Method and device for compensating overlay error of photoetching process and photoetching machine

Abstract

The invention discloses a photoetching process overlay error compensation method, a photoetching process overlay error compensation device and a photoetching machine, which can be used in the field of semiconductor manufacturing. The overlay error distribution data is the sum of the average number of absolute values of overlay errors and triple standard deviation; in the polynomial formula of the overlay error distribution data, all coefficients are compensation parameters; based on the overlay error distribution data, obtaining a target stress compensation scheme through a pre-established stress compensation model; the stress compensation model comprises an association relationship between compensation stress and compensation parameters corresponding to each stress actuator group; and driving a stress actuator to apply compensation stress to the mask plate based on the target stress compensation scheme. Therefore, the compensation stress executed by the stress actuator required for compensating the overlay error is obtained through the overlay error distribution data, and then the compensation stress is applied to the mask plate to cause deformation of the mask plate, so that the compensation of the overlay error in the photoetching process is realized, and the overlay error of the photoetching process can be reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a method, device and lithography machine for compensating overlay errors in a lithography process. Background Art

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

[0003] In semiconductor manufacturing, overlay error refers to the difference between each layer of circuits, which can be quantitatively described as the coordinate deviation between the lithography 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 and it is difficult to meet current requirements for lithography quality.

[0004] Therefore, how to reduce the overlay error of the photolithography process becomes a problem that needs to be solved. Summary of the invention

[0005] Based on the above problems, the present application provides a method, device and lithography machine for compensating overlay error in a lithography process, which can reduce the overlay error in the lithography process.

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

[0007] In a first aspect, an embodiment of the present application provides a method for compensating overlay errors in a lithography process, the method comprising:

[0008] Acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute value of the overlay error and three times the standard deviation; the overlay error is the coordinate deviation between the lithography pattern of each acquisition point and the reference pattern; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter;

[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 a compensation stress performed by the stress actuator; the stress compensation model includes a correlation relationship between compensation stresses corresponding to each of a plurality of stress actuator groups and compensation parameters;

[0010] The stress actuator is driven to apply compensation stress to the mask based on the target stress compensation scheme.

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

[0012] Obtaining overlay error distribution data corresponding to a plurality of stress actuator groups under different compensation stresses;

[0013] Based on the compensation stress and the overlay error distribution data, establishing a correlation relationship between the compensation stress and the compensation parameter;

[0014] A stress compensation model 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 parameter.

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

[0016] Obtaining the corresponding overlay errors of multiple stress actuator groups under different compensation stresses;

[0017] The overlay error is used to fit an overlay error formula, a compensation parameter in the overlay error formula is determined, and overlay error distribution data is obtained.

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

[0019] Based on the overlay error distribution data, extracting a target item in the overlay error distribution data; the target item is a high-order item with a number greater than or equal to 3;

[0020] Through the 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 compensation stress to the mask based on the target stress compensation scheme, the method further includes:

[0022] Monitor the overlay residual after compensation;

[0023] If the overlay residual is greater than the preset threshold value for a continuous number of times greater than the preset number of times, an alarm message is output.

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

[0025] Determine a compensated target compensation parameter based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameter corresponding to the target stress compensation scheme;

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

[0027] In a second aspect, an embodiment of the present application provides a device for compensating overlay errors in a photolithography process, 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 value of the overlay error and three times the standard deviation; the overlay error is the coordinate difference between the lithography pattern of each acquisition point and the reference pattern; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter;

[0029] The scheme determination module is used to obtain a target stress compensation scheme based on the overlay error distribution data through a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and a compensation stress performed by the stress actuator; the stress compensation model includes an association relationship between compensation stresses corresponding to each of a plurality of stress actuator groups and compensation parameters;

[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] In a third aspect, an embodiment of the present application provides a lithography machine, the lithography machine comprising: 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 steps of compensating the overlay error of the lithography process described in any implementation manner of the first aspect.

[0034] Optionally, 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.

