Plasma dry etching process monitoring method and equipment based on metasurface
Through the plasma dry etching process monitoring method based on superstructure surfaces, the etching depth is monitored in real time by using the terahertz reflection spectrum, which solves the problem that the etching depth cannot be accurately controlled in the prior art, and achieves an efficient and accurate etching process.
Patent Information
- Application Number
- CN202510068297.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-06-03
AI Technical Summary
The existing online monitoring methods of plasma dry etching processes cannot accurately control the etching depth, resulting in the problem of over-etching or insufficient etching.
The plasma dry etching process monitoring method based on superstructure surface is adopted to obtain the first and second lithography layouts of the target device, and the etching depth is monitored in real time by acquiring the first and second lithography layouts of the target device, and the etching depth is monitored in real time using the terahertz reflection spectrum.
Real-time, in-situ and non-invasive monitoring of the plasma dry etching process is realized, and the etching depth is accurately controlled, excessive etching or insufficient etching is avoided, and product quality and R&D efficiency are improved.
Smart Images
Figure CN120089612A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular, to a method for monitoring a plasma dry etching process based on a metasurface, a device for monitoring a plasma dry etching process based on a metasurface, an electronic device, and a computer-readable storage medium. Background Art
[0002] At present, due to the development of manufacturing technology showing the characteristics of intelligence, customization, and personalization, it is necessary to accurately monitor the processing status of products online, which is very important for the research and development of new category products and the production of diversified small-batch products, and can avoid the material and time costs brought by multiple rounds of processing experiments to the greatest extent.
[0003] The plasma dry etching process is a common subtractive processing method and plays a key role in the forming process of various types of chips such as integrated circuits, optoelectronic devices, microfluidic devices, microelectromechanical sensors, and actuators. For this processing technology, the current online monitoring methods include reflection anisotropy spectroscopy, optical emission spectroscopy, residual gas mass spectrometry, etc. However, these methods are only applicable to the etching of thin films with a thickness of no more than several micrometers, and the key point signals shown when a layer of material is etched through are not obvious enough to accurately control the etching depth in the plasma dry etching process, resulting in problems of over-etching or under-etching. Summary of the Invention
[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, the first object of the present invention is to propose a method for monitoring a plasma dry etching process based on a metasurface, which can detect the process status in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and then accurately control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, effectively improve the final quality of products without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0005] The second object of the present invention is to propose a device for monitoring a plasma dry etching process based on a metasurface.
[0006] The third object of the present invention is to propose an electronic device.
[0007] The fourth object of the present invention is to propose a computer-readable storage medium.
[0008] To achieve the above object, an embodiment of the first aspect of the present invention provides a method for monitoring a plasma dry etching process based on a metasurface, including: obtaining a first photolithography layout corresponding to all structures of a target device; determining a key structure area of the target device in the first photolithography layout, and periodically repeating the key structure area to form a metasurface of the key structure, and obtaining a corresponding second photolithography layout according to the metasurface; wherein, the key structure is included in all structures; parallelly splicing the second photolithography layout and the first photolithography layout to obtain an overall photolithography layout; performing a plasma dry etching process on the overall photolithography layout; obtaining a terahertz reflection spectrum generated by irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; determining the process state of the plasma dry etching process for the key structure area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum.
[0009] In addition, the method for monitoring a plasma dry etching process based on a metasurface according to the above embodiment of the present invention may further have the following additional technical features:
[0010] According to some embodiments of the present invention, obtaining a first photolithography layout corresponding to all structures of a target device includes: determining all structures of the target device; obtaining first geometric parameters of all structures, and drawing the first photolithography layout according to the first geometric parameters.
[0011] According to some embodiments of the present invention, determining a key structure area of the target device in the first photolithography layout, and periodically repeating the key structure area to form a metasurface of the key structure, and obtaining a corresponding second photolithography layout according to the metasurface includes: selecting a key structure from the first photolithography layout according to a pre-determined selection criterion; obtaining second geometric parameters of the key structure, and periodically repeating the second geometric parameters to form a metasurface of the key structure; drawing the second photolithography layout according to the metasurface; wherein, several key structures are mapped on the second photolithography layout.
[0012] According to some embodiments of the present invention, the selection criterion includes at least one of a geometric line width less than a preset line width threshold, a performance impact on the target device greater than a preset performance threshold, and a success rate of the plasma dry etching process lower than a preset success rate threshold.
[0013] According to some embodiments of the present invention, obtaining the terahertz reflection spectrum generated by irradiating the corresponding area of the second photolithography layout in the overall photolithography layout with an electromagnetic wave beam includes: irradiating the corresponding area of the second photolithography layout in the overall photolithography layout along a first direction; wherein, the wavelength of the electromagnetic wave beam is not less than the structural period of the metasurface; obtaining the terahertz reflection spectrum generated by the polarization of the corresponding area of the second photolithography layout in the overall photolithography layout in a second direction; wherein, the first direction is perpendicular to the second photolithography layout, the second direction is parallel to the second photolithography layout, and the first direction is perpendicular to the second direction.
[0014] According to some embodiments of the present invention, the above method further includes: obtaining the terahertz reflection spectrum generated by the polarization of the second photolithography layout in a third direction; wherein, the third direction is parallel to the second photolithography layout, the first direction is perpendicular to the third direction, and the second direction is perpendicular to the third direction.
[0015] According to some embodiments of the present invention, determining the process state of the plasma dry etching process for the key structural area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum includes: determining the real-time etching depth during the plasma dry etching process for the key structural area in the first photolithography layout according to the frequency of the terahertz reflection spectrum; wherein, the frequency is inversely proportional to the real-time etching depth; determining the mutation point of the terahertz reflection spectrum and using the mutation point as the breakthrough point during the plasma dry etching process for the key structural area in the first photolithography layout; wherein, the mutation point is the point where the frequency of the terahertz reflection spectrum mutates and the reflection amplitude mutates.
