Method and device for configuring overlay error compensation model parameters

Abstract

The present application discloses a method and device for configuring parameters of an overlay error compensation model, which selects model parameters in an overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model. The overlay error measurement data, the configured model and the parameter values of the configured model are calculated to obtain a characterization quantity, and the characterization quantity and the overlay error measurement data are subjected to difference processing to obtain a characterization residual value. The characterization residual value is normalized to obtain an evaluation parameter of the configured model. Different model parameters are selected according to a preset number of parameters to obtain a set of configured models, and the set of configured models is iteratively processed to obtain an evaluation parameter set. Based on the minimum evaluation parameter in the evaluation parameter set, an optimized overlay error compensation model is obtained. The model parameter configuration with the minimum evaluation parameter is optimal, which improves the compensation accuracy of the model in a targeted manner.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a method and device for configuring overlay error compensation model parameters. Background Art

[0002] Overlay error refers to the offset between the current layer and the previous layer during the photolithography process. With the advancement of integrated circuit manufacturing processes, the requirements for controlling overlay error have become increasingly stringent. Excessive overlay error can lead to short circuits and open circuits in devices, affecting product quality. However, overlay error is related to many factors, including deformation of the mask and wafer, the lithography machine projection system itself, and the displacement inconsistency of the wafer workpiece stage. It is also affected by external environmental factors such as temperature, humidity, and vibration.

[0003] Current technology uses advanced process control (APC) systems to correct overlay errors. APC systems include a variety of overlay error compensation models. Calculations are performed based on measured data and preset overlay error compensation models. Model parameters are obtained through algorithm fitting, and subsequent corrections are performed using the model parameters.

[0004] Existing overlay error compensation models have a certain number of parameters, and all parameters in the selected model are fed back during compensation. However, because different products or processes have different factors affecting overlay error, using the same model parameter configuration for compensation results in poor accuracy, which in turn prevents optimal compensation results. Summary of the Invention

[0005] In view of this, an embodiment of the present application provides a method and apparatus for configuring parameters of an overlay error compensation model, aiming to improve the compensation accuracy of the overlay error compensation model.

[0006] In a first aspect, an embodiment of the present application provides a method for configuring parameters of an overlay error compensation model, the method comprising:

[0007] Selecting model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model;

[0008] calculating the overlay error measurement data, the configured overlay error compensation model, and parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and performing a difference processing between the overlay error measurement data and the characterization value to obtain a characterization residual value;

[0009] Normalizing the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model;

[0010] Selecting different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively processing the set of configured overlay error compensation models to obtain a set of evaluation parameters of the configured overlay error compensation models;

[0011] An optimized overlay error compensation model is obtained according to the minimum evaluation parameter in the evaluation parameter set.

[0012] Optionally, the overlay error measurement data includes coordinate positions within an exposure field, coordinate positions between exposure fields, and overlay errors represented by overlay marks at corresponding positions.

[0013] Optionally, the step of obtaining the characterization quantity is specifically as follows:

[0014] The coordinate position within the exposure field, the coordinate position between the exposure fields, the configured overlay error compensation model, and the parameter value of the configured overlay error compensation model are calculated to obtain a characterization value of the configured overlay error compensation model.

[0015] Optionally, the step of obtaining the characterizing residual value is specifically as follows:

[0016] The overlay error represented by the overlay mark at the corresponding position and the represented amount are subjected to difference processing to obtain the represented residual value.

[0017] Optionally, the selecting model parameters in the overlay error compensation model according to a preset number of parameters to obtain the configured overlay error compensation model further includes:

[0018] The model parameters in the overlay error compensation model are selected by using parameter coefficients and the preset number of parameters to obtain the configured overlay error compensation model.

[0019] Optionally, the method further includes:

[0020] Obtain sampling coordinates on the wafer according to a preset spacing;

[0021] Determining patterning parameters according to the parameters in the optimized overlay error compensation model;

[0022] Calculating the sampling coordinates, the graphical parameter values, and the optimized overlay error compensation model to obtain a characterization value of the optimized overlay error compensation model;

[0023] A graph of the graphical parameters is drawn according to the characterization quantity of the optimized overlay error compensation model.

[0024] In a second aspect, an embodiment of the present application provides a device for configuring overlay error compensation model parameters, the device comprising:

[0025] A selection module, configured to select model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model;

[0026] a first obtaining module, configured to calculate the overlay error measurement data, the configured overlay error compensation model, and parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and perform a difference processing between the overlay error measurement data and the characterization value to obtain a characterization residual value;

[0027] a normalization module, configured to perform normalization processing on the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model;

[0028] an iterative processing module, configured to select different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively process the set of configured overlay error compensation models to obtain a set of evaluation parameters of the configured overlay error compensation models;

[0029] The second obtaining module is configured to obtain an optimized overlay error compensation model according to the minimum evaluation parameter in the evaluation parameter set.

