Simulation optimization method, device and equipment for flexible film of polishing head, medium and product

Abstract

The invention relates to the technical field of chemical mechanical polishing, and discloses a simulation optimization method, device and equipment for a flexible film of a polishing head, a medium and a product, and the method comprises the following steps: obtaining a geometric model of a polishing wafer of the polishing head, the geometric model comprises a bearing device of the polishing head, a flexible film of the polishing head, a wafer adsorbed on the flexible film and a polishing pad in contact with a to-be-polished surface of the wafer, and the bearing device is connected with the flexible film; the geometric model is loaded to a finite element analysis model for simulation analysis, and the deformation quantity of the to-be-polished surface under the preset pressure is determined; and the size of the flexible film is optimized according to the deformation quantity of the to-be-polished surface, so that the target flexible film is obtained. Performance verification is carried out on the designed flexible membrane structure in a simulation mode, production is carried out after verification is passed, the research and development period can be shortened, and the research and development cost can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical mechanical polishing, in particular to a simulation optimization method, device, equipment, medium and product of a polishing head flexible film. BACKGROUND

[0002] Chemical mechanical polishing (CMP) is a key technology for realizing semiconductor surface planarization through the synergistic effect of chemical corrosion and mechanical grinding. Its core process relies on the dynamic balance between the chemical activity of the polishing liquid and the mechanical grinding. In the polishing process, the polishing head first adsorbs the wafer on the surface of the flexible film, and then covers the wafer on the surface of the rotating polishing pad through a precise pressure system, and uses the shear force generated by the rotation of the two to drive the nano abrasive in the polishing liquid to continuously remove the surface layer material.

[0003] The polishing head has multiple cavities with adjustable pressure, which can control the local pressure in different zones to optimize the uniformity of material removal. However, there are still problems such as uniformity, consistency, edge effect, and over-polishing or under-polishing of the wafer edge, so the polishing head needs to be continuously optimized and designed.

[0004] However, the traditional polishing head flexible film optimization requires design, production, process verification, optimization of the flexible film structure based on the process verification results, and repetition of the above process until the flexible film meets the process requirements. This research and development process is long in cycle and high in cost. SUMMARY

[0005] Therefore, the present application provides a simulation optimization method, device, equipment, medium and product of a polishing head flexible film to improve the long cycle and high cost of flexible film optimization design.

[0006] In a first aspect, the present application provides a simulation optimization method of a polishing head flexible film, the method comprising: obtaining a geometric model of a polishing head polishing wafer, wherein the geometric model comprises a bearing device of the polishing head, a flexible film of the polishing head, a wafer adsorbed on the flexible film, and a polishing pad in contact with a surface to be polished of the wafer, and the bearing device is connected with the flexible film; loading the geometric model into a finite element analysis model for simulation analysis to determine the deformation amount of the surface to be polished under a preset pressure; and optimizing the size of the flexible film according to the deformation amount of the surface to be polished to obtain a target flexible film.

[0007] The simulation optimization method of the flexible film of the polishing head provided in the embodiment is to load the geometric model to a finite element analysis model for simulation analysis after obtaining the geometric model of the polishing head polishing a wafer, to determine the deformation of the surface to be polished under a preset pressure, and then to optimize the size of the flexible film according to the deformation of the surface to be polished, so as to obtain a target flexible film. The embodiment verifies the performance of the designed flexible film structure in a simulation manner, optimizes the flexible film structure according to the simulation structure, and then puts into production after obtaining the target flexible film, which can not only shorten the research and development cycle and reduce the research and development cost, but also improve the flexibility of the optimized design.

[0008] In an alternative embodiment, the flexible film includes a bottom plate portion for contacting the wafer, a circular ring-shaped edge side wall, and a support, the edge side wall includes a first upright portion extending upward along the edge of the bottom plate portion and a first extension portion extending horizontally inward from the upper end of the first upright portion, the end of the first extension portion away from the first upright portion is connected with the bearing device, the inner side of the intersection of the bottom plate portion and the first upright portion is provided with a first groove portion, the inner side of the intersection of the first upright portion and the first extension portion is provided with a second groove portion, the support includes a second upright portion, a first protrusion portion extending outward from the lower end of the second upright portion, and a second protrusion portion extending outward from the upper end of the second upright portion, the first protrusion portion is located in the first groove portion, and the second protrusion portion is located in the second groove portion; according to the deformation of the polishing surface, the size of the flexible film is optimized, including: according to the deformation of the polishing surface, the size of the first protrusion portion and / or the first groove portion is optimized, so that the first gap is updated to a second gap, wherein the first gap is the distance between the side surfaces of the first protrusion portion and the first groove portion that are close to each other, and the second gap is greater than the first gap.

[0009] In the embodiment, by optimizing the gap between the first groove portion and the first protrusion portion, more gas can enter, which plays a role in buffering the downward pressure, so that the downward pressure at the edge of the wafer is more uniform, and the uniformity at the edge of the wafer is better.