[0016] A method for monitoring a plasma dry etching process based on a metasurface according to an embodiment of the present invention includes: obtaining a first photolithography layout corresponding to all structures of a target device; determining a key structure region of the target device in the first photolithography layout, and periodically repeating the key structure region to form a metasurface of the key structure, and obtaining a corresponding second photolithography layout according to the metasurface; wherein the key structure is included in all structures; splicing the second photolithography layout and the first photolithography layout in parallel to obtain an overall photolithography layout; performing a plasma dry etching process on the overall photolithography layout; obtaining a terahertz reflection spectrum generated by irradiating a region corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; determining the process state of the plasma dry etching process for the key structure region in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum. Thus, this method can detect the process state in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and then precisely control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0017] The second object of the present invention is to propose a device for monitoring a plasma dry etching process based on a metasurface, which can detect the process state in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and then precisely control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0018] To achieve the above object, an embodiment of the second aspect of the present invention provides a plasma dry etching process monitoring device based on a metasurface, including: a first acquisition module configured to acquire a first photolithography layout corresponding to all structures of a target device; a construction module configured to determine a key structure region of the target device in the first photolithography layout, and perform periodic repetition on the key structure region to form a metasurface of the key structure, and obtain a corresponding second photolithography layout according to the metasurface; wherein the key structure is included in all structures; a splicing module configured to perform parallel splicing on the second photolithography layout and the first photolithography layout to obtain an overall photolithography layout; an etching module configured to perform a plasma dry etching process on the overall photolithography layout; a second acquisition module configured to acquire a terahertz reflection spectrum generated by irradiating a region corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; an equivalent substitution module configured to determine the process state of the plasma dry etching process for the key structure region in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum.
[0019] The plasma dry etching process monitoring device based on a metasurface according to an embodiment of the present invention includes: the first acquisition module acquires a first photolithography layout corresponding to all structures of a target device; the construction module determines a key structure region of the target device in the first photolithography layout, and performs periodic repetition on the key structure region to form a metasurface of the key structure, and obtains a corresponding second photolithography layout according to the metasurface; wherein the key structure is included in all structures; the splicing module performs parallel splicing on the second photolithography layout and the first photolithography layout to obtain an overall photolithography layout; the etching module performs a plasma dry etching process on the overall photolithography layout; the second acquisition module acquires a terahertz reflection spectrum generated by irradiating a region corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; the equivalent substitution module determines the process state of the plasma dry etching process for the key structure region in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum. Thus, this device can detect the process state in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and then precisely control the etching depth in the plasma dry etching process, avoiding over-etching or under-etching. It can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0020] To achieve the above object, an embodiment of the third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the above-mentioned plasma dry etching process monitoring method based on a metasurface.
[0021] The electronic device according to the embodiment of the present invention can detect the process state in the plasma dry etching process through the real-time, in-situ, and non-invasive monitoring method by executing the above-mentioned plasma dry etching process monitoring method based on the metasurface, and then precisely control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0022] To achieve the above object, the fourth aspect embodiment of the present invention proposes a computer-readable storage medium, and the computer-readable storage medium stores computer instructions for causing a computer to implement the above-mentioned plasma dry etching process monitoring method based on the metasurface.
[0023] The computer-readable storage medium according to the embodiment of the present invention can detect the process state in the plasma dry etching process through the real-time, in-situ, and non-invasive monitoring method by executing the above-mentioned plasma dry etching process monitoring method based on the metasurface, and then precisely control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0024] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. Description of the Drawings
[0025] Figure 1 It is a flowchart of the plasma dry etching process monitoring method based on the metasurface according to some embodiments of the present invention.
[0026] Figure 2 It is a schematic diagram of the overall lithography layout according to some embodiments of the present invention.
[0027] Figure 3 It is a top view schematic diagram of the first lithography layout according to some embodiments of the present invention.
[0028] Figure 4 It is a three-dimensional schematic diagram of the second lithography layout according to some embodiments of the present invention.
[0029] Figure 5 It is a cross-sectional schematic diagram of the second lithography layout according to some embodiments of the present invention.
[0030] Figure 6Schematic diagram for obtaining the etching process state based on the terahertz reflection spectrum generated by irradiating the corresponding area of the second lithography layout in the overall lithography layout with an electromagnetic wave beam according to some embodiments of the present invention;
[0031] Figure 7 Schematic diagram of the lithography layout of the entire wafer according to some embodiments of the present invention;
[0032] Figure 8 Schematic diagram of the simulation model of the second lithography layout according to some embodiments of the present invention;
[0033] Figure 9 Schematic diagram of the terahertz reflection spectrum of the corresponding area of the second lithography layout in the overall lithography layout changing with the etching depth according to some embodiments of the present invention;
[0034] Figure 10 Schematic diagram of the simulation result of the terahertz reflection spectrum generated by polarization of the corresponding area of the second lithography layout in the overall lithography layout in the second direction and the third direction according to some embodiments of the present invention;
[0035] Figure 11 Schematic block diagram of a plasma dry etching process monitoring device based on a metasurface according to some embodiments of the present invention;
[0036] Figure 12 Schematic block diagram of an electronic device according to some embodiments of the present invention. Detailed implementation manners
[0037] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.
[0038] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should have the ordinary meanings understood by those of ordinary skill in the technical field to which the present invention belongs. The "first", "second" and similar terms used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms such as "include" or "comprise" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connect" or "couple" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0039] As described in the background art section, currently, due to the development of manufacturing technology showing the characteristics of intelligence, customization, and personalization, it is necessary to accurately monitor the processing status of products online, which is very important for the research and development of new types of products and the production of diverse small-batch products, and can largely avoid the material and time costs brought by multiple rounds of processing experiments.
