TW202338507A - A lithography machine matching method - Google Patents

Abstract

The present invention relates to the field of lithography machine technology, particularly to lithography machine matching methods. Get a preset lithographic pattern, There are X key positions in each preset lithographic pattern; The target key dimensions corresponding to the X key positions of each preset lithography pattern are obtained separately on the target lithography machine according to the lithography OPC model; OPC model fitting using the target lithography machine, Get the key dimensions to be adjusted corresponding to the X key positions in each preset lithographic pattern on the pending lithography machine, Calculate the difference between it and the key size of the target; Establish a sensitivity matrix based on the sensitivity of each lithography machine for each key size to be adjusted; According to the sensitivity matrix, Establish the total evaluation function; From this function, Adjust the parameters of the pending lithography to match the key to the target key.

Description

A photolithography machine matching method

The present invention relates to the technical field of photolithography machines, and in particular to a photolithography machine matching method.

The optical process is the modeling of light through the use of optical and chemical models with the help of mathematical formulas. Light is irradiated through the mask to form diffraction and converge on the surface of the photoresist, and the projected light stimulates a chemical reaction on the photoresist and bakes it to make the photoresist locally soluble in the developer. By simulating the reactions that occur on the photoresist, exploring ways to increase the photolithography resolution and process window from calculations is called photolithography OPC modeling.

In mass production, multiple lithography machines used in the same production line may come from different lithography machine suppliers. The functions and performance of the wafer photolithography process may be different in different photolithography machines. That is, different models of photolithography machines may bring about different performance differences in the same photolithography process, which may cause a decrease in the efficiency of mass production. , the yield decrease caused by performance degradation.

In order to solve the existing problem of performance differences between multiple photolithography machines used in the same production line, the present invention provides a photolithography machine matching method.

The solution of the present invention to solve the technical problem is to provide a photolithography machine matching method for matching multiple photolithography machines on the same production line, which includes the following steps:

Obtain the preset lithography pattern. Each preset lithography pattern has X key positions preset, and X is a positive integer;

Obtain the target key dimensions corresponding to the X key positions of each preset lithography pattern on the target lithography machine based on the lithography OPC model;

Use the target lithography machine as the standard to perform OPC model fitting on the lithography machine to be adjusted, obtain the key dimensions to be adjusted corresponding to X key positions in each preset lithography pattern on the lithography machine to be adjusted, and calculate the key dimensions to be adjusted and Difference in target critical dimensions;

Establish a sensitivity matrix based on the sensitivity of each critical dimension to be adjusted to the adjustable parameters of each lithography machine;

According to the sensitivity matrix, establish the overall evaluation function;

According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions.

Preferably, the acquisition of preset photolithography patterns, each of which has X key positions preset, specifically includes the following steps:

Design and select a preset photolithography pattern, the preset photolithography pattern includes a one-dimensional photolithography pattern and/or a two-dimensional photolithography pattern;

Mark the key positions of each preset lithography pattern, and record the key positions in the preset lithography pattern as Gj, j=1, 2,...X.

Preferably, the target key dimensions corresponding to the X key positions of each preset lithography pattern are obtained on the target lithography machine according to the lithography OPC model, which specifically includes the following steps:

Adjust the lithography parameters for each preset lithography pattern on the target lithography machine in turn, and generate the corresponding OPC model;

Simulate each preset photolithography pattern, expose it on the photolithography machine, and obtain the SEM image of the photolithography pattern;

Extract the contour of each SEM image, and extract a total of N target key dimensions CD at key positions in the contour, denoted as Sij, i=1, 2,...M, j=1, 2,...X, M is The number of preset lithography patterns.

Preferably, the lithography machine to be adjusted generates a lithography OPC model matching the target lithography machine according to the lithography OPC model of the target lithography machine, and obtains the lithography pattern in each preset lithography pattern on the lithography machine to be adjusted. The key dimensions to be adjusted corresponding to X key positions include the following steps:

According to the parameters of the target lithography machine, adjust the parameters of the lithography machine to be adjusted so that the lithography OPC model of the lithography machine to be adjusted matches the lithography OPC model of the target lithography machine;

Simulate the lithography machine to be adjusted to obtain the corresponding simulation model, and obtain the key dimensions to be adjusted corresponding to the key positions in the preset lithography pattern from the simulation model.

