Process window determination method and related device

Abstract

The invention provides a process window determination method and a related device, and the method comprises the steps: building a surface plasma photoetching model corresponding to a surface plasma photoetching structure with an air layer, carrying out the simulation through the surface plasma photoetching model, and determining a photoresist pattern after photoetching, and the line width of the photoresist pattern; adjusting the exposure energy in the surface plasma photoetching model and the thickness of the air layer, and repeatedly executing the steps to obtain a plurality of corresponding relations among the exposure energy, the thickness of the air layer and the line width of the photoresist pattern; and determining a process window corresponding to the mask layer based on the corresponding relation and an allowable error range of the photoresist pattern and the mask layer. According to the method, the specific photoetching process of the surface plasma photoetching structure is simulated, and simulation is carried out for multiple times under different exposure energy and air layer thicknesses, so that materials and time are saved, the accuracy of a process window is improved, and the fluctuation tolerance of process parameters of surface plasma photoetching is improved.

Description

Technical Field

[0001] The present application relates to the semiconductor field, 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 through the diffraction limit, represented by surface plasmas (SPs), have gradually been realized. Using surface plasma lithography, a lithography image much smaller than the wavelength of the light source can be achieved with a large wavelength, but this is equivalent to contact lithography and is too inefficient, so a surface plasma lithography structure with an air layer was developed.

[0003] In the surface plasma lithography structure with an air layer, the mask layer and the photoresist layer are separated by the air layer, which is equivalent to near-field projection lithography. In this way, just like traditional projection lithography, the wafer carried by the workpiece table can be moved to expose different areas of the wafer, greatly improving work efficiency.

[0004] However, in the related art, for the surface plasma lithography structure with an air layer, its process window is generally obtained through manual experiments, which requires artificial construction of a lithography model and setting of parameters such as exposure energy. Moreover, due to the large uncertainty of the experiment, this method wastes a lot of manpower and material resources and is inefficient. Therefore, proposing a suitable method for determining the process window has become a technical problem that needs to be solved urgently. 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 comprises 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 through a surface plasma lithography model to determine a photoresist pattern after lithography 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 comprises:

[0012] Adjusting the pattern of the mask layer, and repeatedly executing step 101 to step 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 plasma lithography model includes a spatial light intensity model and a photoresist model;

[0015] The step 102, simulating through 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 by 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 plasma lithography model comprises:

[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 plasma lithography model comprises:

[0021] The exposure energy to the photoresist layer is adjusted in the photoresist model.

[0022] Optionally, performing surface plasma lithography simulation by using the spatial light intensity model to determine the light intensity distribution of the photoresist layer includes:

[0023] In the first simulation software, surface plasma lithography simulation is performed by using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;

[0024] 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, including:

[0025] In the second simulation software, 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.

[0026] Optionally, adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer comprises:

[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 comprises:

[0029] Adjust the thickness of the metal layer, repeat steps 101 to 106, and determine the process window under the thickness of each 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 comprises 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, used for performing simulation through a surface plasma lithography model to determine the photoresist pattern after lithography and the 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, determine the process window corresponding to the mask layer.

[0035] In another aspect, an embodiment of the present application provides a computer device, the 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 embodiment of the present application provides a process window determination method and related devices, 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, simulating through the surface plasma lithography model to determine the photoresist pattern after lithography and the 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, repeating steps 101 to 102, and obtaining a correspondence between multiple exposure energies, the thickness of the air layer and the line width of the photoresist pattern; step 104, determining the process window corresponding to the mask layer based on the correspondence and the allowable error range between the photoresist pattern and the mask layer. In summary, in the present 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 experiments, thus saving materials and time, improving the determination rate and accuracy of the process window, and improving the tolerance to fluctuations in process parameters 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 flow chart 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 plasma 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 objects, 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, but the present application may also be implemented in other ways different from those described herein, and 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, the present application is described in detail with reference to the schematic diagram. When describing the embodiments of the present application in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present application. In addition, in actual production, the three-dimensional dimensions of 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 in conjunction with the accompanying drawings.

[0049] refer to Figure 1 As shown, it is a flow chart of a method for determining a process window provided in an embodiment of the present application. The method may include the following steps.

[0050] Step 101, establishing a surface plasma lithography model corresponding to the surface plasma lithography structure.

