Exposure apparatus, double exposure overlay shift detection method, device, computer equipment and storage medium

Abstract

The present application relates to an exposure device, a double exposure overlay offset detection method, a device, a computer device and a storage medium. The exposure device comprises a stage, a lens assembly and a second detection ruler. The stage comprises a bearing surface, the bearing surface has an exposure area and a detection area, and the exposure area is used for placing a wafer. The lens assembly is installed on the bearing surface of the stage and located in the detection area. The lens assembly comprises a lens unit and a first detection ruler. The lens unit has both transmission and reflection. The first detection ruler is located on the side of the lens unit close to the stage and is used for detecting the position of the light transmitted by the lens unit. The second detection ruler is located on the side of the lens unit away from the stage and is arranged separately from the lens unit and is used for detecting the position of the light reflected by the lens unit. The present application can effectively monitor the overlay offset, thereby facilitating the improvement of product yield.

Description

Technical Field

[0001] This application relates to the field of exposure technology, and in particular to an exposure apparatus, a method and device for detecting double exposure overlay offset, a computer device, and a storage medium. Background Technology

[0002] With the development of semiconductor technology, thick-film photoresists are becoming increasingly widely used to meet the special requirements of processes such as high aspect ratio, strong durability, and 3D integration. These photoresists are relatively thick (e.g., greater than 3µm), therefore requiring double exposure technology to meet customer pattern cross-section requirements. However, in double exposure technology, there will be overlay offset between the two exposures, leading to pattern deformation and affecting product yield. Summary of the Invention

[0003] Therefore, it is necessary to provide an exposure device, a double exposure overlay offset detection method, a device, a computer device, and a storage medium that can effectively monitor overlay offset in order to address the above-mentioned technical problems.

[0004] An exposure apparatus, comprising:

[0005] A stage, including a support surface, the support surface having an exposure area and a detection area, the exposure area being used to place a wafer;

[0006] A lens assembly is mounted on the bearing surface of the stage and located in the detection area. The lens assembly includes a lens unit and a first detection ruler. The lens unit is both transmissive and reflective. The first detection ruler is located on the side of the lens unit closer to the stage and is used to detect the position of the light transmitted by the lens unit.

[0007] The second measuring ruler is located on the side of the lens unit away from the stage and is spaced apart from the lens unit. It is used to detect the position of the light reflected by the lens unit.

[0008] In one embodiment, the exposure apparatus further includes:

[0009] A light emitting module, located on the side of the lens assembly away from the stage, is used to emit fixed emission light to the lens unit.

[0010] In one embodiment, the light emitting module is mounted on the second detection ruler.

[0011] In one embodiment, the exposure device includes a first reading module for reading the position of light on the first detection ruler;

[0012] And / or,

[0013] The exposure device includes a second reading module, which is used to read the position of the light on the second detection ruler.

[0014] The aforementioned exposure apparatus features a detection area on the stage, within which a lens assembly (including a lens unit and a first detection ruler) and a second detection ruler are installed. In double exposure, the first detection ruler detects the first distance between the transmitted light rays reaching it during the two exposures. The second detection ruler detects the second distance between the reflected light rays reaching it during the two exposures. Based on this, the horizontal movement of the stage can be effectively determined, thereby effectively detecting overlay misalignment. In subsequent processes, the detected overlay misalignment can be effectively adjusted and compensated for, thereby significantly improving the yield of subsequent products.

[0015] A double exposure overlay offset detection method, applied to any of the above-described exposure apparatus, the method comprising:

[0016] When performing a standard double exposure on a preset photoresist, a first standard value for a first distance and a second standard value for a second distance are obtained; the first distance is the distance between the transmitted light of the two exposures detected by the first detection ruler during the double exposure process, and the second distance is the distance between the reflected light of the two exposures detected by the second detection ruler during the double exposure process.

[0017] When performing actual double exposure on the preset photoresist, obtain the first actual measurement value of the first distance and the second actual measurement value of the second distance;

[0018] When the second actual measured value is different from the second standard value, the distance component value of the first distance is calculated based on the first standard value, the second standard value, and the second actual measured value.

[0019] The overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the distance component value.

[0020] In one embodiment, the method further includes:

[0021] When the second actual measurement value is the same as the second standard value, the overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the first standard value.

[0022] In one embodiment, the method further includes:

[0023] Obtain a third standard value for the third distance; the third distance is the descent distance of the stage during the double exposure process.

[0024] When the second actual measured value differs from the second standard value, the third actual value of the third distance is calculated based on the third standard value, the second standard value, and the second actual measured value.

[0025] The offset value of the third distance in the actual double exposure is calculated based on the difference between the third actual value and the third standard value.

