A photolithography process for processing a transparent substrate

Abstract

The present invention provides a photolithography process for processing a transparent substrate, comprising: coating a ring-shaped anti-reflection film on the front surface of the transparent substrate, the width of the anti-reflection film being greater than or equal to the detection accuracy of the detector of the photolithography machine; the anti-reflection film being configured to reflect light in the working wavelength band; and performing photolithography processing on the effective area of the front surface of the transparent substrate based on the photolithography machine, the effective area being the area of the front surface of the transparent substrate excluding the anti-reflection film. The photolithography process for processing a transparent substrate provided by an embodiment of the present invention comprises coating a ring-shaped anti-reflection film on the front surface of the transparent substrate, the anti-reflection film being capable of reflecting light in the working wavelength band of the photolithography machine, so that the transparent substrate provided with the anti-reflection film can be recognized by the detector of the photolithography machine after being placed in the photolithography machine, thereby enabling photolithography processing of the transparent substrate; the process is simple, and there is no other metal film on the back of the transparent substrate, which will not contaminate the photolithography machine.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography technology, and in particular to a photolithography process for processing a transparent substrate. Background Art

[0002] When using a lithography machine to produce high-precision products (such as chips and metalenses), the lithography machine's detector (such as an optical sensor) must be able to detect the substrate (also known as the wafer). However, most substrates are transparent, and the lithography machine's detector cannot recognize them. For example, most metalenses for near-infrared and visible light bands use quartz substrates, but DUV (Deep Ultraviolet Lithography) lithography machines cannot recognize quartz substrates (because quartz substrates are transparent to the operating band of the lithography machine's detectors), resulting in exposure failure.

[0003] Currently, the following two technical solutions are generally used to avoid the problem of being unable to identify the substrate.

[0004] Solution ①: Match the substrate with the lithography machine by adjusting parameters such as flatness, warping, and lead angle in the substrate and epitaxial process.

[0005] Solution ②: Use the method of back-side metal deposition to realize the recognition capability of optical sensors.

[0006] The inventors have discovered that the above solution has at least the following problems:

[0007] For solution ①: it is necessary to repeatedly verify the flatness, warping, and lead angle applicable to a specific type of lithography machine, which requires a lot of time, manpower, and material resources. The development cycle is long, it cannot solve the current problem, seriously affects the manufacturing schedule, and the development cost is too high.

[0008] Regarding option ②: When a back-metal substrate enters the machine, metal particles may remain on the equipment tray, which can be transferred to other products, thereby affecting the entire product equipment line. This can easily cause metal ions to contaminate the semiconductor production line. Therefore, most mass production lines prohibit the direct use of substrates with back-metal. Summary of the Invention

[0009] To solve the above problems, an embodiment of the present invention aims to provide a photolithography process for processing a transparent substrate.

[0010] An embodiment of the present invention provides a photolithography process for processing a transparent substrate, comprising:

[0011] A ring-shaped anti-reflection film is plated on the front surface of the transparent substrate, wherein the width of the anti-reflection film is greater than or equal to the detection accuracy of the detector of the photolithography machine; the transparent substrate refers to a substrate selected to be transparent in the working wavelength band of the detector of the photolithography machine, and the anti-reflection film is configured to reflect light in the working wavelength band of the detector of the photolithography machine;

[0012] The front effective area of the transparent substrate is photolithographically processed using a photolithography machine, where the front effective area is an area on the front of the transparent substrate excluding the anti-reflection film.

[0013] In a possible implementation, the anti-reflection film is located at an edge of the transparent substrate, and the front effective area is an area on the front surface of the transparent substrate surrounded by the anti-reflection film.

[0014] In a possible implementation manner, an edge of the anti-reflection film is aligned with an edge of the transparent substrate.

[0015] In a possible implementation, the anti-reflection film is a continuous ring structure; or,

[0016] The anti-reflection film is an annular structure with a gap, and the circumferential length of the gap is smaller than the detection range of the detector of the lithography machine.

[0017] In a possible implementation, the process of coating a ring-shaped anti-reflection film on the front surface of the transparent substrate includes:

[0018] Plating an anti-reflection film layer on the front surface of the transparent substrate;

[0019] Coating photoresist on the surface of the anti-reflection film layer;

[0020] exposing the photoresist to expose a ring-shaped photoresist;

[0021] Etching the anti-reflection film layer;

[0022] The photoresist of the ring structure is removed.

