A photolithography process overlay error compensation method and device, and a photolithography machine

Abstract

This application discloses a method, apparatus, and lithography machine for compensating overlay errors in photolithography processes, applicable to the semiconductor manufacturing field. The method involves acquiring overlay error distribution data, which is the sum of the average absolute value of the overlay errors and three times the standard deviation. In the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters. Based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model. The stress compensation model includes the correlation between the compensation stress and compensation parameters for each of multiple stress actuator groups. Based on the target stress compensation scheme, the stress actuators are driven to apply compensation stress to the photomask. Thus, by using the overlay error distribution data to determine the compensation stress required by the stress actuators to compensate for the overlay error, and then applying compensation stress to the photomask to cause deformation, compensation for overlay errors in the photolithography process is achieved, reducing the overlay error in the photolithography process.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a method, apparatus and lithography machine for compensating for overlay errors in photolithography processes. Background Technology

[0002] With the development of semiconductor technology, the integration of chips has been significantly improved, and the requirements for overlay error in photolithography have become increasingly stringent.

[0003] In semiconductor manufacturing, overlay error refers to the misalignment between each circuit layer, which can be quantitatively described as the coordinate deviation between the lithographic pattern and the reference pattern in the X and Y directions. Traditional projection lithography systems rely on optical lenses to compensate for overlay errors. However, as technology nodes shrink, this compensation capability is gradually approaching its limit, making it difficult to meet current requirements for lithography quality.

[0004] Therefore, how to reduce the overlay error in the photolithography process has become a problem that needs to be solved. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method, apparatus, and lithography machine for compensating overlay errors in photolithography processes, which can reduce overlay errors in photolithography processes.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] In a first aspect, embodiments of this application provide a method for compensating for overlay errors in photolithography processes, the method comprising:

[0008] Acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute values ​​of the overlay errors and three times the standard deviation; the overlay error is the coordinate deviation between the lithographic pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters;

[0009] Based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator; the stress compensation model includes the correlation between the compensation stress and compensation parameters corresponding to each of the multiple stress actuator groups;

[0010] The target stress compensation scheme drives the stress actuator to apply compensation stress to the mask.

[0011] Optionally, the stress compensation model is established using the following method:

[0012] Obtain the overlay error distribution data of multiple stress actuator groups under different compensation stresses;

[0013] Based on the compensation stress and the overlay error distribution data, a correlation between the compensation stress and the compensation parameters is established.

[0014] Based on the overlay error distribution data corresponding to the multiple stress actuator groups under different compensation stresses, and the correlation between the compensation stress and the compensation parameters, a stress compensation model is established.

[0015] Optionally, acquiring the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses includes:

[0016] Obtain the overlay error of multiple stress actuator groups under different compensation stresses;

[0017] By fitting the overlay error formula, the compensation parameter in the overlay error formula is determined, and the overlay error distribution data is obtained.

[0018] Optionally, the step of obtaining a target stress compensation scheme based on the overlay error distribution data and a pre-established stress compensation model includes:

[0019] Based on the overlay error distribution data, target terms are extracted from the overlay error distribution data; the target terms are high-order terms with a degree greater than or equal to 3.

[0020] By using a pre-established stress compensation model, a target stress compensation scheme for compensating the target item is obtained.

[0021] Optionally, after driving the stress actuator to apply compensating stress to the mask based on the target stress compensation scheme, the method further includes:

[0022] Monitor the overlay residuals after compensation;

[0023] If the number of consecutive times the overlay residual exceeds a preset threshold is greater than a preset number, an alarm message will be output.

[0024] Optionally, after obtaining the target stress compensation scheme based on the overlay error distribution data and a pre-established stress compensation model, the method further includes:

[0025] Based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameters corresponding to the target stress compensation scheme, the target compensation parameters after compensation are determined.

[0026] Based on the target compensation parameters, the error compensation distribution of each collection point is displayed in the form of a vector diagram.