[0010] In an alternative embodiment, according to the deformation of the polishing surface, the size of the first protrusion portion and / or the first groove portion is optimized, so that the first gap is updated to a second gap, including: determining whether the uniformity of the deformation of the surface to be polished reaches a preset uniformity; when the uniformity of the deformation of the surface to be polished does not reach the preset uniformity, optimizing the size of the first protrusion portion and / or the first groove portion, so that the first gap is updated to the second gap, and updating the wafer in the geometric model to a wafer that has not been polished; the method further includes: returning to the step of loading the geometric model to the finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under the preset pressure, until the uniformity of the deformation of the surface to be polished reaches the preset uniformity.

[0011] In an optional embodiment, the geometric model is loaded into a finite element analysis model for simulation analysis to determine the deformation amount of the surface to be polished under a preset pressure, comprising: performing mesh division on the geometric model by a mesh division unit of the finite element analysis model to obtain a first model; adding material attribute parameters to the first model by a material setting unit of the finite element analysis model to obtain a second model; adding boundary conditions and pressure loads to the second model by a load processing unit of the finite element analysis model to obtain a third model; and performing solving analysis on the third model by a solver and a post-processing unit of the finite element analysis model to obtain the deformation amount of the surface to be polished under the preset pressure.

[0012] In an optional embodiment, the flexible film is made of rubber material, and the mesh division on the geometric model by the mesh division unit of the finite element analysis model comprises: performing mesh division on the geometric model by the mesh division unit using a mesh self-adaptive method.

[0013] In this embodiment, when the flexible film of the polishing head is made of rubber material, the mesh self-adaptive method is used to divide the mesh, which can avoid the generation of negative volume mesh, thereby reducing the trial and error cost of the calculation mesh and improving the calculation efficiency.

[0014] In an optional embodiment, the mesh division unit activates a nonlinear self-adaptive region, and before the material setting unit of the finite element analysis model adds the material attribute parameters to the first model, the method further comprises: when the skewness of the mesh is greater than 0.9, re-dividing the mesh of the geometric model to update the first model.

[0015] In this embodiment, when the skewness is greater than 0.9 during the calculation process, the mesh is automatically re-divided, which can ensure the smooth completion of the calculation.

[0016] In a second aspect, the present application provides a simulation optimization device for a flexible film of a polishing head, comprising: an acquisition module for acquiring a geometric model of a polishing head polishing a wafer, wherein the geometric model comprises a bearing device of the polishing head, a flexible film of the polishing head, a wafer adsorbed on the flexible film, and a polishing pad in contact with a surface to be polished of the wafer, and the bearing device is connected with the flexible film; a simulation analysis module for loading the geometric model into a finite element analysis model for simulation analysis to determine a deformation amount of the surface to be polished under a preset pressure; and an optimization module for optimizing the size of the flexible film according to the deformation amount of the surface to be polished to obtain a target flexible film.

[0017] In an optional embodiment, the flexible film includes a bottom plate part for contacting the wafer, a circular ring-shaped edge side wall, and a support part, the edge side wall includes a first upright part extending upward along an edge of the bottom plate part and a first extension part extending horizontally inward from an upper end of the first upright part, a distal end of the first extension part from the first upright part is connected with the bearing device, an inner side of an intersection of the bottom plate part and the first upright part is provided with a first groove part, an inner side of an intersection of the first upright part and the first extension part is provided with a second groove part, the support part includes a second upright part, a first protrusion part extending outward from a lower end of the second upright part, and a second protrusion part extending outward from an upper end of the second upright part, the first protrusion part is located in the first groove part, and the second protrusion part is located in the second groove part; the optimization module includes: an optimization unit configured to optimize a size of the first protrusion part and / or the first groove part according to the deformation of the polishing surface, so that the first gap is updated to a second gap, wherein the first gap is a distance between the side surfaces of the first protrusion part and the first groove part that are close to each other, and the second gap is greater than the first gap.

[0018] In an optional embodiment, the optimization unit includes: a first determination subunit configured to determine whether uniformity of the deformation of the surface to be polished reaches a preset uniformity; and a first optimization subunit configured to, when the uniformity of the deformation of the surface to be polished does not reach the preset uniformity, optimize the size of the first protrusion part and / or the first groove part, so that the first gap is updated to the second gap, and update the wafer in the geometric model to a wafer that has not been polished; and the device further includes: a return module configured to return to the step of loading the geometric model to the finite element analysis model for simulation analysis, and determining the deformation of the surface to be polished under the preset pressure, until the uniformity of the deformation of the surface to be polished reaches the preset uniformity.

[0019] In an optional embodiment, the simulation analysis module includes: a division unit configured to perform mesh division on the geometric model by a mesh division unit of the finite element analysis model to obtain a first model; a setting unit configured to add material attribute parameters to the first model by a material setting unit of the finite element analysis model to obtain a second model; an adding unit configured to add boundary conditions and pressure loads to the second model by a load processing unit of the finite element analysis model to obtain a third model; and a solving analysis unit configured to perform solving analysis on the third model by a solver and a post-processing unit of the finite element analysis model to obtain the deformation of the surface to be polished under the preset pressure.

[0020] In an optional embodiment, the flexible film is made of rubber material, and the division unit includes: a division subunit configured to perform mesh division on the geometric model by the mesh division unit using a mesh self-adaption method.