[0051] In the embodiment of the present application, the surface plasma 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, wherein the substrate layer is used to provide support, for example, it may be a silicon substrate, the air layer is a layer with air, and the thickness of the air layer may be several tens of nanometers. The material of the mask layer may be Cr, for example, and under the action of incident light, the pattern of the mask layer may be transferred to the photoresist layer.

[0052] The metal layer may be, for example, Au, Ag or Al, and the insulating layer may be, for example, a PMMA layer. The metal layer has a negative dielectric constant under electromagnetic waves of a specific wavelength band, and the insulating layer has a positive dielectric constant. One of the conditions for the existence of surface plasma is that the two materials must have opposite dielectric constants. In this way, surface plasma can be generated in the two-layer film structure of the metal layer and the insulating layer. Of course, the excitation of surface plasma also requires that the electromagnetic wave is 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, and 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 exposure is performed within the focus value range of -0.15 to +0.1um, the line width (Critical Dimension, CD) of the pattern in the photoresist layer is between 135nm and 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 analogous 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 can be established in the simulation software, and the simulation model can be recorded as a surface plasma lithography model, so as to perform simulation analysis on the lithography process later.

[0058] Step 102, performing simulation through 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, and the pattern formed by the photoresist layer under the action of the mask layer, that is, the photoresist pattern, can be simulated to obtain 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 plasma lithography model includes a spatial light intensity model and a photoresist model; step 102, performing simulation through the surface plasma lithography model to determine the photoresist pattern after lithography and the line width of the photoresist pattern, can be specifically performed by performing surface plasma lithography simulation through 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 through the photoresist model to determine the photoresist pattern after lithography and the line width of the photoresist pattern.

[0062] Specifically, the surface plasma lithography model can be divided into two independent models, namely, the spatial light intensity model and the photoresist model. The film layer structure in the spatial light intensity model is the same as the surface plasma lithography structure, and the model is mainly used to simulate the light intensity distribution of light in the photoresist layer. That is, electromagnetic field simulation calculation can be performed based on the material, thickness, refractive index and other properties of each film layer, and the light intensity of the incident light to the spatial light intensity model, so as 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, without 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 may include only one photoresist layer, or may include other film layers below the photoresist layer. Specifically, the photoresist model may be simulated based on the light intensity distribution to obtain the photoresist pattern after photolithography. In this way, under certain incident light energy, air layer thickness, and mask layer pattern, the line width of the photoresist pattern obtained after photolithography may be determined.

[0066] In summary, by separately simulating the light intensity distribution of light in the photoresist layer and the photoresist pattern formed under the light intensity distribution through 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 a possible implementation, surface plasma lithography simulation is performed through a spatial light intensity model to determine the light intensity distribution of the photoresist layer, which can be specifically performed in a first simulation software by performing surface plasma lithography simulation through a 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 a photoresist model to determine the photoresist pattern after lithography and the line width of the photoresist pattern, which can be specifically performed in a second simulation software by performing photoresist exposure and development simulation based on the light intensity distribution to determine the photoresist pattern after lithography and the line width of the photoresist pattern.

[0068] Specifically, a spatial light intensity model corresponding to the surface plasma lithography structure can be established in the first simulation software. The first simulation software can include FDTD simulation software or RCWA simulation software. Of course, it is not limited to the above software. The first simulation software only needs to have the simulation capability of light intensity, that is, it can determine the light intensity distribution of the photoresist layer by the electromagnetic field simulation method. The spatial light intensity model is simulated by 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, and 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 in 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, so that 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 simulation software and the second simulation software, the exposure energy and the thickness of the air layer are adjusted by simulation, and the process window corresponding to the mask layer is obtained without the need for experiments. The process window can be determined more quickly and accurately, saving materials and time, and improving the determination rate and accuracy of the process window. In addition, the process feasibility can be evaluated more quickly without the need for experiments, thereby improving process efficiency.

[0072] 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 the corresponding relationship between multiple exposure energies, air layer thicknesses and line widths of photoresist patterns.

