Manufacturing method of metasurface lens and metasurface lens

Abstract

The invention discloses a manufacturing method of a metasurface lens and the metasurface lens, and is characterized in that the method can be applied to the technical field of microelectronics, and the method comprises the steps: providing a substrate layer; forming a hard mask layer on the substrate layer; forming a first metasurface structure and a second metasurface structure on the hard mask layer step by step based on different photoetching processes; the pattern line width of the first metasurface structure is smaller than that of the second metasurface structure; and transferring the first metasurface structure and the second metasurface structure on the hard mask layer to the substrate layer. Therefore, when patterns with different line widths are formed on the substrate layer, photoetching is carried out step by step by adopting different photoetching modes, so that the accuracy of each metasurface structure in the metasurface lens is improved.

Description

Technical Field

[0001] The present application relates to the field of microelectronics technology, and in particular, to a manufacturing method of a metasurface lens and a metasurface lens. Background Art

[0002] A metasurface refers to an artificial microstructure array in which many units in a planar space are densely arranged at a sub-wavelength interval. A metasurface lens is an optical device that uses artificial sub-wavelength unit structures to perform wavefront modulation on a traditional medium. It focuses light through precisely designed nanostructures, and has the advantages of thinner volume, lighter weight, lower cost, and better imaging quality.

[0003] The micro-nano structures on the optical metasurface usually consist of a very large number of nano-sized structures, with small linewidth dimensions and large spans. The smallest size is dozens of nanometers, and the largest size is hundreds of nanometers. In the existing metasurface processing process, lithography and etching are usually carried out based on the linewidth size with the largest proportion, which easily causes the structures with small and large linewidths to deviate from the designed dimensions, and then leads to the problem of metasurface structures with low precision in the metasurface lens.

[0004] Therefore, how to improve the precision of each metasurface structure in the metasurface lens is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] Based on the above problems, the present application provides a manufacturing method of a metasurface lens and a metasurface lens. When forming patterns with different linewidths on a substrate layer, different lithography methods are used for step-by-step lithography, which improves the precision of each metasurface structure in the metasurface lens.

[0006] In a first aspect, an embodiment of the present application provides a manufacturing method of a metasurface lens, including:

[0007] Providing a substrate layer;

[0008] Forming a hard mask layer on the substrate layer;

[0009] Based on different lithography processes, forming a first metasurface structure and a second metasurface structure on the hard mask layer step by step; the graphic linewidth of the first metasurface structure is smaller than that of the second metasurface structure;

[0010] Transferring the first metasurface structure and the second metasurface structure on the hard mask layer to the substrate layer.

[0011] Optionally, the forming a first metasurface structure and a second metasurface structure on the hard mask layer step by step based on different lithography processes includes:

[0012] Transfer the patterns on the first-size layout to the hard mask layer based on the first lithography process to form the first metasurface structure; the patterns on the first-size layout are consistent with the patterns of the first metasurface structure.

[0013] Transfer the patterns on the second-size layout to the hard mask layer based on the second lithography process to form the second metasurface structure; the patterns on the second-size layout are consistent with the patterns of the second metasurface structure.

[0014] Optionally, when the first-size layout only contains patterns with a line width less than 130 nm, the first lithography process is an electron beam lithography process.

[0015] Optionally, when the second-size layout only contains patterns with a line width greater than 130 nm, the second lithography process is a DUV lithography process.

[0016] Optionally, the step of transferring the patterns on the first-size layout to the hard mask layer based on the first lithography process to form the first metasurface structure includes:

[0017] Form a first anti-reflection layer and a first photoresist layer on the hard mask layer in sequence;

[0018] Transfer the patterns on the first-size layout to the first photoresist layer based on the electron beam lithography process;

[0019] Etch the first anti-reflection layer and the hard mask layer in sequence to transfer the patterns on the first photoresist layer to the hard mask layer and form the first metasurface structure.

[0020] Optionally, the step of transferring the patterns on the second-size layout to the hard mask layer based on the second lithography process to form the second metasurface structure includes:

[0021] Form a second anti-reflection layer and a second photoresist layer on the hard mask layer in sequence;

[0022] Transfer the patterns on the second-size layout to the second photoresist layer based on the DUV lithography process;

[0023] Etch the second anti-reflection layer and the hard mask layer in sequence to transfer the patterns on the second photoresist layer to the hard mask layer and form the second metasurface structure.

[0024] Optionally, the method further includes: after forming the first metasurface structure, removing the first anti-reflection layer and the first photoresist layer, and cleaning the hard mask layer.