[0021] In an alternative embodiment, the meshing unit activates a nonlinear adaptive region, and the device further comprises an updating module configured to re-mesh the geometric model and update the first model when the skewness of the mesh is greater than 0.9.

[0022] In a third aspect, the present application provides a computer device, comprising a memory and a processor, the memory and the processor being communicatively connected with each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the simulation optimization method of the flexible film of the polishing head according to the first aspect or any one of the corresponding embodiments thereof.

[0023] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions for causing a computer to perform the simulation optimization method of the flexible film of the polishing head according to the first aspect or any one of the corresponding embodiments thereof.

[0024] In a fifth aspect, the present application provides a computer program product, which comprises computer instructions for causing a computer to perform the simulation optimization method of the flexible film of the polishing head according to the first aspect or any one of the corresponding embodiments thereof. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the related art, the drawings needed to be used in the specific embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Figure 1 FIG. 1 is a flowchart of a simulation optimization method of a flexible film of a polishing head according to an embodiment of the present application;

[0027] Figure 2 FIG. 2 is a flowchart of another simulation optimization method of a flexible film of a polishing head according to an embodiment of the present application;

[0028] Figure 3 FIG. 3 is a structural diagram of a geometric model according to an embodiment of the present application;

[0029] Figure 4 FIG. 4 is a structural diagram of a flexible film according to an embodiment of the present application;

[0030] Figure 5 FIG. 5 is a structural diagram of a support according to an embodiment of the present application;

[0031] Figure 6 FIG. 6 is a schematic diagram of a geometric model after adding boundary conditions and pressure loads according to an embodiment of the present application;

[0032] Figure 7 is a deformation cloud diagram of a polished geometric model according to an embodiment of the present application;

[0033] Figure 8 is a curve diagram of a deformation variable of a surface to be polished according to an embodiment of the present application;

[0034] Figure 9 is a structural diagram of a geometric model after optimization of a first gap according to an embodiment of the present application;

[0035] Figure 10 is a structural diagram of a geometric model after addition of boundary conditions, pressure load and optimization of a first gap according to an embodiment of the present application;

[0036] Figure 11 is a deformation cloud diagram of a polished geometric model after optimization of a first gap according to an embodiment of the present application;

[0037] Figure 12 is a curve diagram of a deformation variable of a surface to be polished after optimization of a first gap according to an embodiment of the present application;

[0038] Figure 13 is a comparison diagram of deformation variables before and after optimization of a first gap according to an embodiment of the present application;

[0039] Figure 14 is a structural block diagram of a simulation and optimization device of a polishing head flexible film according to an embodiment of the present application;

[0040] Figure 15 is a hardware structural diagram of a computer device according to an embodiment of the present application.

[0041] FIG. 11 is a structural diagram of a flexible film according to an embodiment of the present application.

[0042] 200, wafer; 300, polishing pad. DETAILED DESCRIPTION

[0043] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. According to the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0044] The chemical mechanical polishing device generally comprises a polishing head, a polishing pad, a worktable bearing the polishing pad, and a polishing liquid supply device. The polishing head comprises a bearing device, a suction device, a multi-zone pressure control device, a flexible film, and a retaining ring. The suction device, the pressure control device, the flexible film, and the retaining ring are all connected with the bearing device.

[0045] During the operation of the chemical mechanical polishing device, the wafer is first adsorbed by the suction device to the side surface of the flexible film facing the polishing pad, and then the wafer is pressed on the rotating polishing pad by the multi-zone pressure control device with a certain pressure. The polishing liquid supply device sprays the polishing liquid composed of sub-micron or nanometer abrasive particles and chemical solution to the surface of the polishing pad, so that the polishing liquid flows between the wafer and the polishing pad and chemically reacts with the material on the surface of the wafer, converting the insoluble substances into soluble substances or softening the substances with high hardness. Then, the chemical reaction products formed on the surface of the wafer are removed by the mechanical action of the abrasive particles, so as to achieve the purpose of planarization in the alternating process of chemical corrosion and mechanical grinding.

[0046] The structural design of the polishing head affects the polishing quality. Specifically, the multi-zone pressure control device can dynamically adjust the wafer surface pressure distribution to improve the removal uniformity; the flexible film compensates for the wafer warpage through adaptive deformation to reduce the risk of surface defects; and the speed matching strategy of the polishing head and the polishing pad can optimize the interfacial shear force distribution, thereby simultaneously improving the polishing efficiency and the surface quality.

[0047] However, during the chemical mechanical polishing process, the flatness of the wafer surface is difficult to achieve the desired accuracy, especially at the edge of the wafer, which is prone to over-polishing or under-polishing problems. Moreover, the larger the diameter of the wafer, the more serious the edge over-polishing or under-polishing problem.

[0048] The deformation problem in the wafer polishing process can be improved by optimizing the structural design of the flexible film of the polishing head, thereby optimizing the polishing quality. However, as described in the background art, the optimization process of the traditional polishing head flexible film needs to be designed, produced, and then verified by process, so as to confirm the design and development cycle, which is long and costly.

[0049] Therefore, the polishing head flexible film simulation optimization method, device, equipment, medium and product are provided, the performance of the designed flexible film structure is verified through the simulation mode, and production is performed after verification, so that the research and development cycle is greatly shortened and the research and development cost is greatly reduced.