[0026] A dual-exposure overlay offset detection device, applied to any of the above-described exposure devices, the dual-exposure overlay offset detection device comprising:

[0027] The first acquisition module is used to acquire a first standard value of a first distance and a second standard value of a second distance when performing standard double exposure on a preset photoresist; the first distance is the distance between transmitted light detected by the first detection ruler during the double exposure process, and the second distance is the distance between reflected light detected by the second detection ruler during the double exposure process.

[0028] The second acquisition module is used to acquire the first actual measurement value of the first distance and the second actual measurement value of the second distance when the preset photoresist is actually double exposed;

[0029] The first calculation module is used to calculate the distance component value of the first distance based on the first standard value, the second standard value, and the second actual measurement value when the second actual measurement value is different from the second standard value.

[0030] The second calculation module is used to calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the distance component value.

[0031] A computer device includes a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of any of the methods described above.

[0032] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0033] The aforementioned double exposure overlay offset detection method, apparatus, computer equipment, and storage medium first determine, by the difference between the second actual measurement value and the second standard value, that in the actual double exposure process, the third distance the stage descends during the second exposure relative to its position during the first exposure is not equal to a pre-set standard distance value. Then, in this case, the distance component value of the first distance is calculated based on the first standard value, the second standard value, and the second actual measurement value. Subsequently, the overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the distance component value, thus accurately and effectively obtaining the overlay offset. At this point, in subsequent processes, the overlay offset of the exposure machine can be effectively adjusted and compensated based on the detected overlay offset, thereby effectively improving the yield of subsequent process products. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram illustrating the principle of double exposure of photoresist in one embodiment;

[0036] Figure 2 This is a schematic cross-sectional view of the exposure apparatus in one embodiment;

[0037] Figure 3 This is a top view of the platform in one embodiment;

[0038] Figure 4 This is a top view of a partial structure of the exposure apparatus in one embodiment;

[0039] Figure 5 This is a schematic cross-sectional view of the lens assembly in one embodiment;

[0040] Figure 6 This is a schematic diagram of a double exposure process using an exposure device in one embodiment;

[0041] Figure 7 This is a schematic diagram illustrating the process of double exposure using an exposure device in another embodiment;

[0042] Figure 8 This is a schematic cross-sectional view of a partial structure of the exposure apparatus in one embodiment;

[0043] Figure 9 This is a schematic cross-sectional view of a partial structure of the exposure apparatus in another embodiment;

[0044] Figure 10 This is a flowchart illustrating a double-exposure overlay offset detection method in one embodiment;

[0045] Figure 11 This is a flowchart illustrating the double exposure overlay offset detection method in another embodiment;

[0046] Figure 12 This is a structural block diagram of a dual-exposure overlay offset detection device in one embodiment.

[0047] Explanation of reference numerals in the attached figures:

[0048] 100-Stage, A1-Exposure area, A2-Detection area, 200-Lens assembly, 210-Lens unit, 220-First detection ruler, 300-Second detection ruler, 400-Lens assembly, 500-Light emission module, 600-Second reading module, 10-First acquisition module, 20-Second acquisition module, 30-First calculation module, 40-Second calculation module, D1-First distance, D2-Second distance, D3-Third distance. Detailed Implementation

[0049] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0051] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0052] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0053] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0054] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0055] As described in the background section, in existing double exposure technology, there is an overlay offset between the two exposures, which leads to pattern distortion and affects product yield. The inventors have discovered that the reason for this problem is:

[0056] During the two exposures, the photoresist PR needs two different focal points, F1 and F2 (see [link to relevant documentation]). Figure 1 To achieve different focal positions, the wafer stage is positioned differently during the two exposures. During the second exposure, the wafer stage moves vertically downwards from its position during the first exposure to its current position. For details on this process, please refer to [link to relevant documentation]. Figure 1 In Figure (a), ideally, the wafer stage only moves that distance in the vertical direction. However, in reality, please refer to [the diagram]. Figure 1 As shown in Figure (b), the wafer stage will also move horizontally, which will cause overlay misalignment and thus affect product yield.

[0057] For the reasons mentioned above, the present invention provides an exposure device, a double exposure overlay offset detection method, a device, a computer device, and a storage medium that can effectively monitor overlay offset.

[0058] In one embodiment, see Figure 2 An exposure apparatus is provided, including a stage 100, a lens assembly 200, and a second detection ruler 300.

[0059] Please see Figure 3 and Figure 4 The stage 100 includes a bearing surface. Exemplarily, the stage 100 may have an upper surface and a lower surface disposed opposite to each other. The upper surface may be the bearing surface.