[0023] In a possible implementation, the process of coating a ring-shaped anti-reflection film on the front surface of the transparent substrate includes:

[0024] A mask is provided on the front surface of the transparent substrate, wherein the area of the front surface of the transparent substrate not covered by the mask is annular;

[0025] Coating an anti-reflection film layer on the front surface of the transparent substrate provided with the mask;

[0026] The mask is removed.

[0027] In a possible implementation, the mask is a closed shape; the size of the mask is smaller than the size of the transparent substrate, and the distance between the edge of the mask and the edge of the transparent substrate is greater than or equal to the detection accuracy of the detector of the lithography machine;

[0028] Alternatively, the mask has an annular vacancy; the size of the outer edge of the annular vacancy is smaller than or equal to the size of the edge of the transparent substrate, and the width of the annular vacancy is greater than or equal to the detection accuracy of the lithography machine detector.

[0029] In a possible implementation, after performing photolithography processing on the front effective area of the transparent substrate using a photolithography machine, the photolithography process further includes:

[0030] The anti-reflection film is removed.

[0031] In a possible implementation, the thickness of the anti-reflection film is greater than 50 nm;

[0032] The width w of the anti-reflection film satisfies: 1mm <w<5mm。

[0033] In a possible implementation, the anti-reflection film is made of metal material or a reflective film system.

[0034] In a possible implementation, the metal includes at least one of aluminum, titanium, gold, copper, and chromium.

[0035] In a possible implementation, the transparent substrate is a quartz-based substrate.

[0036] In the solution provided by the embodiment of the present invention, a ring-shaped anti-reflection film is plated on the front of the transparent substrate. The anti-reflection film can reflect light in the working band of the detector of the photolithography machine, so that after the transparent substrate provided with the anti-reflection film is placed in the photolithography machine, it can be identified by the detector of the photolithography machine, thereby enabling photolithography processing of the transparent substrate. Plating the anti-reflection film on the front of the transparent substrate is simple in process, low in cost and easy to implement, and can conveniently realize the identification of the transparent substrate. The anti-reflection film is a ring-shaped structure, which only occupies a small area of the transparent substrate and basically does not affect the processing of the transparent substrate by the photolithography machine; and the anti-reflection film is located on the front of the transparent substrate, and it will not contaminate the photolithography machine. For example, the anti-reflection film made of metal does not have the problem of metal ion contamination.

[0037] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A flow chart of a photolithography process for processing a transparent substrate provided by an embodiment of the present invention is shown;

[0040] Figure 2 FIG2 shows an axonometric diagram of a transparent substrate with an anti-reflection film provided by an embodiment of the present invention;

[0041] Figure 3 Schematic top view and schematic side cross-sectional view of a transparent substrate with an anti-reflection film provided by an embodiment of the present invention are shown;

[0042] Figure 4 A schematic top view of another transparent substrate with an anti-reflection film provided by an embodiment of the present invention is shown;

[0043] Figure 5 FIG2 shows a top view of another transparent substrate with an anti-reflection film provided by an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of a process for coating an anti-reflection film on a transparent substrate according to an embodiment of the present invention is shown;

[0045] Figure 7 Another schematic diagram of a process for coating an anti-reflection film on a transparent substrate according to an embodiment of the present invention is shown;

[0046] Figure 8 A schematic structural diagram of a mask provided by an embodiment of the present invention is shown;

[0047] Figure 9A A schematic diagram of the structure after photolithography processing in the photolithography process provided by an embodiment of the present invention is shown;

[0048] Figure 9B A schematic structural diagram is shown in the photolithography process provided by an embodiment of the present invention after the anti-reflection film is removed.

[0049] icon:

[0050] 10-transparent substrate, 20-anti-reflection film, 21-gap, 200-anti-reflection film layer, 300-photoresist, 30-photoresist with annular structure, 400-mask, 401-annular vacancy, 500-superlens. DETAILED DESCRIPTION

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0053] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0054] The embodiment of the present invention provides a photolithography process for processing a transparent substrate, which can realize photolithography on a transparent substrate. Figure 1 As shown, the photolithography process includes:

[0055] Step S101: A ring-shaped anti-reflection film is deposited on the front surface of a transparent substrate, wherein the width of the anti-reflection film is greater than or equal to the detection accuracy of the detector of the photolithography machine; the transparent substrate refers to a substrate selected to be transparent in the working band of the photolithography machine detector, and the anti-reflection film is configured to be able to reflect light in the working band of the photolithography machine detector.

