Lithography machine overlay deviation processing method, device and system

Abstract

The application provides a photolithography machine overlay deviation processing method, device and system, and is applied to the technical field of photolithography machines. The photolithography machine overlay deviation processing method comprises the following steps: performing twice exposure on alignment marks respectively, wherein the first time is blind exposure without visible light alignment, and the second time is exposure with visible light alignment, and then determining the overlay deviation according to the deviation between the measurement patterns obtained by exposure. The overlay deviation is determined by the deviation between the two exposures, so that the whole processing process can be carried out at any time and anywhere in the wafer production process. The measurement can be carried out without machine shutdown, the wafer production progress is not delayed, the production efficiency is ensured, the overlay deviation of the machine can be found in time, the measurement process is fast and accurate, and the wafer production needs are met.

Description

Technical Field

[0001] This application relates to the field of lithography machine technology, specifically to a method, apparatus, and system for handling overlay deviations in lithography machines. Background Technology

[0002] Alignment-related components in lithography equipment, such as wafer stages, lenses, and mask stages, which involve visible light alignment, may have changed positions over a long period of equipment use and during equipment maintenance. For example, some time after maintenance, it was found that the second primary mark (2PM) aligned with the 1st primary mark (1PM) had a significant misalignment in subsequent layers aligned with 1PM. Summary of the Invention

[0003] In view of this, the embodiments of this specification provide a method, apparatus and system for processing overlay deviations in a lithography machine, which can perform measurement operations anytime and anywhere based on the wafer production process, and promptly detect whether the overlay deviations meet the wafer production requirements.

[0004] The embodiments in this specification provide the following technical solutions:

[0005] This specification provides an embodiment of a method for handling overlay deviations in a photolithography machine, including:

[0006] A first alignment pattern and a second alignment pattern corresponding to the alignment mark are formed on the first silicon wafer, and a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern are formed. The first alignment pattern is the exposure result obtained by exposure without visible light alignment, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment to the first alignment pattern.

[0007] The overlay deviation is determined based on the deviation between the first measurement pattern and the second measurement pattern.

[0008] This specification also provides an embodiment of a photolithography machine overlay deviation processing device, comprising:

[0009] An exposure module is used to form a first alignment pattern and a second alignment pattern corresponding to an alignment mark on a first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is an exposure result obtained by exposure without visible light alignment, and the second alignment pattern is an exposure result obtained by exposure with visible light alignment of the first alignment pattern.

[0010] The measurement module is used to determine the overlay deviation based on the deviation between the first measurement pattern and the second measurement pattern.

[0011] This specification also provides a lithography machine overlay deviation processing system, including an alignment subsystem, an exposure subsystem, and a measurement subsystem;

[0012] The exposure subsystem is used to form a first alignment pattern and a second alignment pattern corresponding to the alignment mark on the first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is the exposure result obtained by exposure without visible light alignment by the alignment subsystem, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment of the first alignment pattern by the alignment subsystem.

[0013] The measurement subsystem is used to measure the deviation between the first measurement pattern and the second measurement pattern.

[0014] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least:

[0015] By simulating normal production procedures, each machine can perform two exposure operations. The first exposure is a blind exposure, which is exposure without visible light alignment to obtain the first alignment pattern (1PM) and the corresponding first measurement pattern. The second exposure is an alignment exposure, which uses visible light to align the first alignment pattern to obtain the second alignment pattern (2PM) and the corresponding second measurement pattern. Then, by measuring the deviation between the 1PM and 2PM measurement patterns, the machine's overlay error value between the blind exposure and the 1PM alignment is evaluated to determine whether the machine is still suitable for wafer production. For example, after the machine is repaired and then restored, the overlay deviation handling scheme in this manual can be used to immediately determine the overlay deviation of the restored machine, without waiting 6-7 days to perform the measurement. Therefore, the overlay deviation of the machine can be measured anytime and anywhere, and measures can be taken in time to avoid the wafer fab delaying wafer production schedule and causing economic losses due to machine deviation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments 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.

