A process window determination method and related device
By simulating the surface plasma lithography model and adjusting the exposure energy and air layer thickness, the problem of low efficiency in process window determination in the existing technology is solved, faster and more accurate process window determination is achieved, and experimental costs and time are saved.
Patent Information
- Application Number
- CN202411584831.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2044-11-07
AI Technical Summary
In the prior art, the process window of a surface plasma lithography structure with an air layer is determined by manual experiments, which is inefficient and has high uncertainty, resulting in a waste of manpower and material resources.
By establishing a surface plasma lithography model and using simulation software to simulate the lithography process, the exposure energy and air layer thickness are adjusted, the line width and process window of the photoresist pattern are determined, reducing experimental dependence and improving accuracy.
It achieves faster and more accurate determination of the process window, saves materials and time, improves the determination rate and accuracy of the process window, and enhances the tolerance to fluctuations in process parameters.
Smart Images
Figure CN119165745B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductors, and in particular to a process window determination method and related devices. Background Art
[0002] With the development of near-field optics, lithography methods that break the diffraction limit, represented by surface plasmons (SPs), have gradually become feasible. Using surface plasmon lithography, large wavelengths can produce lithographic images much smaller than the wavelength of the light source. However, this is equivalent to contact lithography and is inefficient, leading to the development of surface plasmon lithography structures with air layers.
[0003] In a surface plasma lithography structure with an air layer, the mask layer and photoresist layer are separated by the air layer, which is equivalent to near-field projection lithography. This allows the wafer mounted on the workpiece stage to be moved to expose different areas of the wafer, just like traditional projection lithography, greatly improving work efficiency.
[0004] However, in related technologies, the process window for surface plasma lithography structures with air layers is typically determined through manual experiments. This requires manually constructing a lithography model and setting parameters such as exposure energy. This approach wastes significant manpower and resources, resulting in low efficiency due to the high uncertainty inherent in these experiments. Therefore, developing a suitable method for determining the process window has become an urgent technical challenge. Summary of the Invention
[0005] In view of this, the purpose of this application is to provide a process window determination method and related devices, which can determine the process window faster and more accurately through simulation, saving materials and time and improving the accuracy of the process window. The specific scheme is as follows:
[0006] In one aspect, the present application provides a method for determining a process window, comprising:
[0007] Step 101, establishing a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer, and a mask layer stacked in sequence;
[0008] Step 102, performing simulation using a surface plasma lithography model to determine a photoresist pattern after photolithography and a line width of the photoresist pattern;
[0009] Step 103, adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer, and repeatedly performing steps 101 to 102 to obtain a plurality of corresponding relationships among the exposure energy, the thickness of the air layer, and the line width of the photoresist pattern;
[0010] Step 104 : determining a process window corresponding to the mask layer based on the corresponding relationship and an allowable error range between the photoresist pattern and the mask layer.
[0011] Optionally, the method further includes:
[0012] Adjusting the pattern of the mask layer, and repeatedly performing steps 101 to 104 to determine a plurality of process windows; each process window corresponds to a pattern of the mask layer;
[0013] Based on the multiple process windows, a common process window corresponding to the multiple patterns of the mask layers is determined.
[0014] Optionally, the surface plasmon lithography model includes a spatial light intensity model and a photoresist model;
[0015] The step 102, performing simulation by a surface plasma lithography model to determine the photoresist pattern after lithography and the line width of the photoresist pattern, includes:
[0016] Performing surface plasma lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;
[0017] Based on the light intensity distribution, photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0018] Optionally, adjusting the exposure energy in the surface plasmon lithography model includes:
[0019] The light intensity of the incident light is adjusted in the spatial light intensity model; the light intensity has a corresponding relationship with the exposure energy.
[0020] Optionally, adjusting the exposure energy in the surface plasmon lithography model includes:
[0021] The exposure energy of the photoresist layer is adjusted in the photoresist model.