[0030] Optionally, the overlay error measurement data includes coordinate positions within an exposure field, coordinate positions between exposure fields, and overlay errors represented by overlay marks at corresponding positions.

[0031] Optionally, the step of obtaining the characterization quantity in the first obtaining module specifically includes:

[0032] A calculation unit is used to calculate the coordinate position within the exposure field, the coordinate position between the exposure fields, the configured overlay error compensation model and the parameter value of the configured overlay error compensation model to obtain the characterization value of the configured overlay error compensation model.

[0033] Optionally, the step of obtaining the residual value in the first obtaining module specifically includes:

[0034] The difference processing unit is used to perform difference processing on the overlay error represented by the overlay mark on the corresponding position and the represented amount to obtain the represented residual value.

[0035] Optionally, the overlay error compensation model parameter configuration device further includes:

[0036] A selection unit is configured to select model parameters in the overlay error compensation model by using parameter coefficients and the preset number of parameters to obtain the configured overlay error compensation model.

[0037] Optionally, the overlay error compensation model parameter configuration device further includes:

[0038] An acquisition unit, configured to acquire sampling coordinates on the wafer according to a preset spacing;

[0039] a determining unit, configured to determine parameters of the patterning according to the parameters in the optimized overlay error compensation model;

[0040] an obtaining unit, configured to calculate the sampling coordinates, the graphical parameter values, and the optimized overlay error compensation model to obtain a characterization value of the optimized overlay error compensation model;

[0041] A drawing unit is used to draw a graph of the graphical parameters according to the characterization quantity of the optimized overlay error compensation model.

[0042] In a third aspect, an embodiment of the present application provides a device for configuring overlay error compensation model parameters, the device comprising:

[0043] memory for storing computer programs;

[0044] The processor is configured to execute the computer program so that the device executes the overlay error compensation model parameter configuration method described in the first aspect.

[0045] In a fourth aspect, an embodiment of the present application provides a computer storage medium, on which a computer program is stored. When the computer program is executed, the device running the computer program implements the overlay error compensation model parameter configuration method described in the first aspect.

[0046] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0047] The present invention provides a method and apparatus for configuring overlay error compensation model parameters. First, model parameters in an overlay error compensation model are selected based on a preset number of parameters to obtain a configured overlay error compensation model. Then, overlay error measurement data, the configured overlay error compensation model, and parameter values of the configured overlay error compensation model are calculated to obtain a characterization of the configured overlay error compensation model. The characterization and the overlay error measurement data are then subjected to a difference calculation to obtain a characterization residual. The characterization residual is normalized to obtain evaluation parameters of the configured overlay error compensation model. Different model parameters are selected based on a preset number of parameters to obtain a set of configured overlay error compensation models. The set of configured overlay error compensation models is then iteratively processed to obtain a set of evaluation parameters for the configured overlay error compensation model. Finally, an optimized overlay error compensation model is obtained based on the minimum evaluation parameter in the set of evaluation parameters. This indicates that different evaluation parameters can be obtained by selecting different model parameters. The model parameter configuration with the minimum evaluation parameter is optimal, which specifically improves the compensation accuracy of the model and thus the compensation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in this embodiment or the prior art, the following briefly introduces the drawings required for use in the embodiment or the prior art description. 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 creative work.

[0049] Figure 1 A flowchart of a method for configuring overlay error compensation model parameters provided in an embodiment of the present application;

[0050] Figure 2A A schematic diagram of vectorized representation of overlay error measurement data that can be output during the calculation of the characterization residual value;

[0051] Figure 2B A schematic diagram of a vectorized representation quantity that can be output in the process of calculating the representation residual value;

[0052] Figure 2C A schematic diagram of a vectorized representation of a residual value that can be output during the calculation of the residual value;

[0053] Figure 3A Schematic diagram of the statistical results of the residual value in the X direction;

[0054] Figure 3B It is a schematic diagram of the statistical results of the residual value in the Y direction;

[0055] Figure 4Schematic diagram of the comparison results of the evaluation parameters for all model parameter configuration schemes;

[0056] Figure 5 Schematic diagram of the evaluation parameters of all model parameter configuration schemes when 6 parameters are selected;