[0050] According to the embodiment of the present application, a polishing head flexible film simulation optimization method is provided, and it should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0051] A polishing head flexible film simulation optimization method is provided in the embodiment, which can be used for a polishing head flexible film simulation optimization device, and the polishing head flexible film simulation optimization device can be a tablet computer or a computer device, etc. Figure 1 It is a flowchart of a polishing head flexible film simulation optimization method according to the embodiment of the present application, as shown in Figure 1 The method comprises the following steps:

[0052] In step S101, the geometric model of the polishing head polishing wafer is obtained.

[0053] The geometric model comprises a bearing device of the polishing head, a flexible film of the polishing head, a wafer adsorbed on the flexible film, and a polishing pad in contact with the surface to be polished of the wafer, and the bearing device is connected with the flexible film.

[0054] Specifically, the designer can determine the related sizes of the components (such as the bearing device, the flexible film, the wafer and the polishing pad) required for the polishing head polishing wafer according to the process requirements and experience, and then the geometric model of the overall structure of the polishing head polishing wafer can be constructed through the modeling tool SpaceClaim Direct Modeler (SCDM) in the finite element analysis software (ANSYS), and the polishing head flexible film simulation optimization device obtains the geometric model from SCDM based on the operation of the user.

[0055] For example, the designer can also construct the geometric model through the modeling software such as SolidWorks, so that the polishing head flexible film simulation optimization device obtains the geometric model of the polishing head polishing wafer.

[0056] In step S102, the geometric model is loaded into the finite element analysis model for simulation analysis, and the deformation amount of the surface to be polished under the preset pressure is determined.

[0057] Specifically, the deformation amount can refer to the amount of change in shape or size of the object under the action of external force, which describes the deformation degree of the object under the action of external force. The deformation amount of the polishing surface under the preset pressure can refer to the offset amount of the polishing surface relative to the initial position (the position before polishing). The preset pressure can include the pressure of each sub-zone (chamber), and the preset pressure can be determined by the designer and input into the simulation optimization device, so that the simulation optimization device can obtain the preset pressure.

[0058] For example, the finite element analysis model can be ANSYS, a finite element analysis software. After obtaining the geometric model, the simulation optimization device can import the geometric model into the finite element analysis software, and then perform a series of operations such as pre-processing (defining material properties, meshing and applying loads), solving and post-processing in the finite element analysis software, simulate the actual polishing process, and thus obtain the deformation amount of the polishing surface under the preset pressure.

[0059] In step S103, the size of the flexible film is optimized according to the deformation amount of the polishing surface, to obtain a target flexible film.

[0060] The target flexible film can refer to a flexible film that makes the deformation amount of the polishing surface under the preset pressure meet the processing requirements. When the uniformity of the deformation amount reaches a preset uniformity, it can be determined that the deformation amount of the polishing surface meets the processing requirements. The uniformity of the deformation amount can be represented by a standard deviation, and the smaller the standard deviation, the better the uniformity. The preset uniformity can be determined by the designer and configured in the simulation optimization device.

[0061] Specifically, after obtaining the deformation amount of the polishing surface, the size of the flexible film can be reduced (or increased) based on the deformation amount gradient, and a new deformation amount is simulated according to the newly determined size of the flexible film. The flexible film that makes the deformation amount of the polishing surface under the preset pressure meet the processing requirements is determined as the target flexible film.

[0062] The simulation optimization method of the polishing head flexible film provided in this embodiment loads the geometric model of the polishing head polishing wafer to a finite element analysis model for simulation analysis after obtaining the geometric model, determines the deformation amount of the polishing surface under the preset pressure, and then optimizes the size of the flexible film according to the deformation amount of the polishing surface to obtain a target flexible film. This embodiment verifies the performance of the designed flexible film structure by simulation, and optimizes the flexible film structure according to the simulation structure. After obtaining the target flexible film, production is carried out. This not only shortens the research and development cycle and reduces the research and development cost, but also improves the flexibility of the optimized design.

[0063] In this embodiment, another simulation optimization method of the polishing head flexible film is provided, which can be used in the simulation optimization device of the polishing head flexible film described above, Figure 2is a flowchart of another simulation optimization method of a flexible film of a polishing head according to an embodiment of the present application, as shown in Figure 2 The method comprises the following steps:

[0064] In step S201, a geometric model of the polishing head polishing a wafer is obtained.

[0065] Specifically, as shown in Figure 3 The geometric model includes the flexible film 110, the carrier device 120, the wafer 200, and the polishing pad 300.

[0066] For example, as shown in Figure 3 and Figure 4 The flexible film 110 includes a bottom plate part 111 for contacting the wafer 200, a circular ring-shaped edge side wall 112, and a support part 113. The edge side wall 112 includes a first upright part 1121 extending upward along the edge of the bottom plate part 111 and a first extension part 1122 extending horizontally inward from the upper end of the first upright part 1121. The end of the first extension part 1122 away from the first upright part 1121 is connected to the carrier device 120. The inner side of the intersection of the bottom plate part 111 and the first upright part 1121 is provided with a first groove part 1111. The inner side of the intersection of the first upright part 1121 and the first extension part 1122 is provided with a second groove part 1121a.