[0022] Optionally, performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer includes:
[0023] In a first simulation software, performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;
[0024] Based on the light intensity distribution, performing photoresist exposure and development simulation using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern, including:
[0025] In the second simulation software, based on the light intensity distribution, a photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0026] Optionally, adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer includes:
[0027] The exposure energy in the surface plasma lithography model is adjusted according to a first preset change amount, and the thickness of the air layer is adjusted according to a second preset change amount.
[0028] Optionally, the method further includes:
[0029] Adjusting the thickness of the metal layer, and repeating steps 101 to 106 to determine a process window at each thickness of the metal layer;
[0030] The thickness of the metal layer corresponding to the largest process window is determined as the optimal metal layer thickness of the surface plasma lithography structure.
[0031] The present application provides a process window determination device, comprising:
[0032] An establishing unit is used to establish a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer and a mask layer stacked in sequence;
[0033] A simulation unit, configured to perform simulation using a surface plasma lithography model to determine a photoresist pattern after photolithography and a line width of the photoresist pattern;
[0034] A control unit is used to adjust the exposure energy in the surface plasma lithography model and the thickness of the air layer to obtain a plurality of corresponding relationships among the exposure energies, the thickness of the air layer and the line width of the photoresist pattern; based on the corresponding relationship and the allowable error range between the photoresist pattern and the mask layer, the process window corresponding to the mask layer is determined.
[0035] In another aspect, an embodiment of the present application provides a computer device, comprising a processor and a memory:
[0036] The memory is used to store program code and transmit the program code to the processor;
[0037] The processor is configured to execute the method described above according to the instructions in the program code.
[0038] The present application provides a process window determination method and related apparatus, including step 101, establishing a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer, and a mask layer stacked in sequence; step 102, performing simulation using the surface plasma lithography model to determine a photoresist pattern after lithography and a line width of the photoresist pattern; step 103, adjusting the exposure energy and the thickness of the air layer in the surface plasma lithography model, and repeating steps 101 to 102 to obtain a correspondence between multiple exposure energies, air layer thicknesses, and line widths of the photoresist pattern; and step 104, determining a process window corresponding to the mask layer based on the correspondence and an allowable error range between the photoresist pattern and the mask layer. In summary, in this application, for a surface plasma lithography structure with an air layer, the specific lithography process of the structure is simulated, and multiple simulations are performed under different exposure energies and air layer thicknesses to obtain a process window corresponding to the mask layer. This process window can be determined faster and more accurately without the need for experimental results, saving materials and time, improving the determination rate and accuracy of the process window, and improving the tolerance to process parameter fluctuations of surface plasma lithography. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0040] Figure 1 A schematic diagram of a process window determination method provided in an embodiment of the present application is shown;
[0041] Figure 2 A schematic diagram of a surface plasmon lithography structure provided in an embodiment of the present application is shown;
[0042] Figure 3 A schematic diagram showing another method for determining a process window provided in an embodiment of the present application is shown;
[0043] Figure 4 A schematic diagram of a process window provided in an embodiment of the present application is shown;
[0044] Figure 5 A structural diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION
[0045] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.
[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.
[0047] Secondly, this application is described in detail with reference to schematic diagrams. When describing the embodiments of this application, for ease of explanation, cross-sectional views of device structures may be partially enlarged and not to scale. Furthermore, these schematic diagrams are merely illustrative and should not limit the scope of protection of this application. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.
[0048] For ease of understanding, a process window determination method and related devices provided in an embodiment of the present application are described in detail below with reference to the accompanying drawings.
[0049] refer to Figure 1 1 is a flow chart of a process window determination method provided in an embodiment of the present application. The method may include the following steps.
[0050] Step 101: establishing a surface plasmon lithography model corresponding to a surface plasmon lithography structure.
[0051] In an embodiment of the present application, a surface plasmon lithography structure may include a substrate layer, a photoresist (PR) layer, an air layer, a metal layer, an insulating layer, and a mask layer stacked in sequence. The substrate layer is used to provide support and may be, for example, a silicon substrate. The air layer is a layer containing air and may be tens of nanometers thick. The mask layer may be made of, for example, Cr. Under the action of incident light, the pattern of the mask layer can be transferred to the photoresist layer.