[0057] Figure 6A A schematic diagram showing the residual value of the parameter combination with the minimum evaluation parameters;

[0058] Figure 6B A schematic diagram showing the residual value of the parameter combination with the largest evaluation parameter;

[0059] Figure 7 A flowchart of a method for graphically representing the offset of a model parameter provided in an embodiment of the present application;

[0060] Figure 8 It is a schematic diagram of the graphical results of four position-related parameters in the exposure field;

[0061] Figure 9 Schematic diagram of the graphical results of four position-related parameters between exposure fields;

[0062] Figure 10 Schematic diagram of the vectorized prediction results of the overlay error at different positions across the entire wafer when 10 parameters are selected;

[0063] Figure 11 A structural diagram of an overlay error compensation model parameter configuration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0064] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0065] Current technology uses advanced process control (APC) systems to correct overlay errors. APC systems include a variety of overlay error compensation models. Calculations are performed based on measured data and preset overlay error compensation models. Model parameters are obtained through algorithm fitting, and subsequent corrections are performed using the model parameters.

[0066] Existing overlay error compensation models have a certain number of parameters, and all parameters in the selected model are fed back during compensation. However, because different products or processes have different factors affecting overlay error, using the same model parameter configuration for compensation results in poor accuracy, which in turn prevents optimal compensation results.

[0067] Based on this, to address the above-mentioned issues, in an embodiment of the present application, first, model parameters in an overlay error compensation model are selected based on a preset number of parameters to obtain a configured overlay error compensation model. Then, the overlay error measurement data, the configured overlay error compensation model, and the parameter values of the configured overlay error compensation model are calculated to obtain a characterization of the configured overlay error compensation model. The characterization and the overlay error measurement data are then subjected to a difference calculation to obtain a characterization residual. The characterization residual is normalized to obtain an evaluation parameter of the configured overlay error compensation model. Different model parameters are selected based on a preset number of parameters to obtain a set of configured overlay error compensation models. The set of configured overlay error compensation models is then iterated to obtain a set of evaluation parameters for the configured overlay error compensation model. Finally, an optimized overlay error compensation model is obtained based on the minimum evaluation parameter in the set of evaluation parameters. It can be seen that by selecting different model parameters, different evaluation parameters can be obtained. The model parameter configuration with the minimum evaluation parameter is optimal, which specifically improves the compensation accuracy of the model and thus the compensation effect.

[0068] The specific implementation of the method and device for optimizing the configuration of overlay error compensation model parameters in the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0069] See also Figure 1 , which is a flow chart of a method for configuring overlay error compensation model parameters provided by an embodiment of the present application, combined with Figure 1 Specifically, it may include:

[0070] S101: Selecting model parameters in an overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model.

[0071] In a possible implementation, the model parameters in the overlay error compensation model can be selected according to a preset number of parameters. The preset number of parameters can be customized. The model parameters in the overlay error model can also be selected according to the parameter coefficient and the preset number of parameters to obtain the configured overlay error compensation model. As an example, the parameter coefficient (a1-a 20 ), the overlay error model in the exposure field after adding the coefficient can be expressed by the following formula:

[0072] dx=a1*k1+a3*k3*x+a5*k5*y+a7*k7*x 2 +a9*k9*x*y+a 11 *k 11 *y 2 +a 13 *k 13 *x 3 +a 15 *

[0073] k 15 *x 2 *y+a 17 *k 17 *x*y 2 +a 19 *k 19 *y 13 (Formula 1)

[0074] dy=a2*k2+a4*k4*y+a6*k6*x+a8*k8*y 2 +a 10 *k 10 *y*x+a 12 *k 12 *x 2 +a 14 *k 14 *y 3 +a 16

[0075] *k 16 *y 2 *x+a 18 *k 18 *y*x 2 +a 20 *k 20 *x 3 (Formula 2)

[0076] Among them, formula 1 represents the overlay error compensation model of the x-axis in the exposure field, and formula 2 represents the overlay error compensation model of the y-axis in the exposure field. The a in formula 1 and formula 2 is n represents the parameter coefficient, k n represents the model parameters, and x and y represent the corresponding coordinates.

