesive layer 14 is also provided on the side of base layer 11 facing away from polishing layer 13, allowing the resulting multilayer material to adhere to the polishing test equipment via adhesive layer 14.

[0107] The test found that the rebound rate of the overall multi-layer material did not change much in the early and late stages of use, and was both relatively high, and the polishing effect on the ground substrate (silicon wafer) was stable.

[0108] The above merely represents several exemplary embodiments of the present application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

[0109] It should be understood that the first, second and various numerical numbers involved in this document are only distinguished for the convenience of description and are not intended to limit the scope of this application.

[0110] In this application, "and / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the related objects are in an "or" relationship.

[0111] In this application, "at least one" means one or more, and "more than one" means greater than or equal to two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

Claims

1. A grinding material for substrate surface treatment, characterized in that: The grinding material is a foamed sheet of polyester elastomer, and the loss factor of the grinding material at any temperature within the range of 25-85° C. is less than 0.

1.

2. The abrasive material according to claim 1, characterized in that The loss factor of the grinding material at any temperature within the range of 25-85° C. is less than or equal to 0.

08.

3. The abrasive material according to claim 1 or 2, characterized in that: The elastic recovery rate of the grinding material is above 90%.

4. The grinding material according to any one of claims 1 to 3, characterized in that After the grinding material is subjected to 50,000 compression fatigue tests with a deformation amount of 20%, the elastic recovery rate is above 90%.

5. The grinding material according to any one of claims 1 to 4, characterized in that: The relative standard deviation of the thickness of the same foamed sheet does not exceed 10%.

6. The abrasive material according to any one of claims 1 to 5, characterized in that: The average pore size of the grinding material is 5-50 μm.

7. The abrasive material according to any one of claims 1 to 6, characterized in that: The surface porosity of the grinding material is in the range of 20%-80%.

8. The abrasive material according to any one of claims 1 to 7, characterized in that: The density of the grinding material is 0.3-1.0 g / cm 3 .

9. The abrasive material according to any one of claims 1 to 8, characterized in that: The Shore hardness of the abrasive material at 25° C. is in the range of 15A-60D.

10. The grinding material according to any one of claims 1 to 9, characterized in that: The polyester elastomer comprises a polyester hard segment and a polyether soft segment, wherein the polyester hard segment is selected from one or more of polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate; and the polyether soft segment comprises one or more of a polytetrahydrofuran diol segment, a polyoxypropylene diol segment, and a polyoxyethylene diol segment.

11. The abrasive material according to any one of claims 1 to 10, characterized in that: The grinding material is obtained by subjecting a formed sheet containing the polyester elastomer to vacuum heat treatment and then to supercritical foaming.

12. A method for preparing a grinding material, characterized in that: The following steps are involved: forming a polyester elastomer into a sheet for foaming; The foaming sheet is subjected to vacuum heat treatment and then supercritical foaming to obtain a grinding material; wherein the grinding material is a foaming sheet of a polyester elastomer, and the loss factor of the grinding material at any temperature within the range of 25-85°C is less than 0.

1.

13. The preparation method according to claim 12, characterized in that: The vacuum heat treatment temperature is between T m -20℃ to T m ℃, the treatment time is 1-10 hours; among which, T m represents the melting point of the polyester elastomer.

14. A multilayer material, characterized in that It comprises a base layer, an adhesive layer and a grinding layer which are stacked in sequence, and the grinding layer comprises the grinding material according to any one of claims 1 to 11.

15. The multilayer material according to claim 14, characterized in that A back adhesive layer is also provided on the side of the base layer away from the grinding layer.

16. The multilayer material according to claim 14 or 15, characterized in that The thickness of the grinding layer is 0.3 mm-4 mm.

17. Use of the abrasive material according to any one of claims 1 to 11, or the multilayer material according to any one of claims 14 to 16 in substrate surface treatment.

18. A substrate surface treatment device, characterized in that: The substrate surface treatment device carries the multilayer material according to any one of claims 14-16.

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