Lithography method, device, equipment and storage medium of a photomask

Abstract

The present application discloses a photolithography method, apparatus, device and storage medium for a mask, relating to the technical field of mask manufacturing. The disclosed photolithography method for a mask includes: obtaining an exposure pattern of the mask; inputting the exposure pattern into a position deviation correction model to obtain position correction data of the mask after being corrected by the position deviation model, where the position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient; correcting initial motion data of a lithography machine for lithographing the mask based on the position correction data to obtain corrected motion data of the lithography machine, and controlling the lithography machine to lithograph the mask based on the corrected motion data. That is, the position deviation correction model is used to accurately output position correction data for each graphic area on the mask, so as to improve the effect of correcting the position accuracy deviation of the mask through the position correction data.

Description

Technical Field

[0001] This application relates to the technical field of photomask manufacturing, and particularly to a lithography method, device, equipment and storage medium for photomasks. Background Art

[0002] Photomask: A photomask, also known as a reticle, photomask, lithography mask, mask plate, etc., is an essential core component in integrated circuit manufacturing. The quality of the photomask directly determines the accuracy and performance of the integrated circuit.

[0003] During the lithography process of medium and high-end photomasks, the thermal effect caused by high-energy electron beams bombarding the photoresist will cause local position accuracy deviation. Especially in high-load areas, currently, the position accuracy deviation is reduced by improving the environmental temperature control accuracy, increasing the thermal conductivity coefficient, adjusting the exposure process or method to reduce the thermal effect. However, it may be restricted by physical limitations, cost, and technical feasibility, resulting in low effectiveness in reducing the position accuracy deviation.

[0004] The above content is only used to assist in understanding the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of this application is to provide a lithography method for photomasks, aiming to solve the technical problem that the current methods for reducing position accuracy deviation are restricted by physical limitations, cost, and technical feasibility, resulting in low effectiveness in reducing the position accuracy deviation.

[0006] To achieve the above purpose, this application proposes a lithography method for photomasks, and the method includes:

[0007] Obtain the exposure pattern of the photomask;

[0008] Input the exposure pattern into a position deviation correction model to obtain the position correction data of the photomask after being corrected by the position deviation model. The position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient;

[0009] Based on the position correction data, correct the initial motion data of the lithography machine for lithographing the photomask to obtain the corrected motion data of the lithography machine, and control the lithography machine to lithograph the photomask based on the corrected motion data.

[0010] In an embodiment, before the step of obtaining the exposure pattern of the photomask, it includes:

[0011] Obtain the actual position deviation of each sample measurement target on the sample photomask and the theoretical position deviation obtained based on a pre-set thermal expansion algorithm;

[0012] Based on the actual position deviation and the theoretical position deviation, determine the loading rate correction coefficient and the position correction coefficient of the sample mask;

[0013] Based on the loading rate correction coefficient and the position correction coefficient, correct the thermal diffusion algorithm to obtain a thermal diffusion correction algorithm;

[0014] Build a position deviation correction model according to the thermal diffusion correction algorithm and the thermal expansion algorithm.

[0015] In one embodiment, the step of determining the loading rate correction coefficient and the position correction coefficient of the sample mask based on the actual position deviation and the theoretical position deviation includes:

[0016] Convert the deviation value between the actual position deviation and the theoretical position deviation into a heat deviation;

[0017] Based on the heat deviation, determine the loading rate correction coefficient during the lithography of the sample mask;

[0018] Under the condition that the loading rate is determined, modify the position difference between the auxiliary pattern and the measurement target marked on the sample mask, obtain the actual position deviation of each modification, and obtain the corresponding theoretical position deviation;

[0019] Based on the actual position deviation of each modification and the corresponding theoretical position deviation, determine the position correction coefficient corresponding to each loading rate.