Preferably, the sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted.

Preferably, the perturbation of the input parameters of the lithography machine to be adjusted to obtain a sensitivity matrix specifically includes the following steps:

Adjust any adjustable parameter P of the lithography machine to be adjusted, use the target key size of the key position obtained by the target lithography machine as the standard, model and calculate the target key size of the key position, record the jth key position as The target critical dimension at Gj is CDj, and the sensitivity of CDj to the adjustable parameter P is: Corresponding to the parameters before matching, recorded as small changes;

Combining multiple adjustable parameters P1, P2...PN, the sensitivity matrix is obtained

N is a positive integer.

Preferably, establishing a total evaluation function based on the sensitivity matrix specifically includes the following steps:

According to the sensitivity matrix, adjust different parameters to obtain the change amount of the key dimension to be adjusted under the slight adjustment of different parameters, and superimpose these changes to obtain the cost value of each key dimension to be adjusted; cost is the error after adjustment, or It is the change amount of the key dimension to be adjusted; the formula of cost is: ;

Combining the evaluation function of each parameter, the total evaluation function is obtained; the formula is: .

Preferably, the photolithography machine matching method further includes the following steps:

According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted and simulate the preset lithography pattern, obtain the key dimensions to be measured from the simulation model, and determine whether the obtained key dimensions to be measured match the obtained target key dimensions;

If they match, the adjustment of the lithography machine to be adjusted ends;

If they do not match, the overall evaluation function is further optimized through the image error to obtain an optimized evaluation function, and the lithography machine to be adjusted is adjusted through the optimized evaluation function.

Preferably, according to the total evaluation function, the parameters of the lithography machine to be adjusted are adjusted and the simulation of the preset lithography pattern is performed, the key dimensions to be measured are obtained from the simulation model, and the obtained key dimensions to be measured are judged to be the same as the obtained target key dimensions. Whether it matches; if it matches, the adjustment of the lithography machine to be adjusted is ended; if it does not match, the overall evaluation function is further optimized through the image error to obtain the optimized evaluation function, and the lithography machine to be adjusted is adjusted by optimizing the evaluation function. Includes the following steps:

Simulate the preset photolithography pattern through the adjusted photolithography machine;

Compare the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model acquired by the lithography machine to be adjusted and the value of the target critical dimension in the image acquired by the target lithography machine with a preset threshold;

If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target critical dimension in the image obtained by the target lithography machine is less than or equal to the threshold, then it is judged that the value of the lithography machine to be adjusted is different from that of the target key dimension in the image obtained by the target lithography machine. Target lithography machine matching;

If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target key dimension in the image obtained by the target lithography machine is greater than the threshold, it is judged that the two images do not match. Further optimization is needed to obtain the optimal evaluation function. Preferably, the further optimization means introducing a penalty function into the total evaluation function to obtain an optimized evaluation function. The penalty function is established by presetting additional key positions on each preset photolithography pattern and constructing a sensitivity matrix; The optimized evaluation function obtained after introducing the penalty function is as follows: . in, is the penalty factor, used for regulating exist proportion in.

Compared with the existing technology, the photolithography machine matching method of the present invention has the following advantages:

1. The photolithography machine matching method of the present invention includes the following steps:

Obtain the preset lithography pattern. Each preset lithography pattern is preset with X key positions, and Target key dimensions corresponding to Adjust the key dimensions and calculate the difference between the key dimensions to be adjusted and the target key dimensions; establish a sensitivity matrix based on the sensitivity of each key dimension to be adjusted to the adjustable parameters of each lithography machine; based on the sensitivity matrix, establish a total evaluation function based on the total evaluation Function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions. The sensitivity matrix is obtained by perturbing the input parameters. When matching the lithography machine, the calculation of the sensitivity matrix is used as the evaluation function to quickly and comprehensively obtain the matching parameters of the lithography machine to be adjusted, thereby obtaining performance equivalent to the target lithography machine. The photolithography machine to be adjusted solves the matching problem of multiple photolithography machines on the same production line.