[0040] In the process of implementing the present invention, the applicant found that the plasma dry etching process is a common subtractive processing method, which plays a key role in the forming process of various types of chips such as integrated circuits, optoelectronic devices, microfluidic devices, microelectromechanical sensors, and actuators. For this processing technology, current online monitoring methods include reflection anisotropy spectroscopy, optical emission spectroscopy, residual gas mass spectrometry, etc. However, these methods are only applicable to the etching of thin films with a thickness of no more than several micrometers, and the key point signals shown when a layer of material is etched through are not obvious enough to accurately control the etching depth in the plasma dry etching process, resulting in problems such as over-etching or under-etching. Therefore, real-time, in-situ, non-invasive monitoring of the plasma dry etching process involving large thickness and high aspect ratio is still a technical blank.
[0041] Next, the plasma dry etching process monitoring method based on metasurface, the plasma dry etching process monitoring device based on metasurface, electronic equipment, and storage medium proposed in the embodiments of the present invention will be described with reference to the accompanying drawings.
[0042] Reference Figure 1 , is a flowchart of the plasma dry etching process monitoring method based on metasurface according to some embodiments of the present invention.
[0043] As Figure 1 shown, the plasma dry etching process monitoring method based on metasurface in the embodiments of the present invention may include the following steps:
[0044] S101, obtain the first lithography layout corresponding to all structures of the target device.
[0045] Specifically, all structures of the target device can be obtained by referring to technical documents or analyzing data manuals, and then the technical parameters of all structures of the target device (such as the size, weight, package type, operating temperature range, humidity, vibration, and shock of the device, etc.) are input into electronic design automation software (such as Cadence, Mentor Graphics, etc.). After receiving the technical parameters, the electronic design automation software can obtain the lithography layout corresponding to all structures of the target device according to the technical parameters, and use this lithography layout as the first lithography layout.
[0046] S102. Determine the critical structure region of the target device in the first lithography layout, and perform periodic repetition on the critical structure region to form a metasurface of the critical structure, and obtain the corresponding second lithography layout according to the metasurface; wherein, the critical structure is included in all structures.
[0047] Specifically, after obtaining the first lithography layout corresponding to all the structures of the target device, then, identify and determine the critical structure region of the target device in the first lithography layout of the target device from the first lithography layout corresponding to all the structures of the target device, and perform periodic repetition on the critical structure region to form a metasurface of the critical structure, and according to the metasurface, the lithography layout corresponding to the metasurface of the critical structure can be obtained, and this lithography layout is used as the second lithography layout. Among them, the metasurface is an artificial electromagnetic structure, which is composed of an array of sub-wavelength periodic unit structures fabricated by artificial design and processing to construct various electromagnetic resonance modes, and these electromagnetic resonance modes can usually be reflected in the reflection spectrum of the metasurface.
[0048] S103. Parallelly splice the second lithography layout and the first lithography layout to obtain an overall lithography layout.
[0049] Specifically, after obtaining the second lithography layout and the first lithography layout, parallelly splice the second lithography layout and the first lithography layout to obtain an overall lithography layout, that is, the obtained overall lithography layout includes the second lithography layout and the first lithography layout.
[0050] S104. Perform a plasma dry etching process on the overall lithography layout.
[0051] Specifically, after obtaining the overall lithography layout, perform a plasma dry etching process on the critical structure region in the first lithography layout according to the first lithography layout. At the same time, perform a plasma dry etching process on the critical structure region in the first lithography layout in the overall lithography layout according to the second lithography layout, so as to perform a plasma dry etching process on the overall lithography layout.
[0052] S105. Obtain the terahertz reflection spectrum generated by irradiating the region corresponding to the second lithography layout in the overall lithography layout with an electromagnetic beam.
[0053] Specifically, irradiate the region corresponding to the second lithography layout in the overall lithography layout with an electromagnetic beam, and the terahertz reflection spectrum generated by the region corresponding to the second lithography layout in the overall lithography layout can be measured by a spectrum analyzer or a signal modem, etc.
[0054] S106. Determine the process state of the plasma dry etching process for the critical structure region in the first lithography layout in the overall lithography layout according to the terahertz reflection spectrum.
[0055] Specifically, after obtaining the terahertz reflection spectrum generated in the area corresponding to the second lithography layout in the overall lithography layout, the process state of the plasma dry etching process in the area corresponding to the second lithography layout in the overall lithography layout is determined according to the terahertz reflection spectrum. Furthermore, the process state of the plasma dry etching process in the critical structure area of the first lithography layout can be reflected based on the process state of the plasma dry etching process in the area corresponding to the second lithography layout in the overall lithography layout. For example, when the terahertz reflection spectrum is large, it indicates that the etching depth in the area corresponding to the second lithography layout in the overall lithography layout is small, and thus it can be reflected that the etching depth in the critical structure area of the first lithography layout is small. Another example is that when the terahertz reflection spectrum is small, it indicates that the etching depth in the area corresponding to the second lithography layout in the overall lithography layout is large, and thus it can be reflected that the etching depth in the critical structure area of the first lithography layout is large. Since the electromagnetic resonance mode of the metasurface is mainly determined by its material properties, geometric shape, and size, the material properties or geometric shape and size can be estimated by measuring the terahertz reflection spectrum. Therefore, the process state in the plasma dry etching process can be detected through real-time, in-situ, and non-invasive monitoring methods. Furthermore, the etching depth in the plasma dry etching process can be precisely controlled to avoid over-etching or under-etching, which can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the critical structure of the target device (such as a chip).
[0056] In some embodiments, reference Figure 2 , is a schematic diagram of an overall lithography layout according to some embodiments of the present invention. The first lithography layout corresponding to all the structures of the target device and the second lithography layout corresponding to the critical structure are parallelly spliced to form an overall lithography layout.