[0060] The carrier surface has an exposure area A1 and a detection area A2. The exposure area A1 is used to place the wafer. It is understood that the exposure area A1 and the detection area A2 can be partial areas on the carrier surface, and the carrier surface can also have other areas besides the exposure area A1 and the detection area A2.

[0061] For example, there can be one detection area A2. Detection area A2 can be located on one side of exposure area A1. Of course, there can also be multiple detection areas A2. When there are multiple detection areas A2, different detection areas A2 can be located on different sides of exposure area A1, or they can be located on the same side of exposure area A1.

[0062] Please see Figure 2 and Figure 4 The lens assembly 200 is mounted on the bearing surface of the stage 100 and is located in the testing area A2.

[0063] For example, the lens assembly 200 can be fixedly mounted on the stage 100 to improve system accuracy.

[0064] For example, the lens assembly 200 can also be movably mounted on the stage 100. For instance, the lens assembly 200 can be movably mounted on the stage 100 by means of plugging or snapping. In this case, it is convenient to maintain or replace the lens assembly 200 if a problem occurs.

[0065] For example, a groove may also be provided on the bearing surface of the stage 100. The lens assembly 200 can be installed into the groove to prevent interference with wafer loading and unloading or to prevent wafer impact. Of course, the bearing surface of the stage 100 can also be a completely flat surface. The lens assembly 200 can be installed on the flat surface of the bearing surface.

[0066] The lens assembly 200 includes a lens unit 210 and a first detection ruler 220.

[0067] Lens unit 210 is both transmissive and reflective. For example, lens unit 210 includes a semi-transmissive and semi-reflective lens.

[0068] The first detection ruler 220 is located on the side of the lens unit 210 near the stage 100 and is used to detect the position of the light transmitted by the lens unit 210. Specifically, since the lens unit 210 is both transmissive and reflective, when emitted light is emitted to the lens unit 210, some of the light can pass through the lens unit 210 and illuminate the first detection ruler 220. Therefore, the position of the light transmitted by the lens unit 210 can be detected by the first detection ruler 220.

[0069] For example, the first detection ruler 220 may be, but is not limited to, a grating ruler.

[0070] For example, please refer to Figure 2 The lens unit 210 can directly contact the first detection ruler 220, eliminating any gaps between them and allowing dust particles to enter, thus improving the detection accuracy of the first detection ruler 220. Alternatively, the lens unit 210 can be spaced apart from the first detection ruler 220 (see [link to relevant documentation]). Figure 5 ), to meet other application needs.

[0071] Please see Figure 2 The second detection ruler 300 is located on the side of the lens unit 210 away from the stage 100. The second detection ruler 300 is also spaced apart from the lens unit 210. The position of the second detection ruler 300 in the exposure apparatus can be fixed. For example, the exposure apparatus can expose the lens assembly 400. The lens assembly 400 may include a lens element and a lens frame. The lens element may be mounted within the lens frame. The second detection ruler 300 may, for example, be mounted on the lens frame. Of course, the second detection ruler 300 may also be mounted in other locations; this application is not limited in this regard.

[0072] The second detection ruler 300 is used to detect the position of the light reflected by the lens unit 210. Specifically, since the lens unit 210 is both transmissive and reflective, when emitted light is emitted to the lens unit 210, some of the light can be reflected by the lens unit 210 and thus illuminate the second detection ruler 300. Therefore, the position of the light reflected by the lens unit 210 can be detected by the second detection ruler 300.

[0073] Please see Figure 6 as well as Figure 7During double exposure in the exposure apparatus, emitted light with the same emission angle (fixed emission light) can be emitted towards the lens unit 210 during both the first and second exposures. At this time, the positions of the light rays transmitted to the first detection ruler 220 during the two exposures can be detected, thus detecting the first distance D1 between them. The positions of the light rays reflected to the second detection ruler 300 during the two exposures can be detected, thus detecting the second distance D2 between them. Simultaneously, the stage 100 will descend a third distance D3 relative to its position during the first exposure during the second exposure. It can be understood that the wafer assembly is located on the stage 100; therefore, the third distance D3 by which the stage 100 descends relative to its position during the first exposure during the second exposure is the distance by which the wafer assembly descends in the figure.

[0074] Therefore, ideally, please refer to Figure 6 During the two exposures, the stage 100 does not move horizontally, and the third distance D3 that the stage 100 descends relative to its position during the first exposure is equal to a preset standard distance value. At this time, the third distance D3 has a third standard value, the first distance D1 has a first standard value, and the second distance D2 has a second standard value.