[0077] When selecting the corresponding parameter, when you want to select this parameter, the parameter coefficient a n When it is 1, if you do not want to select this parameter, the parameter coefficient a n 0, the parameters can be flexibly configured by configuring the parameter coefficient. In actual situations, some parameters do not have corresponding compensation actuators and cannot perform overlay error compensation, such as k9, k 15、k 17 、k 18 、k 20 These five parameters can be ignored and the remaining parameters can be selected. The remaining parameters have corresponding compensation actuators. By selecting different model parameters, different overlay error compensation can be performed. Under the premise of sufficient overlay error data, 1 parameter, 2 parameters, 3 parameters, or 15 parameters can be selected. As an example, the preset number of parameters is 3, and any 3 model parameters in the overlay error compensation model can be selected, which can be (k1, k5, k7), to obtain the configured overlay error compensation model.

[0078] Theoretically, more model terms yield higher representation accuracy. This requires a sufficient amount of input overlay error measurement data. Excessive overlay error measurement data inevitably leads to low efficiency and productivity. To achieve optimal overlay error compensation accuracy while fully utilizing the overlay error measurement data, the number of model parameters can be determined based on the amount of overlay error measurement data.

[0079] Furthermore, model parameter calculation requires a certain amount of overlay error measurement data. For example, for a model with six parameters, data from at least three different measurement locations is required to calculate the parameter values. However, since overlay error measurement data may be affected by random factors, a certain degree of redundancy is required. As an example, overlay error measurement data from 12 measurement locations can be selected for subsequent parameter evaluation analysis. These 12 overlay error measurement data points satisfy the calculation requirements for 24 parameters. Since the overlay error compensation model contains 20 parameters, and five of them lack associated compensation mechanisms, a maximum of 15 parameters can be selected, providing a certain degree of data redundancy and ensuring the accuracy of the calculated model parameters. Since each process or equipment has corresponding key characteristics, it is not necessary to use all parameters for correction to achieve the optimal compensation effect. By correcting the combination of model parameters corresponding to the key offset characteristics, the corresponding compensation effect can be achieved, effectively reducing the number of overlay error measurement data required and providing process developers with greater freedom in model selection.

[0080] S102: Calculate the overlay error measurement data, the configured overlay error compensation model and the parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and perform difference processing on the overlay error measurement data and the characterization value to obtain a characterization residual value.

[0081] The overlay error measurement data is the result obtained by measuring the overlay mark on the wafer using special measurement equipment, and can be saved in txt, xml or xls format. The overlay error measurement data may include the coordinate position within the exposure field, the coordinate position between exposure fields, and the overlay error represented by the overlay mark at the corresponding position, that is, the offset between the previous layer and the current layer represented by the overlay mark at the corresponding position. Among them, the coordinate position within the exposure field can be represented by x, y, and the coordinate position between exposure fields can be represented by X, Y. The overlay error between exposure fields takes the center of the wafer as the origin, and reflects the overlay error difference between exposure fields at different distribution positions on the entire wafer. It is mainly affected by the wafer morphology and the displacement accuracy of the lithography machine worktable. The overlay error within the exposure field takes the center of the exposure field as the origin, and represents the overlay error difference at different positions within a single exposure field. It is mainly affected by the projection system of the lithography machine.

[0082] In a possible implementation, the overlay error measurement data and the configured overlay error compensation model are fitted using a least squares algorithm to obtain parameter values of the configured overlay error compensation model.

[0083] See also Figure 2A , Figure 2B , Figure 2C , Figure 2A This is a schematic diagram of the vectorized representation of the overlay error measurement data that can be output during the calculation of the residual value. Figure 2B This is a schematic diagram of the vectorized representation quantity that can be output during the calculation of the representation residual value. Figure 2C A schematic diagram of a vectorized representation of the residual value that can be output during the calculation of the residual value.

[0084] In a possible implementation, the coordinate position within the exposure field, the coordinate position between exposure fields, the configured overlay error compensation model, and the parameter values of the configured overlay error compensation model are calculated to obtain a characterization value of the configured overlay error compensation model.

[0085] In one possible implementation, the overlay error represented by the overlay mark at the corresponding position and the representation quantity are subjected to difference processing to obtain the representation residual value of the configured overlay error compensation model, that is, the representation residual value of the configured overlay error compensation model can be obtained by subtracting the representation quantity of the configured overlay error compensation model from the overlay error represented by the overlay mark at the corresponding position.

[0086] S103: performing normalization processing on the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model.

[0087] In one possible implementation, the absolute values of the mean values of the residual values in the X and Y directions are normalized by adding three times the standard deviation, and then multiplied by the weight coefficients and added together to form the evaluation parameters of the configured overlay error compensation model, which serves as a measure of the model's characterization accuracy. This can be expressed by the following formula:

[0088] m=0.5*(|meanx|+3sigmax+|meany|+3sigmay) (Formula 3)

[0089] Where m represents the evaluation parameter, 0.5 represents the weight coefficient, |meanx|+3sigmax represents the absolute value of the mean value of the residual values in the X direction plus three times the standard deviation, and |meany|+3sigmay represents the absolute value of the mean value of the residual values in the Y direction plus three times the standard deviation.