[0067] As shown in Figure 3 and Figure 5 The support part 113 includes a second upright part 1131, a first protruding part 1132 extending outward from the lower end of the second upright part 1131, and a second protruding part 1133 extending outward from the upper end of the second upright part 1131. The first protruding part 1132 is located in the first groove part 1111, and the second protruding part 1133 is located in the second groove part 1121a. That is, the support part 113 is clamped and fixed to the inner side of the edge side wall 112 through the two protruding parts, enhancing the rigidity of the first upright part 1121.

[0068] Further, as shown in Figure 4 The flexible film 110 further includes a bending part 114 extending outward from the upper end of the first upright part 1121, a second extension part 115 extending horizontally inward from the upper end of the bending part 114, and an inner side wall 116 arranged adjacent to the edge side wall 112 concentrically. The end of the inner side wall 116 away from the bottom plate part 111 is provided with a third extension part 117 extending horizontally inward.

[0069] The second extension part 115 is connected to the bearing device 120 away from one end of the bending part 114, and the third extension part 117 is connected to the bearing device 120 away from one end of the inner side wall 116. The flexible film 110 and the bearing device 120 cooperate to form a plurality of pressure-adjustable chambers. For example, the space surrounded by the second extension part 115, the bending part 114, the first extension part 1122 and the bearing device 120 forms a first chamber 101, the space surrounded by the first extension part 1122, the first upright part 1121, the bottom plate part 111, the inner side wall 116, the third extension part 117 and the bearing device 120 forms a second chamber 102, and the space surrounded by the third extension part 117, the inner side wall 116, the bottom plate part 111, the bearing device 120 and other inner side walls not shown in the figure forms a third chamber 103.

[0070] As shown in the example, Figure 3 The geometric module can further include a holding ring 130 of the polishing head.

[0071] In one example, the thickness of the bottom plate part 111 can be controlled within 0.8mm to 1.2mm, for example, the thickness of the bottom plate part 111 can be 0.8mm, 0.9mm, 1mm, 1.15mm or 1.2mm, etc.

[0072] The thickness of the first upright part 1121 can be controlled within 3.5mm to 4.0mm, for example, the thickness of the first upright part 1121 can be 3.5mm, 3.6mm, 3.8mm, 3.95mm or 4.0mm, etc.

[0073] The edge thickness corresponding to the first recess part 1111 can be controlled within 1.5mm to 2.1mm, for example, the edge thickness corresponding to the first recess part 1111 can be 1.5mm, 1.6mm, 1.8mm, 2.0mm or 2.1mm, etc.

[0074] Step S202, load the geometric model into the finite element analysis model for simulation analysis to determine the deformation amount of the surface to be polished under the preset pressure.

[0075] Specifically, the above step S202 includes:

[0076] Step S2021, the geometric model is meshed by the meshing unit of the finite element analysis model to obtain a first model.

[0077] Specifically, as shown in the example, Figure 3After the geometric model is shown, the geometric model can be imported into the finite element analysis software Workbench, and then the geometric model is meshed by meshing units to discretize the continuous geometric model into a finite number of elements. The elements are connected by nodes to form a finite element mesh. The geometric model after meshing is the first model, and the static structure module is selected when the finite element analysis software Workbench is opened.

[0078] In some embodiments, the flexible film is a rubber material, and the meshing of the geometric model by the meshing units includes: meshing the geometric model by the meshing units using a mesh self-adaptive method.

[0079] Specifically, when the flexible film of the polishing head is a rubber material (which belongs to a nonlinear material), the simulation calculation needs to open the large deformation switch, and during the calculation process, due to large deformation, negative volume mesh is easily generated, which leads to calculation divergence. The mesh self-adaptive method is used to divide the mesh, that is, the mesh is automatically re-divided during the calculation process, which can avoid the generation of negative volume mesh, thereby reducing the trial and error cost of the calculation mesh and improving the calculation efficiency.

[0080] For example, the meshing unit activates the nonlinear adaptive region (Nonlinear Adaptive Region), and before the material setting unit of the finite element analysis model adds the material attribute parameters to the first model, the method further includes: when the skewness of the mesh is greater than 0.9, the geometric model is re-meshed, and the first model is updated.

[0081] The skewness is a quantitative index for measuring the degree of deviation of the shape of the finite element mesh element from the ideal shape, and is one of the standards for evaluating the quality of the mesh. The numerical range of the skewness is usually 0-1. The closer the skewness is to 0, the more ideal the shape of the mesh element is, and the closer the skewness is to 1, the more serious the distortion of the shape of the mesh element is.

[0082] In this embodiment, when the skewness is greater than 0.9 during the calculation process, the mesh is automatically re-divided, which can ensure that the calculation is completed smoothly.

[0083] Step S2022, adding material attribute parameters to the first model by the material setting unit of the finite element analysis model to obtain a second model.

[0084] The material attribute parameters include the material type and attribute parameters of each component in the geometric model, and the attribute parameters are used to reflect the mechanical or thermal properties of the material.

[0085] For example, the property parameters include density, elastic modulus, Poisson's ratio, and yield strength, and the material types corresponding to different components can be shown in Table 1.