2. In the present invention, the preset photolithography patterns selected by design include one-dimensional photolithography patterns and/or two-dimensional photolithography patterns. The diversity of samples is conducive to enhancing the reliability of the matching results of the photolithography machine matching method; and by advance Marking the key positions of each preset photolithography pattern can facilitate subsequent calculations.

3. In the present invention, the lithography parameters are adjusted for each preset lithography pattern on the target lithography machine in turn, and the corresponding OPC model is generated; sufficient sample data is used to ensure the reliability of the final result; and through The outline of the SEM image is used for comparison to improve the accuracy and comprehensiveness of the comparison.

4. In the present invention, a lithography OPC model matching the target lithography machine is generated on the lithography machine to be adjusted according to the lithography OPC model of the target lithography machine; the key points in the preset lithography pattern are obtained through the lithography machine to be adjusted. The key dimension to be adjusted corresponding to the position. By comparing the difference between the two lithography machines, some initial adjustable data can be clarified to prepare for the subsequent establishment of the sensitivity matrix.

5. In the present invention, the sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted; in this way, all the data used to establish the sensitivity matrix can be simply obtained.

6. In the sensitivity formula of the present invention, the rate of change when adjusting the adjustable parameter P is very small, which facilitates accurate control of changes in key dimensions to be adjusted at key positions. Combining multiple adjustable parameters P1, P2...PN to obtain the sensitivity matrix can make the matching between the target lithography machine and the lithography machine to be adjusted more comprehensive.

7. According to the sensitivity matrix of the present invention, different parameters are adjusted to obtain the change amount of the key dimension to be adjusted under the slight adjustment of different parameters, and these changes are superimposed to obtain the cost value of each key dimension to be adjusted; cost is the adjustment The final error is the change in the key dimension to be adjusted; the formula of cost is:; then the evaluation function of each adjustable parameter is combined to obtain the total evaluation function; the formula is: , using the total evaluation function to evaluate the lithography machine to be adjusted is beneficial to improving the matching between the target lithography machine and the lithography machine to be adjusted.

8. In the present invention, the matching results will be further verified. If they do not match, the total evaluation function will be further optimized through the image error to obtain an optimized evaluation function. The lithography machine to be adjusted will be adjusted through the optimized evaluation function, which will help ensure that the lithography machine to be adjusted will be adjusted. The reliability of the final matching result of the lithography machine.

9. In the present invention, the matching degree of the lithography machine to be adjusted and the target lithography machine is judged by the matching degree of the simulation data and the image data, and the value of the key dimension to be adjusted in the simulation data obtained by the lithography machine to be adjusted is The absolute value of the difference between the target critical dimension value in the image acquired by the target lithography machine can intuitively and accurately reflect the matching degree of the image; and it can effectively reduce the computational complexity.

10. In the present invention, additional key point groups are introduced for assistance, which facilitates further optimization of the evaluation function and ensures the reliability of the final lithography machine matching result; regulation is controlled by introducing a penalty function exist The ratio in is conducive to further improving the accuracy of the calculation results of the performance difference between the to-be-adjusted lithography machine and the target lithography machine using this lithography machine matching method.

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and implementation examples. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

As used herein, the terms "vertical", "horizontal", "left", "right", "upper", "lower", "upper left", "upper right", "lower left", "lower right" and the like Representations are for illustrative purposes only.

Please refer to Figure 1. A first embodiment of the present invention provides a photolithography machine matching method for matching multiple photolithography machines on the same production line, which includes the following steps:

Step S1: Obtain a preset photolithography pattern. Each preset photolithography pattern has X key positions preset, and X is a positive integer;

Step S2: Obtain the target key dimensions corresponding to the X key positions of each preset lithography pattern on the target lithography machine according to the lithography OPC model;

Step S3: Perform OPC model fitting on the lithography machine to be adjusted based on the target lithography machine as the standard, obtain the key dimensions to be adjusted corresponding to X key positions in each preset lithography pattern on the lithography machine to be adjusted, and calculate the key dimensions to be adjusted. The difference between the critical dimension and the target critical dimension;

Step S4: Establish a sensitivity matrix based on the sensitivity of each key dimension to be adjusted to each adjustable parameter of the lithography machine;

Step S5: Establish a total evaluation function based on the sensitivity matrix;

Step S6: According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions;

It can be understood that the lithography machine matching method in this embodiment obtains the sensitivity matrix by perturbing the input parameters. When matching the lithography machine, the calculation of the sensitivity matrix is used as the evaluation function to quickly and comprehensively obtain the lithography parameters to be adjusted. The matching parameters of the machine can be obtained to obtain a photolithography machine to be adjusted with performance equivalent to the target photolithography machine, thus solving the matching problem of multiple photolithography machines on the same production line.