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

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

[0037] The present application provides a method for compensating overlay errors in a photolithography process. In the method, first, overlay error distribution data is obtained; the overlay error distribution data is the sum of the average and three times the standard deviation of the absolute value of the overlay error; the overlay error is the coordinate deviation between the photolithography pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter; 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 stress actuator group and a compensation stress executed by the stress actuator; the stress compensation model includes a correlation between the compensation stress corresponding to each of the multiple stress actuator groups and the compensation parameter; finally, based on the target stress compensation scheme, the stress actuator is driven to apply compensation stress to the mask. Thus, through the pre-established model, the compensation stress executed by each stress actuator required to compensate for the overlay error is reversely obtained through the overlay error distribution data, and then the mask is deformed by applying the compensation stress to the mask, thereby achieving compensation for the overlay error in the photolithography process, and reducing the overlay error of the photolithography process. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0039] Figure 1 A flow chart of a method for compensating overlay errors in a photolithography process provided in an embodiment of the present application;

[0040] Figure 2 A flow chart of a method for establishing a stress compensation model provided in an embodiment of the present application;

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

[0042] Figure 4 An overlay error distribution vector diagram provided in an embodiment of the present application;

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

[0044] Figure 6 A vector diagram of an overlay residual provided in an embodiment of the present application;

[0045] Figure 7 A schematic diagram of a photolithography process overlay error compensation device provided in an embodiment of the present application. DETAILED DESCRIPTION

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

[0047] The terms "first", "second", "third" and "fourth" etc. in the specification, claims and drawings of this application are used to distinguish different objects rather than to limit a specific order.

[0048] In the embodiments of the present application, the words "as an example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "as an example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the words "as an example" or "for example" is intended to present the relevant concepts in a specific way.

[0049] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0050] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] See also Figure 1 , which is a flow chart of a method for compensating overlay errors in a lithography process provided in an embodiment of the present application, the method comprising:

[0052] S101: Acquire overlay error distribution data.

[0053] Using a photolithography machine, the mask and the wafer are precisely aligned, and the wafer coated with photoresist is exposed through the light source in the photolithography machine. The photoresist undergoes a chemical reaction under light, and a corresponding photolithography pattern is formed according to the pattern of the mask. Then, the wafer is placed in a developer to remove the exposed photoresist (positive photoresist) or the unexposed photoresist (negative photoresist), revealing the photoresist mask. Among them, a suitable type of photolithography machine can be selected according to actual needs, such as a nanoimprint photolithography machine, a plasma photolithography machine, or a contact photolithography machine; the wafer can be a silicon wafer, a germanium wafer, a quartz glass substrate, or a substrate made of a compound semiconductor material composed of group III elements and group V elements, etc.

[0054] As an example, a high-resolution optical microscope with image recognition and measurement functions can be used to scan the developed lithography 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 at each acquisition point and the reference pattern in the X direction and the Y direction. By fitting the overlay error formula using the overlay error, the compensation parameters in the overlay error formula can be determined to obtain the overlay error distribution data.

[0056] Among them, the overlay error distribution data Overlay x With Overlay y Overlay is the sum of the absolute value of the overlay error and three times the standard deviation |mean|+3δ; x Indicates the overlay error in the x direction. y Indicates the overlay error in the y direction; in the polynomial formula of the overlay error distribution data (i.e., the overlay error formula), the coefficients k1, k2, ..., k i is the compensation parameter.

[0057] The polynomial formula for the overlay error distribution data is: 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 using the overlay error fitting overlay error formula, the compensation parameter k that can be solved is shown in the following Table 1:

[0059] Table 1

[0060] X direction parameter name Parameter Value Y direction parameter name Parameter Value 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, a target stress compensation solution is obtained through a pre-established stress compensation model.

[0062] Since stress can cause deformation of the mask and thus change the overlay error, in the embodiment of the present application, additional compensating stress is applied so that the overlay error caused by the compensating stress is complementary to the original overlay error, thereby achieving compensation for the overlay error.