[0075] However, in practice, please refer to Figure 7 During the two exposures, the stage 100 may move horizontally, causing the lens assembly 200 (including the first detection ruler 220) to move horizontally as well. This affects the reading of the transmitted light position on the first detection ruler 220, which moves simultaneously with the stage 100. Consequently, this affects the difference in the detected transmitted light position on the first detection ruler 220 between the two exposures, thus influencing the first distance D1.

[0076] Meanwhile, in practice, the third distance D3 that the stage 100 descends during the second exposure relative to its descent during the first exposure may not be equal to the preset standard distance value, thus affecting both the first distance D1 and the second distance D2. Specifically, the emitted light emitted to the lens unit 210 during the two exposures is emitted light with the same emission angle (fixed emission light). Therefore, when the stage 100 does not move horizontally, the relationship between the third distance D3, the first distance D1, and the second distance D2 is theoretically fixed. Therefore, changes in the third distance D3 will affect both the first distance D1 and the second distance D2.

[0077] Therefore, in practice, the first actual measurement value of the first distance D1 can be detected by the first detection ruler 220, and the second actual measurement value of the second distance D2 can be detected by the second detection ruler 300. Then, the horizontal movement of the stage 100 can be effectively determined by the second actual measurement value of the second distance D2, the second standard value of the second distance D2, the first actual measurement value of the first distance D1, and the first standard value of the first distance D1, thereby effectively detecting the overlay offset.

[0078] In this embodiment, a detection area A2 is designed on the stage 100 of the exposure apparatus. The detection area A2 contains a lens assembly 200 (including a lens unit 210 and a first detection ruler 220) and a second detection ruler 300. During double exposure, the first detection ruler 220 can detect the first distance D1 between the transmitted light rays transmitted to it during the two exposures. The second detection ruler 300 can detect the second distance D2 between the reflected light rays reflected to it during the two exposures. Based on this, the horizontal movement of the stage 100 can be effectively determined, thereby effectively detecting overlay misalignment. In subsequent processes, the overlay misalignment of the exposure machine can be effectively adjusted and compensated based on the detected overlay misalignment, thereby effectively improving the yield of subsequent products.

[0079] In one embodiment, see Figure 7 The exposure apparatus also includes a light emission module 500. The light emission module 500 is located on the side of the lens assembly 200 away from the stage 100 and is used to emit fixed emission light to the lens unit 210.

[0080] The position of the light emitting module 500 in the exposure device can be fixed, thereby facilitating the emission of emitted light with the same emission angle to the lens unit 210 (fixed emission light).

[0081] In one embodiment, the light emitting module 500 may be mounted on the second detection ruler 300.

[0082] For example, please refer to Figure 7 The second detection ruler 300 can be configured to have a through hole, and the light emitting module 500 can be inserted into the through hole to emit fixed emission light to the lens unit 210 located below it.

[0083] For example, please refer to Figure 8 The light emitting module 500 can be installed below the second detection ruler 300, thereby facilitating the emission of fixed light to the lens unit 210 located below it.

[0084] For example, please refer to Figure 9The light emitting module 500 can also be installed at one end of the second detection ruler 300.

[0085] In this embodiment, by mounting the light emitting module 500 on the second detection ruler 300, the position of the light emitting module 500 can be effectively fixed, thereby facilitating the emission of fixed light to the lens unit 210.

[0086] Of course, in other embodiments, the light emitting module 500 may also be installed in other locations, and this application does not limit this.

[0087] In one embodiment, the exposure apparatus includes a first reading module (not shown). The first reading module is used to read the position of light on a first detection ruler 220.

[0088] For example, the first reading module may include a light receiving sensor, etc., so as to effectively read the position of the light illuminating the first detection ruler 220. Specifically, please refer to... Figure 6 In double exposure, during the first exposure, a fixed emission light is emitted from the light emission module 500 to the lens unit 210. Part of this light passes through the lens unit 210 and illuminates the first detection scale 220. The position a1 of this transmitted light on the first detection scale 220 can then be effectively read by the first reading module. During the second exposure, the fixed emission light is again emitted from the light emission module 500 to the lens unit 210. Part of this light passes through the lens unit 210 and illuminates the first detection scale 220. The position a2 of this transmitted light on the first detection scale 220 can then be effectively read by the first reading module. The distance between the transmitted light position a2 and the transmitted light position a1 is the first distance D1 described above.

[0089] In this embodiment, the position of the transmitted light on the first detection ruler 220 can be effectively read by setting the first reading module. Of course, in other embodiments, the first detection ruler 220 itself can also be configured to have the function of reading the light position. In this case, the first reading module may not be required.

[0090] In one embodiment, see Figure 9 The exposure device includes a second reading module 600. The second reading module 600 is used to read the position of the light on the second detection ruler 300.