[0025] Optionally, the method further includes: after forming the second metasurface structure, removing the second anti-reflection layer and the second photoresist layer, and cleaning the hard mask layer.

[0026] Optionally, the substrate layer is a silicon substrate wafer;

[0027] Forming the hard mask layer on the substrate layer includes:

[0028] Forming a layer of silicon dioxide or silicon nitride on the silicon substrate wafer as the hard mask layer.

[0029] In a second aspect, an embodiment of the present application provides a metasurface lens, including: a substrate layer;

[0030] There are a first metasurface structure and a second metasurface structure on the substrate layer;

[0031] The graphic line width of the first metasurface structure is smaller than that of the second metasurface structure.

[0032] It can be seen from the above technical solutions that, compared with the prior art, the present application has the following advantages:

[0033] A manufacturing method of a metasurface lens provided by the present application includes: first providing a substrate layer and forming a hard mask layer on the substrate layer. Then, based on different lithography processes, the first metasurface structure and the second metasurface structure are formed on the hard mask layer step by step. Among them, the graphic line width of the first metasurface structure is smaller than that of the second metasurface structure. Finally, the first metasurface structure and the second metasurface structure on the hard mask layer are transferred to the substrate layer. In this way, when forming graphics with different line widths on the substrate layer, by using different lithography methods for lithography step by step, the accuracy of each metasurface structure in the metasurface lens is improved. Description of the Drawings

[0034] Figure 1 Is a side cut-away view of a metasurface lens provided by an embodiment of the present application;

[0035] Figure 2 Is a graphic diagram of a metasurface structure provided by an embodiment of the present application;

[0036] Figure 3 Is a flowchart of a manufacturing method of a metasurface lens provided by an embodiment of the present application;

[0037] Figure 4 Is a structural diagram of a substrate layer provided by an embodiment of the present application;

[0038] Figure 5 Is a structural diagram of a hard mask layer provided by an embodiment of the present application;

[0039] Figure 6 A schematic flow chart of an electron beam lithography process provided by an embodiment of the present application;

[0040] Figure 7 A schematic diagram of a device structure after resist stripping provided by an embodiment of the present application;

[0041] Figure 8 A schematic flow chart of a DUV lithography process provided by an embodiment of the present application;

[0042] Figure 9 Another schematic diagram of a device structure after resist stripping provided by an embodiment of the present application;

[0043] Figure 10 A schematic diagram of the structure of a substrate layer after pattern transfer provided by an embodiment of the present application. Detailed implementation manners

[0044] As described above, the existing metasurface processing process will cause the problem of metasurface structures with low accuracy in the metasurface lens. Specifically, the micro-nano structures of the metasurface are usually composed of a very large number of nano-sized structures. The line width dimensions of each structure are small, and the span between them is large. The smallest size is only dozens of nanometers, while the largest size can reach hundreds of nanometers. Thus, for the lithography process, the DUV lithography machines used by traditional wafer fabrication plants can only expose dimensions above 130 nm, and cannot expose dimensions below 130 nm. During the etching process, due to the large line width span at different positions and different densities in different regions, the etching efficiency at different positions on the same wafer is different, and finally the etching depths between the line width dimension structures are different. The existing metasurface processing process usually uses the line width dimension with the largest proportion as the standard for lithography and etching, which will cause the structures with small and large line widths to deviate from the designed dimensions, and thus lead to the problem of metasurface structures with low accuracy in the metasurface lens.

[0045] To solve the above problems, an embodiment of the present application provides a method for manufacturing a metasurface lens. The method first provides a substrate layer and forms a hard mask layer on the substrate layer. Then, based on different lithography processes, a first metasurface structure and a second metasurface structure are formed on the hard mask layer step by step. Among them, the graphic line width of the first metasurface structure is smaller than that of the second metasurface structure. Finally, the first metasurface structure and the second metasurface structure on the hard mask layer are transferred to the substrate layer.

[0046] In this way, when forming patterns with different line width sizes on the substrate layer, by using different lithography methods for lithography step by step, the accuracy of each metasurface structure in the metasurface lens is improved.

[0047] It should be noted that a manufacturing method of a metasurface lens and a metasurface lens provided in this application can be applied to the field of microelectronics technology. The above is only an example and does not limit the application field of a manufacturing method of a metasurface lens and a metasurface lens provided in this application.