[0090] S104: Select different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively process the set of configured overlay error compensation models to obtain a set of evaluation parameters of the configured overlay error compensation models.

[0091] In one possible implementation, different model parameters can be selected based on a preset number of parameters to obtain different model parameter configurations. All model parameter configuration schemes obtained based on the preset number of parameters constitute a set of configured overlay error compensation models. The set of configured overlay error compensation models is iteratively processed according to the above steps to obtain corresponding evaluation parameters, which constitute a set of evaluation parameters for the configured overlay error compensation models. As an example, when the preset number of parameters is 6, different model parameters are selected, resulting in 5005 model parameter configuration schemes. In step S101, only one model parameter configuration is selected as the configured overlay error compensation model. In step S104, the remaining configuration schemes are iteratively processed according to the above steps to obtain corresponding evaluation parameters, which constitute a set of evaluation parameters.

[0092] S105: Obtaining an optimized overlay error compensation model according to the minimum evaluation parameter in the evaluation parameter set.

[0093] See also Figure 3A and Figure 3B , Figure 3A This is a schematic diagram of the statistical results of the residual value in the X direction. Figure 3B This is a schematic diagram of the statistical results of the residual value in the Y direction. Figure 3A and Figure 3B The horizontal axis is the number of model parameters selected. Figure 3A and Figure 3BThe statistical results of the residual values of all model parameter configurations are shown. Figure 3A 、 Figure 3B The statistical results of the residual values in the X and Y directions are multiplied by the weight coefficients and added together to obtain the evaluation parameters of all model parameter configuration schemes. Figure 4 , Figure 4 Schematic diagram of the comparison results of the evaluation parameters for all model parameter configuration schemes, Figure 4 The horizontal axis is the number of model parameters selected, and the vertical axis is the value of the evaluation parameter. Figure 4 It can be seen that the value of the evaluation parameter of the optimal model parameter configuration when 6 parameters are selected is between 0.1 and 0.2. When 15 parameters are selected, the evaluation parameter of the model is almost 0. Therefore, it is believed that selecting any 6 parameters from the 15 parameters can achieve the same effect as selecting all model parameters.

[0094] See also Figure 5 , Figure 5 This is a schematic diagram of the evaluation parameters of all model parameter configuration schemes when 6 parameters are selected, as shown in Figure 5 Shown are the evaluation parameter values of all model parameter configuration schemes obtained by selecting 6 parameters for 12 measurement point data in an embodiment of the present application. The x-axis represents the combination scheme of the parameter configuration, and the y-axis represents the value of the evaluation parameter. The evaluation parameter value of the 64th combination (k1, k2, k3, k5, k6, k15) is 0.1101, which is the smallest evaluation parameter value. The evaluation parameter value of the 4138th combination (k4, k5, k6, k9, k11, k14) is 0.9053, which is the largest evaluation parameter value.

[0095] In order to verify the effects of the two model parameter configuration schemes, the characterization residuals of the overlay error compensation model composed of the above two combinations are calculated respectively. Figure 6A and Figure 6B , Figure 6A A schematic diagram showing the residual value of the parameter combination with the minimum evaluation parameters. Figure 6B Schematic diagram representing the residual value of the parameter combination with the largest evaluation parameter. Figure 6A To select the parameter combination with the minimum evaluation parameters, the residual value of the overlay error compensation model is constructed. Figure 6BThe residual value of the overlay error compensation model is determined by selecting the parameter combination with the largest evaluation parameter. It can be seen that selecting the parameter combination with the smallest evaluation parameter results in a smaller residual value for the overlay error compensation model. Therefore, the overlay error compensation model with the best compensation effect, i.e., the optimized overlay error compensation model, can be obtained based on the smallest evaluation parameter in the evaluation parameter set. Furthermore, to maintain the accuracy of the results, the optimal evaluation parameter combination can be determined as the final configuration model based on the overlay error measurement data of multiple exposure fields or the results of multiple process sheets, thereby increasing the scope for process optimization.

[0096] Through the above solution, R&D personnel can fully analyze the factors affecting overlay error for specific processes or products, determine the key influencing factors, and specify the optimal compensation model that can be used in actual mass production. This can effectively reduce the number of measurements, enhance the correlation between measurement compensation and process characteristics, and enhance the effectiveness of compensation, thereby achieving better overlay error compensation effects.

