WO2024055712A1

WO2024055712A1 - Double-sided superlens processing method

Info

Publication number: WO2024055712A1
Application number: PCT/CN2023/104802
Authority: WO
Inventors: 朱健; 郝成龙; 谭凤泽
Original assignee: 深圳迈塔兰斯科技有限公司
Priority date: 2022-09-15
Filing date: 2023-06-30
Publication date: 2024-03-21
Also published as: CN117742078A

Abstract

The present invention provides a double-sided superlens processing method. The method comprises: providing a first structural layer on a first surface of a substrate, and performing a first photolithography operation on the first structural layer to obtain a first nanostructure and an alignment identification mark; providing a second structural layer on a second surface of the substrate; manufacturing an alignment window at the position of the second structural layer corresponding to the alignment identification mark; and performing alignment on the basis of the alignment identification mark, and performing a second photolithography operation on the second structural layer to obtain a second nanostructure. According to the double-sided superlens processing method provided in the embodiments of the present invention, on the basis of the alignment identification mark obtained from the first photolithography operation and the alignment window at the position of the second structural layer corresponding to the alignment identification mark, the alignment identification mark is identified through the alignment window, alignment is performed, and the second photolithography operation is performed. The method breaks the accuracy limits of conventional backside overlay processes, so that the alignment accuracy in the process of processing the first nanostructure and the second nanostructure is increased to the accuracy of a photolithography machine.

Description

A kind of processing method of double-sided super lens

Technical field

The present invention relates to the technical field of super lens processing, and specifically, to a processing method of a double-sided super lens.

Background technique

At present, the manufacturing of double-sided metalens (such as metalens with different nanostructures on the front and back of the same wafer) usually uses a contact exposure backside overlay process. After processing the nanostructure on the front of a certain wafer, An overlay mark is set on the back side, and the back side of the wafer is identified through a photolithography machine detector to identify the overlay mark, and the nanostructure on the back side is processed to finally obtain the double-sided super lens.

However, the accuracy of this processing method is limited by the accuracy of the traditional overlay process, which is plus or minus 1 μm, which is difficult to meet the alignment requirements of high-precision double-sided metalens.

Contents of the invention

In order to solve the above problems, the purpose of embodiments of the present invention is to provide a processing method of a double-sided super lens.

Embodiments of the present invention provide a method for processing a double-sided super lens, which includes: arranging a first structural layer on the first surface of a substrate, performing a first photolithography operation on the first structural layer, and obtaining a first nanostructure and Alignment identification mark; the substrate is transparent in the working band of the photolithography machine detector; a second structural layer is provided on the second surface of the substrate; and the second structural layer is located at a position corresponding to the alignment identification mark. Make an alignment window, the size of the alignment window is larger than the size of the alignment identification mark; when the second surface is an operating surface, through the alignment window and based on the alignment identification mark Alignment is performed, and a second photolithography operation is performed on the second structural layer to obtain a second nanostructure; the operation surface represents the surface of the substrate currently processed by the photolithography machine.

Optionally, performing a first photolithography operation on the first structural layer includes: coating a first photoresist layer on the surface of the first structural layer, and exposing and exposing the first photoresist layer. Develop to obtain a first reference structure; the first reference structure is the first structural layer exposed after the exposure and development; etching the first reference structure to remove the remaining first photolithography glue layer to obtain the first nanostructure and the Alignment identification mark.

Optionally, making an alignment window at a position corresponding to the second structural layer and the alignment identification mark includes: coating a second photoresist layer on the surface of the second structural layer, and overlaying on the back side The process performs a window photolithography operation on the position corresponding to the alignment identification mark to obtain the alignment window.

Optionally, performing a window photolithography operation on the position corresponding to the alignment identification mark based on a backside overlay process to obtain the alignment window includes: performing a window photolithography operation on the position corresponding to the alignment identification mark. The resist layer is subjected to window exposure and development to obtain an alignment window structure; the alignment window structure is the second structural layer exposed after the window exposure and development; the alignment window structure is etched to obtain The alignment window.

Optionally, performing a second photolithography operation on the second structural layer includes: exposing and developing the second photoresist layer again to obtain a second reference structure, the second reference structure being The second structural layer is exposed after the exposure and development; the second reference structure is etched to remove the remaining second photoresist layer to obtain the second nanostructure.