[0048] In order to make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0049] Figure 1 This is a side cut schematic diagram of a metasurface lens provided in an embodiment of this application. Combining Figure 1 as shown, the metasurface lens includes: a substrate layer 100;

[0050] There are a first metasurface structure 001 and a second metasurface structure 002 on the substrate layer 100;

[0051] The graphic line width of the first metasurface structure 001 is smaller than the graphic line width of the second metasurface structure 002.

[0052] Specifically, a metasurface lens is a revolutionary planar optical element manufactured using metasurface technology for focusing or manipulating light, and its working principle is completely different from that of traditional curved lenses based on refraction or reflection. Among them, a metasurface refers to a two-dimensional form of artificial structured material composed of a large number of nanostructure (metasurface structure) units arranged in a specific pattern. Figure 2 This is a graphic schematic diagram of a metasurface structure provided in an embodiment of this application. Combining Figure 2 as shown, there are a large number of metasurface structures on the substrate layer 100. The graphic line width dimensions of these metasurface structures are all small, and the span between them is large. To ensure manufacturing accuracy, different processes need to be used for preparation. For this reason, each metasurface structure needs to be classified according to its graphic line width dimension. In the embodiments of this application, the metasurface structures are only classified into two categories according to the graphic line width dimension, that is, the first metasurface structure ( Figure 2 a in) and the first metasurface structure ( Figure 2 b in). Among them, the line width of the graphic 003 of the first metasurface structure referred to by a is smaller than the line widths of the graphics 004 and 005 of the second metasurface structure referred to by b. It can be understood that the classification of metasurface structures depends on the manufacturing process. In other possible embodiments, the metasurface structures can also be classified into a third category, a fourth category, etc.

[0053] Figure 3 The flowchart of a manufacturing method of a metasurface lens provided by an embodiment of the present application. In combination with Figure 3 As shown, a manufacturing method of a metasurface lens provided by an embodiment of the present application may include:

[0054] S1: Provide a substrate layer.

[0055] Figure 4 The schematic structural diagram of a substrate layer provided by an embodiment of the present application. In combination with Figure 4 As shown, the substrate layer is the basis of nanomanufacturing and needs to have sufficient flatness, cleanliness, and chemical stability to provide mechanical support for the metasurface structure.

[0056] S2: Form a hard mask layer on the substrate layer.

[0057] In practical applications, the hard mask layer is a crucial temporary auxiliary film. It acts as an "intermediate medium" for pattern transfer, can protect the substrate layer from damage by unnecessary etching processes, and enables the processing of nanostructures with high fidelity and high aspect ratio. Its importance lies in its ability to protectively transfer complex and delicate patterns. Figure 5 The schematic structural diagram of a hard mask layer provided by an embodiment of the present application. In combination with Figure 5 As shown, an embodiment of the present application introduces a hard mask layer 200, forms a hard mask layer on the substrate layer, then transfers the metasurface structure to the hard mask layer first, and then transfers the metasurface structure from the hard mask layer to the substrate layer.

[0058] In addition, since the methods of manufacturing the hard mask layer are different, an embodiment of the present application can illustrate one possible manufacturing method.

[0059] In one case, the substrate layer is a silicon substrate wafer;

[0060] S2: The forming of the hard mask layer on the substrate layer may specifically include:

[0061] Form a layer of silicon dioxide or silicon nitride on the silicon substrate wafer as the hard mask layer.

[0062] In practical applications, a silicon substrate wafer with characteristics such as manufacturability, high precision, easy integration, and scalability can be selected as the substrate layer material. Further, the hard mask layer may correspond to silicon dioxide or silicon nitride and is prepared on the silicon substrate wafer by chemical vapor deposition (CVD).

[0063] S3: Based on different lithography processes, form a first metasurface structure and a second metasurface structure on the hard mask layer step by step; the graphic line width of the first metasurface structure is smaller than that of the second metasurface structure.

[0064] In practical applications, metasurface structures generally need to be formed through lithography and etching processes. Since the line width dimensions between various metasurface structures have a large span, the smallest dimension is only dozens of nanometers, and the largest dimension can reach hundreds of nanometers. However, the resolution of existing exposure equipment is limited, so it is impossible to use a single lithography process to ensure that each metasurface structure has good accuracy. Therefore, in the embodiments of the present application, based on various lithography processes and on the premise of ensuring graphic accuracy, the graphic line widths that can be prepared are used to classify the metasurface structures to be prepared. Then, based on the lithography processes corresponding to each graphic line width, a first metasurface structure and a second metasurface structure are formed on the hard mask layer step by step. After classification, there is an obvious boundary between the graphic line widths of the first metasurface structure and the second metasurface structure. For example, the graphic line width of the first surface structure is less than x, while the graphic line width of the second surface structure is greater than x. It can be understood that in other possible embodiments, the metasurface structure may further include a third surface structure, a fourth surface structure, etc.