[0086] Specifically, the material property parameters can be input into the simulation optimization device by the designer, so that the simulation optimization device obtains the material property parameters and configures the material property parameters to corresponding components in the first model, thereby obtaining the second model.

[0087] Table 1 Material types corresponding to different components Step S2023: Add boundary conditions and pressure loads to the second model through the load processing unit of the finite element analysis model to obtain a third model.

[0088] Specifically, after obtaining the second model, define friction contact as the boundary condition for the contact between different components and apply load constraints to obtain the third model. The second model with added boundary conditions and pressure loads is the third model. The third model can be Figure 6 shown.

[0089] The pressure load can be determined by the designer and input into the simulation optimization device. For example, the pressure load of the first chamber 101 can be 5.5512e-002MPa, the pressure load of the second chamber 102 can be 3.1005e-002MPa, and the pressure load of the third chamber 103 can be 3.1694e-002MPa.

[0090] Step S2024 , performing solution analysis on the third model by using the solver and post-processing unit of the finite element analysis model to obtain the deformation of the surface to be polished under the preset pressure.

[0091] Specifically, after obtaining the third model, the solver can be used to solve the third model, and the results obtained by post-processing analysis can be obtained. Figure 7 The deformation cloud map of the polished geometric model shown in the figure and Figure 8 The deformation of each position point on the surface to be polished is shown.

[0092] Step S203 : optimizing the size of the first protrusion and / or the first groove according to the deformation of the polishing surface, so that the first gap is updated to the second gap.

[0093] The first gap is the distance between the surfaces of one side of the first protrusion and the first groove where the surfaces are close to each other, and the second gap is larger than the first gap.

[0094] Specifically, the inventors have found through research that by optimizing the size of the first protruding part and / or the first recessed part, increasing the distance between the side surfaces of the first protruding part and the second recessed part that are close to each other is more conducive to the flow of gas in the chamber, plays a role in buffering the downward pressure, improves the uniformity of the downward pressure at the edge, and thus ensures the deformation consistency of the polished surface.

[0095] For example, the step S203 includes a step a1 and a step a2.

[0096] The step a1 determines whether the uniformity of the deformation amount of the surface to be polished reaches a preset uniformity.

[0097] Specifically, after obtaining the deformation amount of the surface to be polished, the variance (or standard deviation) can be calculated, and when the variance (or standard deviation) is less than a preset value, it can be determined that the uniformity of the deformation amount of the surface to be polished reaches the preset uniformity.

[0098] In some embodiments, a standard deformation amount curve can be configured in advance, which represents that the uniformity of the deformation amount reaches the preset uniformity. After obtaining the deformation amount curve of the surface to be polished as shown in Figure 8 , the offset between the deformation amount curve and the standard deformation amount curve can be compared, and if the offset is less than a preset offset, it can be determined that the uniformity of the deformation amount of the surface to be polished reaches the preset uniformity.

[0099] The step a2 optimizes the size of the first protruding part and / or the first recessed part when the uniformity of the deformation amount of the surface to be polished does not reach the preset uniformity, updates the first gap to a second gap, and updates the wafer to a wafer that has not been polished.

[0100] Specifically, when the uniformity does not reach the preset uniformity, the first gap can be increased by cutting the side of the first protruding part close to the first recessed part and / or cutting the side surface of the first recessed part close to the first protruding part, the increased first gap is the second gap, and the wafer is reset. At this time, the geometric model can be as shown in Figure 9 .

[0101] After optimizing the geometric model, return to the step of loading the geometric model to the finite element analysis model for simulation analysis to determine the deformation amount of the surface to be polished under a preset pressure (i.e., step S202), and redetermine the deformation amount of the surface to be polished until the uniformity of the deformation amount of the surface to be polished reaches the preset uniformity. When the preset uniformity is reached, the flexible film in the geometric model is the target flexible film.

[0102] For example, after obtaining the geometric model as shown in Figure 9 , the schematic diagram of the third model obtained by re-executing the step S202 can be as shown in Figure 10 , based on Figure 9The obtained deformation cloud map can be Figure 11 As shown, based on Figure 9 The deformation of the surface to be polished can be obtained as follows Figure 12 As shown in the figure, the comparison of deformation before and after optimization can be shown as Figure 13 As shown, from Figure 13 It can be seen that after optimizing the first gap, the deformation of the polished surface of the wafer changes.

[0103] In this embodiment, by optimizing the gap between the first groove portion and the first protrusion portion, more gas can be allowed to enter, thereby buffering the downward pressure, thereby making the downward pressure at the edge of the wafer more uniform, thereby improving the uniformity at the edge of the wafer.

[0104] This embodiment also provides a simulation and optimization device for a flexible membrane in a polishing head. This device is used to implement the above-mentioned embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0105] This embodiment provides a simulation optimization device for a flexible film of a polishing head, such as Figure 14 As shown, including:

[0106] An acquisition module 1401 is configured to acquire a geometric model of a polishing head polishing a wafer, wherein the geometric model includes a supporting device of the polishing head, a flexible membrane of the polishing head, a wafer adsorbed on the flexible membrane, and a polishing pad in contact with a surface to be polished of the wafer, wherein the supporting device is connected to the flexible membrane;

[0107] A simulation analysis module 1402 is used to load the geometric model into a finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under a preset pressure;

[0108] The optimization module 1403 is used to optimize the size of the flexible film according to the deformation of the surface to be polished to obtain a target flexible film.