[0020] In one embodiment, the step of obtaining the actual position deviation of each sample measurement target on the sample mask includes:

[0021] Obtain the initial position accuracy when exposing the sample measurement target and the blank auxiliary pattern on the sample mask, and obtain the deviation position accuracy between the sample measurement target and the sample auxiliary pattern carrying the loading rate;

[0022] Subtract the deviation position accuracy from the initial position accuracy to obtain the actual position deviation of each sample measurement target.

[0023] In one embodiment, the step of inputting the exposed pattern into the position deviation correction model to obtain the position correction data after the mask is corrected by the position deviation model includes:

[0024] Input the exposed pattern into the position deviation correction model, and based on the thermal diffusion correction algorithm in the position deviation correction model, determine the temperature fluctuation map of each graphic area on the mask;

[0025] Based on the thermal expansion algorithm in the position deviation correction model, convert the temperature fluctuation degree into a position deviation map, so that the position deviation model outputs the position correction data of the mask based on the position deviation map.

[0026] In one embodiment, the step of inputting the exposure pattern into the position deviation correction model and determining the temperature fluctuation map of each pattern area on the mask based on the thermal diffusion correction algorithm in the position deviation correction model includes:

[0027] Input the exposure pattern into the position deviation correction model and identify the pattern structure of each pattern area in the exposure pattern;

[0028] Based on the thermal diffusion correction algorithm corresponding to the pattern structure, determine the temperature fluctuation of each pattern area;

[0029] According to the temperature fluctuations, determine the temperature fluctuation map of each pattern area on the mask.

[0030] In addition, to achieve the above object, the present application also proposes a lithography apparatus for a mask, and the lithography apparatus for the mask includes:

[0031] An acquisition module for acquiring the exposure pattern of the mask;

[0032] A data determination module for inputting the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model, and the position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient;

[0033] A correction module for correcting the initial motion data of the lithography machine for lithographing the mask based on the position correction data to obtain the corrected motion data of the lithography machine, and controlling the lithography machine to lithograph the mask based on the corrected motion data.

[0034] In addition, to achieve the above object, the present application also proposes a lithography device for a mask, and the device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the lithography method for the mask as described above.

[0035] In addition, to achieve the above object, the present application also proposes a storage medium, the storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by a processor, the steps of the lithography method for the mask as described above are implemented.

[0036] In addition, to achieve the above object, the present application further provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the photolithography method of the mask as described above.

[0037] One or more technical solutions proposed in the present application have at least the following technical effects:

[0038] In the present application, the exposure pattern of the mask before photolithography can be used to determine the position accuracy deviation of each area according to the graphic structure of the load condition (load rate) of each local area of the mask. Since the temperature of the mask is affected by various factors during the photolithography process, in order to make the thermal diffusion algorithm more in line with the actual situation, therefore, the exposure pattern is input into the position deviation correction model built after repairing the thermal diffusion algorithm with the load rate correction coefficient and the position correction coefficient to determine the influence of the thermal effect generated by the graphic structure on the position accuracy, and obtain the position correction data that needs to be corrected. Furthermore, the position deviation correction model can output the position correction data of each graphic structure on the mask more accurately, and then correct the initial motion data set at the beginning of the lithography machine through the position correction data to obtain the corrected motion data of the lithography machine. When using the corrected motion data to control the lithography machine to lithograph the mask, the effect of correcting the position accuracy deviation of the mask can be improved. Description of the Drawings

[0039] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0040] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic flowchart provided for the first embodiment of the photolithography method of the mask of the present application;

[0042] Figure 2 It is a schematic flowchart provided for the second embodiment of the photolithography method of the mask of the present application;

[0043] Figure 3 It is a schematic diagram showing the initial position exposure pattern provided for the second embodiment of the present application;

[0044] Figure 4 It is a schematic flowchart provided for the third embodiment of the photolithography method of the mask of the present application;

[0045] Figure 5 It is a schematic diagram of the position deviation correction vector provided for the third embodiment of the present application;

[0046] Figure 6 Schematic diagram of the module structure of a lithography apparatus for a mask in an embodiment of the present application;

[0047] Figure 7 Schematic diagram of the device structure of the hardware operating environment involved in the lithography method of the mask in an embodiment of the present application.