[0017] Figure 1 This is a schematic diagram of the lithography machine overlay deviation processing scheme architecture in this application;

[0018] Figure 2 This is a flowchart of the lithography machine overlay deviation processing method in this application;

[0019] Figure 3 This is a schematic diagram of the structure of the inner and outer frames formed by the measurement graphics corresponding to the alignment graphics in this application;

[0020] Figure 4 This is a schematic diagram illustrating the two-round, two-exposure process for each machine in this application to determine the deviation;

[0021] Figure 5 This is a schematic diagram of the lithography machine overlay deviation processing device in this application;

[0022] Figure 6 This is a schematic diagram of the lithography machine overlay deviation processing system in this application. Detailed Implementation

[0023] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0024] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0026] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0028] In the wafer manufacturing process using 1PM alignment and 2PM exposure, alignment components in the lithography machine, such as the silicon wafer stage, lens, and mask stage, which are involved in visible light alignment, have been found to have a large overlay deviation between the current layer aligned with 2PM and the layer aligned with 1PM after prolonged use or after machine repair.

[0029] It should be noted that alignment in photolithography refers to adjusting the exposure system according to the position of the alignment mark pattern on the reference layer on the wafer, so that the current layer's exposed pattern precisely overlaps with the pattern on the wafer; overlay deviation (also known as overlay error) is a parameter used to measure the quality of alignment, which can quantitatively characterize the positional deviation between the current layer and the reference layer.

[0030] Current methods require specialized measurement equipment to measure overlay deviations. Therefore, after transferring the 2PM mark onto the active mask (the current layer) using photoresist patterning onto the silicon wafer, it typically takes 6-7 days before specialized metrology equipment can detect the layer with overlay deviations. This means that it takes at least 6-7 days for the dedicated metrology equipment to detect the deviation. Consequently, after repair, the photolithography equipment needs to wait 6-7 days before being restarted and then measured and calibrated by specialized metrology equipment to confirm that the deviation meets wafer manufacturing requirements before it can continue to be used for wafer manufacturing. Alternatively, if the photolithography equipment is restarted immediately after repair for wafer manufacturing, the machine may carry the potential deviation and requires at least 6-7 days before it can be measured and calibrated by specialized metrology equipment.

[0031] Therefore, both of these processing methods inevitably have a significant impact on wafer manufacturing at the fab. For example, assuming two such machine malfunctions (e.g., maintenance) occur per year, there are currently 5 machines, and approximately 200 active masks pass through per day (an average of 40 wafers per machine). Based on this, approximately 2400 to 2800 silicon wafers would be affected annually. Furthermore, when a large number of machines in the fab exhibit significant deviations, even more silicon wafers will be affected, leading to a sharp increase in wafer manufacturing costs.

[0032] Based on this, this specification proposes a rapid measurement and processing scheme for alignment marks in a lithography machine: such as Figure 1 As shown, for the alignment marks used in the overlay process, the machine can perform two exposure processes to form a first alignment pattern (i.e., 1PM) and a corresponding first measurement pattern, and a second alignment pattern (i.e., 2PM) and a corresponding second measurement pattern. Then, based on the measurement deviation between the two measurement patterns, it can be quickly determined whether the alignment marks may have a large overlay deviation in subsequent overlay processes.

[0033] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0034] like Figure 2 As shown in the embodiments of this specification, a method is provided, which may include:

[0035] Step S202: Form a first alignment pattern and a second alignment pattern corresponding to the alignment mark on the first silicon wafer, and form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is the exposure result obtained by exposure without visible light alignment, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment to the first alignment pattern.

[0036] Step S204: Form a first measurement pattern corresponding to the first alignment pattern, and form a second measurement pattern corresponding to the second alignment pattern;

[0037] Step S206: Determine the overlay deviation based on the deviation between the first measurement pattern and the second measurement pattern.