[0056] In the embodiment of the present invention, see Figure 2 and Figure 3 As shown, Figure 2 The figure shows an axonometric diagram of a transparent substrate coated with an anti-reflection film; Figure 3 It shows the top view and AA cross-sectional view of the transparent substrate after being coated with the anti-reflection film. Figure 3 In the figure, the upper part represents the top view and the lower part represents the AA cross-sectional view.

[0057] The transparent substrate 10 is a substrate selected in the photolithography process, and the transparent substrate 10 is transparent in the operating wavelength band of the photolithography detector. That is, the transparent substrate 10 has a high transmittance to light in the operating wavelength band, for example, the transmittance is greater than a certain threshold (for example, the threshold can be 80%, 90%, 95%, etc.); the photolithography detector generally operates in the infrared band, and accordingly, the operating wavelength band can be the infrared band. Generally, a substrate made of quartz material is selected in the photolithography process, that is, the transparent substrate 10 can be a quartz-based substrate. The quartz-based substrate is generally transparent in the operating wavelength band of the photolithography detector and is also transparent to visible light, ultraviolet light, etc.

[0058] In the embodiment of the present invention, a ring-shaped anti-reflection film 20 is coated on one side of the transparent substrate 10. The side of the transparent substrate 10 coated with the anti-reflection film 20 is the side that will be subsequently subjected to photolithography processing by a photolithography machine. In this embodiment, the side of the transparent substrate 10 coated with the anti-reflection film 20 is referred to as the front side of the transparent substrate 10. The "front side" is the side that needs to be photolithographically processed. For example, the front side of the transparent substrate 10 is the side that faces the ultraviolet light source of the photolithography machine when processing the transparent substrate 10.

[0059] The anti-reflection film 20 is an annular structure; in the embodiment of the present invention, the "annular structure" refers to a frame structure with a hollow center. For example, the annular structure can be a circular ring structure or a square ring structure, which is not limited in this embodiment. Since the transparent substrate 10 used in the lithography machine is generally circular, Figure 2 、 Figure 3 The annular structure is shown as an example. Moreover, the width of the anti-reflection film 20 is greater than or equal to the detection accuracy of the detector of the photolithography machine. The width of the anti-reflection film 20 refers to the width of the anti-reflection film 20 in the radial direction; Figure 3 As shown, the width of the anti-reflection film 20 can be Figure 3 The width w in the figure represents width. To ensure that the anti-reflection film 20 can be detected by the detector (such as an optical sensor) of the lithography machine, the width w of the anti-reflection film 20 must be no less than the detection accuracy of the detector. Optionally, the width of the anti-reflection film 20 is greater than or equal to twice the detection accuracy of the lithography machine detector. For example, if the detection accuracy of the detector is ±0.1 mm, the width w of the anti-reflection film 20 can be no less than 0.1 mm, or no less than 0.2 mm.

[0060] In the embodiment of the present invention, unlike the transparent substrate 10, the anti-reflection film 20 is not transparent to the light in the working band of the photolithography machine detector, but it can reflect the light in the working band, so that the light incident on the anti-reflection film 20 can be reflected to the photolithography machine detector, so that the photolithography machine detector can detect the anti-reflection film 20.

[0061] Optionally, the high-reflection film 20 is made of a metal material. For example, the metal includes at least one of aluminum, titanium, gold, copper, and chromium. Alternatively, the high-reflection film 20 can also adopt a reflective film system. For example, a reflective film system capable of reflecting light in the working wavelength band is formed by multiple layers of organic films or inorganic films. Among them, the metal material process is simpler, and the high-reflection film 20 made of metal material can be preferably adopted.

[0062] In the embodiment of the present invention, when the high-reflection film 20 is made of a metal material, the high-reflection film 20 can be conveniently deposited on the transparent substrate 10. For example, the high-reflection film 20 with a ring structure can be deposited on the front surface of the transparent substrate 10 by vapor-depositing a metal; and, since the high-reflection film 20 is located on the front surface of the transparent substrate 10, even if the transparent substrate 10 with the high-reflection film 20 made of a metal material is placed in a lithography machine, the high-reflection film 20 made of a metal material on the front surface will not contact the tray of the lithography machine, which can avoid metal ion contamination.

[0063] Step S102: Perform lithography processing on the effective area on the front surface of the transparent substrate based on the lithography machine, and the effective area on the front surface is the area on the front surface of the transparent substrate excluding the high-reflection film.