[0091] For example, the second reading module 600 may include a light receiving sensor, etc., so as to effectively read the position of the light illuminating the second detection ruler 300. Specifically, please refer to... Figure 6In double exposure, during the first exposure, a fixed emission light is emitted from the light emission module 500 towards the lens unit 210. A portion of this light is reflected by the lens unit 210 to the second detection scale 300, and the position b1 of this reflected light on the second detection scale 300 can then be effectively read by the second reading module 600. During the second exposure, the fixed emission light is again emitted from the light emission module 500 towards the lens unit 210, and a portion of this reflected light is reflected by the lens unit 210 to the second detection scale 300. The position b2 of this reflected light on the second detection scale 300 can then be effectively read by the second reading module 600. The distance between the reflected light position b2 and the reflected light position b1 is the second distance D2 described above.

[0092] In this embodiment, the position of the reflected light on the second detection ruler 300 can be effectively read by the second reading module 600. Of course, in other embodiments, the second detection ruler 300 itself can also have the function of reading the light position. In this case, the second reading module 600 may not be required.

[0093] In one embodiment, see Figure 10 Furthermore, a dual-exposure overlay offset detection method is provided, applied to the exposure apparatus described above, the method comprising the following steps:

[0094] Step S100: Obtain the first standard value of the first distance D1 and the second standard value of the second distance D2 when performing standard double exposure on the preset photoresist; the first distance D1 is the distance between the transmitted light of the two exposures detected by the first detection ruler 220 during the double exposure process, and the second distance D2 is the distance between the reflected light of the two exposures detected by the second detection ruler 300 during the double exposure process.

[0095] Step S200: Obtain the first actual measurement value of the first distance D1 and the second actual measurement value of the second distance D2 when performing actual double exposure on the preset photoresist.

[0096] Step S300: When the second actual measured value is different from the second standard value, calculate the distance component value of the first distance D1 based on the first standard value, the second standard value and the second actual measured value;

[0097] Step S400: Calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the distance component value.

[0098] In step S100, the preset photoresist can be a preset type of photoresist with a preset theoretical thickness. "Preset theoretical thickness" can be understood as follows: using a preset coating process, a preset amount of preset type of photoresist is coated on a wafer of preset size, and theoretically, a photoresist thickness can be obtained.

[0099] A standard double exposure is an ideal and compliant double exposure performed on a preset photoresist. For example, one double exposure process can be selected from a fixed process formulation as the standard double exposure. Then, the distance between the transmitted light from the two exposures detected by the first detection ruler 220 during this double exposure process is taken as the first standard value of the first distance D1, and the distance between the reflected light from the two exposures detected by the second detection ruler 300 is taken as the second standard value of the second distance D2.

[0100] In step S200, the actual double exposure can be a double exposure processed using the same process formula as the standard double exposure.

[0101] In actual double exposure and standard double exposure, both are performed on a preset photoresist. That is, the photoresist used in actual double exposure and standard double exposure are the same type and have the same theoretical thickness (both are preset theoretical thicknesses).

[0102] The distance between the transmitted light of the two exposures detected by the first detection ruler 220 during the actual double exposure process can be used as the first actual measurement value of the first distance D1, and the distance between the reflected light of the two exposures detected by the second detection ruler 300 can be used as the second actual measurement value of the second distance D2.

[0103] In step S300, when the second actual measured value of the second distance D2 is different from the second standard value, it indicates that the third distance D3 that the stage 100 drops during the second exposure relative to the first exposure is not equal to the preset standard distance value.

[0104] Specifically, as explained above, in the actual double exposure process, the third distance D3 that the stage 100 descends during the second exposure relative to its position during the first exposure may not be equal to the preset standard distance value, thus affecting both the first distance D1 and the second distance D2. Simultaneously, during the actual double exposure process, the stage 100 may move horizontally, affecting the reading of the transmitted light on the first detection ruler 220, which moves simultaneously with the stage 100, thus affecting the first distance D1. However, the second distance D2 is the distance detected on the fixed-position second detection ruler 300. Furthermore, the surface of the lens unit 210 is flat, and when fixed emitted light is incident on the lens unit 210 at the same angle, the reflected light is the same regardless of the position of the incident light on the lens unit 210. Therefore, horizontal movement of the stage 100 will not affect the second distance D2.

[0105] Therefore, in the actual double exposure process, the first actual measurement value of the first distance D1 is related to both the actual value of the third distance D3 and the horizontal movement of the stage 100. The second actual measurement value of the second distance D2 is related to the actual value of the third distance D3, but not to the horizontal movement of the stage 100.

[0106] Therefore, the second actual measurement value of the second distance D2 is different from the second standard value, indicating that the third distance D3, which decreases relative to its value during the first exposure, is not equal to the preset standard distance value.