Optionally, before making an alignment window at a position corresponding to the second structural layer and the alignment identification mark, the double-sided super lens processing method further includes: aligning one side surface of the bonding substrate Spin-coating temporary bonding glue; the first surface of the substrate having the first nanostructure is temporarily bonded to the bonding substrate through the temporary bonding glue.

Optionally, after obtaining the second nanostructure, the double-sided hyperlens processing method further includes: debonding the first surface of the substrate with the first nanostructure and the bonding substrate. , the double-sided super lens is obtained.

Optionally, debonding the first surface of the substrate with the first nanostructure from the bonding substrate includes: dissolving the temporary bonding glue.

Optionally, arranging a first structural layer on the first surface of the substrate includes: evaporating the first structural layer on the first surface of the substrate; and arranging a second structural layer on the second surface of the substrate. , including: evaporating the second structural layer on the second surface of the substrate.

Optionally, the substrate is a glass substrate.

Optionally, the glass substrate includes: quartz wafer.

Optionally, both the first structural layer and the second structural layer are made of polysilicon material.

In the solution provided above in the embodiment of the present invention, by performing the first photolithography operation on the first structural layer, at the same time The first nanostructure and the alignment identification mark are obtained, and an alignment window is made on the surface of the second structural layer corresponding to the position of the alignment identification mark, so that the photolithography machine can align the operating surface (second surface) with the first nanostructure and the alignment identification mark. Before the second photolithography operation is performed on the second structural layer, micron-level alignment identification marks can be identified through the alignment window. Based on the accuracy of the photolithography machine itself, the second photolithography operation is performed and the double-layer structure is finally produced. Surface metal lens. This method can break the accuracy limit of the traditional backside overlay process, improve the alignment accuracy when processing the first nanostructure and the second nanostructure to the accuracy of the photolithography machine itself, and improve the alignment accuracy of the front and back super lenses. For example, the alignment accuracy is controlled below 100nm.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 shows a flow chart of a double-sided super lens processing method provided by an embodiment of the present invention;

Figure 2 shows a schematic diagram of arranging a first structural layer on the first surface of the substrate in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 3 shows a schematic diagram of the first nanostructure in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 4 shows a schematic diagram of the alignment identification mark in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 5 shows a schematic diagram of the arrangement of multiple alignment identification marks in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 6 shows a schematic diagram of disposing a second structural layer on the second surface of the substrate in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 7 shows a schematic diagram of making an alignment window in the second structural layer in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 8 shows the second nanostructure in the double-sided hyperlens processing method provided by the embodiment of the present invention. schematic diagram;

Figure 9 shows a flow chart of performing a first photolithography operation on the first structural layer in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 10 shows a schematic diagram of disposing a first photoresist layer on the surface of the first structural layer in the double-sided super lens processing method provided by an embodiment of the present invention;

Figure 11 shows a schematic diagram of arranging a first reference structure on the surface of the first photoresist layer in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 12 shows a schematic diagram of coating a second photoresist layer on the surface of the second structural layer in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 13 shows a schematic diagram of an alignment window structure being provided on the surface of the second photoresist layer in the double-sided hyperlens processing method provided by an embodiment of the present invention;

Figure 14 shows a schematic diagram of the alignment window in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 15 shows a flow chart of performing a second photolithography operation on the second structural layer in the processing method of a double-sided super lens provided by an embodiment of the present invention;

Figure 16 shows a schematic diagram of arranging a second reference structure on the surface of the second photoresist layer in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 17 shows a schematic diagram of the second nanostructure in the double-sided hyperlens processing method provided by the embodiment of the present invention;

Figure 18 shows a schematic diagram of spin-coating temporary bonding glue on the bonding substrate in the double-sided super lens processing method provided by the embodiment of the present invention;

Figure 19 shows a schematic diagram of temporary bonding using temporary bonding glue in the processing method of a double-sided super lens provided by an embodiment of the present invention.

icon:
1-Substrate, 21-First structural layer, 22-Second structural layer, 31-First photoresist layer, 32-Second photoresist layer, 211-First nanostructure, 212-Alignment identification mark, 221-Second nanostructure, 10-Alignment window, 4-Bonding substrate, 5-Temporary bonding glue layer.