[0027] Secondly, embodiments of this application provide a photolithography process overlay error compensation device, the device comprising: an acquisition module, a scheme determination module, and a driving module;

[0028] The acquisition module is used to acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute values ​​of the overlay errors and three times the standard deviation; the overlay error is the coordinate difference between the lithographic pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters.

[0029] The scheme determination module is used to obtain a target stress compensation scheme based on the overlay error distribution data and a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator; the stress compensation model includes the correlation between the compensation stress and compensation parameters corresponding to each of the multiple stress actuator groups;

[0030] The driving module is used to drive the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme.

[0031] Thirdly, embodiments of this application provide a lithography machine, which includes: a controller and a stress actuator;

[0032] The controller is electrically connected to the stress actuator;

[0033] The controller is used to drive the stress actuator according to the step of photolithography process overlay error compensation as described in any embodiment of the first aspect.

[0034] Optionally, the lithography machine includes 16 stress actuators; the stress actuators are symmetrically arranged around the mask; and every four stress actuators are arranged on the same side of the mask.

[0035] Optionally, the stress actuator is a piezoelectric brake.

[0036] Compared with the prior art, this application has the following beneficial effects:

[0037] This application provides a method for compensating overlay errors in photolithography. First, overlay error distribution data is acquired. This data is the sum of the average absolute value of the overlay error and three times the standard deviation. The overlay error is the coordinate deviation between the photolithographic pattern and the reference pattern at each acquisition point. In the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters. Then, based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model. The stress compensation scheme includes a group of stress actuators and the compensation stresses performed by the actuators. The stress compensation model includes the correlation between the compensation stresses and compensation parameters corresponding to each of the multiple stress actuator groups. Finally, based on the target stress compensation scheme, the stress actuators are driven to apply compensation stress to the photomask. Thus, by using a pre-established model and the overlay error distribution data, the compensation stresses performed by each stress actuator required to compensate for the overlay error are derived. Furthermore, by applying compensation stress to the photomask to induce deformation, compensation for overlay errors in the photolithography process is achieved, thereby reducing the overlay error. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0039] Figure 1 A flowchart of a photolithography process overlay error compensation method provided in this application embodiment;

[0040] Figure 2 A flowchart illustrating a method for establishing a stress compensation model as provided in an embodiment of this application;

[0041] Figure 3 A schematic diagram of stress actuator distribution provided in an embodiment of this application;

[0042] Figure 4 A vector diagram illustrating the overlay error distribution provided in this application embodiment;

[0043] Figure 5 An error compensation distribution vector diagram provided in an embodiment of this application;

[0044] Figure 6 A vector diagram of overlay residuals provided in an embodiment of this application;

[0045] Figure 7 This is a schematic diagram of a photolithography process overlay error compensation device provided in an embodiment of this application. Detailed Implementation

[0046] The method, apparatus and lithography machine for compensating overlay errors in photolithography provided in this application can be used in the semiconductor manufacturing field. The above is only an example and does not limit the application field of the method, apparatus and lithography machine for compensating overlay errors in photolithography provided in this application.

[0047] The terms "first," "second," "third," and "fourth," etc., used in this application specification, claims, and drawings are used to distinguish different objects, not to limit a specific order.

[0048] In the embodiments of this application, the terms "as an example" or "for example" are used to indicate that they are examples, illustrations, or explanations. Any embodiment or design that is described as "as an example" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of terms such as "as an example" or "for example" is intended to present the relevant concepts in a specific manner.

[0049] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0050] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0051] See Figure 1 The figure is a flowchart of a photolithography process overlay error compensation method provided in an embodiment of this application. The method includes:

[0052] S101: Obtain overlay error distribution data.

[0053] Using a photolithography machine, a photomask and a wafer are precisely aligned. The wafer, coated with photoresist, is exposed to light through a light source in the machine. Under light, the photoresist undergoes a chemical reaction, forming a photolithographic pattern based on the pattern on the photomask. The wafer is then placed in a developing solution to remove the exposed photoresist (positive photoresist) or the unexposed photoresist (negative photoresist), revealing the photoresist mask. The appropriate type of photolithography machine can be selected based on actual needs, such as a nanoimprint lithography machine, a plasma lithography machine, or a contact lithography machine. The wafer can be a silicon wafer, a germanium wafer, a quartz glass substrate, or a substrate made of compound semiconductor materials composed of Group III and Group V elements.