[0107] At the same time, the first actual measured value of the first distance D1 includes a distance component value corresponding to the actual value of the third distance D3. This distance component value is the distance component value of the first distance D1 corresponding to the actual value of the third distance D3 when the platform 100 does not move horizontally. Furthermore, as explained above, when the platform 100 does not move horizontally, the relationship between the third distance D3, the first distance D1, and the second distance D2 is theoretically fixed regardless of the actual value of the third distance D3. Therefore, the distance component value corresponding to the actual value of the first distance D1 and the third distance D3 is also the distance component value corresponding to the actual value of the first distance D1 and the second distance D2 (the second actual measured value).

[0108] Therefore, the distance component value of the first distance D1 can be calculated based on the first standard value, the second standard value, and the second actual measurement value.

[0109] Specifically, the first standard value can be denoted as L11. The second standard value can be denoted as L21. The second actual measurement value can be denoted as L22. Assuming that the platform 100 does not move horizontally, the distance component value corresponding to the second actual measurement value of the first distance D1 and the second distance D2 can be denoted as L1'.

[0110] Therefore, L11:L21 = L1':L22. Thus, L1' = (L11 * L22) / L21.

[0111] In step S400, the difference between the first actual measured value and the distance component value, that is, in the first actual measured value of the first distance D1, the distance component value corresponding to the second actual measured value of the second distance D2 is removed, that is, in the first actual measured value of the first distance D1, the distance component value corresponding to the actual value of the third distance D3 is removed.

[0112] Meanwhile, as explained above, in the actual double exposure process, the first actual measurement value of the first distance D1 is related to both the actual value of the third distance D3 and the horizontal movement of the stage 100.

[0113] Therefore, the first actual measurement value of the first distance D1 includes both the distance component value corresponding to the actual value of the third distance D3 and the horizontal movement of the platform 100.

[0114] Therefore, based on the difference between the first actual measured value and the distance component value, the horizontal movement of the stage 100 in the actual double exposure can be obtained, thus accurately and effectively obtaining the overlay offset.

[0115] In this embodiment, firstly, by distinguishing between the second actual measured value and the second standard value, it can be determined that during the actual double exposure process, the third distance D3 that the stage 100 descends during the second exposure relative to its position during the first exposure is not equal to the preset standard distance value. Then, in this case, the distance component value of the first distance D1 is calculated based on the first standard value, the second standard value, and the second actual measured value. Subsequently, based on the difference between the first actual measured value and the distance component value, the overlay offset of the actual double exposure is calculated, thereby accurately and effectively obtaining the overlay offset. At this point, in subsequent processes, the overlay offset of the exposure machine can be effectively adjusted and compensated based on the detected overlay offset, thereby effectively improving the yield of subsequent process products.

[0116] In one embodiment, see Figure 11 The double exposure overlay offset detection method also includes:

[0117] Step S500: When the second actual measurement value is the same as the second standard value, calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the first standard value.

[0118] When the second actual measurement value is the same as the second standard value, it means that the third distance D3 that the stage 100 drops during the second exposure relative to its first exposure is equal to the preset standard distance value.

[0119] At this point, the first actual measurement value of the first distance D1 is only related to the horizontal movement of the stage 100. That is, the deviation between the first actual measurement value and the first standard value is only related to the horizontal movement of the stage 100.

[0120] Therefore, the overlay offset of the actual double exposure can be calculated by the difference between the first actual measured value and the first standard value of the first distance D1.

[0121] In one embodiment, the double exposure overlay offset detection method further includes:

[0122] Step S600: Obtain the third standard value of the third distance D3; the third distance D3 is the descent distance of the stage 100 during the double exposure process.

[0123] Step S700: When the second actual measured value is different from the second standard value, calculate the third actual value of the third distance D3 based on the third standard value, the second standard value, and the second actual measured value.

[0124] Step S800: Calculate the offset value of the third distance D3 in the actual double exposure based on the difference between the third actual value and the third standard value.

[0125] In step S600, the third standard value of the third distance D3 can be understood as the distance by which the stage 100 descends during the second exposure relative to the distance during the first exposure in the standard double exposure process. This distance can be equal to a preset standard distance value.

[0126] In step S700, as explained above, when the second actual measured value of the second distance D2 is different from the second standard value, it means that the third distance D3 that the stage 100 drops during the second exposure relative to the first exposure is not equal to the preset standard distance value, that is, it is not equal to the third standard value.