[0038] In practice, when it is necessary to measure the overlay deviation of the measuring equipment, the wafer manufacturing process can be simulated. This process is identical to the normal wafer manufacturing process, where the test wafer is exposed twice against the alignment marks on the reference layer: the first exposure is a blind exposure, meaning it is exposed without visible light alignment, resulting in the first alignment pattern; the second exposure is a standard alignment exposure, where the first alignment pattern is aligned with visible light, resulting in the second alignment pattern. This yields measurement patterns at 1PM and 2PM, and the deviation between these patterns is used to assess the equipment's operating condition.

[0039] Through the above steps S202 to S206, whenever the machine needs to measure the overlay deviation, such as when moving components involving visible light alignment, such as silicon wafer stage, lens, and mask stage during machine repair, the overlay deviation is determined by performing the aforementioned exposure twice and then measuring the pattern deviation based on the exposure results.

[0040] In some implementations, the first measurement pattern can be used as the outer frame pattern and the second measurement pattern as the inner frame pattern, and the overlay deviation can be quickly determined by the deviation between the inner and outer frame patterns.

[0041] like Figure 3 As shown, in the first process, a first alignment pattern and a first measurement pattern (outer frame pattern) are created on the silicon wafer using blind exposure. In the second process, a second alignment pattern and a second measurement pattern (inner frame pattern) are created using the first alignment pattern as an identifier. This method measures the deviation between the inner and outer frame measurement patterns to reflect the deviation between the first and second alignment patterns.

[0042] In practice, the first measurement pattern can be used as the first outer frame pattern, and the second measurement pattern can be used as the first inner frame pattern. Then, the overlay deviation can be determined by the deviation between the inner and outer frame patterns.

[0043] It should be noted that the first and second aligned graphics are the same size and shape, only their positions are different.

[0044] In some implementations, such as Figure 4 As shown, a test pattern (such as a test reference pattern) can be formed based on two exposures when the machine is in good condition, and another test pattern (such as an actual pattern) can be formed based on two exposures during measurement. Then, the overlay deviation of the machine can be obtained quickly and accurately based on the deviation between these two patterns.

[0045] In practice, a first measurement reference pattern and a second measurement reference pattern are acquired by pre-recording the first measurement reference pattern. The first measurement reference pattern is the measurement pattern corresponding to the first exposure pattern obtained by exposing the alignment mark on the second silicon wafer without visible light alignment under normal machine operating conditions. The second measurement reference pattern is the measurement pattern corresponding to the second exposure pattern obtained by exposing the first exposure pattern with visible light alignment. The first measurement reference pattern is used as the second outer frame pattern, and the second measurement reference pattern is used as the second inner frame pattern. Finally, the overlay deviation is determined based on the deviation between the second inner frame pattern and the second outer frame pattern.

[0046] In practice, under good machine conditions, two exposures are performed sequentially, and the results of these two exposures are used as the measurement benchmark for that machine. The two exposures are the same as the previously mentioned first blind exposure and second alignment exposure process. Furthermore, each machine, under good machine conditions, can perform the aforementioned two exposures (i.e., first blind exposure, second alignment exposure), and the data collected under good machine conditions is used as the measurement benchmark for that machine.

[0047] In practice, when the equipment is in good condition, a wafer can be selected as a test wafer during the wafer production process, and a measurement reference pattern corresponding to the first alignment pattern and the second alignment pattern can be formed on the wafer. When it is necessary to measure the overlay deviation of the measuring machine, the wafer production process can be simulated to expose a wafer (which can be the same as or different from the wafer used for the previous measurement reference) twice to form a new measurement pattern corresponding to the first alignment pattern and the second alignment pattern.

[0048] Therefore, the overlay deviation can be obtained quickly and accurately by comparing the difference between the measurement benchmark obtained when the machine is in good condition and the measurement pattern obtained when the measurement is required.