[0054] As an example, a high-resolution optical microscope with image recognition and measurement capabilities can be used to scan the revealed lithographic pattern through an automated measurement system to obtain the overlay error.

[0055] Specifically, the overlay error is the coordinate deviation (x, y) between the lithographic pattern and the reference pattern at each acquisition point in the X and Y directions. By fitting the overlay error formula with the overlay error, the compensation parameters in the overlay error formula can be determined, and the overlay error distribution data can be obtained.

[0056] Among them, the overlay error distribution data x With Overlay y The sum of the mean and three standard deviations of the absolute values ​​of the overlay error is |mean| + 3δ; x This indicates the overlay error in the x-direction. y This represents the case of overlay error in the y-direction; in the polynomial formula for the overlay error distribution data (i.e., the overlay error formula), the coefficients k1, k2, ..., k... i For compensation parameters.

[0057] The polynomial formula for the overlay error distribution data is: Overlay x =k1+k3·x+k5·y+k7·x 2 +k9·xy+k 11 ·y 2 +k 13 ·x 3 +k 15 ·x 2 y+k 17 ·xy 2 +k 19 ·y 3 Overlay y = k2 + k4·y + k6·x + k8·y 2 +k 10 ·xy+k 12 ·x 2 +k 14 ·y 3 +k 16 ·y 2 x+k 18 ·yx 2 +k 20 ·x 3 .

[0058] As an example, by fitting the overlay error formula using the overlay error, the compensation parameter k can be obtained as shown in Table 1 below:

[0059] Table 1

[0060] X-direction parameter name Parameter values Y-direction parameter name Parameter values K1 4.9221 K2 3.2503 K3 0.4663 K4 -4.8021 K5 9.2399 K6 0.8041 K7 -0.9395 K8 0.3926 K9 0.0394 K10 -0.8819 K11 0.7801 K12 -0.3396 K13 -0.0541 K14 -0.0772 K15 -0.0378 K16 -0.0543 K17 0.0304 K18 -0.0868 K19 -0.0449 K20 -0.0436

[0061] S102: Based on the overlay error distribution data, the target stress compensation scheme is obtained through a pre-established stress compensation model.

[0062] Since stress can cause mask deformation, which in turn changes the overlay error, in this embodiment of the application, by applying additional compensating stress, the overlay error caused by the compensating stress is made complementary to the original overlay error, thereby achieving compensation for the overlay error.

[0063] As an example, a stress compensation model can be achieved through, for instance... Figure 2 The steps shown are as follows:

[0064] S21: Obtain the overlay error distribution data of multiple stress actuator groups under different compensation stresses.

[0065] See Figure 3 Multiple stress actuators can be set around the mask, for example, 16 stress actuators F0 to F15. Based on the basic principles of torque balance and symmetrical stress, multiple stress actuator groups containing different stress actuators can be designed. For example, 16 combinations of stress actuators can be designed, including 8 schemes where stress actuators appear in pairs, 4 schemes with two symmetrical features, and 4 schemes with symmetrical features.

[0066] A simulation model can be built based on the actual process conditions of the mask in near-field lithography to simulate the execution of various stress compensation schemes. These schemes include stress actuator groups and the compensation stresses applied by the actuators. As an example, finite element method (FEM) software can be used to simulate mask deformation under different compensation stresses with different stress actuator groups, and overlay errors can be collected. By fitting the overlay error formula to the overlay error, the compensation parameters in the formula can be solved, yielding the overlay error distribution data.

[0067] S22: Based on the compensation stress and overlay error distribution data, establish the correlation between compensation stress and compensation parameters.

[0068] By analyzing the experimental results under simulation, the management relationship between the compensation stress F and the compensation parameter k can be obtained in different stress actuator groups.

