Design method for topological variable-density lattice of optical machine alignment bracket

Abstract

The invention discloses a topology variable density lattice design method for an optical machine alignment bracket. The design method comprises the following steps: constructing an initial three-dimensional model of the ray machine alignment bracket, and carrying out topological optimization of maximum frequency on the model to obtain a three-dimensional model of the ray machine alignment bracket after topological optimization; aiming at the three-dimensional model after topological optimization of the ray machine alignment bracket, carrying out maximum frequency lattice lattice structure design to obtain a maximum frequency lattice lattice structure; and according to the strain energy density of the ray machine alignment bracket, filling the topological optimized three-dimensional model of the ray machine alignment bracket with a maximum frequency lattice lattice structure. According to the design method disclosed by the invention, through topological optimization and lattice dot matrix filling design, the inherent frequency of the ray machine alignment bracket is remarkably improved and reaches 2000Hz or above. The optical machine alignment bracket with high inherent frequency is beneficial to reducing the influence of vibration on the precision of the photoetching machine, so that the precision of chip manufacturing is improved.

Description

Technical Field

[0001] The invention relates to a photolithography machine parts manufacturing technology, and in particular to a photomechanical alignment bracket topology variable density lattice design method. Background Art

[0002] The lithography machine is a very critical equipment in the semiconductor industry. The alignment machine is its core component, which is responsible for accurately aligning the pattern in the lithography process to ensure the accuracy of chip manufacturing. This component needs to work at high precision and high speed and is very sensitive to vibration, because any tiny vibration may affect the final manufacturing result.

[0003] The alignment machine is based on an optical machine alignment bracket, which is a mechanical structure used to support and fix the alignment machine. Its design and performance directly affect the stability and accuracy of the alignment machine. The optical machine alignment bracket needs to have sufficient rigidity and appropriate natural frequency to reduce the impact of vibration on the manufacturing process.

[0004] In short, the alignment optical machine is a device that performs precise alignment tasks, and the optical machine alignment bracket is a supporting structure that ensures that the device can work stably and accurately.

[0005] In order to improve the performance of lithography machines, high modality and lightweight structural design are key. Topology optimization technology achieves the design of high-performance lightweight structures by finding the best material layout based on finite element analysis to meet design constraints while maximizing or minimizing design goals. In addition, lattice filling structures also show their advantages in design due to their high specific stiffness, high thermal resistance, and high damping.

[0006] The main problems at present are:

[0007] Problem 1: The existing optical-mechanical alignment bracket has a low natural frequency and is very sensitive to external vibrations, which affects the stability and quality of the photolithography process. Vibrations can cause inaccurate pattern transfer, which in turn affects chip performance.

[0008] Problem 2: Due to the large mass of the optomechanical alignment bracket, the inertia effect is significant, making precise control difficult, especially in the photolithography process that requires extremely high precision. This inaccurate alignment will affect the correct replication of tiny features on the wafer, which in turn affects product quality. Summary of the invention

[0009] The purpose of the present invention is to provide a topological variable density lattice design method for an optomechanical alignment bracket. In this design method, the natural frequency of the optomechanical alignment bracket is significantly improved through topological optimization and lattice point filling design, thereby improving the accuracy of chip manufacturing by a lithography machine.

[0010] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0011] A method for designing a topological variable density lattice of an optical-mechanical alignment bracket, the design method comprising:

[0012] Constructing an initial three-dimensional model of the optomechanical alignment bracket, and performing topological optimization of the model to maximize the frequency, thereby obtaining a topologically optimized three-dimensional model of the optomechanical alignment bracket;

[0013] For the topologically optimized three-dimensional model of the optical-mechanical alignment bracket, the maximum frequency lattice structure design is performed to obtain the maximum frequency lattice structure;

[0014] According to the strain energy density of the optomechanical alignment bracket, a maximum frequency lattice structure is filled into the topologically optimized three-dimensional model of the optomechanical alignment bracket.