It should be noted that the numbers of each step do not strictly limit their order.

Please combine Figure 1 and Figure 2. Step S1 specifically includes the following steps:

Step S11: Design and select a preset photolithography pattern. The preset photolithography pattern includes a one-dimensional photolithography pattern and/or a two-dimensional photolithography pattern.

It is understandable that the diversification of photolithography patterns is conducive to enhancing the reliability of the matching results of the photolithography machine matching method; and by marking the key positions of each preset photolithography pattern in advance, subsequent calculations can be facilitated.

Step S12: Mark the key positions of each preset lithography pattern, and record the key positions in the preset lithography pattern as Gj, j=1, 2,...X, and M is the number of the preset lithography patterns.

Please combine Figure 1 and Figure 3. Step S2 specifically includes the following steps:

Step S21: Adjust the lithography parameters for each preset lithography pattern on the target lithography machine in sequence, and generate a corresponding OPC model.

Further, adjusting the lithography parameters includes setting the lighting mode of the lithography machine, the numerical aperture of the projection objective lens, the pupil distribution of the lighting system, the exposure dose, the defocus rate, the mechanical vibration of the optical system of the lithography machine, and the Adjustable parameters on the lithography machine such as wavelength.

Step S22: Simulate each preset photolithography pattern, perform exposure on a photolithography machine, and obtain an SEM image of the photolithography pattern; the SEM image is a scanning electron microscope image.

Step S23: Extract the contour of each SEM image, and extract a total of N key dimensions to be adjusted at the target key position in the contour, recorded as Sij, i=1, 2,...M, j=1, 2,... X.

It can be understood that in the lithography machine matching method of this embodiment, the lithography parameters will be adjusted for each preset lithography pattern on the target lithography machine in turn, and the corresponding OPC model will be generated; through sufficient sample data, Ensure the reliability of the final result.

Please combine Figure 1 and Figure 4. Step S3 specifically includes the following steps:

Step S31: According to the parameters of the target lithography machine, adjust the parameters of the lithography machine to be adjusted so that the lithography OPC model of the lithography machine to be adjusted matches the lithography OPC model of the target lithography machine.

Specifically, the adjustable parameters such as the lighting mode of the lithography machine to be adjusted, the numerical aperture of the projection objective, the pupil distribution of the lighting system, the exposure dose, the defocus rate, the mechanical vibration of the optical system, and the wavelength are adjusted to the target lithography machine. consistent.

Step S32: Perform simulation through the lithography machine to be adjusted to obtain the corresponding simulation model, and obtain the key dimensions to be adjusted corresponding to the key positions in the preset lithography pattern from the simulation model.

It is understandable that by comparing the difference between the two lithography machines, some initial adjustable data can be clarified to prepare for the subsequent establishment of the sensitivity matrix.

Please combine Figure 1 and Figure 5. Step S4 specifically includes the following steps:

Step S41: Calculate the sensitivity of the target key size at the key position to a single parameter;

Specifically: adjust any adjustable parameter P of the lithography machine to be adjusted, use the target key size of the key position obtained by the target lithography machine as the standard, model and calculate the target key size of the key position, record the jth key The key dimension to be adjusted at position Gj is CDj, and CDj is for the adjustable parameter The sensitivity is: Corresponding to the parameters before matching, recorded as small changes;

It can be understood that small changes are achieved by adjusting the corresponding parameters of the lithography machine to be adjusted. For example, when the adjustable parameter P is the numerical aperture of the projection objective lens of the lithography machine, a small amount of change can be achieved by only making small adjustments to the numerical aperture of the projection objective lens of the lithography machine.

Step S42: Combine multiple adjustable parameters P1, P2...PN to obtain the sensitivity matrix

N is a positive integer.

It can be understood that the parameter before the adjustable parameter PN is matched can be expressed as PN0.