[0109] In some optional embodiments, the flexible film comprises a bottom plate part for contacting the wafer, a circular edge side wall, and a support part, the edge side wall comprises a first upright part extending upward along an edge of the bottom plate part and a first extension part extending horizontally inward from an upper end of the first upright part, a distal end of the first extension part away from the first upright part is connected with the bearing device, an inner side of a joint of the bottom plate part and the first upright part is provided with a first groove part, an inner side of a joint of the first upright part and the first extension part is provided with a second groove part, the support part comprises a second upright part, a first protrusion part extending outward from a lower end of the second upright part, and a second protrusion part extending outward from an upper end of the second upright part, the first protrusion part is located in the first groove part, and the second protrusion part is located in the second groove part;

[0110] The optimization module 1403 comprises:

[0111] An optimization unit is configured to optimize the size of the first protrusion part and / or the first groove part according to the deformation of the polishing surface, so as to update the first gap to the second gap, wherein the first gap is the distance between the side surfaces of the first protrusion part and the first groove part close to each other, and the second gap is greater than the first gap.

[0112] In some optional embodiments, the optimization unit comprises:

[0113] A first determination subunit is configured to determine whether the uniformity of the deformation of the surface to be polished reaches the preset uniformity.

[0114] A first optimization subunit is configured to optimize the size of the first protrusion part and / or the first groove part so as to update the first gap to the second gap, and update the wafer to the wafer that has not been polished, when the uniformity of the deformation of the surface to be polished does not reach the preset uniformity.

[0115] The device further comprises a return module configured to return to the step of loading the geometric model to the finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under the preset pressure, until the uniformity of the deformation of the surface to be polished reaches the preset uniformity.

[0116] In some optional embodiments, the simulation analysis module 1402 comprises:

[0117] A division unit is configured to perform mesh division on the geometric model by a mesh division unit of the finite element analysis model to obtain a first model.

[0118] A setting unit is configured to add material attribute parameters to the first model by a material setting unit of the finite element analysis model to obtain a second model.

[0119] An adding unit is configured to add boundary conditions and pressure loads to the second model by a load processing unit of the finite element analysis model to obtain a third model.

[0120] The solution analysis unit is used to solve and analyze the third model through the solver and post-processing unit of the finite element analysis model to obtain the deformation of the surface to be polished under a preset pressure.

[0121] In some optional embodiments, the flexible membrane is made of rubber material, and the dividing unit includes:

[0122] The sub-unit division is used to divide the geometric model into grids by mesh division units and adopt the mesh adaptive method.

[0123] In some optional embodiments, the grid division unit activates the nonlinear adaptive region, and the apparatus further comprises:

[0124] The updating module is used to re-mesh the geometric model and update the first model when the skewness of the mesh is greater than 0.9.

[0125] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0126] The simulation optimization device for the flexible membrane of the polishing head in this embodiment is presented in the form of a functional unit, where the unit refers to an application-specific integrated circuit (ASIC) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0127] The embodiment of the present invention also provides a computer device, such as Figure 15 As shown, the computer device includes: one or more processors 1510, a memory 1520, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components utilize different buses to communicate with each other and can be installed on a common motherboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 15 A processor 1510 is taken as an example.

[0128] The processor 1510 can be a central processing unit, a network processing unit, or a combination thereof. The processor 1510 can further include a hardware chip. The hardware chip can be an application specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device can be a complex programmable logic device, a field programmable logic device, a general array logic, or any combination thereof.

[0129] The memory 1520 stores instructions executable by the at least one processor 1510 to cause the at least one processor 1510 to perform the methods illustrated in the above embodiments.

[0130] The memory 1520 can include a program storage area and a data storage area. The program storage area can store an operating system, application programs required by at least one function, and the like. The data storage area can store data created according to the use of the computer device, and the like. In addition, the memory 1520 can include a high-speed random access memory, and can further include a non-transitory memory such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid state storage device. In some alternative embodiments, the memory 1520 can optionally include a memory disposed remotely from the processor 1510, which can be connected to the computer device through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0131] The memory 1520 can include a volatile memory such as a random access memory, and can also include a non-volatile memory such as a flash memory, a hard disk, or a solid state disk. The memory 1520 can further include a combination of the above-mentioned types of memories.

[0132] The computer device further includes an input device 1530 and an output device 1540. The processor 1510, the memory 1520, the input device 1530, and the output device 1540 can be connected by a bus or other means, Figure 15 For example, by a bus connection.

[0133] The input device 1530 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touchpad, a pointing stick, one or more mouse buttons, a trackball, a joystick, and the like. The output device 1540 can include a display device, an auxiliary lighting device (e.g., an LED), a tactile feedback device (e.g., a vibration motor), and the like. The display device includes, but is not limited to, a liquid crystal display, a light emitting diode, a display, and a plasma display. In some alternative embodiments, the display device can be a touch screen.