[0065] In addition, since the step-by-step manufacturing methods are different, the embodiments of the present application can illustrate one possible manufacturing method.

[0066] In one case, the forming of the first metasurface structure and the second metasurface structure on the hard mask layer step by step based on different lithography processes includes:

[0067] Transfer the graphics on the first-size layout to the hard mask layer based on the first lithography process to form a first metasurface structure; the graphics on the first-size layout are consistent with the graphics of the first metasurface structure;

[0068] Transfer the graphics on the second-size layout to the hard mask layer based on the second lithography process to form a second metasurface structure; the graphics on the second-size layout are consistent with the graphics of the second metasurface structure.

[0069] In practical applications, the lithography process is the most core patterning technology in the metasurface lens, which is used to transfer nanostructure patterns onto a substrate or a functional layer. Its precision directly determines the performance of the device (such as diffraction efficiency and aberration control). Different metasurface structures have their corresponding layouts, and the graphics of the two are consistent. Therefore, similar to the metasurface structure, the layout is also divided into different categories of size layouts. Taking the first metasurface structure corresponding to the first size layout and the second metasurface structure corresponding to the second size layout as an example, it is necessary to transfer the graphics on the first size layout onto the hard mask layer step by step through the first lithography process corresponding to the graphic line width on the first size layout; and transfer the graphics on the second size layout onto the hard mask layer through the second lithography process corresponding to the graphic line width on the second size layout. It can be understood that there is no obvious requirement for the sequence of preparing the first metasurface structure and the second metasurface structure on the hard mask layer. Generally, the graphics with a small line width will be prepared first.

[0070] In addition, since the graphics on the first size layout are different and the corresponding lithography methods are not the same, the embodiments of the present application can illustrate one possible lithography method.

[0071] In one case, when the first size layout only contains graphics with a line width less than 130 nm, the first lithography process is an electron beam exposure process.

[0072] In practical applications, the lithography machines used in wafer fabrication plants generally can only expose sizes above 130 nm, and cannot expose when the size is less than 130 nm. For this reason, the embodiments of the present application can divide the layout for exposure into two categories. One category of layout only contains graphics larger than 130 nm (i.e., the second size layout), and the other category of layout only contains graphics smaller than 130 nm (i.e., the first size layout). When it is necessary to transfer the graphics on the first size layout onto the hard mask layer, that is, to prepare graphics with a line width less than 130 nm, the (first) lithography process adopted by the embodiments of the present application is an electron beam exposure process. Electron beam exposure is the nanoscale patterning technology with the highest resolution and the strongest flexibility in the manufacturing of metasurface lenses.

[0073] In addition, since different lithography methods are used to manufacture graphics of different sizes, the embodiments of the present application can illustrate one possible graphics manufacturing method.

[0074] In one case, transferring the graphics on the first size layout onto the hard mask layer based on the first lithography process to form the first metasurface structure includes:

[0075] Sequentially forming a first anti-reflection layer and a first photoresist layer on the hard mask layer;

[0076] Transfer the patterns on the first-size layout to the first photoresist layer based on the electron beam lithography process;

[0077] Etch the first anti-reflection layer and the hard mask layer in sequence to transfer the patterns on the first photoresist layer to the hard mask layer, forming a first metasurface structure.

[0078] Figure 6 It is a schematic flow chart of an electron beam lithography process provided by an embodiment of the present application. Combining Figure 6 As shown, first, a first anti-reflection layer 300 and a first photoresist layer 400 are sequentially formed on the hard mask layer (such as Figure 6 a in). Then, place the first-size layout above the first photoresist layer, align the patterns in the first-size layout with the area on the first photoresist layer where the first metasurface structure is to be formed, and then perform the electron beam lithography process. After development, the same patterns as those on the first-size layout will be obtained on the first photoresist layer (such as Figure 6 b in). Further, first use the corresponding etching process to etch the first anti-reflection layer to transfer the patterns to the first anti-reflection layer (such as Figure 6 c in). The first anti-reflection layer (BARC) is coated between the hard mask layer and the first photoresist layer to suppress the reflected light of the substrate layer (hard mask layer) and reduce the standing wave effect and reflection notch in the first photoresist layer. Thereby improving the pattern resolution and the critical dimension precision. The etching process needs to be selected according to the material type and inheritance structure of BARC. Generally, the etching of organic BARC (such as carbon-based polymers) requires oxygen plasma, while the etching of inorganic BARC (such as titanium nitride, silicon nitride) requires fluorine-based or chlorine-based gases. Then use the corresponding etching process to etch the hard mask layer to transfer the patterns to the hard mask layer (such as Figure 6 d in). Combining the above, the hard mask layer is silicon dioxide or silicon nitride. Among them, for the etching of silicon dioxide, hydrofluoric acid (wet etching) or oxygen plasma (dry etching) is required, and for the etching of silicon nitride, phosphoric acid (wet etching) or fluorine-containing gas + silicon source is required.