That is to say, step S4 is to obtain the sensitivity of the key dimension to be adjusted at each key position to the parameter by adjusting a single parameter of the lithography machine to be adjusted; and then to obtain the sensitivity of the key dimension to be adjusted at each key position to each parameter. to establish a sensitivity matrix;

Furthermore, as a small amount of change, it is obtained by fine-tuning the corresponding parameters in the lithography machine to be tested; and when fine-tuning the corresponding parameters, it is necessary to take the difference between the critical dimension to be adjusted and the target critical dimension as benchmark to achieve the effect of gradually reducing the error between the lithography machine to be tested and the target lithography machine.

Further, please combine Figure 1 and Figure 6. The sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted. It can be understood that in this embodiment, the sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted; in this way, all the data used to establish the sensitivity matrix can be simply obtained.

Please combine Figure 1 and Figure 6. Step S5 specifically includes the following steps:

Step S51: Establish an evaluation function for each adjustable parameter;

Specifically: according to the sensitivity matrix, adjust different parameters to obtain the change amount of the key dimension to be adjusted under the slight adjustment of different parameters, and superimpose these changes to obtain the cost value of each key dimension to be adjusted; cost is the adjusted The error is the change in the key dimension to be adjusted; the formula for cost is:

It is understandable that according to the sensitivity matrix, different parameters of the lithography machine to be adjusted can be adjusted to obtain the changes in the key dimensions to be adjusted under slight adjustments of different parameters, and by superimposing these changes (i.e. errors), the jth item can be obtained The cost value of the key dimension to be adjusted.

Step S52: Comprehensive evaluation function of each adjustable parameter to obtain the total evaluation function; the formula of the total evaluation function is: .

Further, the photolithography machine matching method also includes the following steps:

Step S7: According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted and simulate the preset lithography pattern, obtain the key dimensions to be measured from the simulation model, and determine whether the key dimensions to be measured match the key dimensions to be obtained. ;

If they match, the adjustment of the lithography machine to be adjusted ends;

If they do not match, the overall evaluation function is further optimized through the image error to obtain an optimized evaluation function, and the lithography machine to be adjusted is adjusted through the optimized evaluation function.

Further, step S7 specifically includes the following steps:

Step S71: Simulate the preset lithography pattern through the adjusted lithography machine to be adjusted;

Step S72: Compare the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target key dimension in the image obtained by the target lithography machine with a preset threshold;

If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target critical dimension in the image obtained by the target lithography machine is less than or equal to the threshold, then it is judged that the value of the lithography machine to be adjusted is different from that of the target key dimension in the image obtained by the target lithography machine. Target lithography machine matching;

If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target key dimension in the image obtained by the target lithography machine is greater than the threshold, it is judged that the two images do not match. Further optimization is needed to obtain the optimal evaluation function.

It should be noted that in this embodiment, the lithography machine to be adjusted obtains data from the simulation model, and what is used for comparison is the image of the lithography pattern obtained by the target lithography machine, and this image is an SEM image. picture.

It can be understood that in this embodiment, the matching degree of the lithography machine to be adjusted and the target lithography machine is judged by using the matching degree of the data in the simulation model and the data in the SEM image to ensure that the lithography machine can be adjusted intuitively and accurately. It not only reflects the matching degree of SEM images, but also effectively reduces the amount of calculation.

Further, further optimization refers to introducing a penalty function into the total evaluation function to obtain an optimized evaluation function. The penalty function is established by presetting additional key positions on each preset photolithography pattern and constructing a sensitivity matrix.

It is understandable that introducing additional key point groups for assistance will help further optimize the evaluation function and ensure the reliability of the final lithography machine matching result.

Specifically, in this embodiment, the threshold value is zero, and when the absolute value of the difference between the value of the critical dimension to be adjusted and the value of the target critical dimension in the image acquired by the target lithography machine is greater than zero, a penalty function is introduced.

Further, the data when establishing the penalty function is the data obtained from the SEM image obtained by the lithography machine to be adjusted.

It can be understood that adding the calculation error of SEM image contour extraction to the function can improve the matching accuracy of the lithography machine matching technology at non-critical measurement positions, and obtain the optical parameters of the lithography machine to be adjusted that are equivalent to the performance of the target lithography machine. .