[0073] Specifically, in order to determine the process window under the mask layer, the exposure energy and the thickness of the air layer in the surface plasma lithography model can be adjusted. Each time the exposure energy or the thickness of the air layer is adjusted, steps 101 to 102 can be repeatedly performed to obtain the line width of the photoresist pattern corresponding to the exposure energy or the thickness of the air layer. The thickness of the air layer can be directly modified in the first simulation software, and the adjustment of the exposure energy can be implemented in the first simulation software or in 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 from 10mj / cm 2 Start with 0.1 mj / cm 2 For intervals, 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 has a corresponding relationship with the exposure energy.

[0078] Specifically, the light intensity incident to the surface plasma lithography structure can be adjusted in the spatial light intensity model. The unit of light intensity is the square of the amplitude, that is, the amplitude of the incident light is adjusted. Different light intensities correspond to different exposure energies. Adjusting the light intensity of the incident light in the spatial light intensity model means adjusting the exposure energy. By adjusting the incident light, a more accurate process window can be obtained.

[0079] In a possible implementation manner, adjusting the exposure energy in the surface plasma 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 in the photoresist model. That is, in the spatial light intensity model, the light intensity of the incident light is set to the same value, and the exposure energy is set in the photoresist model. The photoresist model can adjust the light intensity distribution based on the set exposure energy, so that the adjusted light intensity distribution acts on the photoresist model and outputs the line width size of the photoresist pattern. In this way, by directly setting the exposure energy, the exposure energy can be adjusted more conveniently, and the flexibility of exposure energy adjustment is improved.

[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 change amount can be increased or decreased, that is, the first preset change amount. Each time the thickness of the air layer is adjusted, the same change amount can be increased or decreased, that is, the second preset change amount. 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 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 are used as the process window corresponding to the mask layer. 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 the present 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 experiments, thus saving materials and time, improving the rate and accuracy of determining the process window, and improving the tolerance to fluctuations in process parameters 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 change 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 process window corresponding to 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, 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 a possible implementation, the thickness of the metal layer can also be adjusted, and steps 101 to 104 are 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 plasma lithography structure can also be adjusted, for example, the thickness of the metal layer can be adjusted, so as to determine the process window corresponding to the thickness of each metal layer, and the metal layer thickness corresponding to the maximum process window can be used as the optimal metal layer thickness, so as to maximize the process window from the film layer structure. In addition, the material of the film layer can also be changed, and the process window under different materials can be calculated, 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, the 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 comprises 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, used for performing simulation through a surface plasma lithography model to determine the photoresist pattern after lithography and the 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 executing step 101 to step 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 plasma lithography model includes a spatial light intensity model and a photoresist model;

[0101] The simulation unit is used for:

[0102] Performing surface plasma lithography simulation by 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 to the photoresist layer is adjusted in the photoresist model.

[0108] Optionally, the simulation unit is used to:

[0109] In the first simulation software, surface plasma lithography simulation is performed by using the spatial light intensity model to determine the light intensity distribution of the photoresist layer;

[0110] 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, including:

[0111] In the second simulation software, 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.

[0112] Optionally, the control unit is used 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 used to:

[0115] Adjust the thickness of the metal layer, repeat steps 101 to 104, and determine the process window under the thickness of each 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] In another aspect, 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, wherein the computer device 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 used 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] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by program instruction hardware, and the above program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the above 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] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0123] The above is only a preferred implementation 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 of equivalent changes. Therefore, any simple modification, equivalent change and modification 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 still falls 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 comprises 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 through a 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 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 executing step 101 to step 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, simulating through 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 by 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 step of adjusting the exposure energy in the surface plasma 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 step of adjusting the exposure energy in the surface plasma lithography model comprises: The exposure energy to the photoresist layer is adjusted in the photoresist model.

6. The method according to claim 3, characterized in that Performing surface plasma lithography simulation by using the spatial light intensity model to determine the light intensity distribution of the photoresist layer includes: In the first simulation software, surface plasma lithography simulation is performed by 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, including: In the second simulation software, 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.

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: Adjust the thickness of the metal layer, repeat steps 101 to 106, and 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.

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 comprises 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, used for performing simulation through a surface plasma lithography model to determine the photoresist pattern after lithography and the line width of the photoresist pattern; A control unit, used for adjusting the exposure energy in the surface plasma lithography model and the thickness of the air layer, and obtaining 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 comprises 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 the instructions in the program code.

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