[0048] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0049] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0050] In order to better understand the technical solutions of the present application, the following will be described in detail with reference to the accompanying drawings of the specification and specific implementation manners.

[0051] The main solution of the embodiment of the present application is: the lithography control platform obtains the exposure pattern of the mask; inputs the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model, and the position deviation correction model is built based on the thermal diffusion algorithm corrected by the load rate correction coefficient and the position correction coefficient; corrects the initial motion data of the lithography machine for lithographing the mask based on the position correction data to obtain the corrected motion data of the lithography machine, and controls the lithography machine to lithograph the mask based on the corrected motion data.

[0052] In this embodiment, for the convenience of description, the following will be described with the lithography control platform as the execution subject.

[0053] Since in the prior art, during the lithography process of mid- to high-end masks, the thermal effect caused by the bombardment of the photoresist by high-energy electron beams will cause local position accuracy deviation. Especially in the high load rate area, currently, by improving the environmental temperature control accuracy, increasing the thermal conductivity coefficient, adjusting the exposure process or method to reduce the thermal effect, so as to reduce the position accuracy deviation. However, it may be restricted by physical limitations, cost and technical feasibility, resulting in a low effect of reducing the position accuracy deviation.

[0054] The present application provides a solution. Through the exposure pattern of the mask before lithography, the position accuracy deviation of each region can be determined according to the graphic structure of the load condition (load rate) included in each local region of the mask. Since the temperature of the mask is affected by various factors during the lithography process, in order to make the thermal diffusion algorithm more in line with the actual situation, therefore, the exposure pattern is input into the position deviation correction model built after repairing the thermal diffusion algorithm by the load rate correction coefficient and the position correction coefficient to determine the influence of the thermal effect generated by the graphic structure on the position accuracy, and obtain the position correction data that needs to be corrected. Furthermore, the position deviation correction model can more accurately output the position correction data of each graphic structure on the mask, and then correct the initial motion data set at the beginning of the lithography machine through the position correction data to obtain the corrected motion data of the lithography machine. When using the corrected motion data to control the lithography of the mask by the lithography machine, the effect of correcting the position accuracy deviation of the mask is improved.

[0055] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication, and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, a lithography control platform, etc. that can implement the above functions. Hereinafter, taking the lithography control platform as an example, this embodiment and the following embodiments will be described.

[0056] Based on this, the embodiment of the present application provides a lithography method for a mask, referring to Figure 1 , Figure 1 which is a schematic flowchart of the first embodiment of the lithography method for the mask of the present application.

[0057] In this embodiment, the lithography method for the mask includes steps S10 to S40:

[0058] Step S10, obtain the exposure pattern of the mask;

[0059] It should be noted that the exposure pattern can be that the light emitted by the illumination source passes through the converging lens and irradiates on the mask, and the diffracted light beams are generated through the mask. These diffracted light beams carry the graphic information on the mask, and the light beams are focused on the wafer surface through the projection lens to form an image of the mask pattern on the wafer surface.

[0060] It can be understood that since the exposure pattern includes a graphic area carrying the load rate, where the load rate can be the proportion of the graphic area in a certain area to the total area, therefore, the position deviation of the mask can be accurately determined through the graphic area in the exposure pattern.

[0061] Step S20: Input the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model. The position deviation correction model is built based on the thermal diffusion algorithm corrected by the load rate correction coefficient and the position correction coefficient.

[0062] It should be noted that the position deviation correction model can be a model for determining the position accuracy deviation on the mask caused by temperature changes. In order to accurately reflect the relationship between heat and position, therefore, the thermal diffusion algorithm is included in the position deviation correction model. The position correction data can be the position deviation of each graphic area in the exposure pattern affected by heat. The load rate correction coefficient can be the coefficient required to repair the load rate. The position correction coefficient can be the correction coefficient for the position deviation corresponding to the corrected load rate.