[0049] In some implementations, a deviation (reference deviation) can be formed from the two exposure results when the machine is in good condition, and another deviation (actual deviation) can be formed from the two exposure results during measurement. The overlay deviation of the machine can then be obtained quickly and accurately by comparing these two deviations.

[0050] Specifically, when determining the overlay deviation, the first measurement pattern is used as the first outer frame pattern, the second measurement pattern is used as the first inner frame pattern, and the deviation between the first inner frame pattern and the first outer frame pattern is used as the first measurement deviation.

[0051] Furthermore, by acquiring a pre-recorded first measurement reference pattern and a second measurement reference pattern, wherein the first measurement reference pattern is a measurement pattern corresponding to a first exposure pattern obtained by exposing the alignment mark on the second silicon wafer without visible light alignment under normal machine operating conditions, and the second measurement reference pattern is a measurement pattern corresponding to a second exposure pattern obtained by exposing the first exposure pattern with visible light alignment, the first measurement reference pattern is used as a second outer frame pattern, and the second measurement reference pattern is used as a second inner frame pattern, and the deviation between the second inner frame pattern and the second outer frame pattern is used as a second measurement deviation.

[0052] Therefore, the overlay deviation can be determined based on the difference between the first measurement deviation and the second measurement deviation.

[0053] It should be noted that the deviation between the inner and outer frames of the measurement graphic can be obtained based on common image processing methods, and no limitations are imposed on image processing methods here.

[0054] In practice, exposure can be performed using an exposure system to obtain the exposure result graphics corresponding to the two exposures. At this time, the obtained exposure result graphics can be cached and stored using a measurement machine, and the graphics can be processed using the measurement machine. No limitation is made here.

[0055] By constructing inner and outer boxes on the silicon wafer using alignment marks, the deviation between two exposures can be quickly obtained. When the equipment is in good condition, this deviation is usually small and meets the overlay requirements. However, when the equipment deteriorates, such as when the visible light alignment components have been moved during maintenance and not calibrated, the deviation between the two exposures will be larger. Therefore, the overlay deviation can be directly compared to quickly determine whether it meets the requirements for wafer production.

[0056] In some implementations, overlay deviations can be obtained directly from the comparison processing of the alignment pattern obtained from the exposure.

[0057] In practice, when determining the overlay deviation, the first measurement pattern is used as the outer frame pattern and the second measurement pattern is used as the inner frame pattern to merge into the first test pattern; and the first measurement reference pattern is used as the outer frame pattern and the second measurement reference pattern is used as the inner frame pattern to merge into the second test pattern; finally, the overlay deviation is determined based on the difference between the first test pattern and the second test pattern.

[0058] By comparing the differences in the overall graphics, that is, by comparing the overall measurement graphics obtained when the machine is in good condition (i.e., the second test graphics) with the overall measurement graphics obtained when the measurement is to be performed (i.e., the first test graphics), the overlay deviation of the machine can be determined quickly and accurately.

[0059] In some implementations, a lithography machine can be used for development before exposure to obtain a clearer exposure pattern, which is beneficial for improving processing accuracy. Specifically, before obtaining the first alignment pattern and the second alignment pattern for the first alignment mark pattern, a coating is applied to the wafer to be exposed. Thick photoresist is used for development during exposure, making the alignment signal clearer during exposure.

[0060] It should be noted that the selection and thickness of the photoresist can be determined according to actual needs, and the coating... The thickness of the photoresist is only used as an example.

[0061] In some implementations, pre-recorded measurement references can be stored in the measurement equipment. Therefore, when measurement is required, the first and second measurement reference graphics corresponding to the first and second measurement graphics, respectively, are retrieved from the measurement equipment. It should be noted that the processing of overprinting deviations can be performed within the measurement equipment; therefore, the exposure results can be cached in the measurement equipment, allowing the processing power of the measurement equipment to quickly and accurately process and obtain the overprinting deviations.