[0064] In the embodiment of the present invention, after the above step S101, the transparent substrate 10 provided with the high-reflection film 20 can be placed in a lithography machine, and the transparent substrate 10 can be identified by recognizing the high-reflection film 20. Specifically, since the high-reflection film 20 can reflect light in the working wavelength band, the light can be reflected to the detector of the lithography machine, so that the detector can detect the high-reflection film 20, and then the existence of the transparent substrate 10 can be indirectly identified. Due to the existence of the high-reflection film 20 on the front surface of the transparent substrate 10, the area corresponding to the high-reflection film 20 cannot be processed by the lithography machine, that is, the area that the lithography machine can perform lithography processing on is the area on the front surface of the transparent substrate 10 excluding the high-reflection film 20. For the convenience of description, in this embodiment, the area on the front surface of the transparent substrate 10 excluding the high-reflection film 20 is called the "effective area on the front surface", that is, the lithography machine can perform lithography processing on this effective area on the front surface. For example, chips, superlenses, etc. can be processed and manufactured on this effective area on the front surface.

[0065] Among them, in order to avoid the high-reflection film 20 occupying too much area as much as possible, the width of the high-reflection film 20 should not be too large. For example, the width w of the high-reflection film 20 satisfies: 1 mm < w < 5 mm. In addition, to ensure the reflection effect of the high-reflection film 20, the thickness of the high-reflection film 20 should not be too small. For example, the thickness of the high-reflection film 20 is greater than 50 nm; optionally, the thickness of the high-reflection film 20 is greater than 100 nm. Among them, the thickness of the high-reflection film 20 refers to the thickness of the high-reflection film 20 in the axial direction. For details, please refer to Figure 3 as shown Figure 3 in which d represents the thickness of the high-reflection film 20.

[0066] The embodiment of the present invention provides a photolithography process for processing a transparent substrate, in which a ring-shaped anti-reflection film 20 is plated on the front surface of the transparent substrate 10. The anti-reflection film 20 can reflect light in the working wavelength band of the detector of the photolithography machine, so that the transparent substrate 10 provided with the anti-reflection film 20 can be identified by the detector of the photolithography machine after being placed in the photolithography machine, thereby enabling photolithography processing of the transparent substrate 10. Plating the anti-reflection film 20 on the front surface of the transparent substrate 10 is a simple process with low cost and easy implementation, which can conveniently realize the identification of the transparent substrate 10. The anti-reflection film 20 is a ring-shaped structure, which only occupies a small area of the transparent substrate 10 and basically does not affect the processing of the transparent substrate 10 by the photolithography machine; and the anti-reflection film 20 is located on the front surface of the transparent substrate 10 and will not contaminate the photolithography machine. For example, the anti-reflection film 20 made of metal does not have the problem of metal ion contamination.

[0067] Alternatively, as Figure 2 and Figure 3 As shown, the anti-reflection film 20 is located at the edge of the transparent substrate 10 , and the front effective area is specifically the area on the front surface of the transparent substrate 10 surrounded by the anti-reflection film 20 .

[0068] In an embodiment of the present invention, the anti-reflection film 20 can be set at the edge of the transparent substrate 10, that is, the distance between the anti-reflection film 20 and the edge of the transparent substrate 10 is less than a certain threshold (for example, 3 mm, 1 mm, 0.5 mm, etc.), so that most of the front area of the transparent substrate 10 is surrounded by the anti-reflection film 20. At this time, the connected area surrounded by the anti-reflection film 20 on the front side of the transparent substrate 10 can be used as the front effective area. The photolithography machine only needs to perform photolithography processing on the connected area, which can further reduce the impact of the anti-reflection film 20 on the photolithography processing process.

[0069] Alternatively, see Figure 4 As shown, the edge of the anti-reflection film 20 is aligned with the edge of the transparent substrate 10, that is, the anti-reflection film 20 is located at the outermost periphery of the transparent substrate 10; Figure 4 For example, if the radius of the circular transparent substrate 10 is R, the outer radius of the anti-reflection film 20 is also R, and correspondingly, the inner radius is Rw. By placing the anti-reflection film 20 at the outermost edge of the transparent substrate 10, the ineffective area on the front surface of the transparent substrate 10 can be minimized, thereby improving the utilization rate of the transparent substrate 10.