[0052] The metal layer can be, for example, Au, Ag, or Al, and the insulating layer can be, for example, PMMA. The metal layer has a negative dielectric constant under electromagnetic waves of a specific wavelength band, while the insulating layer has a positive dielectric constant. One of the conditions for the existence of surface plasmons is that the two materials have opposite dielectric constants. Thus, surface plasmons can be generated within the two-layer film structure. Of course, the excitation of surface plasmons also requires that the electromagnetic waves be TM polarized light.
[0053] refer to Figure 2As shown, a schematic diagram of a surface plasma lithography structure provided by an embodiment of the present application may include a substrate layer 10, a silver layer 11, a photoresist layer 12, an air layer 13, a metal layer 14, an insulating layer 15, a mask layer 16 and a quartz layer 17 stacked in sequence. The incident light is incident from top to bottom, and the silver layer 11 is used to increase reflection. Figure 3 As shown, (a) shows a top view of the mask layer, including multiple lines.
[0054] In actual production, due to various reasons, the lithography machine will produce disturbances in exposure energy and focus value, causing the actual exposure energy and focus value to deviate from the set values. Among them, the deviation of exposure energy often comes from the stability of the light source, and the deviation of focus value often comes from the inherent deviation of the lens group and the mechanical deviation of focus position control.
[0055] The process window refers to the range of exposure energy and focus values allowed. Within this range, after the pattern on the mask layer is exposed, the error between the pattern on the photoresist layer and the pattern on the mask layer is within an acceptable range. For example, when the exposure energy is between 16 and 22 mj / cm 2 When the focus value is exposed within the range of -0.15 to +0.1um, the line width (Critical Dimension, CD) of the pattern in the photoresist layer is 135nm to 165nm, that is, the error value is within ±15nm (10% error is an acceptable range).
[0056] In a surface plasma lithography structure with an air layer, the air layer can be compared to the focus value in traditional projection lithography, and the focus value can be measured by the thickness of the air layer. At this time, the deviation of the exposure energy still comes from the stability of the light source, and the deviation of the air layer thickness comes from mechanical control.
[0057] Specifically, a simulation model corresponding to the surface plasma lithography structure may be established in the simulation software. The simulation model may be recorded as a surface plasma lithography model, so as to facilitate subsequent simulation analysis of the lithography process.
[0058] Step 102 , performing simulation using a surface plasma lithography model to determine the photoresist pattern after lithography and the line width of the photoresist pattern.
[0059] Specifically, the surface plasma lithography model can be used to simulate the lithography process, simulating the pattern formed by the photoresist layer under the action of the mask layer, that is, the photoresist pattern, thereby obtaining the photoresist pattern after lithography and the line width (line width) in the photoresist pattern.
[0060] Specifically, during the simulation process, the process of light passing through the surface plasma lithography structure is simulated, and the pattern formed by the photoresist layer under light illumination is simulated.
[0061] In one possible implementation, the surface plasmon lithography model includes a spatial light intensity model and a photoresist model; step 102, performing simulation using the surface plasmon lithography model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern, can specifically include performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer; based on the light intensity distribution, performing photoresist exposure and development simulation using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0062] Specifically, the surface plasmon lithography model can be divided into two independent models: a spatial light intensity model and a photoresist model. The film layer structure in the spatial light intensity model is identical to that of the surface plasmon lithography model. This model is primarily used to simulate the intensity distribution of light in the photoresist layer. Specifically, electromagnetic field simulation calculations can be performed based on the material, thickness, and refractive index properties of each film layer, as well as the intensity of the incident light entering the spatial light intensity model, to obtain the light intensity distribution in the photoresist layer.
[0063] In other words, the spatial light intensity model can be used to determine the intensity distribution of the light incident on the photoresist layer under the action of each film layer, thus eliminating the need for manual experiments. In addition, the light intensity data can be output for the light intensity distribution in the photoresist layer. Figure 3 As shown, (b) shows the light intensity distribution in the photoresist layer.