[0069] S23: Based on the overlay error distribution data of multiple stress actuator groups under different compensation stresses, and the correlation between compensation stress and compensation parameters, a stress compensation model is established.

[0070] Specifically, code can be written based on the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses, as well as the correlation between compensation stress and compensation parameters, to establish a stress compensation model that includes the correlation between compensation stress and compensation parameters for each of the multiple stress actuator groups. This model can then match a suitable stress actuator group based on the input overlay error distribution data and inversely solve for the compensation stress performed by each stress actuator in the stress actuator group, thereby obtaining the target stress compensation scheme.

[0071] Optionally, see Figure 4 This figure is a vector diagram of overlay error distribution provided in an embodiment of this application, wherein the overlay error of each collection point is represented... The distribution is displayed in the form of a vector diagram, and the overlay error distribution data in the X and Y directions are marked in the vector diagram, so as to more intuitively show the overlay error distribution and make it easier for technicians to quickly understand the overlay error that will occur when performing photolithography under the current conditions.

[0072] The overlay error distribution data is input into the stress compensation model. The stress compensation model can provide a suitable set of stress actuators, and based on the correlation between the compensation stress and the compensation parameters, the compensation stress that minimizes the overlay error is derived in reverse, thus obtaining the target stress compensation scheme. As an example, as shown in Table 2, the stress actuator sets that need to be activated in the obtained target stress compensation scheme are F0, F2, F3, F4, F5, F6, F7, F8, and F9. 11 F 13 F 14 and F 15 The required compensation stress for each stress actuator is shown in Table 2.

[0073] Table 2

[0074]

[0075] S103: Drive the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme.

[0076] As an example, the stress actuator could be a piezoelectric brake or other device that can apply stress around the mask, such as... Figure 3 The device is shown under the stress condition. By manipulating the stress actuator to execute the target stress compensation scheme, compensation for overlay errors can be achieved.

[0077] Optionally, after obtaining the target stress compensation scheme, based on the compensation stress in the target stress compensation scheme and the correlation between the corresponding compensation stress and compensation parameters, the target compensation parameters after compensation can be determined. This yields the target compensation parameters after stress compensation as shown in Table 3. Furthermore, based on these target compensation parameters, methods such as... Figure 5The error compensation distribution vector diagram shown displays the error compensation distribution of each acquisition point in vector form. It also shows the coordinate deviation of the photolithography pattern after compensation and before compensation at each acquisition point, making it easy for users to intuitively view the error compensation situation at each acquisition point.

[0078] Table 3

[0079]

[0080]

[0081] Optionally, after driving the stress actuator based on the target stress compensation scheme, the remaining overlay residuals after compensation can be monitored during the execution of the lithography procedure using the same method as acquiring the overlay error distribution data. As an example, a vector diagram of the overlay residuals is shown below. Figure 6 As shown, in this example, the overlay residual |mean|+3δ is determined by... Figure 4 The nanometers in the model have been reduced from tens of nanometers to below 2nm, achieving effective compensation for overlay errors.

[0082] If the number of consecutive times the overlay residual exceeds the preset threshold is greater than the preset number, an alarm message will be output.

[0083] For example, the preset number of times can be three. If the overlay residual is greater than the preset threshold three times consecutively starting from the first lithography after the execution of the target stress compensation scheme, it can be considered that the overlay error cannot be effectively compensated by the method provided in this application embodiment. At this time, an alarm message is output and the lithography operation is stopped. If the overlay residual of the first lithography after the execution of the target stress compensation scheme is less than or equal to the preset threshold, and the overlay residual is greater than the preset threshold three times consecutively during the subsequent lithography process, it can be considered that the overlay error has changed further with the increase of the number of operations. At this time, an alarm message can be output to prompt the re-determination of the target stress compensation scheme.