[0070] Alternatively, see Figures 2 to 4 As shown, the anti-reflection film 20 is a continuous ring structure, that is, the anti-reflection film 20 does not have any discontinuous parts, and is a continuous overall ring structure.

[0071] Alternatively, see Figure 5As shown, the anti-reflection film 20 is a ring structure with a gap 21, and the circumferential length of the gap 21 is smaller than the detection range of the detector of the photolithography machine. In the embodiment of the present invention, the ring structure can be allowed to have a gap 21; Figure 5 As shown, the anti-reflection film 20 has a gap 21, which is similar to a snap ring structure. The gap 21 cannot be too large to avoid the problem of the detector not being able to detect. Specifically, the circumferential length of the gap 21 is smaller than the detection range of the detector of the lithography machine. The circumferential length of the gap 21 refers to the length in the circumferential direction, or in other words, the circumferential length of the gap 21 is the distance between the anti-reflection films 20 on both sides of the gap 21; Figure 5 As shown, the circumferential length of the notch 21 is a. In the embodiments of the present invention, the detection range of the detector refers to the range that the detector can detect, which is different from the detection accuracy. Generally, the detection range is greater than the detection accuracy. The circumferential length of the notch 21 is smaller than the detection range of the lithography machine detector, so that when the detector detects the location of the notch 21, it can also identify the anti-reflection film 20 on at least one side of the notch 21. In other words, the detector can still identify the anti-reflection film 20.

[0072] Optionally, a photolithography process may be used to deposit an anti-reflection film 20 on the transparent substrate 10. Figure 6 As shown, the above step S101 of "plating an anti-reflection film with a ring structure on the front surface of the transparent substrate" includes:

[0073] Step S601: prepare a transparent substrate 10.

[0074] Step S602 : depositing an anti-reflective film 200 on the front surface of the transparent substrate 10 .

[0075] like Figure 6 As shown, the upward side of the transparent substrate 10 is the front side, and the anti-reflection film layer 200 can be made of metal. A layer of anti-reflection film layer 200 can be deposited on the front side of the transparent substrate 10 by evaporation. The anti-reflection film layer 200 is a layered structure.

[0076] Step S603 : coating the photoresist 300 on the surface of the anti-reflective film layer 200 .

[0077] A layer of photoresist 300 may be coated on the side of the anti-reflection film 200 away from the transparent substrate 10 by spin coating; Figure 6 As shown, the photoresist 300 is a layered structure.

[0078] Step S604 : exposing the photoresist 300 to expose the photoresist 30 with a ring structure.

[0079] In this embodiment of the present invention, the presence of the anti-reflective film 200 allows the photolithography machine to identify the transparent substrate 10 and, therefore, expose the photoresist 300. Furthermore, the anti-reflective film 200 is located on the front side of the transparent substrate 10 and does not contaminate the photolithography machine. By exposing the layered photoresist 300 as desired, the desired ring-shaped photoresist 30 can be obtained. Figure 6 The structure shown is a cross-sectional view coplanar with the central axis of the transparent substrate 10 , which only shows two cross-sectional portions of the photoresist 30 .

[0080] Step S605 : etching the anti-reflection film layer 200 .

[0081] For example, the anti-reflection film layer 200 may be etched by using an etching gas to obtain an anti-reflection film 20 that matches the photoresist 30 with a ring structure. The anti-reflection film 20 also has a ring structure.

[0082] Step S606: removing the photoresist 30 of the ring structure.

[0083] In the embodiment of the present invention, after removing the photoresist 30 with the ring structure, a structure in which the anti-reflection film 20 is provided on the front surface of the transparent substrate 10 can be obtained, and the anti-reflection film 20 is a ring structure.

[0084] Alternatively, a mask process can be used to produce the anti-reflection film 20 with a ring structure. Figure 7 As shown, the above step S101 of "plating an anti-reflection film 20 with a ring structure on the front surface of the transparent substrate 10" includes:

[0085] Step S701: Select a mask 400.

[0086] In the embodiment of the present invention, the mask 400 is used to shield the area of the transparent substrate 10 where the anti-reflection film 20 does not need to be plated.