[0064] After determining the light intensity distribution in the photoresist layer, it is necessary to simulate the exposure of the photoresist layer under the light intensity distribution, that is, which part of the photoresist can be retained and which part of the photoresist is removed, so as to form a pattern in the photoresist layer that is consistent with the pattern of the mask layer.
[0065] The photoresist model can include only one photoresist layer or other layers beneath it. Specifically, the photoresist model can be simulated based on the light intensity distribution to obtain the photoresist pattern after photolithography. In this way, the line width of the photoresist pattern obtained after photolithography can be determined under certain conditions: incident light energy, air layer thickness, and mask layer pattern.
[0066] In summary, by separately simulating the light intensity distribution in the photoresist layer and the photoresist pattern formed under the light intensity distribution using the spatial light intensity model and the photoresist model, each simulation result can be made more accurate, thereby enabling a more precise simulation of the photolithography process.
[0067] In one possible implementation, surface plasmon lithography simulation is performed using a spatial light intensity model to determine the light intensity distribution of the photoresist layer. Specifically, in a first simulation software, surface plasmon lithography simulation is performed using the spatial light intensity model to determine the light intensity distribution of the photoresist layer. Based on the light intensity distribution, a photoresist exposure and development simulation is performed using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern. Specifically, in a second simulation software, based on the light intensity distribution, a photoresist exposure and development simulation is performed using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0068] Specifically, a spatial light intensity model corresponding to the surface plasmon lithography structure can be established in first simulation software. The first simulation software can include FDTD simulation software or RCWA simulation software. Of course, the first simulation software is not limited to the above software. As long as the first simulation software has the ability to simulate light intensity, that is, it can determine the light intensity distribution of the photoresist layer through electromagnetic field simulation methods. The spatial light intensity model is simulated using the first simulation software, and the light intensity distribution can be obtained after the simulation.
[0069] Specifically, a photoresist model can be established in the second simulation software. The second simulation software is used to simulate the pattern formed in the photoresist layer based on a certain light intensity distribution. The second simulation software includes Prolith simulation software or S-litho simulation software. Of course, the second simulation software is not limited to the above software. The first simulation software and the second simulation software can be installed on the same computer.
[0070] The light intensity distribution in the photoresist layer output by the first simulation software can be input into the second simulation software. Thus, the second simulation software can simulate the photoresist model based on the light intensity distribution to obtain the photoresist pattern after photolithography. In addition, the line width and period (Pitch) of the photoresist pattern can also be output in the second simulation software. Figure 3 As shown, (c) shows the photoresist pattern after photolithography, including three lines.
[0071] In this way, by combining the first and second simulation software, the process window corresponding to the mask layer can be determined by simulating the adjustment of exposure energy and air layer thickness, eliminating the need for experimental determination. This allows for faster and more accurate determination of the process window, saving materials and time, and improving the speed and accuracy of process window determination. Furthermore, process feasibility can be evaluated more quickly without the need for experimental testing, thereby improving process efficiency.
[0072] Step 103, adjusting the exposure energy and the thickness of the air layer in the surface plasma lithography model, repeating steps 101 to 102, and obtaining a plurality of corresponding relationships between exposure energies, thicknesses of the air layer and line widths of the photoresist pattern.
[0073] Specifically, to determine the process window below the mask layer, the exposure energy and air layer thickness in the surface plasmon lithography model can be adjusted. Each time the exposure energy or air layer thickness is adjusted, steps 101 to 102 are repeated to obtain the line width of the photoresist pattern corresponding to the exposure energy or air layer thickness. The air layer thickness can be directly modified in the first simulation software, and the exposure energy can be adjusted in either the first simulation software or the second simulation software.
[0074] For example, first fix the pattern of the mask layer, assuming that the pattern of the mask layer is a line pattern with CD = 90nm and Pitch = 180nm. Set the air layer thickness to 50nm and the exposure energy to 10mj / cm 2 Start with 0.1 mj / cm 2 As an interval, gradually increase to 18mj / cm 2 Correspondingly, the CD of the photoresist pattern under different exposure energies will be obtained. Assuming that 10% is the allowable error range, when the CD of the photoresist pattern is between 81nm and 99nm, the corresponding exposure energy is recorded.