[0084] In this embodiment, firstly, overlay error distribution data is acquired. This data is the sum of the average absolute value of the overlay error and three times its standard deviation. The overlay error is the coordinate deviation between the lithographic pattern and the reference pattern at each acquisition point. In the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters. Then, based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model. The stress compensation scheme includes a group of stress actuators and the compensation stresses performed by these actuators. The stress compensation model includes the correlation between the compensation stresses and compensation parameters corresponding to each of the multiple stress actuator groups. Finally, based on the target stress compensation scheme, the stress actuators are driven to apply compensation stress to the photomask. Thus, by using a pre-established model and the overlay error distribution data, the compensation stresses performed by each stress actuator required to compensate for the overlay error are derived. Furthermore, by applying compensation stress to the photomask to induce deformation, compensation for overlay errors in the lithography process is achieved, thereby reducing the overlay error in the lithography process.

[0085] In one embodiment provided in this application, a target stress compensation scheme can be obtained by compensating all items in the overlay error distribution data using a pre-established stress compensation model. Therefore, all items in the overlay error distribution data are within the scope of the target stress compensation scheme, which can compensate for more than 90% of the overlay error, providing precise and effective compensation and greatly improving the accuracy of pattern transfer.

[0086] In another embodiment provided in this application, target items can be extracted from the overlay error distribution data, for example, extracting items such as k. 13 ·x 3 k 15 ·x 2 y, k 17 ·xy 2 and k 19 ·y 3 Higher-order terms (3 or greater) are used as target terms. A pre-established stress compensation model is used to compensate for these higher-order terms in the overlay error distribution data, resulting in a target stress compensation scheme. Therefore, the target stress compensation scheme only needs to consider the higher-order terms in the overlay error distribution data. This significantly reduces the difficulty of calculating the target stress compensation scheme using the stress compensation model, saving computational resources and reducing program execution time. Furthermore, it can reduce overlay errors by more than 50%, achieving effective compensation for overlay errors.

[0087] See Figure 7 The figure is a schematic diagram of a photolithography process overlay error compensation device provided in an embodiment of this application. The device includes: an acquisition module 701, a scheme determination module 702, and a driving module 703.

[0088] The acquisition module 701 is used to acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute values ​​of the overlay errors and three times the standard deviation; the overlay error is the coordinate difference between the lithographic pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters.

[0089] The scheme determination module 702 is used to obtain the target stress compensation scheme based on the overlay error distribution data and through a pre-established stress compensation model. The stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator. The stress compensation model includes the correlation between the compensation stress and compensation parameters of each of the multiple stress actuator groups.

[0090] The drive module 703 is used to drive the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme.

[0091] Therefore, by using a pre-established model and the overlay error distribution data, the compensation stress required by each stress actuator to compensate for the overlay error can be derived in reverse. Then, by applying the compensation stress to the mask to cause the mask to deform, the compensation for the overlay error in the photolithography process can be achieved, thereby reducing the overlay error in the photolithography process.

[0092] Optionally, another photolithography process overlay error compensation device provided in this application further includes: a model establishment module; used to acquire overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses; establish the correlation between compensation stress and compensation parameters based on compensation stress and overlay error distribution data; and establish a stress compensation model based on the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses and the correlation between compensation stress and compensation parameters.

[0093] Optionally, the model building module can be used to obtain the overlay errors corresponding to multiple stress actuator groups under different compensation stresses; by fitting the overlay error formula with the overlay error, the compensation parameters in the overlay error formula are determined, and the overlay error distribution data is obtained.

[0094] Optionally, the scheme determination module 702 is specifically used to extract target terms including higher-order terms from the overlay error distribution data based on the overlay error distribution data; and to obtain a target stress compensation scheme for compensating the target terms through a pre-established stress compensation model.

[0095] Optionally, another photolithography process overlay error compensation device provided in this application further includes: an alarm module; used to monitor the overlay residual after compensation; if the number of consecutive times the overlay residual is greater than a preset threshold is greater than a preset number, then an alarm message is output.

[0096] Optionally, another photolithography process overlay error compensation device provided in this application further includes: a visualization module; used to determine the target compensation parameters after compensation based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameters corresponding to the target stress compensation scheme; and to display the error compensation distribution of each acquisition point in the form of a vector diagram based on the target compensation parameters.