[0079] Further, in order not to affect the manufacturing of the second metasurface structure, an embodiment of the present application can illustrate a possible processing method.

[0080] In one case, the method further includes: after forming the first metasurface structure, removing the first anti-reflection layer and the first photoresist layer, and cleaning the hard mask layer.

[0081] Figure 7 It is a schematic diagram of a device structure after degluing provided by an embodiment of the present application. Combining Figure 7As shown, first, the first photoresist layer is removed through processes such as organic solvent or oxygen plasma ashing, and then the underlying first anti-reflection layer can be continuously removed using the above etching process for the first anti-reflection layer. Further, a suitable solvent (which can remove the particles of the first photoresist layer and the first anti-reflection layer without causing loss of the hard mask layer and the substrate layer) is used to clean the overall structure to ensure the accuracy of manufacturing the second metasurface structure.

[0082] In addition, since the patterns on the second-size layout are different and the corresponding lithography methods are not the same, the embodiments of the present application can illustrate another possible lithography method.

[0083] In another case, when the second-size layout only contains patterns with a line width greater than 130 nm, the second lithography process is a DUV lithography process.

[0084] In practical applications, as described above, the lithography machines used by wafer fabrication plants generally can only expose patterns with a size of more than 130 nm, and cannot expose when the size is less than 130 nm. For this reason, the embodiments of the present application can divide the layout for exposure into two categories, one of which only contains patterns larger than 130 nm, and the other only contains patterns smaller than 130 nm. When it is necessary to transfer the patterns on the second-size layout to the hard mask layer, that is, to fabricate patterns with a line width greater than 130 nm, the (second) lithography process adopted by the embodiments of the present application is a DUV lithography process.

[0085] In addition, since the lithography methods used to fabricate different-size patterns are not the same, the embodiments of the present application can illustrate another possible pattern fabrication method.

[0086] In another case, transferring the patterns on the second-size layout to the hard mask layer based on the second lithography process to form a second metasurface structure includes:

[0087] A second anti-reflection layer and a second photoresist layer are sequentially formed on the hard mask layer;

[0088] Based on the DUV lithography process, the patterns on the second-size layout are transferred to the second photoresist layer;

[0089] The second anti-reflection layer and the hard mask layer are etched sequentially to transfer the patterns on the second photoresist layer to the hard mask layer to form a second metasurface structure.

[0090] Figure 8 A schematic flow diagram of a DUV lithography process provided by the embodiments of the present application. Combining Figure 8 As shown, first, a second anti-reflection layer 500 and a second photoresist layer 600 are sequentially formed on the hard mask layer (as Figure 8in a). The second anti-reflection layer and the second photoresist layer may be made of the same materials as the first anti-reflection layer and the first photoresist layer. Then, place the second-sized layout above the second photoresist layer, align the patterns in the second-sized layout with the area on the second photoresist layer where the second metasurface structure is to be formed, and then perform the DUV lithography process. After development, the same patterns as those on the second-sized layout will be obtained on the second photoresist layer (such as Figure 8 in b). Further, as described above, first use the corresponding etching process to etch the second anti-reflection layer to transfer the patterns to the second anti-reflection layer (such as Figure 8 in c). Then use the corresponding etching process to etch the hard mask layer, thereby transferring the patterns to the hard mask layer (such as Figure 8 in d).

[0091] Further, in order not to affect the transfer of the metasurface structure to the substrate layer, an embodiment of the present application can illustrate a possible processing method.

[0092] In one case, the method further includes: after forming the second metasurface structure, removing the second anti-reflection layer and the second photoresist layer, and cleaning the hard mask layer.