[0075] The thickness of the air layer is set to 51 nm, and steps 101 to 105 are repeated. The thickness of the air layer is set to 52 nm, and steps 101 to 105 are repeated until sufficient data is obtained.
[0076] That is to say, the correspondence between multiple exposure energies, air layer thicknesses and line widths of photoresist patterns can be obtained, that is, under a set of exposure energies, air layer thicknesses and mask layer patterns, there is a corresponding line width of the pattern of the formed photoresist layer.
[0077] In a possible implementation, adjusting the exposure energy in the surface plasmon lithography model may specifically be adjusting the light intensity of the incident light in the spatial light intensity model; the light intensity and the exposure energy have a corresponding relationship.
[0078] Specifically, the intensity of the light incident on the surface plasmon lithography structure can be adjusted within the spatial light intensity model. The unit of light intensity is the square of the amplitude, which means adjusting the amplitude of the incident light. Different light intensities correspond to different exposure energies. Adjusting the intensity of the incident light within the spatial light intensity model effectively adjusts the exposure energy. By adjusting the incident light, a more accurate process window can be achieved.
[0079] In a possible implementation, adjusting the exposure energy in the surface plasmon lithography model may specifically be adjusting the exposure energy of the photoresist layer in the photoresist model.
[0080] Specifically, the exposure energy can also be adjusted within the photoresist model. Specifically, in the spatial light intensity model, the incident light intensity is set to the same value. The exposure energy level is then set within the photoresist model. Based on the set exposure energy, the photoresist model adjusts the light intensity distribution. This adjusted light intensity distribution is then applied to the photoresist model, outputting the line width of the photoresist pattern. This direct setting of the exposure energy level allows for more convenient adjustment, increasing flexibility in exposure energy adjustment.
[0081] In one possible implementation, adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer can be specifically adjusting the exposure energy in the surface plasma lithography model according to a first preset change amount and adjusting the thickness of the air layer according to a second preset change amount.
[0082] That is to say, each time the exposure energy is adjusted, the same amount of change can be increased or decreased, that is, the first preset amount of change. Each time the thickness of the air layer is adjusted, the same amount of change can be increased or decreased, that is, the second preset amount of change. This allows the line width size under the exposure energy or air layer thickness to be uniformly obtained, making the change of the independent variable in the corresponding relationship more balanced and the data more complete and sufficient.
[0083] Step 104 : determining the process window corresponding to the mask layer based on the corresponding relationship and the allowable error range between the photoresist pattern and the mask layer.
[0084] Specifically, the corresponding relationship can reflect the size of the line width of the photoresist layer formed under a certain exposure energy, air layer thickness and mask layer pattern. The allowable error range is the pre-set allowable line width difference between the photoresist pattern and the mask layer pattern, and will not affect the process production within the allowable error range.
[0085] Based on the allowable error range, the line width within the allowable error range can be selected from the corresponding relationship, and the exposure energy and air layer thickness corresponding to the line width can be used as the process window corresponding to the mask layer. Among them, the process window corresponding to the mask layer is the process window corresponding to the pattern of the mask layer. The process window can be represented by a coordinate diagram, refer to Figure 4 As shown, the horizontal axis can represent the thickness of the air layer, the vertical axis can represent the exposure energy, and the square box in the figure is the process window.
[0086] In summary, in this application, for a surface plasma lithography structure with an air layer, the specific lithography process of the structure is simulated, and multiple simulations are performed under different exposure energies and air layer thicknesses to obtain the process window corresponding to the mask layer. This does not require experimental acquisition, and the process window can be determined faster and more accurately, saving materials and time, improving the determination rate and accuracy of the process window, and improving the tolerance to process parameter fluctuations of surface plasma lithography.
[0087] In a possible implementation, the pattern of the mask layer may be adjusted, and steps 101 to 104 may be repeated to determine multiple process windows. Based on the multiple process windows, a common process window corresponding to the patterns of the multiple mask layers may be determined.