[0057] In some embodiments of the present invention, obtaining the first lithography layout corresponding to all the structures of the target device includes: determining all the structures of the target device; obtaining the first geometric parameters of all the structures, and drawing the first lithography layout according to the first geometric parameters.
[0058] Specifically, first, determine all the structures of the target device, where all the structures may include a substrate, a pattern layer, a photoresist layer, a micro-nano structure, a mechanical structure, an optical structure, etc. Then, obtain the first geometric parameters of all the structures of the target device (such as the size of the device, geometric line width, product performance, shape, relative position, etc.) according to the data sheet of all the structures of the target device. Finally, reference Figure 3, which is a top view schematic diagram of the first lithography layout according to some embodiments of the present invention. The first geometric parameters of all structures of the target device are input into the electronic design automation software, and the electronic design automation software draws the first lithography layout according to the first geometric parameters of all structures of the target device.
[0059] In some embodiments of the present invention, a key structure region of the target device in the first lithography layout is determined, and the key structure region is periodically repeated to form a metasurface of the key structure, and a corresponding second lithography layout is obtained according to the metasurface, including: selecting key structures from the first lithography layout according to a pre-determined selection criterion; obtaining second geometric parameters of the key structures, and periodically repeating the second geometric parameters to form a metasurface of the key structure; drawing the second lithography layout according to the metasurface; wherein, a plurality of key structures are mapped on the second lithography layout.
[0060] Specifically, first, key structures are selected from the first lithography layout of the target device according to a pre-determined selection criterion, and then, second geometric parameters (such as device size, geometric line width, product performance, shape, relative position, etc.) of the key structures of the target device are obtained according to the data sheet of the key structures of the target device, and the second geometric parameters are periodically repeated to form a metasurface of the key structure. Finally, referring to Figure 4 , which is a three-dimensional schematic diagram of the second lithography layout according to some embodiments of the present invention, and referring to Figure 5 , which is a cross-sectional schematic diagram of the second lithography layout according to some embodiments of the present invention, the metasurface of the key structures of the target device is input into the electronic design automation software, and the electronic design automation software draws the second lithography layout according to the metasurface of the key structures of the target device. Since the lithography layout of the key structures of the target device is used to obtain the second lithography layout through periodic repetition, a plurality of key structures are mapped on the second lithography layout.
[0061] In some embodiments of the present invention, the selection criterion includes at least one of a geometric line width less than a preset line width threshold, a performance impact on the target device greater than a preset performance threshold, and a success rate of plasma dry etching process lower than a preset success rate threshold.
[0062] Specifically, the selection criterion may be that the geometric line width of the key structure of the target device is less than a preset line width threshold. Alternatively, the selection criterion may be that the impact of the key structure of the target device on the performance of the target device is greater than a preset performance threshold. Alternatively, the selection criterion may be that the success rate of the plasma dry etching process for the key structure of the target device is lower than a preset success rate threshold. Alternatively, the selection criterion may be that the geometric line width of the key structure of the target device is less than a preset line width threshold and the impact of the key structure of the target device on the performance of the target device is greater than a preset performance threshold. Alternatively, the selection criterion may be that the geometric line width of the key structure of the target device is less than a preset line width threshold and the success rate of the plasma dry etching process for the key structure of the target device is lower than a preset success rate threshold. Alternatively, the selection criterion may be that the impact of the key structure of the target device on the performance of the target device is greater than a preset performance threshold and the success rate of the plasma dry etching process for the key structure of the target device is lower than a preset success rate threshold. Alternatively, the selection criterion may be that the geometric line width of the key structure of the target device is less than a preset line width threshold, the impact of the key structure of the target device on the performance of the target device is greater than a preset performance threshold, and the success rate of the plasma dry etching process for the key structure of the target device is lower than a preset success rate threshold.
[0063] In some embodiments, the selection criterion may also be that the insulation ability of the key structure of the target device is less than a preset insulation threshold, the selection criterion may also be that the electrical clearance of the key structure of the target device is less than a preset electrical clearance threshold, and the selection criterion may also be that the heat resistance of the key structure of the target device is less than a preset heat resistance threshold.
[0064] In some embodiments of the present invention, obtaining the terahertz reflection spectrum generated by irradiating the corresponding area of the second photolithography layout in the overall photolithography layout with an electromagnetic wave beam includes: irradiating the corresponding area of the second photolithography layout in the overall photolithography layout along a first direction; wherein, the wavelength of the electromagnetic wave beam is not less than the structural period of the metasurface; obtaining the terahertz reflection spectrum generated by the polarization of the corresponding area of the second photolithography layout in the overall photolithography layout in a second direction; wherein, the first direction is perpendicular to the second photolithography layout, the second direction is parallel to the second photolithography layout, and the first direction is perpendicular to the second direction.
[0065] Specifically, referring to Figure 6 , it is a schematic diagram for obtaining the etching process state according to the terahertz reflection spectrum generated by irradiating the corresponding area of the second photolithography layout in the overall photolithography layout with an electromagnetic wave beam in some embodiments of the present invention. The electromagnetic wave beam irradiates the corresponding area of the second photolithography layout in the overall photolithography layout along a first direction ( Figure 6 the negative z-axis direction in Figure 6 ), wherein, the wavelength of the electromagnetic wave beam is greater than or equal to the structural period of the metasurface. The terahertz reflection spectrum generated by the polarization of the corresponding area of the second photolithography layout in the overall photolithography layout in a second direction ( Figure 6 the positive x-axis direction in Figure 6 ) can be obtained by a spectrum analyzer. As can be seen from Figure 6 , the first direction (Figure 6 The negative z-axis direction in Figure 6 the positive x-axis direction in Figure 6 is perpendicular to the second lithography layout, and the first direction ( Figure 6 the negative z-axis direction in
[0066] In some embodiments of the present invention, the above method further includes: obtaining a terahertz reflection spectrum generated by the polarization of the second lithography layout in a third direction; wherein, the third direction is parallel to the second lithography layout, the first direction is perpendicular to the third direction, and the second direction is perpendicular to the third direction.