[0015] Furthermore, the design method also includes:

[0016] When constructing an initial three-dimensional model of the optomechanical alignment bracket, a design area and a non-design area of ​​the optomechanical alignment bracket to be optimized are established using three-dimensional modeling software;

[0017] When performing topological optimization for maximizing frequency, the constructed initial three-dimensional model of the optomechanical alignment bracket is imported into the topological optimization software, and then the material properties of the optomechanical alignment bracket model are set, constraints and loads are applied to the optomechanical alignment bracket model, and the optomechanical alignment bracket model is topologically optimized with the maximizing frequency as the constraint, thereby obtaining a preliminary optimized optomechanical alignment bracket model, and the preliminary optimized optomechanical alignment bracket model is smoothed and continuously processed to eliminate irregular structures.

[0018] Furthermore, when performing topology optimization for maximizing frequency, the material properties of the optomechanical alignment bracket model are set to 316L stainless steel, the main optimization area of ​​the optomechanical alignment bracket model is set to the design area, and constraints and loads are applied to the non-design area.

[0019] Furthermore, when performing topology optimization for maximizing frequency, SIMP method topology optimization was selected, and the optimization goal was set to maintain maximum stiffness, and the mass was reduced by 30%, the frequency constraint was set to maximize frequency, and the thickness constraint was set to 10 mm.

[0020] Furthermore, the three-dimensional model after topological optimization of the optical-mechanical alignment bracket is subjected to a maximum frequency lattice structure design, and its specific implementation method includes:

[0021] Design the lattice structure for the optical-mechanical alignment bracket model, constrain and load the single cubic unit, and use the topology optimization software to perform topological simulation optimization on the cubic unit to obtain the optimized lattice structure model;

[0022] Using three-dimensional modeling software, the optimized lattice structure model is remodeled to obtain a maximum frequency lattice structure model;

[0023] The lattice structure model obtained after the remodeling is preprocessed, and the lattice structure model obtained after the remodeling is added to the model processing software to form a filling structure.

[0024] Furthermore, the optical-mechanical alignment bracket model is designed to design a lattice structure, constrain and load a single cubic unit, and use topology optimization software to perform topological simulation optimization on the cubic unit. The specific implementation method includes:

[0025] Draw a single cube CAD model;

[0026] Import the drawn single cube CAD model into the topology optimization software, add constraints and loads to the single cube CAD model, and add them by fixing the four bottom corners of the bottom surface of the single cube CAD model, applying three components of the same magnitude pointing to the body center at the four top corners of the top surface of the single cube CAD model and the geometric center of the four sides, and applying symmetry constraints on the XY, YZ, and XZ planes passing through the body center;

[0027] The single cube CAD model after adding constraints and force processing is subjected to topological optimization for maximizing frequency. The optimization quality target is set to 50% of the total volume of the design space, and the minimum thickness constraint is added to 2.5 mm for topological optimization.

[0028] Furthermore, the method of filling the three-dimensional model of the topology optimized optomechanical alignment bracket with a maximum frequency lattice structure according to the strain energy density of the optomechanical alignment bracket includes:

[0029] Preprocessing the topologically optimized three-dimensional model of the optical-mechanical alignment bracket, importing the topologically optimized three-dimensional model of the optical-mechanical alignment bracket into the finite element analysis software ANSYS, and after setting the conditions, performing finite element simulation and analysis on the topologically optimized three-dimensional model of the optical-mechanical alignment bracket to obtain the strain energy density data of the optical-mechanical alignment bracket;

[0030] Based on the strain energy density data of the optical-mechanical alignment bracket, lattice optimization was selected in ANSYSWORKBENCH of the finite element analysis software ANSYS to obtain the filling density based on the strain energy density, and the filling density range was set to 0.2 to 1;

[0031] Using model processing software, the optomechanical alignment bracket model is populated with a maximized frequency lattice structure according to strain energy density;

[0032] The optomechanical alignment bracket model filled with the lattice structure is preprocessed, and the preprocessed optomechanical alignment bracket model is imported into the finite element analysis software to verify the natural frequency of the optomechanical alignment bracket model.