[0088] Specifically, the pattern changes of the mask layer can also be adjusted, for example, the line width or period of the mask layer can be adjusted. Each time the pattern of the mask layer changes, steps 101 to 104 are repeated to determine the corresponding process window under each mask layer, that is, each process window corresponds to a pattern of the mask layer.
[0089] For multiple process windows corresponding to multiple mask layer patterns, the overlapping parts of the multiple process windows can be used as a common process window. Within the common process window, the patterns of the multiple mask layers can obtain photoresist patterns within an acceptable error range.
[0090] In this way, the patterns of multiple mask layers are simulated through simulation, so that the common process window can be determined more quickly and accurately without manual experiments, which greatly saves experimental time and can more flexibly adjust the patterns of the mask layers.
[0091] In one possible implementation, the thickness of the metal layer can also be adjusted, and steps 101 to 104 can be repeated to determine the process window under the thickness of each metal layer; the thickness of the metal layer corresponding to the largest process window is determined as the optimal metal layer thickness of the surface plasma lithography structure.
[0092] Specifically, the thickness of each film layer in the surface plasmon lithography structure can be adjusted. For example, the thickness of the metal layer can be adjusted to determine the process window corresponding to each metal layer thickness. The metal layer thickness corresponding to the maximum process window can be used as the optimal metal layer thickness, thereby maximizing the process window from the perspective of the film layer structure. Furthermore, the film layer material can be changed to calculate the process window for different materials, and the film layer material corresponding to the maximum process window can be used as the optimal material.
[0093] Based on the above process window determination method, an embodiment of the present application further provides a process window determination device, which may include:
[0094] An establishing unit is used to establish a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer and a mask layer stacked in sequence;
[0095] A simulation unit, configured to perform simulation using a surface plasma lithography model to determine a photoresist pattern after photolithography and a line width of the photoresist pattern;
[0096] A control unit is used to adjust the exposure energy and the thickness of the air layer in the surface plasma lithography model to obtain the corresponding relationship between multiple exposure energies, the thickness of the air layer and the line width of the photoresist pattern; based on the corresponding relationship and the allowable error range between the photoresist pattern and the mask layer, the process window corresponding to the mask layer is determined.
[0097] Optionally, the control unit is further configured to:
[0098] Adjusting the pattern of the mask layer, and repeatedly performing steps 101 to 104 to determine a plurality of process windows; each process window corresponds to a pattern of the mask layer;
[0099] Based on the multiple process windows, a common process window corresponding to the multiple patterns of the mask layers is determined.
[0100] Optionally, the surface plasmon lithography model includes a spatial light intensity model and a photoresist model;
[0101] The simulation unit is used to:
[0102] Performing surface plasma lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;
[0103] Based on the light intensity distribution, photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0104] Optionally, the simulation unit is used to:
[0105] The light intensity of the incident light is adjusted in the spatial light intensity model; the light intensity has a corresponding relationship with the exposure energy.
[0106] Optionally, the simulation unit is used to:
[0107] The exposure energy of the photoresist layer is adjusted in the photoresist model.
[0108] Optionally, the simulation unit is used to:
[0109] In a first simulation software, performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;
[0110] Based on the light intensity distribution, performing photoresist exposure and development simulation using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern, including:
[0111] In the second simulation software, based on the light intensity distribution, a photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
[0112] Optionally, the control unit is configured to:
[0113] The exposure energy in the surface plasma lithography model is adjusted according to a first preset change amount, and the thickness of the air layer is adjusted according to a second preset change amount.
[0114] Optionally, the control unit is configured to:
[0115] Adjusting the thickness of the metal layer, and repeating steps 101 to 104 to determine the process window at each thickness of the metal layer;
[0116] The thickness of the metal layer corresponding to the largest process window is determined as the optimal metal layer thickness of the surface plasma lithography structure.
[0117] On the other hand, the embodiment of the present application provides a computer device, referring to Figure 5 , which is a structural diagram of a computer device provided in an embodiment of the present application, includes a processor 310 and a memory 320:
[0118] The memory 320 is used to store program codes and transmit the program codes to the processor 310;
[0119] The processor 310 is configured to execute the method provided in the above embodiment according to the instructions in the program code.