[0097] Furthermore, this application embodiment also provides a lithography machine, which includes: a controller and a stress actuator; the controller is electrically connected to the stress actuator; the controller is used to drive the stress actuator according to the above-described steps for overlay error compensation in the lithography process.

[0098] Optionally, such as Figure 3 As shown, the lithography machine includes 16 stress actuators; the stress actuators are symmetrically arranged around the mask; and every 4 stress actuators are arranged on the same side of the mask.

[0099] Alternatively, the stress actuator may be a piezoelectric brake.

[0100] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separate. The components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0101] The above description is merely one 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 compensating for overlay errors in photolithography processes, characterized in that, The method includes: Acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute values ​​of the overlay errors and three times the standard deviation; the overlay error is the coordinate deviation between the lithographic pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters; Based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator; the stress compensation model includes the correlation between the compensation stress and compensation parameters corresponding to each of the multiple stress actuator groups; Based on the target stress compensation scheme, the stress actuator is driven to apply compensation stress to the mask plate; Monitor the overlay residuals after compensation; If the number of consecutive times the overlay residual exceeds a preset threshold is greater than a preset number, an alarm message will be output.

2. The method according to claim 1, characterized in that, The stress compensation model is established using the following method: Obtain the overlay error distribution data of multiple stress actuator groups under different compensation stresses; Based on the compensation stress and the overlay error distribution data, a correlation between the compensation stress and the compensation parameters is established. Based on the overlay error distribution data corresponding to the multiple stress actuator groups under different compensation stresses, and the correlation between the compensation stress and the compensation parameters, a stress compensation model is established.

3. The method according to claim 2, characterized in that, The acquisition of overlay error distribution data for multiple stress actuator groups under different compensation stresses includes: Obtain the overlay error of multiple stress actuator groups under different compensation stresses; By fitting the overlay error formula, the compensation parameter in the overlay error formula is determined, and the overlay error distribution data is obtained.

4. The method according to claim 1, characterized in that, Based on the overlay error distribution data, a target stress compensation scheme is obtained through a pre-established stress compensation model, including: Based on the overlay error distribution data, target terms are extracted from the overlay error distribution data; the target terms are high-order terms with a degree greater than or equal to 3. By using a pre-established stress compensation model, a target stress compensation scheme for compensating the target item is obtained.

5. The method according to claim 1, characterized in that, After obtaining the target stress compensation scheme based on the overlay error distribution data and a pre-established stress compensation model, the method further includes: Based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameters corresponding to the target stress compensation scheme, the target compensation parameters after compensation are determined. Based on the target compensation parameters, the error compensation distribution of each collection point is displayed in the form of a vector diagram.

6. A photolithography process overlay error compensation device, characterized in that, The device includes: an acquisition module, a scheme determination module, a driving module, and an alarm module; The acquisition module is used to acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute values ​​of the overlay errors and three times the standard deviation; the overlay error is the coordinate difference between the lithographic pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, the coefficients of each term are compensation parameters. The scheme determination module is used to obtain a target stress compensation scheme based on the overlay error distribution data and a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator; the stress compensation model includes the correlation between the compensation stress and compensation parameters corresponding to each of the multiple stress actuator groups; The driving module is used to drive the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme; An alarm module is used to monitor the overlay residual after compensation. If the overlay residual is greater than a preset threshold for more than a preset number of consecutive times, an alarm message is output.

7. A lithography machine, characterized in that, The lithography machine includes: a controller and a stress actuator; The controller is electrically connected to the stress actuator; The controller is used to drive the stress actuator in the step of photolithography process overlay error compensation according to any one of claims 1 to 5.

8. The lithography machine according to claim 7, characterized in that, The lithography machine includes 16 stress actuators; the stress actuators are symmetrically arranged around the mask; and every 4 stress actuators are arranged on the same side of the mask.

9. The lithography machine according to claim 7, characterized in that, The stress actuator is a piezoelectric brake.

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