[0033] Compared with the prior art, the design method of the present invention has the following beneficial effects:

[0034] 1) Through topology optimization and lattice filling design, the natural frequency of the optical-mechanical alignment bracket is significantly improved. The optical-mechanical alignment bracket with a high natural frequency helps to reduce the impact of vibration on the accuracy of the lithography machine, thereby improving the accuracy of chip manufacturing;

[0035] 2) Using topology optimization technology, according to the distribution of strain energy density of the optomechanical alignment bracket, it is decided which areas should be filled with the lattice structure. This achieves the lightweight of the optomechanical alignment bracket while ensuring structural strength and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of the optical-mechanical alignment bracket involved in the design method of the present invention;

[0037] Figure 2 Schematic diagram of the three-dimensional structure of the design area for the initial model of the optomechanical alignment bracket;

[0038] Figure 3 Schematic diagram of constraints and load processing for the optomechanical alignment bracket model;

[0039] Figure 4 Schematic diagram of the results of preliminary topology optimization of the initial model of the optomechanical alignment bracket;

[0040] Figure 5 This is a schematic diagram of the smoothing and continuous processing of the topologically optimized three-dimensional model of the optical-mechanical alignment bracket;

[0041] Figure 6 A schematic diagram of performing lattice structure constraint processing on the optical machine alignment bracket model;

[0042] Figure 7 Isometric view of the lattice structure optimization model that reduces the weight of the optomechanical alignment bracket model by 30%;

[0043] Figure 8 The strain energy density contour diagram of the designed optomechanical alignment bracket;

[0044] Fig. 9A schematic cross-sectional view of the optomechanical alignment support model after filling the variable density lattice structure;

[0045] Fig.10 The natural frequency results of the optomechanical alignment bracket model filled with the lattice structure are measured. DETAILED DESCRIPTION

[0046] The present invention will be further described below with specific embodiments:

[0047] This embodiment provides a method for designing a topological variable density lattice of an optomechanical alignment bracket. Figure 1 shown.

[0048] The design method of this embodiment includes the following steps S1 to S3.

[0049] S1, see Figure 2 In a computer, a three-dimensional model of the optomechanical alignment bracket is constructed using three-dimensional modeling software, and the constructed three-dimensional model is used as an initial three-dimensional model of the optomechanical alignment bracket; then, a topological optimization of maximizing frequency is performed on the constructed initial three-dimensional model of the optomechanical alignment bracket to obtain a topologically optimized three-dimensional model of the optomechanical alignment bracket, see Figure 4 The three-dimensional model after topology optimization is a three-dimensional model of the optomechanical alignment bracket with a large natural frequency.

[0050] S2, for the three-dimensional model of the optomechanical alignment bracket after topology optimization constructed in step S1, a maximum frequency lattice structure design is performed to obtain a maximum frequency lattice structure.

[0051] S3, filling the three-dimensional model of the optomechanical alignment bracket after topology optimization in step S1 with the maximized frequency lattice structure designed in step S2 according to the strain energy density of the optomechanical alignment bracket.

[0052] After the above steps S1 to S3, the optical-mechanical alignment bracket is further reduced in weight.

[0053] The step S1 specifically includes S11 to S12.

[0054] S11, see Figure 3 ,When constructing the initial three-dimensional model of the optomechanical alignment bracket, the design area and non-design area of ​​the optomechanical alignment bracket to be optimized are established using three-dimensional modeling software.

[0055] In this way, compared with the conventional design idea of ​​simply using the original structure as the design area, by performing spatial analysis on the external structure, the entire area available for design is obtained, and the design based on this helps to obtain a structure with better performance.

[0056] S12, when performing the topology optimization of maximizing the frequency, the constructed initial three-dimensional model of the optomechanical alignment bracket is imported into the existing topology optimization software, and then the material properties of the optomechanical alignment bracket model are set, constraints and loads are applied to the optomechanical alignment bracket model, and the optomechanical alignment bracket model is topologically optimized with the maximizing frequency as the constraint, so as to obtain the optomechanical alignment bracket model after preliminary optimization, and the optomechanical alignment bracket model after preliminary optimization is smoothed and continuously processed to eliminate irregular structures (such as Figure 5 Finally, a three-dimensional model of the optomechanical alignment bracket after topology optimization is obtained.

[0057] More specifically,

[0058] In this embodiment, the material property of the optomechanical alignment bracket model is set to 316L stainless steel material, the main optimization area of ​​the optomechanical alignment bracket model is set to the design area, and constraints and loads are applied to the non-design area.

[0059] It should be noted that during the optimization operation, the SIMP method topology optimization was selected, the optimization goal was set to "maintain maximum stiffness and reduce mass by 30%", the frequency constraint was set to "maximum frequency", the thickness constraint was set to 10 mm, and then the preliminary optimization was started.