[0120] The computer device may include a terminal device or a server, and the aforementioned apparatus may be configured in the computer device.
[0121] Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned method embodiment can be completed by program instruction hardware, and the above-mentioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the above-mentioned storage medium can be at least one of the following media: read-only memory (English: Read-only Memory, abbreviated: ROM), RAM, magnetic disk or optical disk, etc., various media that can store program codes.
[0122] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences from the other embodiments. In particular, the device embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.
[0123] The above is only a preferred embodiment of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of protection of the technical solution of the present application.
Claims
1. A method for determining a process window, characterized in that: include: Step 101, establishing a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer, and a mask layer stacked in sequence; Step 102, performing simulation using a surface plasma lithography model to determine a photoresist pattern after photolithography and a line width of the photoresist pattern; Step 103, adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer, and repeatedly performing steps 101 to 102 to obtain a plurality of corresponding relationships among the exposure energy, the thickness of the air layer, and the line width of the photoresist pattern; Step 104 : determining a process window corresponding to the mask layer based on the corresponding relationship and an allowable error range between the photoresist pattern and the mask layer.
2. The method according to claim 1, characterized in that The method further comprises: Adjusting the pattern of the mask layer, and repeatedly performing steps 101 to 104 to determine a plurality of process windows; each process window corresponds to a pattern of the mask layer; Based on the multiple process windows, a common process window corresponding to the multiple patterns of the mask layers is determined.
3. The method according to claim 1 or 2, characterized in that The surface plasma lithography model includes a spatial light intensity model and a photoresist model; The step 102, performing simulation by a surface plasma lithography model to determine the photoresist pattern after lithography and the line width of the photoresist pattern, includes: Performing surface plasma lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer; Based on the light intensity distribution, photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
4. The method according to claim 3, characterized in that The adjusting the exposure energy in the surface plasmon lithography model comprises: The light intensity of the incident light is adjusted in the spatial light intensity model; the light intensity has a corresponding relationship with the exposure energy.
5. The method according to claim 3, characterized in that The adjusting the exposure energy in the surface plasmon lithography model comprises: The exposure energy of the photoresist layer is adjusted in the photoresist model.
6. The method according to claim 3, characterized in that Performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer includes: In a first simulation software, performing surface plasmon lithography simulation using the spatial light intensity model to determine the light intensity distribution of the photoresist layer; Based on the light intensity distribution, performing photoresist exposure and development simulation using the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern, including: In the second simulation software, based on the light intensity distribution, a photoresist exposure and development simulation is performed through the photoresist model to determine the photoresist pattern after photolithography and the line width of the photoresist pattern.
7. The method according to claim 1, characterized in that Adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer comprises: The exposure energy in the surface plasma lithography model is adjusted according to a first preset change amount, and the thickness of the air layer is adjusted according to a second preset change amount.
8. The method according to claim 1, characterized in that The method further comprises: Adjusting the thickness of the metal layer, and repeating steps 101 to 106 to determine a process window at each thickness of the metal layer; The thickness of the metal layer corresponding to the largest process window is determined as the optimal metal layer thickness of the surface plasma lithography structure.
9. A process window determination device, characterized in that: include: An establishing unit is used to establish a surface plasma lithography model corresponding to a surface plasma lithography structure; the surface plasma lithography structure includes a substrate layer, a photoresist layer, an air layer, a metal layer, an insulating layer and a mask layer stacked in sequence; A simulation unit, configured to perform simulation using a surface plasma lithography model to determine a photoresist pattern after photolithography and a line width of the photoresist pattern; A control unit, configured to adjust the exposure energy in the surface plasma lithography model and the thickness of the air layer to obtain a plurality of corresponding relationships among the exposure energy, the thickness of the air layer, and the line width of the photoresist pattern; Based on the corresponding relationship and the allowable error range between the photoresist pattern and the mask layer, a process window corresponding to the mask layer is determined.
10. A computer device, characterized in that: The computer device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method according to any one of claims 1 to 8 according to instructions in the program code.
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