[0062] In some implementations, when the determined overlay deviation exceeds a first preset threshold, the overlay deviation can be calibrated and compensated by modifying the machine parameters. The first preset threshold can be a threshold indicating that the overlay deviation of the machine is no longer suitable for wafer production, and the machine parameters can be the machine parameters corresponding to the visible light alignment components that caused the overlay deviation to exceed the first preset threshold, such as the position parameters of the silicon wafer stage, lens, mask stage, etc., within the machine.

[0063] By adjusting the machine parameters, calibration and compensation can be performed in a timely manner when the overlay deviation of the machine does not meet the requirements of wafer production, so that the machine can be calibrated without stopping production.

[0064] In some implementations, when it is determined that the overlay deviation does not exceed a second preset threshold, the first measurement pattern and the second measurement pattern are respectively used as new measurement benchmarks, wherein the second preset threshold can be a preset threshold that characterizes the overlay deviation of the machine as still suitable for wafer production.

[0065] In wafer manufacturing, the aforementioned two exposure operations can be performed at any time. Therefore, the exposure value obtained when the machine is in good condition can be used as the measurement benchmark. When measurement is required, the aforementioned two exposure operations are performed again. The overlay deviation can then be obtained by comparing the results of the two exposures.

[0066] Based on the same inventive concept, this specification also provides a lithography machine overlay deviation processing device and system to perform overlay deviation processing based on the lithography machine overlay deviation processing method described in any of the foregoing examples.

[0067] like Figure 5 As shown, a lithography machine overlay deviation processing device includes: an exposure module 301, used to form a first alignment pattern and a second alignment pattern corresponding to alignment marks on a first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is an exposure result obtained by exposure without visible light alignment, and the second alignment pattern is an exposure result obtained by exposure with visible light alignment of the first alignment pattern; and a measurement module 305, used to determine the overlay deviation based on the deviation between the first measurement pattern and the second measurement pattern.

[0068] Optionally, the measurement module is specifically used to: use the first measurement pattern as the first outer frame pattern and the second measurement pattern as the first inner frame pattern, so as to determine the overlay deviation based on the deviation between the first inner frame pattern and the first outer frame pattern.

[0069] Optionally, the lithography machine overlay deviation processing device further includes: an acquisition module 303, which is used to acquire a pre-recorded first measurement reference pattern and a second measurement reference pattern. The first measurement reference pattern is a measurement pattern corresponding to a first exposure pattern obtained by exposing the alignment mark on the second silicon wafer without visible light alignment under normal machine operating conditions. The second measurement reference pattern is a measurement pattern corresponding to a second exposure pattern obtained by exposing the first exposure pattern on the second silicon wafer with visible light alignment after machine calibration.

[0070] The measurement module is specifically used for:

[0071] The first measurement graphic is used as the second outer frame graphic, and the second measurement graphic is used as the second inner frame graphic, so as to merge the first test graphic.

[0072] The first measurement reference graphic is used as the third outer frame graphic, and the second measurement reference graphic is used as the third inner frame graphic, so as to merge the second test graphic.

[0073] Based on the difference between the first test pattern and the second test pattern, the overlay deviation is determined.

[0074] Optionally, the lithography machine overlay deviation processing device further includes: for determining a first deviation and a second deviation respectively, wherein the first deviation is the difference between the first measurement pattern and the second measurement pattern in the first test pattern, and the second deviation is the deviation between the first measurement reference pattern and the second measurement reference pattern in the second test pattern;

[0075] The measurement module is specifically used to: determine the overlay deviation based on the difference between the first deviation and the second deviation.

[0076] Optionally, the lithography machine overlay misalignment processing device further includes a developing unit (not shown in the figure), used to coat the first alignment pattern and the second alignment pattern before acquiring the first alignment mark pattern respectively. The photoresist of a certain thickness is developed during exposure.