[0063] Among them, since the position deviation of each graphic area may be different, therefore, when the position deviation correction model corrects the position deviation of the graphic areas in the exposure pattern, it is necessary to determine the corresponding position correction coefficient according to the graphic area, and correct the thermal diffusion algorithm through the load rate correction coefficient and the position correction coefficient corresponding to the graphic area.

[0064] It can be understood that since the position deviation correction model is built based on the thermal diffusion algorithm corrected by the load rate correction coefficient and the position correction coefficient, the relationship between temperature and position can be determined through the thermal diffusion algorithm. Since there are various factors in the lithography process of the mask that affect the load rate and the formation of the exposure pattern, therefore, the thermal diffusion algorithm is corrected by the load rate correction coefficient and the position correction coefficient to make the corrected thermal diffusion algorithm more in line with the actual situation, so as to improve the accuracy of position deviation repair.

[0065] Step S30: Correct the initial motion data of the lithography machine for lithographing the mask based on the position correction data to obtain the corrected motion data of the lithography machine, and control the lithography machine to lithograph the mask based on the corrected motion data.

[0066] It should be noted that the initial motion data can be the motion data of the lithography machine set by the user for lithographing the mask, or the uncorrected motion data formed according to the graphic areas in the diffraction exposure pattern of the mask, etc. The corrected motion data can be the motion data of the lithography machine corresponding to each graphic area after correcting the position accuracy deviation of the graphic areas in the exposure pattern.

[0067] It can be understood that since the lithography machine performs lithography on the mask, it is necessary to determine the movement trajectory of the lithography machine, that is, the initial movement trajectory. And since the movement trajectory of the lithography machine corresponds to the position of the graphic area, after correcting the position accuracy deviation of the graphic area, the correction data for the position accuracy deviation of the graphic area is also applicable to the correction of the movement trajectory of the lithography machine. Therefore, according to the position correction data, the initial movement data of the lithography machine is corrected to obtain the corrected movement data of the lithography machine, so that the lithography machine can correct the movement accuracy according to the local high temperature of the mask, so as to improve the effect of correcting the position accuracy deviation of the mask.

[0068] This embodiment provides a lithography method for a mask. Through the exposure pattern of the mask before lithography, the position accuracy deviation of each area can be determined according to the graphic structure of each graphic area of the mask. Since the temperature of the mask is affected by various factors during the lithography process, in order to make the thermal diffusion algorithm more in line with the actual situation, therefore, the exposure pattern is input into the position deviation correction model built after repairing the thermal diffusion algorithm by the load rate correction coefficient and the position correction coefficient to determine the influence of the thermal effect generated by the graphic structure on the position accuracy, and obtain the position correction data that needs to be corrected. Furthermore, the position deviation correction model can output the position correction data of each graphic structure on the mask more accurately. Then, the initial movement data set at the beginning of the lithography machine is corrected by the position correction data to obtain the corrected movement data of the lithography machine. When using the corrected movement data to control the lithography machine to lithograph the mask, the effect of correcting the position accuracy deviation of the mask is improved.

[0069] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar content as the above-mentioned embodiment 1 can be referred to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 2 , before step S10, the lithography method of the mask further includes steps S01 to S04:

[0070] Step S01, obtain the actual position deviation of each sample measurement target on the sample mask and the theoretical position deviation obtained based on the pre-set thermal expansion algorithm;

[0071] It should be noted that the measurement target can be the point on the mask that needs to be measured for the position change caused by the temperature change. The actual position deviation can be the position accuracy deviation of the measurement target caused by the high-temperature part of the mask, and the position accuracy deviation obtained through actual measurement. The thermal expansion algorithm can be an algorithm used to calculate the expansion or contraction amount of materials under temperature changes. The theoretical position deviation can be the ideal position deviation calculated according to the parameters required by the thermal expansion algorithm, and this theoretical position deviation ignores the influence of actual factors. Among them, the position accuracy can be the difference between the position coordinates of the exposure pattern made on the mask and the design coordinates, indicating the accuracy of the mask graphic position, and the smaller the difference, the better.