[0067] Specifically, continuing to refer to Figure 6 , the terahertz reflection spectrum generated by the polarization of the second lithography layout in the third direction ( Figure 6 the positive y-axis direction in Figure 6 can be obtained by a spectrum analyzer. It can be known from Figure 6 that the third direction ( Figure 6 the positive y-axis direction in Figure 6 is parallel to the second lithography layout, the first direction ( Figure 6 the negative z-axis direction in Figure 6 is perpendicular to the third direction (
[0068] In some embodiments of the present invention, determining the process state of the plasma dry etching process for the key structure area in the first lithography layout in the overall lithography layout according to the terahertz reflection spectrum includes: determining the real-time etching depth of the key structure area in the first lithography layout during the plasma dry etching process according to the frequency of the terahertz reflection spectrum; wherein, the frequency is inversely proportional to the real-time etching depth; determining the mutation point of the terahertz reflection spectrum, and using the mutation point as the breakthrough point during the plasma dry etching process for the key structure area in the first lithography layout; wherein, the mutation point is the point where the frequency of the terahertz reflection spectrum mutates and the reflection amplitude mutates.
[0069] Specifically, after obtaining the frequency of the terahertz reflection spectrum, the process state of the plasma dry etching process for the corresponding area of the second photolithography layout in the overall photolithography layout can be determined according to the frequency of the terahertz reflection spectrum. Furthermore, the real-time etching depth during the plasma dry etching process for the key structure area in the first photolithography layout can be reflected based on the process state of the plasma dry etching process for the corresponding area of the second photolithography layout in the overall photolithography layout, enabling precise control of the etching depth in the plasma dry etching process and avoiding over-etching or under-etching. The greater the frequency of the terahertz reflection spectrum, the smaller the real-time etching depth during the plasma dry etching process for the corresponding area of the second photolithography layout in the overall photolithography layout, and the smaller the real-time etching depth during the plasma dry etching process for the key structure area in the first photolithography layout; the smaller the frequency of the terahertz reflection spectrum, the greater the real-time etching depth during the plasma dry etching process for the corresponding area of the second photolithography layout in the overall photolithography layout, and the greater the real-time etching depth during the plasma dry etching process for the key structure area in the first photolithography layout (i.e., the frequency of the terahertz reflection spectrum is inversely proportional to the real-time etching depth during the plasma dry etching process for the key structure area in the first photolithography layout). Determine whether the terahertz reflection spectrum has a mutation. When the terahertz reflection spectrum has a mutation, it indicates that both the frequency and the reflection amplitude of the terahertz reflection spectrum have mutated. At this time, determine the mutation point of the terahertz reflection spectrum and use the mutation point as the breakthrough point during the plasma dry etching process for the key structure area in the first photolithography layout. When the terahertz reflection spectrum has no mutation, it indicates that neither the frequency nor the reflection amplitude of the terahertz reflection spectrum has mutated. At this time, continue to determine the real-time etching depth during the plasma dry etching process for the key structure area in the first photolithography layout according to the frequency of the terahertz reflection spectrum.
[0070] In some embodiments, as the etching depth continuously increases, the geometric dimensions of the metasurface change continuously, and its terahertz reflection spectrum also changes continuously. The value of the etching depth can be inversely solved through this change in the terahertz reflection spectrum. When a certain layer of material is etched through (broken through), the topological structure of the metasurface mutates, and its terahertz reflection spectrum mutates. The critical time node when a certain layer of material is broken through can be judged through this change in the terahertz reflection spectrum.
[0071] As a specific embodiment, refer to Figure 7 , which is a schematic diagram of the photolithography layout of the entire wafer according to some embodiments of the present invention.
[0072] Taking the gyroscope as the target device as an example for illustration, the gyroscope is a silicon-based microelectromechanical device. Obtain the first lithography layout corresponding to all the structures of the gyroscope (including the gyro rotor, inner and outer frames, support structures, comb structures, etc.), and determine the key structure area of the target device in the first lithography layout. Since the comb structure is usually the part with the narrowest line width in the gyroscope and is an important functional structure for the device to sense angular velocity, its processing quality has an important impact on the device performance. Therefore, select the comb structure as the key structure area, and perform periodic repetition on the key structure area to form a metasurface of the key structure. Then, obtain the corresponding second lithography layout according to the metasurface, and parallelly splice the second lithography layout corresponding to the comb structure with the first lithography layout corresponding to the gyroscope to form the lithography layout of the entire wafer.
[0073] Continue to refer to Figure 6 , and perform processing according to the processing steps of the gyroscope. In the dry etching step, simultaneously perform dry etching on the key structure area of the target device in the first lithography layout and the corresponding area of the second lithography layout in the overall lithography layout. Irradiate the corresponding area of the second lithography layout in the overall lithography layout with an electromagnetic beam, and measure its terahertz reflection spectrum. Among them, the wavelength of the electromagnetic beam is greater than or equal to the structural period of the metasurface. In this example, terahertz waves in the frequency range of 0.2 - 2.1 THz are used. As the etching depth continuously increases, the geometric size of the metasurface continuously changes, and its terahertz reflection spectrum continuously changes. The value of the etching depth can be inversely solved through this change in the terahertz reflection spectrum. When a certain layer of material is etched through (etched through), the topological structure of the metasurface undergoes a mutation, and its terahertz reflection spectrum undergoes a mutation. The critical time node when a certain layer of material is etched through can be judged through this change in the terahertz reflection spectrum.
[0074] Refer to Figure 8 , which is a schematic diagram of the simulation model of the second lithography layout according to some embodiments of the present invention.