[0077] Optionally, the acquisition module acquires the first measurement reference pattern and the second measurement reference pattern from the measurement machine.

[0078] Optionally, the lithography machine overlay deviation processing device further includes: a calibration compensation module (not shown in the figure), used to modify the machine parameters to calibrate and compensate for the overlay deviation when the determined overlay deviation exceeds a first preset threshold.

[0079] Optionally, the lithography machine overlay deviation processing device further includes: a storage module (not shown in the figure), used to take the first measurement pattern and the second measurement pattern as new measurement references when it is determined that the overlay deviation does not exceed the second preset threshold.

[0080] It should be noted that the lithography machine overlay deviation processing device shown above corresponds to the aforementioned lithography machine overlay deviation processing method, and therefore will not be described in detail.

[0081] like Figure 4 As shown, a lithography machine overlay deviation processing system includes an alignment subsystem 401, an exposure subsystem 403, and a measurement subsystem 405.

[0082] The exposure subsystem is used to form a first alignment pattern and a second alignment pattern corresponding to the alignment mark on the first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern. The first alignment pattern is the exposure result obtained by exposure without visible light alignment by the alignment subsystem, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment of the first alignment pattern by the alignment subsystem.

[0083] The measurement subsystem is used to measure the deviation between the first measurement pattern and the second measurement pattern.

[0084] It should be noted that the alignment subsystem may include all the alignment components required for lithography, such as the mask stage, optical path, and objective lens; the exposure subsystem may include exposure-related equipment, such as the exposure stage and exposure pattern acquisition (e.g., camera); and the measurement subsystem may include measurement-related equipment, such as measurement devices and measurement stages. These subsystems can be the equipment found in existing lithography machines. Furthermore, the subsystems in the lithography machine overlay misalignment processing system can be set and adjusted according to the operations involved in the aforementioned lithography machine overlay misalignment processing method, which will not be elaborated upon here.

[0085] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the product embodiments described later are relatively simple since they correspond to the methods; relevant parts can be referred to the descriptions in the system embodiments.

[0086] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for handling overlay deviations in a photolithography machine, characterized in that, include: A first alignment pattern and a second alignment pattern corresponding to the alignment mark are formed on the first silicon wafer, and a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern are formed. The first alignment pattern is the exposure result obtained by exposure without visible light alignment, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment to the first alignment pattern. Acquire a first measurement reference pattern and a second measurement reference pattern that have been pre-recorded. The first measurement reference pattern is a measurement pattern corresponding to the first exposure pattern obtained by exposing the alignment mark on the second silicon wafer without visible light alignment under normal machine operating conditions. The second measurement reference pattern is a measurement pattern corresponding to the second exposure pattern obtained by exposing the first exposure pattern with visible light alignment. Based on the deviation between the first measurement pattern and the second measurement pattern, the overlay deviation is determined as follows: The first measurement graphic is used as the second outer frame graphic, and the second measurement graphic is used as the second inner frame graphic, so as to merge the first test graphic. The first measurement reference graphic is used as the third outer frame graphic, and the second measurement reference graphic is used as the third inner frame graphic, so as to merge the second test graphic. Based on the difference between the first test pattern and the second test pattern, the overlay deviation is determined; The first deviation and the second deviation are determined respectively, wherein the first deviation is the deviation between the first measurement pattern and the second measurement pattern in the first test pattern, and the second deviation is the deviation between the first measurement reference pattern and the second measurement reference pattern in the second test pattern; Determining the overlay deviation based on the difference between the first test pattern and the second test pattern includes: determining the overlay deviation based on the difference between the first deviation and the second deviation; When it is determined that the overlay deviation does not exceed the second preset threshold, the first measurement pattern and the second measurement pattern are respectively used as new measurement references.