[0072] It is understandable that since the position deviation directly calculated according to the thermal expansion algorithm may not conform to the actual situation, thus generating an error from the actual position deviation. Therefore, the actual position deviation measured by the position measuring instrument can be obtained, and the theoretical position deviation calculated according to the thermal expansion algorithm, so as to facilitate correcting the thermal expansion algorithm with the actual position deviation to make the thermal expansion algorithm more in line with the actual situation.

[0073] Step S02: Based on the actual position deviation and the theoretical position deviation, determine the load rate correction coefficient and the position correction coefficient of the sample mask;

[0074] It is understandable that since there are various uncontrollable factors affecting the theoretical heat during actual lithography mask making, thus affecting the position deviation measured for the mask. Therefore, it is necessary to determine the load rate correction coefficient and the position correction coefficient of the sample mask according to the difference between the actual position deviation and the theoretical position deviation, so that the corrected thermal expansion algorithm can reduce the influence of the lithography environment and obtain a position deviation closer to the actual situation.

[0075] Step S03: Based on the load rate correction coefficient and the position correction coefficient, correct the thermal diffusion algorithm to obtain the thermal diffusion correction algorithm;

[0076] Step S04: Build a position deviation correction model according to the thermal diffusion correction algorithm and the thermal expansion algorithm.

[0077] It is understandable that building a position deviation correction model using the thermal diffusion algorithm and the thermal expansion algorithm can correct the influence of heat on the position deviation after the mask is deformed. Therefore, the position deviation of the mask affected by temperature can be corrected more accurately according to the position correction model built using the thermal diffusion correction algorithm and the thermal expansion algorithm.

[0078] Furthermore, step S02 may further include:

[0079] Convert the deviation value between the actual position deviation and the theoretical position deviation into a heat deviation;

[0080] Based on the heat deviation, determine the load rate correction coefficient during lithography of the sample mask;

[0081] Under the condition that the load rate is determined, modify the position difference between the auxiliary pattern and the measurement target marked on the sample mask, obtain the modified actual position deviation, and obtain the corresponding theoretical position deviation;

[0082] Based on the modified actual position deviation and the corresponding theoretical position deviation, determine the position correction coefficient corresponding to each load rate.

[0083] It should be noted that the deviation value can be the difference between the actual position deviation and the theoretical position deviation.

[0084] It can be understood that when lithography is performed on a mask, the high-energy beam hitting the photoresist causes a thermal effect, resulting in a local position accuracy deviation. That is, after the exposed pattern is affected by high temperature, the substrate of the mask will undergo thermal expansion, causing a precision deviation in the position of the circuit diagram on the mask. In order to avoid repeated correction of the thermal diffusion algorithm, therefore, the load rate related to temperature can be determined first to correct the error coefficient between the actual temperature and the theoretical temperature at the time of design. That is, the load rate correction coefficient. By determining the load rate correction coefficient of the mask first, the range of position deviation correction can be determined, thereby improving the efficiency of position accuracy correction during mask lithography.

[0085] In a specific implementation, the thermal diffusion equation can be: Q = (K)(T1 - T2) / r. The specific correction of the thermal diffusion equation can be: subtract the measured theoretical position deviation value from the actual position deviation value to determine the error between the theory and the actual. Then, convert the deviation value into heat through the thermal expansion coefficient of the mask substrate, thereby obtaining the Q correction coefficient A under this condition. That is, obtaining the preliminary thermal diffusion algorithm: AQ = (K)(T1 - T2) / r. And by changing different load rates, determine the load rate correction coefficient corresponding to the load rate. Then, according to the thermal expansion coefficient, determine the change range of the position accuracy corresponding to each load rate, and after determining the load rate, by changing the distance between the measurement target and the auxiliary pattern, determine the position deviation correction coefficient B corresponding to different positions for each load rate, and obtain the final thermal diffusion correction algorithm: AQ = B(K)(T1 - T2) / r. Where Q is heat, K is thermal conductivity, T1 and T2 are the temperatures at the starting point and the ending point, and r is the distance between the two points. Among them, the starting point is the midpoint of the measurement target or the midpoint of the auxiliary image, and the ending point is the midpoint of the auxiliary pattern or the midpoint of the measurement target.