[0097] The above is a method for configuring overlay error compensation model parameters provided in an embodiment of the present application. First, model parameters in the overlay error compensation model are selected according to a preset number of parameters to obtain the configured overlay error compensation model. Then, the overlay error measurement data, the configured overlay error compensation model, and the parameter values of the configured overlay error compensation model are calculated to obtain a characterization value of the configured overlay error compensation model. The characterization value and the overlay error measurement data are then subjected to a difference calculation to obtain a characterization residual value. The characterization residual value is normalized to obtain an evaluation parameter of the configured overlay error compensation model. Different model parameters are selected according to a preset number of parameters to obtain a set of configured overlay error compensation models. The set of configured overlay error compensation models is then iterated to obtain a set of evaluation parameters for the configured overlay error compensation model. Finally, an optimized overlay error compensation model is obtained based on the minimum evaluation parameter in the evaluation parameter set. It can be seen that by selecting different model parameters, different evaluation parameters can be obtained. The model parameter configuration with the minimum evaluation parameter is optimal, which specifically improves the compensation accuracy of the model and thus improves the compensation effect.

[0098] See also Figure 7 , which is a flow chart of a method for graphically representing the offset of model parameters provided by an embodiment of the present application, combined with Figure 7 Specifically, it may include:

[0099] S701: Acquire sampling coordinates on the wafer according to a preset spacing.

[0100] First, obtain the parameter information of the wafer. The parameter information of the wafer mainly includes the wafer size (diameter), exposure field size and grid offset. Among them, the wafer size is generally 300mm, 200mm and 150mm, and the maximum exposure field is usually 26mm*33mm. The grid offset refers to the offset size of the exposed exposure field grid distribution relative to the center of the wafer.

[0101] In one possible implementation, obtaining sampling coordinates on the wafer based on a preset spacing can define finer sampling coordinates within the wafer at 2 mm intervals. To ensure coordinate consistency across exposure fields, the coordinates of one exposure field can be defined first. Then, the coordinates of the exposure field near the center of the wafer can be determined based on the acquired grid offset and exposure field size. Finally, the coordinates of the remaining exposure fields can be derived based on the exposure field size.

[0102] S702: Determine the parameters of the graphics according to the parameters in the optimized overlay error compensation model.

[0103] Parameters for graphically representing offset features may be selected based on the parameters in the optimized overlay error compensation model.

[0104] S703: Calculate the sampling coordinates, the graphical parameter values, and the optimized overlay error compensation model to obtain a representation of the optimized overlay error compensation model.

[0105] In one possible implementation, the parameters that are not selected for graphics in the optimized overlay error compensation model are set to 0, and then the parameter values to be graphics and the sampling coordinates defined in step S701 are substituted into the optimized overlay error compensation model for calculation, so as to obtain the characterization value of the optimized overlay error compensation model.

[0106] S704: Drawing a graph of graphical parameters according to the characterization quantity of the optimized overlay error compensation model.

[0107] In a possible implementation, a vector graph of the parameter to be graphically represented may be drawn according to the coordinate position defined in step S701 and the model representation calculated in step S703. Figure 8 , Figure 8 This is a schematic diagram of the graphical results of four position-related parameters in the exposure field, such as Figure 8 The following shows the results of the four position-related parameters in the exposure field when 10 parameters are selected, which respectively reflect the effects of symmetry, asymmetry, rotation, magnification or reduction. Figure 8 The area in the upper left corner shows the symmetrical enlargement or reduction effect. Figure 8 The area in the upper right corner shows the asymmetrical zooming in or out effect. Figure 8The area in the lower left corner shows the effect of symmetrical rotation. Figure 8 The area in the lower right corner shows the effect of asymmetric rotation, where the parameters k1 and k2 are constants and are independent of position. Figure 9 , Figure 9 This is a schematic diagram of the graphical results of four position-related parameters between exposure fields, such as Figure 9 The following are the results of the four position-related parameters between exposure fields, which respectively reflect the expansion, distortion and rotation effects of the wafer. Figure 9 The area in the upper left corner shows the effect of expansion in the X direction. Figure 9 The area in the lower left corner shows the effect of expansion in the Y direction. Figure 9 The area in the upper right corner shows the distortion effect. Figure 9 The area in the lower right corner shows the effect of rotation. Figure 8 and Figure 9 It is the result of a graphical representation of a single parameter in the model. It can also be used to graphically represent the offset characteristics of any two, three, or any number of parameters superimposed. When the number of selected items is the same as the total number of model parameters, this graphical method can be used to obtain the corresponding model's prediction of the size of the overlay error at unmeasured positions within the wafer range.