[0075] In some embodiments, in order to illustrate that the terahertz reflection spectrum of the corresponding area of the second lithography layout in the overall lithography layout changes with the change of the etching depth, in this embodiment, a full-wave electromagnetic simulation is performed on the second lithography layout. Refer to Table 1, which shows the geometric parameters of the simulation model of the second lithography layout. Construct the simulation model of the second lithography layout according to the geometric parameters of the simulation model of the second lithography layout. During the simulation process, periodic boundary conditions are adopted in the positive x-axis direction and the positive y-axis direction to simulate the second lithography layout, and the terahertz wave is incident along the negative z-axis direction and polarized along the positive x-axis direction.
[0076] Table 1
[0077] Parameter Definition Value (μm) <![CDATA[P x > Period in the positive x-axis direction 140 <![CDATA[P y > Period in the positive y-axis direction 52 <![CDATA[T p > Photoresist thickness 10 <![CDATA[T d > Device thickness 90 <![CDATA[T a > Thickness of the gap between the device and the glass 20 <![CDATA[T g > Glass thickness 100 <![CDATA[L c > Comb length 65 <![CDATA[L f > Root length of the comb 25 <![CDATA[L o > Overlap length of the comb 25 <![CDATA[W a > Space gap thickness 13 <![CDATA[W c > Comb width 13 D Etching depth 0-100
[0078] Refer to Figure 9, which is a schematic diagram of the terahertz reflection spectrum of the corresponding region of the second photolithography layout in the overall photolithography layout changing with the etching depth according to some embodiments of the present invention.
[0079] The terahertz reflection spectrum generated by the polarization of the corresponding region of the second photolithography layout in the overall photolithography layout in the second direction (positive x-axis direction) exhibits obvious resonance characteristics, that is, the reflectivity reaches the minimum value at a certain frequency (30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm), and this frequency is called the resonance frequency of the metasurface. From Figure 9 it can be seen that as the etching depth increases, the resonance frequency of the corresponding region of the second photolithography layout in the overall photolithography layout gradually decreases; when reaching the etching end point or the breakthrough point (etching depth reaches 90μm), the reflection spectrum of the corresponding region of the second photolithography layout in the overall photolithography layout undergoes a mutation.
[0080] Refer to Figure 10 , which is a schematic diagram of the simulation results of the terahertz reflection spectrum generated by the polarization of the corresponding region of the second photolithography layout in the overall photolithography layout in the second direction (positive x-axis direction) and the third direction (positive y-axis direction) according to some embodiments of the present invention.
[0081] It can be seen from Figure 10 that the change in the frequency of the terahertz reflection spectrum generated by the polarization in the second direction (positive x-axis direction) with the reaching of the etching end point or the breakthrough point is relatively large, and the change in the frequency of the terahertz reflection spectrum generated by the polarization in the third direction (positive y-axis direction) with the reaching of the etching end point or the breakthrough point is relatively small. Therefore, in the present invention, Figure 9 the embodiments with relatively large changes in the frequency of the terahertz reflection spectrum with mutations are described.
[0082] In summary, according to the plasma dry etching process monitoring method based on metasurface of the embodiment of the present invention, it includes: obtaining a first photolithography layout corresponding to all structures of a target device; determining a key structure region of the target device in the first photolithography layout, and performing periodic repetition on the key structure region to form a metasurface of the key structure, and obtaining a corresponding second photolithography layout according to the metasurface; wherein, the key structure is included in all structures; splicing the second photolithography layout and the first photolithography layout in parallel to obtain an overall photolithography layout; performing a plasma dry etching process on the overall photolithography layout; obtaining a terahertz reflection spectrum generated by irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; determining the process state of the plasma dry etching process for the key structure region in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum. Thus, this method can detect the process state in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and then precisely control the etching depth in the plasma dry etching process, avoid over-etching or under-etching, can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0083] It should be noted that the method of the embodiment of the present invention can be executed by a single device, such as a computer or a server, etc. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In this case of a distributed scenario, one of the multiple devices can only execute one or more steps of the method of the embodiment of the present invention, and these multiple devices will interact with each other to complete the above method.
[0084] It should be noted that some embodiments of the present invention are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be executed in a different order from those in the above embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.
[0085] Corresponding to the above embodiment, the present invention also proposes a plasma dry etching process monitoring device based on metasurface.
[0086] As Figure 11As shown in the figure, the plasma dry etching process monitoring device based on the metasurface according to the embodiment of the present invention may include: a first acquisition module 1110, a construction module 1120, a splicing module 1130, an etching module 1140, a second acquisition module 1150, and an equivalent substitution module 1160.
[0087] Among them, the first acquisition module 1110 is configured to acquire a first photolithography layout corresponding to all structures of the target device; the construction module 1120 is configured to determine the key structure area of the target device in the first photolithography layout, perform periodic repetition on the key structure area to form a metasurface of the key structure, and obtain a corresponding second photolithography layout according to the metasurface; wherein, the key structure is included in all structures; the splicing module 1130 is configured to perform parallel splicing on the second photolithography layout and the first photolithography layout to obtain an overall photolithography layout; the etching module 1140 is configured to perform a plasma dry etching process on the overall photolithography layout; the second acquisition module 1150 is configured to acquire a terahertz reflection spectrum generated by irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; the equivalent substitution module 1160 is configured to determine the process state of the plasma dry etching process for the key structure area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum.
[0088] In some embodiments of the present invention, the first acquisition module 1110 acquires a first photolithography layout corresponding to all structures of the target device, specifically for: determining all structures of the target device; acquiring first geometric parameters of all structures, and drawing the first photolithography layout according to the first geometric parameters.