[0086] Furthermore, step S01 further includes:

[0087] Obtain the initial position accuracy when exposing the sample measurement target and the blank auxiliary pattern on the sample mask, and obtain the deviation position accuracy between the sample measurement target and the sample auxiliary pattern carrying the load rate;

[0088] Subtract the initial position accuracy from the deviation position accuracy to obtain the actual position deviation of each sample measurement target.

[0089] It should be noted that the blank auxiliary pattern can be an auxiliary pattern having a certain distance from the measurement target in a certain direction. Refer to Figure 3, the blank auxiliary pattern represents an auxiliary pattern without a load rate, that is, the temperature within the auxiliary pattern range is similar to the temperature at the measurement mark, and no local expansion of the reticle occurs. The sample auxiliary pattern can be an auxiliary pattern with a certain load rate, where the direction of the arrow represents the correction direction of the position deviation, and the length of the line segment represents the correction amount of the position offset.

[0090] It can be understood that since the temperature of each graphic area on the reticle may be different, in order to determine the influence of temperature on the position accuracy of the measurement mark, therefore, when building the position deviation correction model, it is necessary to first expose the exposure pattern of the measurement mark and the blank auxiliary pattern to determine the position accuracy when the reticle is not affected by high temperature according to this exposure pattern, and then expose the measurement mark and the sample auxiliary pattern with a load rate to determine the position accuracy when the reticle is affected by temperature according to this exposure pattern. According to the position accuracy difference between the two, determine the actual position deviation of each sample measurement mark to determine the actual position offset amount after the reticle is affected by temperature.

[0091] Based on the first and second embodiments of the present application, in the third embodiment of the present application, the same or similar content as the above embodiments can be referred to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 4 , step S20 further includes steps S1 to S2:

[0092] Step S1, input the exposure pattern into the position deviation correction model, and based on the heat diffusion correction algorithm in the position deviation correction model, determine the temperature fluctuation map of each graphic area on the reticle;

[0093] Step S2, based on the thermal expansion algorithm in the position deviation correction model, convert the temperature fluctuation degree into a position deviation map, so that the position deviation model outputs the position correction data of the reticle based on the position deviation map.

[0094] It should be noted that the temperature fluctuation map can be a graph representing the temperature fluctuation of each graphic area on the reticle. The position deviation map can be a vector map representing each auxiliary pattern caused by temperature (refer to Figure 5 ).

[0095] It can be understood that using the heat diffusion correction algorithm in the position deviation correction model to determine the temperature fluctuation of each graphic area on the reticle, since the heat diffusion correction algorithm in the position offset correction model is an algorithm that has been corrected for load rate and position accuracy, it can be more in line with the actual situation. Therefore, using the heat diffusion correction algorithm in the position deviation correction model to accurately determine the temperature fluctuation map of each graphic area to improve the reference accuracy for subsequent correction of the motion data of the lithography machine, thereby improving the efficiency of correcting the position accuracy deviation of the reticle.

[0096] It can be understood that after obtaining the temperature fluctuation map, the local temperature situation of the reticle can be obtained. In order to convert the temperature fluctuation into a position deviation, therefore, through the thermal expansion algorithm in the position deviation correction model, according to the thermal expansion coefficient of the reticle substrate, the temperature fluctuation map is converted into a position deviation map to determine the degree to which the position accuracy of each graphic area is affected by temperature.