[0063] As an example, the stress compensation model can be Figure 2 The steps shown establish:

[0064] S21: Obtaining the overlay error distribution data corresponding to the plurality of stress actuator groups under different compensation stresses.

[0065] See also Figure 3 , multiple stress actuators can be set around the mask, for example, 16 stress actuators F0 to F15 are set, and based on the basic principles of moment 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 in which stress actuators appear in pairs, 4 schemes with two symmetrical features, and 4 schemes with symmetrical features.

[0066] Based on the process conditions of the mask in actual near-field lithography, a simulation model can be constructed to simulate and execute multiple stress compensation schemes, wherein the stress compensation scheme includes a stress actuator group and the compensation stress executed by the stress actuator. As an example, finite element software can be used to simulate the deformation of the mask under different compensation stresses of different stress actuator groups, and collect the overlay error. Using the overlay error to fit the overlay error formula, the compensation parameters in the overlay error formula can be solved to obtain the overlay error distribution data.

[0067] S22: Based on the compensation stress and the overlay error distribution data, a correlation relationship between the compensation stress and the compensation parameter is established.

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

[0069] S23: Establishing a stress compensation model based on the overlay error distribution data corresponding to the plurality of stress actuator groups under different compensation stresses, and the correlation between the compensation stress and the compensation parameter.

[0070] Specifically, a code can be written based on the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses, and the correlation between the compensation stress and the compensation parameter, to establish a stress compensation model including the correlation between the compensation stress and the compensation parameter corresponding to each of the multiple stress actuator groups, so as to match a suitable stress actuator group according to the input overlay error distribution data, and inversely solve the compensation stress executed by each stress actuator in the stress actuator group, thereby obtaining a target stress compensation scheme.

[0071] Alternatively, see Figure 4 , which is a distribution vector diagram of overlay error provided by an embodiment of the present application, wherein the overlay error of each acquisition point is 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 display the overlay error distribution and help technicians quickly understand the overlay error that will be caused by lithography under current conditions.

[0072] The overlay error distribution data is input into the stress compensation model. The stress compensation model can provide a suitable stress actuator group, and based on the correlation between the compensation stress and the compensation parameter, the compensation stress that can minimize the overlay error is reversely deduced, thereby obtaining the target stress compensation scheme. As an example, as shown in Table 2, in the obtained target stress compensation scheme, the stress actuator groups to be activated are F0, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, F13, F14, F15, F16, F17, F18, F19, F20, F21, F22, F33, F4, F5, F6, F74, F8, F19, F10, F11, F12, F13, F14, F15 11 、F 13 、F 14 and F 15 The compensation stress that each stress actuator needs to execute is shown in Table 2.

[0073] Table 2

[0074]

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

[0076] As an example, the stress actuator can be a piezoelectric actuator or other device that can apply a force around the mask. Figure 3 The device under the stress condition shown. By manipulating the stress actuator to execute the target stress compensation scheme, the overlay error can be compensated.

[0077] Optionally, after obtaining the target stress compensation scheme, the compensated target compensation parameters can be determined based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameter corresponding to the target stress compensation scheme, and the target compensation parameters after stress compensation shown in Table 3 can be obtained. Then, based on the target compensation parameters, the following can be provided: Figure 5The error compensation distribution vector diagram shown displays the error compensation distribution of each acquisition point in the form of a vector diagram, that is, displays the coordinate deviation of the lithography pattern before and after compensation at each acquisition point, so that users can intuitively view the error compensation status of each acquisition point.

[0078] Table 3

[0079]

[0080]

[0081] Optionally, after driving the stress actuator based on the target stress compensation scheme, the overlay residual remaining after compensation can be monitored during the execution of the lithography process by the same method as that for acquiring the overlay error distribution data. As an example, the vector diagram of the overlay residual is as follows: Figure 6 As shown in this example, the overlay residual |mean|+3δ is given by Figure 4 The dozens or even tens of nanometers in the image are reduced to below 2nm, achieving effective compensation for the overlay error.