Detailed ways

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions or positions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. The relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore It should not be construed as a limitation of the present invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

An embodiment of the present invention provides a method for processing a double-sided super lens. As shown in Figure 1 , the method includes the following steps 101 to 104.

Step 101: Set the first structural layer 21 on the first surface of the substrate 1, perform the first photolithography operation on the first structural layer 21, and obtain the first nanostructure 211 and the alignment identification mark 212; the substrate 1 is detected in the photolithography machine The operating band of the device is transparent.

In the embodiment of the present invention, the substrate 1 has two surfaces, such as a first surface and a second surface. The first surface may be the front surface of the substrate 1, and correspondingly, the second surface may be the back surface of the substrate 1; or, the first surface The surface may be the back surface of the substrate 1 , and accordingly, the second surface may be the front surface of the substrate 1 , which is not limited in this embodiment of the present invention. As shown in Figure 2, a first structural layer 21 is provided on the first surface of the substrate 1. The first structural layer 21 is a material layer used to make the first nanostructure 211. The material of the first structural layer 21 is a Materials with high transmittance for light in the working band (such as the working band of the photolithography machine detector). In the embodiment of the present invention, the substrate 1 is transparent in the working band of the photolithography machine detector, and optionally, the substrate 1 is a glass substrate; because the working band of the photolithography machine detector used in the embodiment of the present invention can be the visible light band and/or infrared light band. Therefore, the material of the substrate 1 can be selected to have high resistance to the light in the above working band. Glass materials with high transmittance, such as crown glass, flint glass, etc., can be selected as the substrate 1; optionally, the glass substrate can include: quartz wafer, such as fused quartz (a kind of glassy quartz). In the embodiment of the present invention, a quartz wafer is selected as the substrate 1, so that the substrate 1 of the double-sided hyperlens has a lower thermal expansion coefficient, a longer service life, and higher stability. Moreover, the material of the quartz wafer has a low thermal expansion coefficient under visible light. The wavelength band and/or the infrared light band are transparent, and as the substrate 1, the photolithography machine detector can identify the other side through the substrate 1; in addition, the quartz wafer is also suitable for common photolithography machines.

In the embodiment of the present invention, the photolithography process performed on the first structural layer 21 is called a first photolithography operation. Compared with the traditional photolithography process, the first photolithography operation is In the process of photolithography of the first structural layer 21 to obtain the first nanostructure 211, it is also necessary to obtain the alignment identification mark 212, as shown in Figures 3 and 4. Figure 3 is a schematic side view of obtaining the first nanostructure 211. Among them, in order to easily distinguish the first nanostructure 211 and the alignment identification mark 212, different patterns are used in the drawings, but in fact, the first nanostructure 211 and the alignment identification mark 212 are both etched from the first structural layer 21. The obtained structures are made of the same material; Figure 4 is a top view of the alignment identification mark 212; the alignment identification mark 212 is a mark made by a photolithography machine, which is a micron-level mark with high precision; During the subsequent processing of the second surface of the substrate 1, it can play a role in aligning the substrate 1 with the photolithography machine. It can include one or more cross patterns. For example, a row or a column can be set on the edge of the substrate 1. The alignment identification mark 212 of the cross structure (shown in Figure 5).

Step 102: Set the second structural layer 22 on the second surface of the substrate 1 .

Among them, as shown in FIG. 6 , a method consistent with arranging the first structural layer 21 for the first surface can be used to dispose the second structural layer 22 for the second surface of the substrate 1 . The second structural layer 22 is used to make The material layer of the second nanostructure 221 and the second structural layer 22 can also be a material with high transmittance for light in the working wavelength band.

It should be noted that the embodiment of the present invention can perform step 102 after step 101, or can also perform step 102 while setting the first structural layer 21 in step 101, that is, setting corresponding structures on both surfaces of the substrate 1 at the same time. layer.

Step 103: Make an alignment window 10 at a position corresponding to the second structural layer 22 and the alignment identification mark 212. The size of the alignment window 10 is larger than the size of the alignment identification mark 212.