[0087] The mask 400 may be a closed shape, that is, the area corresponding to the mask 400 is a simply connected area; Figure 7 As shown, the mask 400 is circular in shape; Figure 7 In the structure corresponding to each step, the upper half represents a top view, and the lower half represents a side cross-sectional view. In the embodiment of the present invention, if the mask 400 is a closed shape, it is possible to set an anti-reflection film 30 (such as Figure 4In this case, the size of the mask 400 needs to be smaller than that of the transparent substrate 10, so that the transparent substrate 10 can completely cover the mask 400, or in other words, the mask 400 does not cover the edge of the transparent substrate 10; and the distance between the edge of the mask 400 and the edge of the transparent substrate 10 is greater than or equal to the detection accuracy of the detector of the photolithography machine, so that the edge area of the transparent substrate 10 not covered by the mask 400 is wide enough to form a sufficiently wide anti-reflection film 20. The distance between the edge of the mask 400 and the edge of the transparent substrate 10 corresponds to the width w of the anti-reflection film 20.

[0088] Or, alternatively, see Figure 8 As shown, the mask 400 has an annular vacancy 401; the size of the outer edge of the annular vacancy 401 is less than or equal to the size of the edge of the transparent substrate 10, and the width of the annular vacancy 401 is greater than or equal to the detection accuracy of the detector of the photolithography machine. Specifically, in the embodiment of the present invention, the shape of the annular vacancy 401 is consistent with the shape of the anti-reflection film 20, and the width of the annular vacancy 401 is the width w of the anti-reflection film 20; and the size of the outer edge of the annular vacancy 401 is less than or equal to the size of the edge of the transparent substrate 10, so that the transparent substrate 10 can completely cover the annular vacancy 401. For example, Figure 8 Take the shape shown as an example, Figure 8 The upper part is a mask 400 having an annular vacancy 401, and the lower part is a transparent substrate 10; if the radius of the transparent substrate 10 is R, the annular vacancy 401 is a circular ring, the radius of its inner edge (i.e., the inner ring radius) is r1, and the radius of its outer edge (i.e., the outer ring radius) is r2, then r2≤R, and r2-r1=w.

[0089] It should be noted that if the size of the outer edge of the annular vacancy 401 (such as Figure 8 The outer ring radius r2) is larger than the edge size of the transparent substrate 10 (such as Figure 8 In the process of coating the antireflection film, the mask plate outside the annular vacancy 401 (such as Figure 8 The mask corresponding to the annular part in the middle) may not work, and it is essentially still using a closed-shape mask (such as Figure 8 The mask corresponding to the middle circular part is coated with the anti-reflection film 20.

[0090] Step S702 : a mask 400 is disposed on the front surface of the transparent substrate 10 , wherein the area of the front surface of the transparent substrate 10 not covered by the mask 400 is annular.

[0091] In the embodiment of the present invention, by selecting a mask 400 of suitable shape, when the mask 400 is placed on the front surface of the transparent substrate 10, part of the front surface of the transparent substrate 10 may not be covered by the mask 400, and the area not covered by the mask 400 is annular. Figure 7 As shown, a mask 400 smaller than the transparent substrate 10 can be selected, and the two are coaxially arranged. In this case, the outermost area of the transparent substrate 10 is not covered by the mask 400, and the shape of the area is annular.

[0092] Step S703 : depositing an anti-reflective film 200 on the front surface of the transparent substrate 10 on which the mask 400 is disposed.

[0093] In the embodiment of the present invention, similar to the above step S602, an anti-reflection film layer 200 may be deposited on the front surface of the transparent substrate 10 by evaporation or the like. Figure 7 As shown, since a mask plate 400 has been set on the front side of the transparent substrate 10, the plated anti-reflection film layer 200 is not in the same plane. Part of the anti-reflection film layer 200 is on the surface of the mask plate 400, and the other part of the anti-reflection film layer 200 is on the front side of the transparent substrate 10, and the anti-reflection film layer 200 located on the front side of the transparent substrate 10 is a ring structure.

[0094] Step S704: removing the mask 400.

[0095] After the anti-reflection film layer 200 is plated, the mask 400 can be removed, and the anti-reflection film layer 200 on the surface of the mask 400 can be removed simultaneously, and finally only a portion of the anti-reflection film layer 200 is left on the front surface of the transparent substrate 10. The anti-reflection film layer 200 has a ring structure. In the embodiment of the present invention, the anti-reflection film layer 200 with a ring structure is used as the required anti-reflection film 20, thereby achieving the effect of plating the anti-reflection film 20 with a ring structure on the front surface of the transparent substrate 10. Figure 7 Taking the mask 400 as a closed shape of a single connected area as an example, for the mask 400 with an annular vacancy 401, the process flow is similar to this and will not be described in detail here.