[0134] The embodiments of the present application also provide a computer readable storage medium, and the method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or stored in a remote storage medium or a non-transitory machine readable storage medium and downloaded to a local storage medium to be stored in the local storage medium through network downloading of computer code, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid state disk, etc. Further, the storage medium can also include a combination of the above-mentioned types of memories. It can be understood that the computer, processor, microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the method shown in the above embodiments.

[0135] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, the method and / or technical solutions according to the present application can be called or provided. Those skilled in the art should understand that the form of computer program instructions in a computer readable medium includes but is not limited to source files, executable files, installation package files, etc. Correspondingly, the way of executing computer program instructions by computer includes but is not limited to: the computer directly executes the instructions, or the computer executes the corresponding compiled program after compiling the instructions, or the computer reads and executes the instructions, or the computer executes the corresponding installed program after reading and installing the instructions. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0136] In the description of the present application, the description of the terms "the embodiment", "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0137] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0138] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations shall all fall within the scope defined by the present invention.

Claims

1. A simulation optimization method for a flexible membrane of a polishing head, characterized in that: The method comprises: Obtaining a geometric model of a polishing head polishing a wafer, wherein the geometric model includes a carrier of the polishing head, a flexible membrane of the polishing head, a wafer adsorbed on the flexible membrane, and a polishing pad in contact with a surface to be polished of the wafer, wherein the carrier is connected to the flexible membrane; Loading the geometric model into a finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under a preset pressure; According to the deformation amount of the surface to be polished, the size of the flexible film is optimized to obtain a target flexible film.

2. The method according to claim 1, characterized in that The flexible membrane includes a bottom plate portion for contacting the wafer, an annular edge side wall and a support member, the edge side wall including a first upright portion extending upwardly along the edge of the bottom plate portion and a first extension portion extending horizontally inwardly from the upper end of the first upright portion, the first extension portion being connected to the carrying device at one end away from the first upright portion, a first groove portion being provided on the inner side of the intersection of the bottom plate portion and the first upright portion, a second groove portion being provided on the inner side of the intersection of the first upright portion and the first extension, the support member including a second upright portion, a first protrusion extending outwardly from the lower end of the second upright portion and a second protrusion extending outwardly from the upper end of the second upright portion, the first protrusion being located in the first groove portion, and the second protrusion being located in the second groove portion; Optimizing the size of the flexible film according to the deformation of the polishing surface includes: According to the deformation of the polishing surface, the size of the first protrusion and / or the first groove is optimized so that the first gap is updated to the second gap, wherein the first gap is the distance between the side surfaces of the first protrusion and the first groove where they are close to each other, and the second gap is larger than the first gap.

3. The method according to claim 2, characterized in that Optimizing the size of the first protrusion and / or the first groove according to the deformation of the polishing surface so as to update the first gap to the second gap includes: Determining whether the uniformity of the deformation amount of the surface to be polished reaches a preset uniformity; When the uniformity of the deformation amount of the surface to be polished does not reach the preset uniformity, optimizing the size of the first protrusion and / or the first groove, updating the first gap to the second gap, and updating the wafer in the geometric model to an unpolished wafer; The method further includes: returning to the step of loading the geometric model into a finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under a preset pressure until the uniformity of the deformation of the surface to be polished reaches the preset uniformity.

4. The method according to any one of claims 1 to 3, characterized in that The step of loading the geometric model into a finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under a preset pressure includes: Meshing the geometric model using a meshing unit of the finite element analysis model to obtain a first model; Adding material property parameters to the first model through the material setting unit of the finite element analysis model to obtain a second model; Adding boundary conditions and pressure loads to the second model through the load processing unit of the finite element analysis model to obtain a third model; The third model is solved and analyzed by the solver and post-processing unit of the finite element analysis model to obtain the deformation of the surface to be polished under a preset pressure.

5. The method according to claim 4, characterized in that The flexible membrane is made of rubber material, and meshing the geometric model using a meshing unit of the finite element analysis model includes: The geometric model is meshed by using the mesh division unit and a mesh adaptive method.

6. The method according to claim 4, characterized in that The meshing unit activates a nonlinear adaptive region, and before adding material property parameters to the first model through the material setting unit of the finite element analysis model, the method further includes: When the skewness of the grid is greater than 0.9, the geometric model is re-grid-divided and the first model is updated.

7. A simulation optimization device for a flexible film of a polishing head, characterized in that: The device comprises: an acquisition module, configured to acquire a geometric model of a wafer polished by a polishing head, wherein the geometric model includes a carrying device of the polishing head, a flexible membrane of the polishing head, a wafer adsorbed on the flexible membrane, and a polishing pad in contact with a surface to be polished of the wafer, wherein the carrying device is connected to the flexible membrane; A simulation analysis module, configured to load the geometric model into a finite element analysis model for simulation analysis to determine the deformation of the surface to be polished under a preset pressure; The optimization module is used to optimize the size of the flexible film according to the deformation of the surface to be polished to obtain a target flexible film.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the simulation optimization method for the flexible membrane of the polishing head according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the simulation optimization method for the flexible membrane of a polishing head according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the simulation optimization method for a flexible membrane of a polishing head according to any one of claims 1 to 6.

Images