[0097] It should be noted that the reticle substrate can be quartz glass, because it has advantages such as high transmittance, high flatness, and low expansion coefficient, and is usually used to produce high-precision reticle products. The thermal expansion coefficient can be a physical quantity that describes the dimensional change of a substance under temperature change, including the linear expansion coefficient α, that is, the expansion coefficient of quartz glass in the transverse direction.

[0098] In a specific implementation, according to the thermal expansion coefficient of the substrate, the temperature fluctuation value is converted into a position deviation value. Taking the quartz substrate as an example, the linear expansion coefficient of quartz is 0.53×10 -6 / ℃, that is, when the temperature rises by 1℃, a 100mm quartz glass will expand by 53nm.

[0099] α = ΔL / (L*ΔT);

[0100]

[0101] Among them, α represents the linear expansion coefficient of the glass, ΔL represents the change value of the glass substrate, L represents the value of the original length, and ΔT represents the temperature change. represents the offset compensation amount of the quartz glass in the x direction. represents the offset compensation amount of the quartz glass in the y direction, θ represents the direction of the position offset, x represents the position offset amount of the quartz glass in the x direction, and y represents the position offset amount of the quartz glass in the y direction.

[0102] Furthermore, step S1 further includes:

[0103] Input the exposure pattern into the position deviation correction model to identify the graphic structure of each graphic area in the exposure pattern;

[0104] Based on the thermal diffusion correction algorithm corresponding to the graphic structure, determine the temperature fluctuation of each graphic area;

[0105] According to each temperature fluctuation, determine the temperature fluctuation map of each graphic area on the reticle.

[0106] It can be understood that since the loading rate represents the loading amount of the reticle in the graphic area, different loading amounts correspond to different amounts of heat. In order to accurately determine the temperature of each graphic area, therefore, using the thermal diffusion correction algorithm can more accurately determine the temperature fluctuation of each graphic area.

[0107] In a specific implementation, participate in Figure 5 , combined with the actual exposure pattern, to form a temperature fluctuation MAP graph caused by the internal heat effect across the entire plate. According to the thermal expansion coefficient of the glass substrate, convert the temperature difference into the linear expansion amount of the glass substrate, so as to obtain the position deviation across the entire plate caused by the thermal effect (such as Figure 5 ), and then correct the position deviation to the position accuracy MAP of the lithography machine.

[0108] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the lithography method of the mask template of this application. Based on this technical concept, more forms of simple transformations are within the protection scope of this application.

[0109] This application also provides a lithography device for a mask template. Please refer to Figure 6 , the lithography device for the mask template includes:

[0110] An acquisition module 10, configured to acquire the exposure pattern of the mask template;

[0111] A data determination module 20, configured to input the exposure pattern into a position deviation correction model to obtain position correction data of the mask template after being corrected by the position deviation model. The position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient;

[0112] A correction module 30, configured to correct the initial motion data of the lithography machine for lithographing the mask template based on the position correction data to obtain the corrected motion data of the lithography machine, and control the lithography machine to lithograph the mask template based on the corrected motion data.

[0113] Optionally, the data determination module 20 is further configured to acquire the actual position deviation of each sample measurement target on the sample mask template and the theoretical position deviation obtained based on a preset thermal expansion algorithm; based on the actual position deviation and the theoretical position deviation, determine the load rate correction coefficient and the position correction coefficient of the sample mask template; based on the load rate correction coefficient and the position correction coefficient, correct the thermal diffusion algorithm to obtain a thermal diffusion correction algorithm; build a position deviation correction model according to the thermal diffusion correction algorithm and the thermal expansion algorithm.

[0114] Optionally, the data determination module 20 is further configured to convert the deviation value between the actual position deviation and the theoretical position deviation into a heat deviation; based on the heat deviation, determine the load rate correction coefficient during lithography of the sample mask template; when the load rate is determined, modify the position difference between the auxiliary pattern and the measurement target marked on the sample mask template to obtain the modified actual position deviation of each, and acquire the corresponding theoretical position deviation; based on the modified actual position deviation of each and the corresponding theoretical position deviation, determine the position correction coefficient corresponding to each load rate.