[0060] It should be noted that after obtaining the preliminary topologically optimized optomechanical alignment bracket model, the optomechanical alignment bracket model is smoothed and coated, and finally a new topologically optimized optomechanical alignment bracket model with a regular structure is obtained.

[0061] The step S2 specifically includes S21 to S23.

[0062] S21, for the optomechanical alignment bracket model constructed in step S1, design a lattice structure, constrain and load process a single cubic unit, use topology optimization software to perform topological simulation optimization on the cubic unit, and obtain an optimized lattice structure model.

[0063] The step S21 specifically includes steps S211 to S213.

[0064] S211, draw a single cube CAD model.

[0065] S212, see Figure 6, import the single cube CAD model drawn in step S211 into the topology optimization software, add constraints and loads to the single cube CAD model, and add the four bottom corners of the bottom surface of the single cube CAD model, and add three components of the same magnitude pointing to the body center at the four top corners of the top surface of the single cube CAD model and the geometric center of the four sides, and apply symmetry constraints on the XY, YZ, and XZ planes passing through the body center. The lattice structure obtained by this constraint processing is easier to be formed by additive manufacturing.

[0066] S213, see Figure 7 , a single cube CAD model after adding constraints and force processing was subjected to topological optimization to maximize the frequency, and its optimization quality target was set to "50% of the total volume of the design space". A minimum thickness constraint of 2.5 mm was added, and topological optimization was performed to obtain the optimized lattice structure model.

[0067] S22, using three-dimensional modeling software, remodeling the lattice structure model optimized in step S21, so as to obtain a maximum frequency lattice structure model.

[0068] S23, preprocessing the lattice structure model obtained after the remodeling in step S22, adding the lattice structure model obtained after the remodeling in step S22 to the existing model processing software to form a filling structure.

[0069] Specifically, step S3 includes S31 to S34:

[0070] S31, preprocessing the topologically optimized three-dimensional model of the optomechanical alignment bracket constructed in step S1, importing the topologically optimized three-dimensional model of the optomechanical alignment bracket into the finite element analysis software ANSYS, and after setting conditions, performing finite element simulation and solution analysis on the topologically optimized three-dimensional model of the optomechanical alignment bracket, so as to obtain the strain energy density data of the optomechanical alignment bracket through analysis.

[0071] S32, see Figure 8 Based on the strain energy density data of the optomechanical alignment bracket obtained in S31, lattice optimization is selected in ANSYSWORKBENCH of the finite element analysis software ANSYS to obtain the filling density based on the strain energy density, and the filling density range is set to 0.2 to 1.

[0072] S33, see Fig. 9 , using the model processing software, the optical machine is aligned with the bracket model to fill the maximum frequency lattice structure obtained in step S2 according to the strain energy density; in this way, a high-performance variable density lattice is achieved under the working conditions.

[0073] S34, see Fig.10 , the optomechanical alignment bracket model filled with the lattice structure is preprocessed, and the preprocessed optomechanical alignment bracket model is imported into the finite element analysis software to verify the natural frequency of the optomechanical alignment bracket model.

[0074] The design method of this embodiment significantly improves the natural frequency of the optical-mechanical alignment bracket to more than 2000 Hz through topology optimization and lattice filling design. The optical-mechanical alignment bracket with a high natural frequency helps reduce the impact of vibration on the accuracy of the lithography machine, thereby improving the accuracy of chip manufacturing.

[0075] In addition, topology optimization technology is used to determine which areas to fill with the lattice structure based on the distribution of the strain energy density of the optomechanical alignment bracket. Areas with high strain energy density mean that these areas are more likely to deform when subjected to force, so more material is needed to provide additional stiffness and strength; while areas with low strain energy density can be filled with less material to reduce weight. In this embodiment, the lightweighting of the optomechanical alignment bracket is achieved while ensuring structural strength and performance. The weight reduction effect is significant, reaching 51.2%.

[0076] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for designing a topological variable density lattice of an optical-mechanical alignment bracket, characterized in that: The design method comprises: Constructing an initial three-dimensional model of the optomechanical alignment bracket, and performing topological optimization of the model to maximize the frequency, thereby obtaining a topologically optimized three-dimensional model of the optomechanical alignment bracket; For the topologically optimized three-dimensional model of the optical-mechanical alignment bracket, the maximum frequency lattice structure design is performed to obtain the maximum frequency lattice structure; According to the strain energy density of the optomechanical alignment bracket, a maximum frequency lattice structure is filled into the topologically optimized three-dimensional model of the optomechanical alignment bracket.

2. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 1, characterized in that: The design method further comprises: When constructing an initial three-dimensional model of the optomechanical alignment bracket, a design area and a non-design area of ​​the optomechanical alignment bracket to be optimized are established using three-dimensional modeling software; When performing topological optimization for maximizing frequency, the constructed initial three-dimensional model of the optomechanical alignment bracket is imported into the topological optimization software, and then the material properties of the optomechanical alignment bracket model are set, constraints and loads are applied to the optomechanical alignment bracket model, and the optomechanical alignment bracket model is topologically optimized with the maximizing frequency as the constraint, thereby obtaining a preliminary optimized optomechanical alignment bracket model, and the preliminary optimized optomechanical alignment bracket model is smoothed and continuously processed to eliminate irregular structures.

3. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 2, characterized in that: When performing topology optimization to maximize frequency, the material properties of the optomechanical alignment bracket model are set to 316L stainless steel, the main optimization area of ​​the optomechanical alignment bracket model is set to the design area, and constraints and loads are applied to the non-design area.

4. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 1, characterized in that: When performing topology optimization for maximizing frequency, SIMP topology optimization was selected, and the optimization goal was set to maintain maximum stiffness, and the mass was reduced by 30%. The frequency constraint was set to maximize frequency, and the thickness constraint was set to 10 mm.

5. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 1, characterized in that: The method for designing a maximizing frequency lattice structure for the topologically optimized three-dimensional model of the optical-mechanical alignment bracket includes: Design the lattice structure for the optical-mechanical alignment bracket model, constrain and load the single cubic unit, and use the topology optimization software to perform topological simulation optimization on the cubic unit to obtain the optimized lattice structure model; Using three-dimensional modeling software, the optimized lattice structure model is remodeled to obtain a maximum frequency lattice structure model; The lattice structure model obtained after the remodeling is preprocessed, and the lattice structure model obtained after the remodeling is added to the model processing software to form a filling structure.

6. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 1, characterized in that: The method of designing a lattice structure for the optical-mechanical alignment bracket model, constraining and loading a single cubic unit, and using topology optimization software to perform topological simulation optimization on the cubic unit includes: Draw a single cube CAD model; Import the drawn single cube CAD model into the topology optimization software, add constraints and loads to the single cube CAD model, and add them by fixing the four bottom corners of the bottom surface of the single cube CAD model, applying three components of the same magnitude pointing to the body center at the four top corners of the top surface of the single cube CAD model and the geometric center of the four sides, and applying symmetry constraints on the XY, YZ, and XZ planes passing through the body center; The single cube CAD model after adding constraints and force processing is subjected to topological optimization for maximizing frequency. The optimization quality target is set to 50% of the total volume of the design space, and the minimum thickness constraint is added to 2.5 mm for topological optimization.

7. The method for designing a topological variable density lattice of an optical-mechanical alignment bracket according to claim 1, characterized in that: The method of filling the three-dimensional model of the topology optimized optical-mechanical alignment bracket with a maximum frequency lattice structure according to the strain energy density of the optical-mechanical alignment bracket includes: Preprocessing the topologically optimized three-dimensional model of the optical-mechanical alignment bracket, importing the topologically optimized three-dimensional model of the optical-mechanical alignment bracket into the finite element analysis software ANSYS, and after setting the conditions, performing finite element simulation and analysis on the topologically optimized three-dimensional model of the optical-mechanical alignment bracket to obtain the strain energy density data of the optical-mechanical alignment bracket; Based on the strain energy density data of the optical-mechanical alignment bracket, lattice optimization was selected in ANSYSWORKBENCH of the finite element analysis software ANSYS to obtain the filling density based on the strain energy density, and the filling density range was set to 0.2 to 1; Using model processing software, the optomechanical alignment bracket model is populated with a maximized frequency lattice structure according to strain energy density; The optomechanical alignment bracket model filled with the lattice structure is preprocessed, and the preprocessed optomechanical alignment bracket model is imported into the finite element analysis software to verify the natural frequency of the optomechanical alignment bracket model.

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