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

[0083] For example, the preset number of times may be three times. If the overlay residual is greater than the preset threshold three times in a row since the first photolithography 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 the embodiment of the present application. At this time, an alarm message is output and the photolithography operation is stopped. If the overlay residual of the first photolithography after the execution of the target stress compensation scheme is less than or equal to the preset threshold, and in the subsequent execution of the photolithography process, the overlay residual is greater than the preset threshold three times in a row, it can be considered that the overlay error has further changed with the increase in the number of operations. At this time, an alarm message can be output to prompt the target stress compensation scheme to be re-determined.

[0084] In the embodiment of the present application, first, the overlay error distribution data is obtained; the overlay error distribution data is the sum of the average and three times the standard deviation of the absolute value of the overlay error; the overlay error is the coordinate deviation between the lithography pattern and the reference pattern at each acquisition point; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter; 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 stress actuator group and a compensation stress executed by the stress actuator; the stress compensation model includes a correlation between the compensation stress corresponding to each of the multiple stress actuator groups and the compensation parameter; finally, based on the target stress compensation scheme, the stress actuator is driven to apply compensation stress to the mask. Thus, through the pre-established model, the compensation stress executed by each stress actuator required to compensate for the overlay error is reversely obtained through the overlay error distribution data, and then the mask is deformed by applying compensation stress to the mask, thereby achieving compensation for the overlay error in the lithography process, and reducing the overlay error of the lithography process.

[0085] In one embodiment provided by the present application, all items in the overlay error distribution data can be compensated by a pre-established stress compensation model to obtain a target stress compensation scheme. Thus, all items in the overlay error distribution data are within the consideration range of the target stress compensation scheme, and the obtained target stress compensation scheme can compensate for more than 90% of the overlay error, accurately and effectively compensate for the overlay error, and greatly improve the accuracy of the pattern transfer.

[0086] In another embodiment provided by the present application, target items in the overlay error distribution data may be extracted, for example, k 13 ·x 3 , k 15 ·x 2 y, k 17 ·xy 2 and k 19 ·y 3 The high-order terms with the same order greater than or equal to 3 are taken as the target terms, and the high-order terms in the overlay error distribution data are compensated by the pre-established stress compensation model to obtain the target stress compensation scheme for compensating the high-order terms. Therefore, the target stress compensation scheme only needs to consider the high-order terms in the overlay error distribution data, and the difficulty of calculating the target stress compensation scheme by the stress compensation model is greatly reduced, which can save the computing power occupied by the program running, reduce the program running time, and can also reduce the overlay error by more than 50%, thereby realizing effective compensation for the overlay error.

[0087] See also Figure 7 , this figure is a schematic diagram of a lithography process overlay error compensation device provided in an embodiment of the present application, and 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 value of the overlay error and three times the standard deviation; the overlay error is the coordinate difference between the lithographic pattern of each acquisition point and the reference pattern; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter;

[0089] A scheme determination module 702 is used to obtain a target stress compensation scheme based on the overlay error distribution data through a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and a compensation stress performed by the stress actuator; the stress compensation model includes a correlation relationship between the compensation stress corresponding to each of the multiple stress actuator groups and the compensation parameter;

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

[0091] Therefore, through the pre-established model, the compensating stress performed by each stress actuator required to compensate for the overlay error is reversely derived through the overlay error distribution data, and then the compensation stress is applied to the mask to cause the mask to deform, thereby achieving compensation for the overlay error in the lithography process, which can reduce the overlay error of the lithography process.

[0092] Optionally, another lithography process overlay error compensation device provided by the present application also includes: a model building module; used to obtain the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses; based on the compensation stress and the overlay error distribution data, establish a correlation between the compensation stress and the compensation parameter; based on the overlay error distribution data corresponding to multiple stress actuator groups under different compensation stresses, and the correlation between the compensation stress and the compensation parameter, establish a stress compensation model.

[0093] Optionally, the model building module can be specifically used to obtain the overlay errors corresponding to multiple stress actuator groups under different compensation stresses; use the overlay error to fit the overlay error formula, determine the compensation parameters in the overlay error formula, and obtain the overlay error distribution data.