[0093] Figure 9 is a schematic diagram of the device structure after another type of resist stripping provided by the embodiment of the present application. Combining Figure 9 as shown, first remove the second photoresist layer through processes such as organic solvents or oxygen plasma ashing, and then the etching process provided above can be used to continue removing the underlying second anti-reflection layer. Further, use a suitable solvent to clean the overall structure to ensure the accuracy of subsequent pattern transfer.

[0094] S4: Transfer the first metasurface structure and the second metasurface structure on the hard mask layer to the substrate layer.

[0095] Figure 10 is a schematic diagram of the structure of the substrate layer after pattern transfer provided by the embodiment of the present application. Combining Figure 10 as shown, use the corresponding etching process to etch the substrate layer (this etching process has little impact on the hard mask layer), such as KOH solution, TMAH solution, etc., thereby transferring the patterns from the hard mask layer to the substrate layer to form the first metasurface structure and the second metasurface structure. Further, remove the hard mask layer to complete the manufacturing of the variable-sized metasurface lens.

[0096] In summary, a manufacturing method of a metasurface lens provided by the present application includes: first, providing a substrate layer and forming a hard mask layer on the substrate layer. Then, based on different lithography processes, a first metasurface structure and a second metasurface structure are formed on the hard mask layer step by step. Among them, the line width of the pattern of the first metasurface structure is smaller than that of the second metasurface structure. Finally, the first metasurface structure and the second metasurface structure on the hard mask layer are transferred to the substrate layer. In this way, when forming patterns with different line widths on the substrate layer, by using different lithography methods for lithography step by step, the accuracy of each metasurface structure in the metasurface lens is improved.

[0097] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A manufacturing method of a metasurface lens, characterized in that, The method includes: Providing a substrate layer; Forming a hard mask layer on the substrate layer; Based on different lithography processes, step by step forming a first metasurface structure and a second metasurface structure on the hard mask layer; the graphic line width of the first metasurface structure is smaller than that of the second metasurface structure; Transferring the first metasurface structure and the second metasurface structure on the hard mask layer to the substrate layer.

2. The method according to claim 1, wherein The step of, based on different lithography processes, step by step forming a first metasurface structure and a second metasurface structure on the hard mask layer includes: Transferring the graphics on the first-size layout to the hard mask layer based on the first lithography process to form a first metasurface structure; the graphics on the first-size layout are consistent with those of the first metasurface structure; Transferring the graphics on the second-size layout to the hard mask layer based on the second lithography process to form a second metasurface structure; the graphics on the second-size layout are consistent with those of the second metasurface structure.

3. The method according to claim 2, wherein When only graphics with a line width less than 130 nm are included in the first-size layout, the first lithography process is an electron beam exposure process.

4. The method according to claim 2, wherein When only graphics with a line width greater than 130 nm are included in the second-size layout, the second lithography process is a DUV lithography process.

5. The method according to claim 3, wherein The step of transferring the graphics on the first-size layout to the hard mask layer based on the first lithography process to form a first metasurface structure includes: Successively forming a first anti-reflection layer and a first photoresist layer on the hard mask layer; Transferring the graphics on the first-size layout to the first photoresist layer based on the electron beam exposure process; Successively etching the first anti-reflection layer and the hard mask layer to transfer the graphics on the first photoresist layer to the hard mask layer to form a first metasurface structure.

6. The method according to claim 3, characterized in that, The step of transferring the graphics on the second-size layout to the hard mask layer based on the second lithography process to form a second metasurface structure includes: Successively forming a second anti-reflection layer and a second photoresist layer on the hard mask layer; Transferring the graphics on the second-size layout to the second photoresist layer based on the DUV lithography process; Successively etching the second anti-reflection layer and the hard mask layer to transfer the graphics on the second photoresist layer to the hard mask layer to form a second metasurface structure.

7. The method according to claim 5, wherein The method further includes: after forming the first metasurface structure, removing the first anti-reflection layer and the first photoresist layer, and cleaning the hard mask layer.

8. The method according to claim 6, characterized in that, The method further includes: after forming the second metasurface structure, removing the second anti-reflection layer and the second photoresist layer, and cleaning the hard mask layer.

9. The method according to claim 1, characterized in that, The substrate layer is a silicon substrate wafer; The step of forming a hard mask layer on the substrate layer includes: Forming a layer of silicon dioxide or silicon nitride on the silicon substrate wafer as the hard mask layer.

10. A metasurface lens, characterized in that, The metasurface lens includes: a substrate layer; There are a first metasurface structure and a second metasurface structure on the substrate layer; The graphic line width of the first metasurface structure is smaller than that of the second metasurface structure.

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