[0089] In some embodiments of the present invention, the construction module 1120 determines the key structure area of the target device in the first photolithography layout, performs periodic repetition on the key structure area to form a metasurface of the key structure, and obtains a corresponding second photolithography layout according to the metasurface, specifically for: selecting the key structure from the first photolithography layout according to a pre-determined selection criterion; acquiring second geometric parameters of the key structure, performing periodic repetition on the second geometric parameters to form a metasurface of the key structure; drawing the second photolithography layout according to the metasurface; wherein, a plurality of key structures are mapped on the second photolithography layout.
[0090] In some embodiments of the present invention, the selection criterion includes at least one of a geometric line width less than a preset line width threshold, a performance impact on the target device greater than a preset performance threshold, and a success rate of the plasma dry etching process lower than a preset success rate threshold.
[0091] In some embodiments of the present invention, the second acquisition module 1150 acquires the terahertz reflection spectrum generated by irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam, specifically: irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam along a first direction; wherein the wavelength of the electromagnetic beam is not less than the structural period of the metasurface; acquiring the terahertz reflection spectrum generated by the polarization of the area corresponding to the second photolithography layout in the overall photolithography layout in a second direction; wherein the first direction is perpendicular to the second photolithography layout, the second direction is parallel to the second photolithography layout, and the first direction is perpendicular to the second direction.
[0092] In some embodiments of the present invention, the second acquisition module 1150 is further configured to acquire the terahertz reflection spectrum generated by the polarization of the second photolithography layout in a third direction; wherein the third direction is parallel to the second photolithography layout, the first direction is perpendicular to the third direction, and the second direction is perpendicular to the third direction.
[0093] In some embodiments of the present invention, the equivalent substitution module 1160 determines the process state of the plasma dry etching process for the key structure area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum, specifically: determining the real-time etching depth when the plasma dry etching process is performed on the key structure area in the first photolithography layout according to the frequency of the terahertz reflection spectrum; wherein the frequency is inversely proportional to the real-time etching depth; determining the mutation point of the terahertz reflection spectrum and using the mutation point as the breakthrough point when the plasma dry etching process is performed on the key structure area in the first photolithography layout; wherein the mutation point is the point at which the frequency of the terahertz reflection spectrum mutates and the reflection amplitude mutates.
[0094] It should be noted that for the details not disclosed in the plasma dry etching process monitoring device based on the metasurface in the embodiments of the present invention, please refer to the details disclosed in the plasma dry etching process monitoring method based on the metasurface in the embodiments of the present invention, which will not be elaborated herein.
[0095] In summary, the plasma dry etching process monitoring device based on metasurface according to the embodiments of the present invention includes: a first acquisition module that acquires a first photolithography layout corresponding to all structures of a target device; a construction module that determines a key structure area of the target device in the first photolithography layout, and performs periodic repetition on the key structure area to form a metasurface of the key structure, and obtains a corresponding second photolithography layout according to the metasurface; wherein the key structure is included in all structures; a splicing module that splices the second photolithography layout and the first photolithography layout in parallel to obtain an overall photolithography layout; an etching module that performs a plasma dry etching process on the overall photolithography layout; a second acquisition module that acquires a terahertz reflection spectrum generated by irradiating the area corresponding to the second photolithography layout in the overall photolithography layout with an electromagnetic beam; an equivalent substitution module that determines the process state of the plasma dry etching process for the key structure area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum. Thus, the present device can detect the process state in the plasma dry etching process through a real-time, in-situ, non-invasive monitoring method, and further precisely control the etching depth in the plasma dry etching process, avoiding over-etching or under-etching. It can effectively improve the final quality of the product without affecting the processing process, improve the R & D efficiency of new category products, reduce the time and material costs brought by multiple rounds of processing experiments, and achieve the precise forming of the key structure of the target device (chip).
[0096] For the convenience of description, when describing the above system, various modules are described separately according to their functions. Of course, when implementing the present invention, the functions of each module can be implemented in one or more software and / or hardware.
[0097] The system of the above embodiment is used to implement the corresponding method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be elaborated herein.
[0098] Corresponding to the above embodiment, the present invention also proposes an electronic device.
[0099] Reference Figure 12 , which is a block diagram of an electronic device according to some embodiments of the present invention, showing a more specific schematic diagram of the hardware structure of the electronic device provided in this embodiment. The device may include: a processor 1210, a memory 1220, an input / output interface 1230, a communication interface 1240, and a bus 1250. Among them, the processor 1210, the memory 1220, the input / output interface 1230, and the communication interface 1240 are communicatively connected to each other inside the device through the bus 1250.
[0100] The processor 1210 can be implemented in the form of a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.
[0101] The memory 1220 can be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1220 can store an operating system and other application programs. When implementing the technical solutions provided in the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory 1220 and are called and executed by the processor 1210.
[0102] The input / output interface 1230 is used to connect to the input / output module to implement information input and output. The input / output module can be configured as a component in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Among them, the input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device can include a display, a speaker, a vibrator, an indicator light, etc.
[0103] The communication interface 1240 is used to connect to a communication module (not shown in the figure) to implement communication interaction between this device and other devices. Among them, the communication module can implement communication in a wired manner (such as USB, network cable, etc.) or in a wireless manner (such as mobile network, WIFI, Bluetooth, etc.).
[0104] The bus 1250 includes a path for transmitting information between various components of the device (such as the processor 1210, the memory 1220, the input / output interface 1230, and the communication interface 1240).
[0105] It should be noted that although the above device only shows the processor 1210, the memory 1220, the input / output interface 1230, the communication interface 1240, and the bus 1250, in the specific implementation process, this device may also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device may also only include the components necessary to implement the solutions of the embodiments of this specification, and do not necessarily include all the components shown in the figure.
[0106] The electronic device in the above embodiment is used to implement the corresponding method in any of the foregoing embodiments and has the beneficial effects of the corresponding method embodiments, which will not be elaborated here.
[0107] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, the present invention further provides a computer-readable storage medium storing computer instructions for causing a computer to execute the method of any of the above embodiments.