[0108] As an example, when the model has 10 parameters and the graphical parameters are also 10, see Figure 10 , Figure 10 This is a schematic diagram of the vectorized prediction results of the overlay error size at different locations within the entire wafer range when 10 parameters are selected. Since more precise coordinates within the entire wafer range are defined in step S701, this graphical method can be used to obtain the corresponding model's prediction of the overlay error size at unmeasured locations within the wafer range. Of course, the graphical prediction of the overlay error size at different locations provided in the embodiment of the present application is only one way of expression, and other similar methods can also be used. This application does not specifically limit the specific method of graphicalization, and it does not affect the implementation of the embodiment of the present application.

[0109] The above is a method for graphically representing the offset of model parameters provided in an embodiment of the present application. First, the sampling coordinates on the wafer are obtained according to the preset spacing, and the graphical parameters are determined according to the parameters in the optimized overlay error compensation model. Then, the sampling coordinates, the graphical parameter values and the optimized overlay error compensation model are calculated to obtain the characterization quantity of the optimized overlay error compensation model. Finally, a graph of the graphical parameters is drawn according to the characterization quantity of the optimized overlay error compensation model. It can be seen that a single parameter in the model can be graphically represented, and the offset characteristics of any two, three or any number of allowed parameters can be graphically represented. When the number of selected items is the same as the total number of model parameters, the prediction of the size of the overlay error at the unmeasured position within the wafer range by the corresponding model can be obtained through this graphical method, and the graphical overlay error analysis capability can be obtained.

[0110] The above are some specific implementations of the method for configuring parameters of the overlay error compensation model provided in the embodiment of the present application. Based on this, the present application also provides a corresponding device. The device provided in the embodiment of the present application will be introduced from the perspective of functional modularization.

[0111] See also Figure 11 , which is a schematic structural diagram of an overlay error compensation model parameter configuration device 1100 provided in an embodiment of the present application. The device 1100 may include:

[0112] A selection module 1101 is configured to select model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model;

[0113] A first obtaining module 1102 is configured to calculate the overlay error measurement data, the configured overlay error compensation model, and the parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and perform a difference processing between the overlay error measurement data and the characterization value to obtain a characterization residual value;

[0114] A normalization module 1103 is used to perform normalization processing on the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model;

[0115] An iterative processing module 1104 is configured to select different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively process the set of configured overlay error compensation models to obtain a set of evaluation parameters for the configured overlay error compensation models;

[0116] The second obtaining module 1105 is configured to obtain an optimized overlay error compensation model according to the minimum evaluation parameter in the evaluation parameter set.

[0117] In an embodiment of the present application, by cooperating with the selection module 1101, the first acquisition module 1102, the normalization module 1103, the iterative processing module 1104 and the second acquisition module 1105, different evaluation parameters can be obtained by selecting different model parameters. The model parameter configuration with the smallest evaluation parameter is optimal, which specifically improves the compensation accuracy of the model and thus improves the compensation effect.

[0118] As an implementation manner, the overlay error measurement data includes coordinate positions within an exposure field, coordinate positions between exposure fields, and overlay errors represented by overlay marks at corresponding positions.

[0119] As an embodiment, the step of obtaining the characterization quantity in the first obtaining module 1102 specifically includes:

[0120] The calculation unit is used to calculate the coordinate position within the exposure field, the coordinate position between the exposure fields, the configured overlay error compensation model and the parameter value of the configured overlay error compensation model to obtain the characterization value of the configured overlay error compensation model.

[0121] As an implementation manner, the step of obtaining the residual value in the first obtaining module 1102 specifically includes:

[0122] The difference processing unit is used to perform difference processing on the overlay error and the characterization amount represented by the overlay mark at the corresponding position to obtain the characterization residual value.

[0123] As an implementation manner, the overlay error compensation model parameter configuration device 1100 further includes:

[0124] The selection unit is used to select model parameters in the overlay error compensation model through parameter coefficients and a preset number of parameters to obtain the configured overlay error compensation model.

[0125] As an embodiment, the apparatus 1100 for optimizing and configuring overlay error compensation model parameters further includes:

[0126] An acquisition unit, configured to acquire sampling coordinates on the wafer according to a preset spacing;

[0127] A determination unit, configured to determine the parameters of the graphics according to the parameters in the optimized overlay error compensation model;

[0128] An obtaining unit, configured to calculate the sampling coordinates, the graphical parameter values and the optimized overlay error compensation model to obtain a characterization value of the optimized overlay error compensation model;

[0129] The drawing unit is used to draw a graph of the graphical parameters according to the characterization quantity of the optimized overlay error compensation model.