[0127] Furthermore, as explained above, assuming the stage 100 does not move horizontally, the relationship between the third distance D3, the first distance D1, and the second distance D2 is theoretically fixed regardless of the actual value of the third distance D3. The second distance D2 is the distance detected by the fixed-position second detection ruler 300, while the third distance D3 is the vertical distance. Therefore, even if the stage 100 moves horizontally, it will not affect the relationship between the second distance D2 and the third distance D3. Thus, regardless of whether the stage 100 moves horizontally, the relationship between the third distance D3 and the second distance D2 remains constant.

[0128] Therefore, based on the third standard value of the third distance D3, the second standard value of the second distance D2, and the second actual measurement value, the third actual value of the third distance D3 can be calculated.

[0129] Specifically, the third standard value can be denoted as L31. The second standard value can be denoted as L21. The second actual measured value can be denoted as L22. The third actual value of the third distance D3 can be denoted as L3'.

[0130] Therefore, L31:L21 = L3':L22. Thus, L3' = (L31 * L22) / L21.

[0131] In step S800, the offset value of the third distance D3 in the actual double exposure is calculated based on the difference between the third actual value and the third standard value.

[0132] At this point, in subsequent processes, the stage 100 descent distance can be effectively adjusted and compensated based on the detected offset value of the third distance D3 during the double exposure process, thereby effectively improving the product yield of subsequent processes.

[0133] It should be understood that, although Figures 10-11 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figures 10-11 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0134] In one embodiment, see Figure 12 A dual-exposure overlay offset detection device is provided, comprising: a first acquisition module 10, a second acquisition module 20, a first calculation module 30, and a second calculation module 40, wherein:

[0135] The first acquisition module 10 is used to acquire the first standard value of the first distance D1 and the second standard value of the second distance D2 when performing standard double exposure on the preset photoresist; the first distance D1 is the distance between transmitted light detected by the first detection ruler 220 during the double exposure process, and the second distance D2 is the distance between reflected light detected by the second detection ruler 300 during the double exposure process.

[0136] The second acquisition module 20 is used to acquire the first actual measurement value of the first distance D1 and the second actual measurement value of the second distance D2 when the preset photoresist is actually double exposed.

[0137] The first calculation module 30 is used to calculate the distance component value of the first distance D1 based on the first standard value, the second standard value, and the second actual measurement value when the second actual measurement value is different from the second standard value.

[0138] The second calculation module 40 is used to calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the distance component value.

[0139] In one embodiment, the double exposure overlay offset detection device further includes a third calculation module. The third calculation module is used to calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the first standard value when the second actual measurement value is the same as the second standard value.

[0140] In one embodiment, the double exposure overlay offset detection device further includes a third acquisition module, a fourth calculation module, and a fifth calculation module.

[0141] The third acquisition module is used to acquire the third standard value of the third distance D3; the third distance D3 is the descent distance of the stage 100 during the double exposure process.

[0142] The fourth calculation module is used to calculate the third actual value of the third distance D3 based on the third standard value, the second standard value, and the second actual measurement value when the second actual measurement value is different from the second standard value.

[0143] The fifth calculation module is used to calculate the offset value of the third distance D3 in the actual double exposure based on the difference between the third actual value and the third standard value.

[0144] Specific limitations regarding the double exposure overlay offset detection device can be found in the limitations of the double exposure overlay offset detection method described above, and will not be repeated here. Each module in the aforementioned double exposure overlay offset detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. It should be noted that the module division in this embodiment is illustrative and only represents a logical functional division; other division methods may be used in actual implementation.

[0145] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0146] When performing a standard double exposure on a preset photoresist, obtain the first standard value of the first distance D1 and the second standard value of the second distance D2; the first distance D1 is the distance between the transmitted light of the two exposures detected by the first detection ruler 220 during the double exposure process, and the second distance D2 is the distance between the reflected light of the two exposures detected by the second detection ruler 300 during the double exposure process.

[0147] When performing actual double exposure on a preset photoresist, obtain the first actual measured value of the first distance D1 and the second actual measured value of the second distance D2;

[0148] When the second actual measurement value is different from the second standard value, the distance component value of the first distance D1 is calculated based on the first standard value, the second standard value, and the second actual measurement value.

[0149] The overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the distance component value.

[0150] In one embodiment, when the processor executes the computer program, it further performs the following steps: when the second actual measurement value is the same as the second standard value, calculating the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the first standard value.

[0151] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining a third standard value of a third distance D3; the third distance D3 is the descent distance of the stage 100 during the double exposure. When the second actual measurement value differs from the second standard value, a third actual value of the third distance D3 is calculated based on the third standard value, the second standard value, and the second actual measurement value. Based on the difference between the third actual value and the third standard value, the offset value of the third distance D3 in the actual double exposure is calculated.