[0108] The above computer-readable storage medium may be any available medium or data storage device accessible by a computer, including but not limited to magnetic memory (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical memory (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor memory (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drives (SSDs), etc.).
[0109] The computer instructions stored in the storage medium of the above embodiments are used to cause a computer to execute the method of any of the embodiments in the above exemplary method section, and have the beneficial effects of the corresponding method embodiments, which will not be elaborated herein.
[0110] In addition, although the operations of the method of the present invention are described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all of the shown operations must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart may be changed in the order of execution. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.
[0111] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.
[0112] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the embodiments of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0113] Although the spirit and principles of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the specific embodiments disclosed, and the division of each aspect does not mean that the features in these aspects cannot be combined for benefits. Such division is only for convenience of expression. The present invention aims to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Claims
1. A method for monitoring a plasma dry etching process based on a metasurface, characterized in that: include: Obtaining a first photolithography layout corresponding to all structures of the target device; Determine the key structure area of the target device in the first lithography layout, and periodically repeat the key structure area to form a metasurface of the key structure, and obtain a corresponding second lithography layout according to the metasurface; wherein the key structure is included in the entire structure; Parallel splicing of the second photolithography pattern and the first photolithography pattern to obtain an overall photolithography pattern; Performing a plasma dry etching process on the overall photolithography pattern; Acquire a terahertz reflection spectrum generated by irradiating a region corresponding to the second photolithography pattern in the overall photolithography pattern with an electromagnetic wave beam; The process state of the plasma dry etching process in the key structure area in the first photolithography in the overall photolithography is determined according to the terahertz reflection spectrum.
2. The method for monitoring a plasma dry etching process based on a metasurface according to claim 1, characterized in that: The step of obtaining a first lithography layout corresponding to all structures of the target device includes: Determine the overall structure of the target device; The first geometric parameters of the entire structure are obtained, and the first photolithography pattern is drawn according to the first geometric parameters.
3. The method for monitoring a plasma dry etching process based on a metasurface according to claim 2, characterized in that: The determining of the key structure region of the target device in the first lithography layout, periodically repeating the key structure region to form a metasurface of the key structure, and obtaining a corresponding second lithography layout according to the metasurface includes: Selecting the key structure from the first photolithography layout according to a predetermined selection criterion; Acquiring a second geometric parameter of the key structure, and periodically repeating the second geometric parameter to form a metasurface of the key structure; The second photolithography layout is drawn according to the metasurface; wherein the second photolithography layout maps a plurality of the key structures.
4. The method for monitoring a plasma dry etching process based on a metasurface according to claim 3, characterized in that: The selection criteria include at least one of a geometric line width smaller than a preset line width threshold, an impact on the performance of a target device greater than a preset performance threshold, and a success rate of a plasma dry etching process lower than a preset success rate threshold.
5. The method for monitoring a plasma dry etching process based on a metasurface according to claim 1, characterized in that: The step of obtaining a terahertz reflection spectrum generated by irradiating an area corresponding to the second lithography pattern in the overall lithography pattern with an electromagnetic wave beam comprises: Irradiating a region corresponding to the second photolithography pattern in the overall photolithography pattern with an electromagnetic wave beam along a first direction; wherein the wavelength of the electromagnetic wave beam is not less than the structural period of the metasurface; Obtain a terahertz reflection spectrum generated by polarization in a second direction in an area corresponding to the second lithography pattern in the overall lithography pattern; wherein the first direction is perpendicular to the second lithography pattern, the second direction is parallel to the second lithography pattern, and the first direction is perpendicular to the second direction.
6. The method for monitoring a plasma dry etching process based on a metasurface according to claim 5, characterized in that: The method further comprises: A terahertz reflection spectrum generated by polarization of the second lithography pattern in a third direction is obtained; wherein the third direction is parallel to the second lithography pattern, the first direction is perpendicular to the third direction, and the second direction is perpendicular to the third direction.
7. The method for monitoring a plasma dry etching process based on a metasurface according to claim 5 or 6, characterized in that: The step of determining the process state of the plasma dry etching process in the key structure area in the first photolithography layout in the overall photolithography layout according to the terahertz reflection spectrum includes: Determining the real-time etching depth of the key structure area in the first photolithography when the plasma dry etching process is performed according to the frequency of the terahertz reflection spectrum; wherein the frequency is inversely proportional to the real-time etching depth; Determine a mutation point of the terahertz reflection spectrum, and use the mutation point as an etching point when the key structure area in the first photolithography pattern is subjected to the plasma dry etching process; wherein the mutation point is a point where the frequency of the terahertz reflection spectrum mutates and the reflection amplitude mutates.
8. A plasma dry etching process monitoring device based on a metasurface, characterized in that: include: A first acquisition module is configured to acquire a first lithography layout corresponding to all structures of the target device; A construction module is configured to determine a key structure region of the target device in the first lithography layout, and periodically repeat the key structure region to form a metasurface of the key structure, and obtain a corresponding second lithography layout according to the metasurface; wherein the key structure is included in the entire structure; A splicing module is configured to splice the second photolithography pattern with the first photolithography pattern in parallel to obtain an overall photolithography pattern; An etching module, configured to perform a plasma dry etching process on the entire photolithography pattern; A second acquisition module is configured to acquire a terahertz reflection spectrum generated by irradiating a region corresponding to the second lithography pattern in the overall lithography pattern with an electromagnetic beam; The equivalent replacement module is configured to determine the process state of the plasma dry etching process in the key structure area in the first photolithography in the overall photolithography according to the terahertz reflection spectrum.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the plasma dry etching process monitoring method based on the metasurface is implemented as described in any one of claims 1 to 7.
10. A computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable the computer to implement the plasma dry etching process monitoring method based on the metasurface according to any one of claims 1 to 7.
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