As shown in FIG. 7 , the embodiment of the present invention can use the traditional backside overlay process to identify the area corresponding to the alignment identification mark 212 on the surface of the second structural layer 22 , and make a size update for this area. A large alignment window 10; in other words, if the alignment window 10 is produced and projected onto the first surface, the first surface at the orthographic projection position will have the alignment identification mark 212; or it can also be It is considered that the orthographic projection of the alignment identification mark 212 located on the first surface does not exceed the range of the alignment window 10 , which is equivalent to the alignment identification mark 212 being included in the alignment window 10 . Among them, since the alignment window 10 obtained in this step is only used to represent the approximate position of the alignment identification mark 212, and the overlay accuracy of the traditional backside overlay process is plus or minus 1 μm, therefore, the size of the alignment window 10 (eg, area) should be larger than the size (eg, area) of the alignment identification mark 212 by a certain value, such as at least greater than an accuracy of one unit. For example, if the size of the alignment identification mark 212 is 2 μm×2 μm, the size of the produced alignment window 10 may be 3 μm×3 μm.

Step 104: When the second surface is the operating surface, align through the alignment window 10 and based on the alignment identification mark 212, and perform a second photolithography operation on the second structural layer 22 to obtain the second nanostructure. 221; The operating surface indicates the surface of substrate 1 currently processed by the photolithography machine.

In the embodiment of the present invention, the surface currently being processed by the photolithography machine is called the operating surface. The orientation of the operating surface is generally upward, that is, the second surface of the substrate 1 faces upward (that is, the second surface is the operating surface). ) (as shown in Figure 7), the lithography machine can identify the alignment identification mark 212 located on the first surface through the alignment window 10 (located on the second surface) produced in step 103, and By aligning the alignment identification mark 212, the lithography machine and the substrate 1 can be aligned with nanometer-level precision, which is equivalent to directly improving the alignment accuracy of the first nanostructure 211 and the second nanostructure 221 to the lithography machine. its own accuracy; and perform a second photolithography operation based on the aligned second structural layer 22. For example, the second photolithography operation may be a traditional semiconductor photolithography process to obtain a second nanostructure 221 (as shown in FIG. 8 (shown) to realize the processing and production of double-sided super lenses. Those skilled in the art can understand that when the photolithography machine performs the first photolithography operation, the operating surface is the first surface.

In the embodiment of the present invention, the first nanostructure 211 and the alignment identification mark 212 are simultaneously obtained by performing the first photolithography operation on the first structural layer 21, and the second structural layer corresponding to the position of the alignment identification mark 212 is obtained. 22. Make the alignment window 10 so that the photolithography machine can identify through the alignment window 10 that the position accuracy is nanometer level before performing the second photolithography operation on the second structural layer 22 of the operating surface (second surface). Align the identification marks 212, align based on the accuracy of the photolithography machine itself, and perform a second photolithography operation to finally produce a double-sided super lens. This method can break the accuracy limit of the traditional backside overlay process, improve the alignment accuracy when processing the first nanostructure and the second nanostructure to the accuracy of the photolithography machine itself, and improve The alignment accuracy of the front and back metalens, for example, is controlled to less than 100nm.

Optionally, referring to FIG. 9 , performing the first photolithography operation on the first structural layer 21 may include the following steps 1011-1012.

Step 1011: Coat the first photoresist layer 31 on the surface of the first structural layer 21, and expose and develop the first photoresist layer 31 to obtain the first reference structure; the first reference structure is after exposure and development The first structural layer 21 is exposed.

As shown in FIG. 10 , according to the embodiment of the present invention, photoresist can be coated on the surface of the first structural layer 21 by spin coating to obtain the first photoresist layer 31 . The photoresist is a kind of material used in traditional semiconductor processes. Materials that can change the solubility during the photolithography step; spin coating is the abbreviation of the spin coating method. The equipment usually used is a glue dispensing machine, which is controlled by controlling the time, rotation speed, drop volume, and concentration and viscosity of the solution used. The thickness of the film is controlled to make the thickness of the coated first photoresist layer 31 uniform and controllable. Among them, one side surface (such as the first surface) of the substrate provided with the first photoresist layer 31 is facing upward and put into a photolithography machine for exposure and development. It should be noted that at this time, because of the One surface faces upward, so the first surface is the operating surface that the photolithography machine currently needs to process; during the exposure and development process, the first photoresist layer 31 will be dissolved, exposing the first reference structure ; The first reference structure is the first structural layer 21 corresponding to the dissolved first photoresist layer 31. In other words, the first reference structure is exposed without the first photoresist layer 31 on the surface. The first structural layer 21 has a groove structure as shown in Figure 11; in addition, the exposure process includes but is not limited to ultraviolet exposure, deep ultraviolet exposure and extremely deep ultraviolet exposure.