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

[0095] Optionally, another lithography process overlay error compensation device provided by the present application also includes: an alarm module; 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, output an alarm message.

[0096] Optionally, another lithography process overlay error compensation device provided by the present application also includes: a visualization module; used to determine the compensated target compensation parameters 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; based on the target compensation parameters, display the error compensation distribution of each acquisition point in the form of a vector diagram.

[0097] In addition, an embodiment of the present application 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-mentioned lithography process overlay error compensation steps.

[0098] Alternatively, if 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 actuator.

[0100] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device embodiment described above is merely schematic, in which the unit described as a separate component may or may not be physically separated, and the component prompted as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0101] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for compensating overlay error in a photolithography process, characterized in that: The method comprises: Acquire overlay error distribution data; the overlay error distribution data is the sum of the average of the absolute value of the overlay error and three times the standard deviation; the overlay error is the coordinate deviation between the lithography pattern of each acquisition point and the reference pattern; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter; 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 a compensation stress performed by the stress actuator; the stress compensation model includes a correlation relationship between compensation stresses corresponding to each of a plurality of stress actuator groups and compensation parameters; The stress actuator is driven to apply compensation stress to the mask based on the target stress compensation scheme.

2. The method according to claim 1, characterized in that The stress compensation model is established by the following method: Obtaining overlay error distribution data corresponding to a plurality of stress actuator groups under different compensation stresses; Based on the compensation stress and the overlay error distribution data, establishing a correlation relationship between the compensation stress and the compensation parameter; A stress compensation model 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 parameter.

3. The method according to claim 2, characterized in that The obtaining of overlay error distribution data corresponding to the plurality of stress actuator groups under different compensation stresses includes: Obtaining the corresponding overlay errors of multiple stress actuator groups under different compensation stresses; The overlay error is used to fit an overlay error formula, a compensation parameter in the overlay error formula is determined, and overlay error distribution data is obtained.

4. The method according to claim 1, characterized in that: The method of obtaining a target stress compensation scheme based on the overlay error distribution data through a pre-established stress compensation model includes: Based on the overlay error distribution data, extracting a target item in the overlay error distribution data; the target item is a high-order item with a number greater than or equal to 3; Through the 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 driving the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme, the method further includes: Monitor the overlay residual after compensation; If the overlay residual is greater than the preset threshold value for a continuous number of times greater than the preset number of times, an alarm message is output.

6. The method according to claim 1, characterized in that After obtaining a target stress compensation solution based on the overlay error distribution data through a pre-established stress compensation model, the method further includes: Determine a compensated target compensation parameter based on the compensation stress in the target stress compensation scheme and the correlation between the compensation stress and the compensation parameter corresponding to the target stress compensation scheme; Based on the target compensation parameters, the error compensation distribution of each acquisition point is displayed in the form of a vector diagram.

7. A device for compensating overlay error in a photolithography process, characterized in that: The device comprises: an acquisition module, a scheme determination module and a driving 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 value of the overlay error and three times the standard deviation; the overlay error is the coordinate difference between the lithography pattern of each acquisition point and the reference pattern; in the polynomial formula of the overlay error distribution data, each coefficient is a compensation parameter; The scheme determination module is used to obtain a target stress compensation scheme based on the overlay error distribution data through a pre-established stress compensation model; the stress compensation scheme includes a stress actuator group and a compensation stress performed by the stress actuator; the stress compensation model includes an association relationship between compensation stresses corresponding to each of a plurality of stress actuator groups and compensation parameters; The driving module is used to drive the stress actuator to apply compensation stress to the mask based on the target stress compensation scheme.

8. A photolithography machine, characterized in that: The lithography machine comprises: 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 step of overlay error compensation in the lithography process according to any one of claims 1 to 6.

9. The photolithography machine according to claim 8, characterized in that: The photolithography machine comprises 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.

10. The photolithography machine according to claim 8, characterized in that: The stress actuator is a piezoelectric brake.

Images