[0130] The embodiments of the present application also provide corresponding devices and computer storage media for implementing the solutions provided by the embodiments of the present application.

[0131] The device includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program, so that the device executes the overlay error compensation model parameter configuration method described in any embodiment of the present application.

[0132] The computer storage medium stores a computer program. When the code is executed, the device executing the computer program implements the method for configuring overlay error compensation model parameters as described in any embodiment of the present application.

[0133] The "first" and "second" in the names such as "first" and "second" (if any) mentioned in the embodiments of this application are only used as name identifiers and do not represent the first or second in order.

[0134] Through the description of the above embodiments, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above embodiment methods can be implemented by means of software plus a general hardware platform. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment or certain parts of the embodiments of the present application.

[0135] 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 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 illustrative, wherein the units described as separate components may or may not be physically separated, and the components indicated as units may or may not be physical units, that is, they may be located in one place, or they 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 solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0136] The above is merely one specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for configuring overlay error compensation model parameters, characterized in that: The method comprises: Selecting model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model; calculating the overlay error measurement data, the configured overlay error compensation model, and parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and performing a difference processing between the overlay error measurement data and the characterization value to obtain a characterization residual value; Normalizing the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model; Selecting different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively processing the set of configured overlay error compensation models to obtain a set of evaluation parameters of the configured overlay error compensation models; An optimized overlay error compensation model is obtained according to the minimum evaluation parameter in the evaluation parameter set.

2. The method according to claim 1, characterized in that The overlay error measurement data includes coordinate positions within an exposure field, coordinate positions between exposure fields, and overlay errors represented by overlay marks at corresponding positions.

3. The method according to claim 2, characterized in that The steps for obtaining the characterization quantity are specifically as follows: The coordinate position within the exposure field, the coordinate position between the exposure fields, the configured overlay error compensation model, and the parameter value of the configured overlay error compensation model are calculated to obtain a characterization value of the configured overlay error compensation model.

4. The method according to claim 2, characterized in that The steps for obtaining the characterizing residual value are specifically as follows: The overlay error represented by the overlay mark at the corresponding position and the represented amount are subjected to difference processing to obtain the represented residual value.

5. The method according to claim 1, wherein The step of selecting model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model further includes: The model parameters in the overlay error compensation model are selected by using parameter coefficients and the preset number of parameters to obtain the configured overlay error compensation model.

6. The method according to claim 1, characterized in that The method further comprises: Obtain sampling coordinates on the wafer according to a preset spacing; Determining patterning parameters according to the parameters in the optimized overlay error compensation model; Calculating the sampling coordinates, the graphical parameter values, and the optimized overlay error compensation model to obtain a characterization value of the optimized overlay error compensation model; A graph of the graphical parameters is drawn according to the characterization quantity of the optimized overlay error compensation model.

7. A device for configuring overlay error compensation model parameters, characterized in that: The device comprises: A selection module, configured to select model parameters in the overlay error compensation model according to a preset number of parameters to obtain a configured overlay error compensation model; a first obtaining module, configured to calculate the overlay error measurement data, the configured overlay error compensation model, and parameter values of the configured overlay error compensation model to obtain a characterization value of the configured overlay error compensation model, and perform a difference processing between the overlay error measurement data and the characterization value to obtain a characterization residual value; a normalization module, configured to perform normalization processing on the characterization residual value to obtain evaluation parameters of the configured overlay error compensation model; an iterative processing module, configured to select different model parameters according to a preset number of parameters to obtain a set of configured overlay error compensation models, and iteratively process the set of configured overlay error compensation models to obtain a set of evaluation parameters of the configured overlay error compensation models; The second obtaining module is used to obtain an optimized overlay error compensation model according to the minimum evaluation parameter in the evaluation parameter set.

8. The device according to claim 7, characterized in that The overlay error measurement data includes coordinate positions within an exposure field, coordinate positions between exposure fields, and overlay errors represented by overlay marks at corresponding positions.

9. A device for configuring overlay error compensation model parameters, characterized in that: The device comprises: Memory for storing computer programs; A processor is configured to execute the computer program so as to enable the device to perform the steps of the method for configuring overlay error compensation model parameters as described in any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for configuring overlay error compensation model parameters according to any one of claims 1 to 6 are implemented.

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