2. The method for handling overlay deviation in a photolithography machine according to claim 1, characterized in that, Based on the deviation between the first measurement pattern and the second measurement pattern, the overlay deviation is determined as follows: The first measurement pattern is used as the first outer frame pattern, and the second measurement pattern is used as the first inner frame pattern, so as to determine the overlay deviation based on the deviation between the first inner frame pattern and the first outer frame pattern.

3. The method for handling overlay deviation in a photolithography machine according to claim 1 or 2, characterized in that, The method for handling overlay deviations in a photolithography machine also includes: Before obtaining the first alignment pattern and the second alignment pattern for the alignment mark, the first silicon wafer is coated with a photoresist with a thickness of 8300 Å for development during exposure. And / or, when the determined overlay deviation exceeds a first preset threshold, the machine parameters are modified to calibrate and compensate for the overlay deviation.

4. A photolithography machine overlay deviation processing device, characterized in that, The lithography machine overlay deviation processing method according to claim 1 or 2 includes: An exposure module is used to form a first alignment pattern and a second alignment pattern corresponding to an alignment mark on a first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is an exposure result obtained by exposure without visible light alignment, and the second alignment pattern is an exposure result obtained by exposure with visible light alignment of the first alignment pattern. The measurement module is used to determine the overlay deviation based on the deviation between the first measurement pattern and the second measurement pattern.

5. The lithography machine overlay deviation processing device according to claim 4, characterized in that, The measurement module is specifically used for: The first measurement pattern is used as the first outer frame pattern, and the second measurement pattern is used as the first inner frame pattern, so as to determine the overlay deviation based on the deviation between the first inner frame pattern and the first outer frame pattern.

6. The lithography machine overlay deviation processing device according to claim 4, characterized in that, The lithography machine overlay deviation processing device further includes: an acquisition module, which is used to acquire a pre-recorded first measurement reference pattern and a second measurement reference pattern. The first measurement reference pattern is a measurement pattern corresponding to a first exposure pattern obtained by exposing the alignment mark on the second silicon wafer without visible light alignment under normal machine operating conditions. The second measurement reference pattern is a measurement pattern corresponding to a second exposure pattern obtained by exposing the first exposure pattern on the second silicon wafer with visible light alignment after machine calibration. The measurement module is specifically used for: The first measurement graphic is used as the second outer frame graphic, and the second measurement graphic is used as the second inner frame graphic, so as to merge the first test graphic. The first measurement reference graphic is used as the third outer frame graphic, and the second measurement reference graphic is used as the third inner frame graphic, so as to merge the second test graphic. Based on the difference between the first test pattern and the second test pattern, the overlay deviation is determined.

7. The lithography machine overlay deviation processing device according to claim 6, characterized in that, The lithography machine overlay deviation processing device also includes: The deviation determination module is used to determine a first deviation and a second deviation respectively, wherein the first deviation is the difference between the first measurement pattern and the second measurement pattern in the first test pattern, and the second deviation is the deviation between the first measurement reference pattern and the second measurement reference pattern in the second test pattern; The measurement module is specifically used to: determine the overlay deviation based on the difference between the first deviation and the second deviation.

8. A lithography machine overlay deviation processing system, characterized in that, The lithography machine overlay deviation processing method according to claim 1 or 2 includes: an alignment subsystem, an exposure subsystem, and a measurement subsystem; The exposure subsystem is used to form a first alignment pattern and a second alignment pattern corresponding to the alignment mark on the first silicon wafer, and to form a first measurement pattern corresponding to the first alignment pattern and a second measurement pattern corresponding to the second alignment pattern, wherein the first alignment pattern is the exposure result obtained by exposure without visible light alignment by the alignment subsystem, and the second alignment pattern is the exposure result obtained by exposure with visible light alignment of the first alignment pattern by the alignment subsystem. The measurement subsystem is used to measure the deviation between the first measurement pattern and the second measurement pattern.

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