Furthermore, the optimized evaluation function obtained after introducing the penalty function is as follows: . It's understandable, That is the penalty function; where, is the penalty factor, used for regulating exist proportion in.

It can be understood that this design is conducive to further improving the accuracy of the calculation results of the performance difference between the to-be-adjusted lithography machine and the target lithography machine using the lithography machine matching method.

Compared with the existing technology, the photolithography machine matching method of the present invention has the following advantages:

1. The photolithography machine matching method of the present invention includes the following steps:

Obtain the preset lithography pattern. Each preset lithography pattern is preset with X key positions, and Target key dimensions corresponding to Adjust the key dimensions and calculate the difference between the key dimensions to be adjusted and the target key dimensions; establish a sensitivity matrix based on the sensitivity of each key dimension to be adjusted to the adjustable parameters of each lithography machine; based on the sensitivity matrix, establish a total evaluation function based on the total evaluation Function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions. The sensitivity matrix is obtained by perturbing the input parameters. When matching the lithography machine, the calculation of the sensitivity matrix is used as the evaluation function to quickly and comprehensively obtain the matching parameters of the lithography machine to be adjusted, thereby obtaining performance equivalent to the target lithography machine. The photolithography machine to be adjusted solves the matching problem of multiple photolithography machines on the same production line.

2. In the present invention, the preset photolithography patterns selected by design include one-dimensional photolithography patterns and/or two-dimensional photolithography patterns. The diversity of samples is conducive to enhancing the reliability of the matching results of the photolithography machine matching method; and by advance Marking the key positions of each preset photolithography pattern can facilitate subsequent calculations.

3. In the present invention, the lithography parameters are adjusted for each preset lithography pattern on the target lithography machine in turn, and the corresponding OPC model is generated; sufficient sample data is used to ensure the reliability of the final result; and through The outline of the SEM image is used for comparison to improve the accuracy and comprehensiveness of the comparison.

4. In the present invention, a lithography OPC model matching the target lithography machine is generated on the lithography machine to be adjusted according to the lithography OPC model of the target lithography machine; the key points in the preset lithography pattern are obtained through the lithography machine to be adjusted. The key dimension to be adjusted corresponding to the position. By comparing the difference between the two lithography machines, some initial adjustable data can be clarified to prepare for the subsequent establishment of the sensitivity matrix.

5. In the present invention, the sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted; in this way, all the data used to establish the sensitivity matrix can be simply obtained.

6. In the sensitivity formula of the present invention, the rate of change when adjusting the adjustable parameter P is very small, which facilitates accurate control of changes in key dimensions to be adjusted at key positions. Combining multiple adjustable parameters P1, P2...PN to obtain the sensitivity matrix can make the matching between the target lithography machine and the lithography machine to be adjusted more comprehensive.

7. According to the sensitivity matrix of the present invention, different parameters are adjusted to obtain the change amount of the key dimension to be adjusted under the slight adjustment of different parameters, and these changes are superimposed to obtain the cost value of each key dimension to be adjusted; cost is the adjustment The final error is the change in the key dimension to be adjusted; the formula for cost is: ;Then the evaluation function of each adjustable parameter is combined to obtain the total evaluation function; the formula is: , using the total evaluation function to evaluate the lithography machine to be adjusted is beneficial to improving the matching between the target lithography machine and the lithography machine to be adjusted.

8. In the present invention, the matching results will be further verified. If they do not match, the total evaluation function will be further optimized through the image error to obtain an optimized evaluation function. The lithography machine to be adjusted will be adjusted through the optimized evaluation function, which will help ensure that the lithography machine to be adjusted will be adjusted. The reliability of the final matching result of the lithography machine.

9. In the present invention, the matching degree of the lithography machine to be adjusted and the target lithography machine is judged by the matching degree of the simulation data and the image data, and the value of the key dimension to be adjusted in the simulation data obtained by the lithography machine to be adjusted is The absolute value of the difference between the target critical dimension value in the image acquired by the target lithography machine can intuitively and accurately reflect the matching degree of the image; and it can effectively reduce the computational complexity.