Step 1012: Etch the first reference structure and remove the remaining first photoresist layer 31 to obtain the first nanostructure 211 and the alignment identification mark 212.

In the embodiment of the present invention, by etching the first reference structure (such as the exposed first structural layer 21), the first reference structure (such as the exposed first structural layer 21) is etched away, and the The remaining first photoresist layer 31 on the surface of the first structural layer 21 finally obtains the first nanostructure 211 and the alignment identification mark 212 as shown in FIG. 3 (ie, the remaining first structural layer 21).

Optionally, making the alignment window 10 at the position corresponding to the second structural layer 22 and the alignment identification mark 212 may include the following step 1031.

Step 1031: Coat the second photoresist layer 32 on the surface of the second structural layer 22, and perform a window photolithography operation at the corresponding position of the alignment identification mark 212 based on the backside overlay process to obtain the alignment window 10.

Among them, as shown in FIG. 12 , the method of coating the first photoresist layer on the surface of the first structural layer 22 may be used. 31 The second photoresist layer 32 is coated on the surface of the second structural layer 22 by the same means, such as spin coating, and the material of the second photoresist layer 32 can be the same as the material of the first photoresist layer 31 are the same; and, based on the traditional backside overlay process, the alignment identification mark 212 on the first structural layer 21 obtained in the above step 101 is identified on the surface of the second photoresist layer 32 away from the second structural layer 22, and A window photolithography operation is performed on the surface of the second photoresist layer 32 away from the second structural layer 22 at a position corresponding to the alignment identification mark 212 . The window photolithography operation is an operation for obtaining the alignment window 10 process; after the window photolithography operation, the structure shown in Figure 7 can be obtained.

In the embodiment of the present invention, the alignment window 10 obtained by using the traditional backside overlay process has low accuracy due to the micron-level precision of the corresponding overlay process. Therefore, the embodiment of the present invention does not directly use this alignment The window 10 is used as the basis for alignment, but the alignment window 10 is used to lock the truly required alignment identification mark 212. The alignment identification mark 212 corresponds to micron-level accuracy, and its accuracy is relatively high. This method can process the second The alignment accuracy of the first nanostructure and the second nanostructure is improved to the accuracy of the lithography machine itself.

Optionally, performing a window photolithography operation on the corresponding position of the alignment identification mark 212 based on the backside overlay process to obtain the alignment window 10 may include the following steps A1-A2.

Step A1: Perform window exposure and development on the second photoresist layer 32 at the corresponding position of the alignment identification mark 212 to obtain an alignment window structure; the alignment window structure is the second structural layer exposed after window exposure and development. twenty two.

The window exposure and development process performed in the embodiment of the present invention is the same as the exposure and development process performed on the first photoresist layer 31 in the above-mentioned step 1011, except that the structural layer targeted by the two processes is different from the resulting structure; window Exposure and development are operations performed on the second photoresist layer 32, and the alignment window structure can be obtained by dissolving the second photoresist layer 32 at the position corresponding to the alignment identification mark 212 (see FIG. 13 ), the alignment window structure is the second structural layer 22 corresponding to the dissolved second photoresist layer 32. In other words, the alignment window structure has no second photoresist layer 32 on the surface and is exposed. The second structural layer 22 is located at the upper groove structure as shown in FIG. 13 .

Step A2: Etch the alignment window structure to obtain the alignment window 10.

Among them, the etching process performed on the alignment window structure in the embodiment of the present invention is the same as the etching process performed on the first reference structure in step 1012, that is, the alignment window structure (such as the exposed second structure) is etched away. layer 22), obtaining the alignment window 10 (ie, the exposed substrate 1) as shown in Figure 14.

Optionally, referring to FIG. 15 , performing the second photolithography operation on the second structural layer 22 may include the following steps 1041-1042.

Step 1041: Expose and develop the second photoresist layer 32 again to obtain a second reference structure. The second reference structure is the second structural layer 22 exposed after being exposed and developed again.