[0152] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0153] When performing a standard double exposure on a preset photoresist, obtain the first standard value of the first distance D1 and the second standard value of the second distance D2; the first distance D1 is the distance between the transmitted light of the two exposures detected by the first detection ruler 220 during the double exposure process, and the second distance D2 is the distance between the reflected light of the two exposures detected by the second detection ruler 300 during the double exposure process.

[0154] When performing actual double exposure on a preset photoresist, obtain the first actual measured value of the first distance D1 and the second actual measured value of the second distance D2;

[0155] When the second actual measurement value is different from the second standard value, the distance component value of the first distance D1 is calculated based on the first standard value, the second standard value, and the second actual measurement value.

[0156] The overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the distance component value.

[0157] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: when the second actual measurement value is the same as the second standard value, calculating the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the first standard value.

[0158] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining a third standard value of a third distance D3; the third distance D3 is the descent distance of the stage 100 during the double exposure. When the second actual measurement value differs from the second standard value, a third actual value of the third distance D3 is calculated based on the third standard value, the second standard value, and the second actual measurement value. Based on the difference between the third actual value and the third standard value, an offset value of the third distance D3 in the actual double exposure is calculated.

[0159] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0160] In the description of this specification, references to terms such as "one embodiment," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0161] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An exposure apparatus, characterized in that, include: A stage, including a support surface, the support surface having an exposure area and a detection area, the exposure area being used to place a wafer; A lens assembly is mounted on the bearing surface of the stage and located in the detection area. The lens assembly includes a lens unit and a first detection ruler. The lens unit is both transmissive and reflective. The first detection ruler is located on the side of the lens unit closer to the stage and is used to detect the position of the light transmitted by the lens unit. The second measuring ruler is located on the side of the lens unit away from the stage and is spaced apart from the lens unit. It is used to detect the position of the light reflected by the lens unit.

2. The exposure apparatus according to claim 1, characterized in that, The exposure apparatus further includes: A light emitting module, located on the side of the lens assembly away from the stage, is used to emit fixed emission light to the lens unit.

3. The exposure apparatus according to claim 2, characterized in that, The light emitting module is installed on the second detection ruler.

4. The exposure apparatus according to claim 1, characterized in that, The exposure device includes a first reading module, which is used to read the position of light on the first detection ruler; And / or, The exposure device includes a second reading module, which is used to read the position of the light on the second detection ruler.

5. A method for detecting overlay offset in dual exposure, characterized in that, The method, applied to the exposure apparatus according to any one of claims 1-4, comprises: When performing a standard double exposure on a preset photoresist, a first standard value for a first distance and a second standard value for a second distance are obtained; the first distance is the distance between the transmitted light of the two exposures detected by the first detection ruler during the double exposure process, and the second distance is the distance between the reflected light of the two exposures detected by the second detection ruler during the double exposure process. When performing actual double exposure on the preset photoresist, obtain the first actual measurement value of the first distance and the second actual measurement value of the second distance; When the second actual measured value is different from the second standard value, the distance component value of the first distance is calculated based on the first standard value, the second standard value, and the second actual measured value. The overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the distance component value.

6. The double exposure overlay offset detection method according to claim 5, characterized in that, The method further includes: When the second actual measurement value is the same as the second standard value, the overlay offset of the actual double exposure is calculated based on the difference between the first actual measurement value and the first standard value.

7. The double exposure overlay offset detection method according to claim 5, characterized in that, The method further includes: Obtain a third standard value for the third distance; the third distance is the descent distance of the stage during the double exposure process. When the second actual measured value differs from the second standard value, the third actual value of the third distance is calculated based on the third standard value, the second standard value, and the second actual measured value. The offset value of the third distance in the actual double exposure is calculated based on the difference between the third actual value and the third standard value.

8. A dual-exposure overlay offset detection device, characterized in that, When applied to the exposure apparatus according to any one of claims 1-4, the dual exposure overlay offset detection device comprises: The first acquisition module is used to acquire a first standard value of a first distance and a second standard value of a second distance when performing standard double exposure on a preset photoresist; the first distance is the distance between transmitted light detected by the first detection ruler during the double exposure process, and the second distance is the distance between reflected light detected by the second detection ruler during the double exposure process. The second acquisition module is used to acquire the first actual measurement value of the first distance and the second actual measurement value of the second distance when the preset photoresist is actually double exposed; The first calculation module is used to calculate the distance component value of the first distance based on the first standard value, the second standard value, and the second actual measurement value when the second actual measurement value is different from the second standard value. The second calculation module is used to calculate the overlay offset of the actual double exposure based on the difference between the first actual measurement value and the distance component value.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 5 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 5 to 7.

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