10. In the present invention, additional key point groups are introduced for assistance, which facilitates further optimization of the evaluation function and ensures the reliability of the final lithography machine matching result; regulation is controlled by introducing a penalty function exist The ratio in is conducive to further improving the accuracy of the calculation results of the performance difference between the to-be-adjusted lithography machine and the target lithography machine using this lithography machine matching method.

The above is a detailed introduction to a lithography machine matching method disclosed in the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation modes of the present invention. The description of the above embodiments is only used to help understand the method of the present invention. and its core idea; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation and application scope according to the idea of the present invention. In summary, the content of this description should not be understood as a limitation of the present invention. Any modifications, equivalent substitutions and improvements made within the principles of the present invention shall be included in the protection scope of the present invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a flow chart of a photolithography machine matching method provided by the first embodiment of the present invention.

FIG. 2 is a flow chart of S1 of the photolithography machine matching method provided by the first embodiment of the present invention.

FIG. 3 is a flow chart of S2 of the photolithography machine matching method provided by the first embodiment of the present invention.

FIG. 4 is a flow chart of S3 of the photolithography machine matching method provided by the first embodiment of the present invention.

FIG. 5 is a flow chart of S4 of the lithography machine matching method provided by the first embodiment of the present invention.

FIG. 6 is a flow chart of S5 of the lithography machine matching method provided by the first embodiment of the present invention.

S1: Obtain the preset lithography pattern. Each preset lithography pattern has X key positions preset, and X is a positive integer.

S2: Obtain the target key dimensions corresponding to the X key positions of each preset lithography pattern based on the lithography OPC model on the target lithography machine.

S3: Use the target lithography machine as the standard to perform OPC model fitting on the lithography machine to be adjusted, obtain the key dimensions to be adjusted corresponding to X key positions in each preset lithography pattern on the lithography machine to be adjusted, and calculate the key dimensions to be adjusted. Difference between size and target key size

S4: Establish a sensitivity matrix based on the sensitivity of each key dimension to be adjusted to the adjustable parameters of each lithography machine

S5: Establish a total evaluation function based on the sensitivity matrix

S6: According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions.

Claims (10)