Among them, on the basis of the structure shown in Figure 14, the remaining second photoresist layer 32 is exposed and developed twice. The structure obtained by this exposure and development is the second reference structure, in order to be able to undergo subsequent The etching process obtains the final desired second nanostructure 221. Among them, the second reference structure is the second structural layer 22 corresponding to the second photoresist layer 32 that was dissolved this time. In other words, the pair of second reference structures does not have the second photoresist layer 32 on the surface. And it is the second structural layer 22 exposed this time, which is the groove structure located on the uppermost layer as shown in FIG. 16 .

Step 1042: Etch the second reference structure and remove the remaining second photoresist layer 32 to obtain the second nanostructure 221.

In the embodiment of the present invention, by etching the second reference structure (such as the exposed second structural layer 22), the second reference structure (such as the exposed second structural layer 22) is etched away, and the The remaining second photoresist layer 32 on the surface of the second structural layer 22 finally obtains the second nanostructure 221 as shown in FIG. 17 (ie, the remaining second structural layer 22 after this step).

Normally, after the first nanostructure 211 is processed, the operating surface needs to be replaced. For example, the operating surface is replaced from the first surface to a second surface that needs to continue processing the second nanostructure 221. However, the existing processing technology cannot process the first nanostructure 211. After completing the first nanostructure 211 on the first surface, vacuum adsorption is used to adsorb the first surface. For example, the first surface with the first nanostructure 211 is vacuum adsorbed on the workbench, but due to the first The existence of the nanostructure 211 and the gaps on the first surface may cause the vacuum adsorption to be weak and cause vacuum leakage of the slide.

Optionally, the embodiment of the present invention can perform the following steps B1-B2 before the above-mentioned step 103 of "making the alignment window 10 at the position corresponding to the second structural layer 22 and the alignment identification mark 212" to avoid slide leakage. Vacuum problem.

Step B1: Spin-coat temporary bonding glue on one side of the bonding substrate 4 .

As shown in Figure 18, the bonding substrate 4 is essentially a substrate, which can be a silicon wafer; in embodiments of the present invention, temporary bonding glue can be spin-coated on one side of the bonding substrate 4, as shown in Figure 18 The temporary bonding glue layer 5 shown in , the material used for the temporary bonding glue may be a base resin.

Step B2: Temporarily bond the first surface of the substrate 1 with the first nanostructure 211 to the bonding substrate 4 through temporary bonding glue.

As shown in FIG. 19 , the embodiment of the present invention can bond the first surface with the first nanostructure 211 to the temporary bonding glue layer 5 composed of temporary bonding glue. The temporary bonding glue can be bonded through the temporary bonding glue. In a manner, the first surface with the first nanostructure 211 is fixed on the bonding substrate 4 .

In the embodiment of the present invention, the first surface with the first nanostructure 211 is temporarily bonded to the bonding substrate 4, so that the first surface with the first nanostructure 211 is fixed, which facilitates the photolithography machine to directly process the second surface. The surface (operating surface) is processed; and the temporary bonding process can also protect the first nanostructure 211, avoid the first nanostructure 211 from being contaminated and damaged, and at the same time solve the problem of vacuum leakage on the slide. .

Optionally, after obtaining the second nanostructure 221, the method may further include step C.

Step C: Debonding the first surface of the substrate 1 having the first nanostructure 211 from the bonding substrate 4 to obtain a double-sided superlens.

When the second nanostructure 221 on the second surface is also prepared, debonding can be performed by heating or dissolving, and the first surface with the first nanostructure 211 is separated from the bonding substrate 4 to obtain the completed product. Double-sided metalens.

Optionally, debonding the first surface of the substrate 1 with the first nanostructure 211 and the bonding substrate 4 includes: dissolving the temporary bonding glue; for example, a solvent that can dissolve the temporary bonding glue can be used to debond, to obtain the production Completed double-sided metalens.

Optionally, disposing the first structural layer 21 on the first surface of the substrate 1 includes: evaporating the first structural layer 21 on the first surface of the substrate 1; disposing the second structural layer 22 on the second surface of the substrate 1 includes: : The second structural layer 22 is evaporated on the second surface of the substrate 1 .