[0096] Optionally, after step S102, a product manufactured on the front surface of the transparent substrate 10, such as a chip or a superlens, can be obtained. The desired product can be ultimately manufactured without removing the anti-reflection film 20. Alternatively, after step S102, the process may further include removing the anti-reflection film 20.

[0097] In the embodiment of the present invention, since multiple products may be processed on the front side of the transparent substrate 10, it is convenient to cut out the desired products after removing the anti-reflection film 20. Figure 9A As shown, Figure 9AFIG. 1 shows a schematic diagram of the structure obtained after photolithography processing. A plurality of super lenses 500 are fabricated on the front surface of the transparent substrate 10 by a photolithography machine. Afterwards, each super lens 500 can be directly cut out without removing the anti-reflection film 20. Alternatively, the anti-reflection film 20 can be removed to avoid the influence of the anti-reflection film 20. Figure 9B This is a schematic diagram of the structure after removing the anti-reflection film 20. The structure mainly includes a transparent substrate 10 and a super lens 500 located on the front side, and is compatible with more cutting processes.

[0098] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solution that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A photolithography process for processing a transparent substrate, characterized in that: include: A ring-shaped anti-reflection film is plated on the front surface of the transparent substrate, wherein the width of the anti-reflection film is greater than or equal to the detection accuracy of the detector of the photolithography machine; The transparent substrate refers to a substrate that is transparent in the operating wavelength band of the detector of the lithography machine, and the anti-reflection film is configured to reflect light in the operating wavelength band of the detector of the lithography machine; wherein the light incident on the anti-reflection film is reflected to the detector of the lithography machine, so that the detector of the lithography machine can detect the anti-reflection film, and thus can indirectly identify the transparent substrate; The front effective area of the transparent substrate is photolithographically processed using a photolithography machine, where the front effective area is an area on the front of the transparent substrate excluding the anti-reflection film.

2. The photolithography process according to claim 1, wherein: The anti-reflection film is located at an edge of the transparent substrate, and the front effective area is an area on the front surface of the transparent substrate surrounded by the anti-reflection film.

3. The photolithography process according to claim 2, wherein: An edge of the anti-reflection film is aligned with an edge of the transparent substrate.

4. The photolithography process according to claim 1, wherein: The anti-reflection film is a continuous ring structure; or, The anti-reflection film is an annular structure with a gap, and the circumferential length of the gap is smaller than the detection range of the detector of the lithography machine.

5. The photolithography process according to any one of claims 1 to 4, characterized in that: The method of coating a ring-shaped anti-reflection film on the front surface of a transparent substrate comprises: Plating an anti-reflection film layer on the front surface of the transparent substrate; Coating photoresist on the surface of the anti-reflection film layer; exposing the photoresist to expose a ring-shaped photoresist; Etching the anti-reflection film layer; The photoresist of the ring structure is removed.

6. The photolithography process according to any one of claims 1 to 4, characterized in that: The method of coating a ring-shaped anti-reflection film on the front surface of a transparent substrate comprises: A mask is provided on the front surface of the transparent substrate, wherein the area of the front surface of the transparent substrate not covered by the mask is annular; Coating an anti-reflection film layer on the front surface of the transparent substrate provided with the mask; The mask is removed.

7. The photolithography process according to claim 6, wherein: The mask is of a closed shape; the size of the mask is smaller than the size of the transparent substrate, and the distance between the edge of the mask and the edge of the transparent substrate is greater than or equal to the detection accuracy of the detector of the lithography machine; Alternatively, the mask has an annular vacancy; the size of the outer edge of the annular vacancy is smaller than or equal to the size of the edge of the transparent substrate, and the width of the annular vacancy is greater than or equal to the detection accuracy of the lithography machine detector.

8. The photolithography process according to claim 1, wherein: After performing photolithography processing on the front effective area of the transparent substrate using a photolithography machine, the method further includes: The anti-reflection film is removed.

9. The photolithography process according to claim 1, wherein: The thickness of the anti-reflection film is greater than 50 nm; The width w of the anti-reflection film satisfies: 1mm <w<5mm。 10. The photolithography process according to claim 1, wherein: The anti-reflection film is made of metal material or a reflective film system.

11. The photolithography process according to claim 10, wherein: The metal includes at least one of aluminum, titanium, gold, copper and chromium.

12. The photolithography process according to claim 1, wherein: The transparent substrate is a quartz-based substrate.

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