A photolithography machine matching method, used to match multiple photolithography machines on the same production line, is characterized by including the following steps: Obtain the preset lithography pattern. Each preset lithography pattern has X key positions preset, and X is a positive integer; Obtain the target key dimensions corresponding to the X key positions of each preset lithography pattern on the target lithography machine based on the lithography OPC model; Use the target lithography machine as the standard to perform OPC model fitting on the lithography machine to be adjusted, obtain the key dimensions to be adjusted corresponding to X key positions in each preset lithography pattern on the lithography machine to be adjusted, and calculate the key dimensions to be adjusted and Difference in target critical dimensions; Establish a sensitivity matrix based on the sensitivity of each critical dimension to be adjusted to the adjustable parameters of each lithography machine; According to the sensitivity matrix, establish the overall evaluation function; According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted to adjust the critical dimensions to be measured to match the target critical dimensions. The lithography machine matching method described in item 1 of the patent application scope is characterized in that the preset lithography pattern is obtained, and X key positions are preset in each preset lithography pattern, which specifically includes the following steps : Design and select a preset photolithography pattern, the preset photolithography pattern includes a one-dimensional photolithography pattern and/or a two-dimensional photolithography pattern; Mark the key positions of each preset lithography pattern, and record the key positions in the preset lithography pattern as Gj, j=1, 2,...X. The lithography machine matching method described in item 1 of the patent scope is characterized in that the target key dimensions corresponding to the X key positions of each preset lithography pattern are obtained on the target lithography machine according to the lithography OPC model. , specifically including the following steps: Adjust the lithography parameters for each preset lithography pattern on the target lithography machine in turn, and generate the corresponding OPC model; Simulate each preset photolithography pattern, expose it on the photolithography machine, and obtain the SEM image of the photolithography pattern; Extract the contour of each SEM image, and extract a total of N key dimensions to be adjusted at the key positions of the target in the contour, recorded as Sij, i=1, 2,...M, j=1, 2,...X, M It is the number of preset photolithography patterns. The lithography machine matching method described in item 1 of the patent application scope is characterized in that the lithography machine to be adjusted generates a lithography OPC that matches the target lithography machine based on the lithography OPC model of the target lithography machine. model to obtain the key dimensions to be adjusted corresponding to X key positions in each preset lithography pattern on the lithography machine to be adjusted, including the following steps: According to the parameters of the target lithography machine, adjust the parameters of the lithography machine to be adjusted so that the lithography OPC model of the lithography machine to be adjusted matches the lithography OPC model of the target lithography machine; Simulate the lithography machine to be adjusted to obtain the corresponding simulation model, and obtain the key dimensions to be adjusted corresponding to the key positions in the preset lithography pattern from the simulation model. The lithography machine matching method described in item 1 of the patent application scope is characterized in that: the sensitivity matrix of the lithography machine to be adjusted is obtained by perturbing the input parameters of the lithography machine to be adjusted. The lithography machine matching method described in item 5 of the patent application scope is characterized in that said perturbing the input parameters of the lithography machine to be adjusted to obtain a sensitivity matrix specifically includes the following steps: Matching any of the lithography machines to be adjusted An adjustable parameter P is used to adjust, and the target critical size of the key position obtained by the target lithography machine is used as the standard. The target critical size of the key position is modeled and calculated. The key size to be adjusted at the jth key position Gj is recorded as CDj , the sensitivity of CDj to the adjustable parameter P is: Corresponding to the parameters before matching, recorded as small changes; by integrating multiple adjustable parameters P ₁ , P ₂ ...P _N , the sensitivity matrix is obtained, , N is a positive integer. The lithography machine matching method described in item 1 of the patent application scope is characterized by establishing a total evaluation function according to the sensitivity matrix, which specifically includes the following steps: adjusting different parameters according to the sensitivity matrix to obtain the key dimensions to be adjusted in different parameters The amount of change under small adjustments, and these changes are superimposed to obtain the cost value of each key dimension to be adjusted; cost is the error after adjustment, which is the change amount of the key dimension to be adjusted; the formula of cost is: ; Combine the evaluation function of each adjustable parameter to obtain the total evaluation function; the formula is: . The photolithography machine matching method described in item 1 of the patent application is characterized in that the photolithography machine matching method further includes the following steps: According to the total evaluation function, adjust the parameters of the lithography machine to be adjusted and simulate the preset lithography pattern, obtain the key dimensions to be measured from the simulation model, and determine whether the obtained key dimensions to be measured match the obtained target key dimensions; If they match, the adjustment of the lithography machine to be adjusted ends; If they do not match, the overall evaluation function is further optimized through the image error to obtain an optimized evaluation function, and the lithography machine to be adjusted is adjusted through the optimized evaluation function. The lithography machine matching method described in item 1 of the patent application scope is characterized in that according to the total evaluation function, the parameters of the lithography machine to be adjusted are adjusted and the simulation of the preset lithography pattern is performed, which is obtained from the simulation model. The key size to be measured is used to determine whether the obtained key size to be measured matches the obtained target key size; if they match, the adjustment of the lithography machine to be adjusted is ended; if they do not match, the total evaluation function is further optimized through the image error to obtain Optimize the evaluation function and adjust the lithography machine to be adjusted by optimizing the evaluation function, which specifically includes the following steps: Simulate the preset photolithography pattern through the adjusted photolithography machine; Compare the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model acquired by the lithography machine to be adjusted and the value of the target critical dimension in the image acquired by the target lithography machine with a preset threshold; If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target critical dimension in the image obtained by the target lithography machine is less than or equal to the threshold, then it is judged that the value of the lithography machine to be adjusted is different from that of the target key dimension in the image obtained by the target lithography machine. Target lithography machine matching; If the absolute value of the difference between the value of the key dimension to be adjusted in the simulation model obtained by the lithography machine to be adjusted and the value of the target key dimension in the image obtained by the target lithography machine is greater than the threshold, it is judged that the two images do not match. Further optimization is needed to obtain the optimal evaluation function. The lithography machine matching method described in item 1 of the patent application scope is characterized in that it also includes the following steps: The further optimization refers to introducing a penalty function into the total evaluation function to obtain an optimized evaluation function, and the penalty function is passed in each Preset additional key positions on a preset photolithography pattern, and construct a sensitivity matrix to establish the acquisition; the optimized evaluation function obtained after introducing the penalty function is as follows ; is the penalty factor, used for regulating exist proportion in.