In the embodiment of the present invention, the first structural layer 21 and the second structural layer 22 can be respectively provided on both sides of the substrate 1 (such as the first surface and the second surface) by evaporation; optionally, the first Both the structural layer 21 and the second structural layer 22 are made of polysilicon material. For example, the first structural layer 21 and the second structural layer 22 may be evaporated using polysilicon materials. The polysilicon materials may include: titanium oxide, silicon nitride, fused quartz, aluminum oxide, gallium nitride, gallium phosphide, Amorphous silicon, crystalline silicon or hydrogenated amorphous silicon, etc.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention. Alternative technical solutions should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

A method for processing a double-sided super lens, which is characterized by including:

A first structural layer (21) is provided on the first surface of the substrate (1), and a first photolithography operation is performed on the first structural layer (21) to obtain a first nanostructure (211) and an alignment identification mark (212) ); the substrate (1) is transparent in the working band of the photolithography machine detector;

A second structural layer (22) is provided on the second surface of the substrate (1);

An alignment window (10) is made at a position corresponding to the second structural layer (22) and the alignment identification mark (212). The size of the alignment window (10) is larger than the alignment identification mark (212). )size of;

In the case where the second surface is an operating surface, alignment is performed through the alignment window (10) and based on the alignment identification mark (212), and is performed on the second structural layer (22). A second photolithography operation is performed to obtain a second nanostructure (221); the operation surface represents the surface of the substrate (1) currently processed by the photolithography machine.
The method of claim 1, wherein performing a first photolithography operation on the first structural layer (21) includes:

Coat a first photoresist layer (31) on the surface of the first structural layer (21), and expose and develop the first photoresist layer (31) to obtain a first reference structure; A reference structure is the first structural layer (21) exposed after the exposure and development;

The first reference structure is etched to remove the remaining first photoresist layer (31) to obtain the first nanostructure (211) and the alignment identification mark (212).
The method according to claim 1, characterized in that, making an alignment window (10) at a position corresponding to the second structural layer (22) and the alignment identification mark (212) includes:

A second photoresist layer (32) is coated on the surface of the second structural layer (22), and a window photolithography operation is performed on the corresponding position of the alignment identification mark (212) based on the backside overlay process to obtain the Describe the alignment window (10).
The method according to claim 3, characterized in that, based on the backside overlay process, a window photolithography operation is performed on the corresponding position of the alignment identification mark (212) to obtain the alignment window (10), including :

Perform windowing on the second photoresist layer (32) at the position corresponding to the alignment identification mark (212). Expose and develop to obtain an alignment window structure; the alignment window structure is the second structural layer (22) exposed after the window exposure and development;

The alignment window structure is etched to obtain the alignment window (10).
The method of claim 4, wherein performing a second photolithography operation on the second structural layer (22) includes:

The second photoresist layer (32) is exposed and developed again to obtain a second reference structure. The second reference structure is the second structural layer (22) exposed after the exposure and development again. ;

The second reference structure is etched to remove the remaining second photoresist layer (32) to obtain the second nanostructure (221).
The method according to claim 1, characterized in that before making the alignment window (10) at the position corresponding to the second structural layer (22) and the alignment identification mark (212), it further includes:

Spin-coat temporary bonding glue on one side of the bonding substrate (4);

The first surface of the substrate (1) having the first nanostructure (211) is temporarily bonded to the bonding substrate (4) through the temporary bonding glue.
The method according to claim 6, characterized in that, after obtaining the second nanostructure (221), further comprising:

The first surface of the substrate (1) having the first nanostructure (211) is debonded to the bonding substrate (4) to obtain the double-sided super lens.
The method according to claim 7, characterized in that debonding the first surface of the substrate (1) with the first nanostructure (211) and the bonding substrate (4), including: Dissolve the temporary bonding glue.
The method according to any one of claims 1 to 8, characterized in that: arranging the first structural layer (21) on the first surface of the substrate (1) includes: Evaporate the first structural layer (21);

The method of arranging the second structural layer (22) on the second surface of the substrate (1) includes evaporating the second structural layer (22) on the second surface of the substrate (1).
The method according to any one of claims 1 to 8, characterized in that the substrate (1) is a glass substrate.
The method of claim 10, wherein the glass substrate includes: quartz wafer.
The method according to claim 11, characterized in that both the first structural layer (21) and the second structural layer (22) are made of polysilicon material.