[0115] Optionally, the data determination module 20 is further configured to obtain the initial position accuracy when the sample measurement marks and the blank auxiliary patterns are exposed on the sample mask, and obtain the deviation position accuracy between the sample measurement marks and the sample auxiliary patterns with a carrying load rate; subtract the deviation position accuracy from the initial position accuracy to obtain the actual position deviation of each sample measurement mark.

[0116] Optionally, the data determination module 20 is further configured to input the exposure pattern into a position deviation correction model, and based on the thermal diffusion correction algorithm in the position deviation correction model, determine the temperature fluctuation map of each graphic area on the mask; based on the thermal expansion algorithm in the position deviation correction model, convert the temperature fluctuation degree into a position deviation map, so that the position deviation model outputs the position correction data of the mask based on the position deviation map.

[0117] Optionally, the data determination module 20 is further configured to input the exposure pattern into a position deviation correction model, identify the graphic structure of each graphic area in the exposure pattern; based on the thermal diffusion correction algorithm corresponding to the graphic structure, determine the temperature fluctuation of each graphic area; and determine the temperature fluctuation map of each graphic area on the mask according to each temperature fluctuation.

[0118] The lithography apparatus for a mask provided in this application adopts the lithography method for a mask in the above embodiment, and can solve the technical problem that the current method for reducing the position accuracy deviation is restricted by physical limitations, cost, and technical feasibility, resulting in a low effect of reducing the position accuracy deviation. Compared with the prior art, the beneficial effects of the lithography apparatus for a mask provided in this application are the same as those of the lithography method for a mask provided in the above embodiment, and other technical features in the lithography apparatus for a mask are the same as those disclosed in the method of the above embodiment, and will not be elaborated here.

[0119] This application provides a lithography device for a mask. The lithography device for a mask includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the lithography method for a mask in the first embodiment above.

[0120] Next, refer to Figure 7, which shows a schematic structural diagram of a lithography apparatus suitable for implementing a mask according to an embodiment of the present application. The lithography apparatus for the mask in the embodiments of the present application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistant), PADs (Portable Application Description), PMPs (Portable Media Player), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 7 The shown lithography apparatus for the mask is merely an example and should not impose any limitation on the functions and usage scope of the embodiments of the present application.

[0121] As Figure 7 shown, the lithography apparatus for the mask may include a processing device 1001 (such as a central processing unit, a graphics processing unit, etc.), which may perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM: Random Access Memory) 1004. In the RAM 1004, various programs and data required for the operation of the lithography apparatus for the mask are also stored. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems may be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 may allow the lithography apparatus for the mask to communicate with other devices wirelessly or wiredly to exchange data. Although the figure shows a lithography apparatus for the mask having various systems, it should be understood that it is not required to implement or have all the shown systems. More or fewer systems may be alternatively implemented or had.

[0122] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product that includes a computer program carried on a computer-readable medium, and the computer program includes program code for performing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by a processing device 1001, the above functions defined in the methods of the embodiments disclosed in the present application are performed.

[0123] The lithography apparatus for a mask provided by the present application adopts the lithography method for a mask in the above embodiments, and can solve the technical problem that the current methods for reducing the position accuracy deviation are restricted by physical limitations, cost, and technical feasibility, resulting in low effectiveness in reducing the position accuracy deviation. Compared with the prior art, the beneficial effects of the lithography apparatus for a mask provided by the present application are the same as those of the lithography method for a mask provided by the above embodiments, and other technical features in the lithography apparatus for a mask are the same as the features disclosed in the method of the previous embodiment, and will not be elaborated herein.

[0124] It should be understood that the various parts disclosed in the present application can be implemented by hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0125] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and all of them should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

[0126] The present application provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to perform the lithography method for a mask in the above embodiments.

[0127] The computer-readable storage medium provided by the present application can be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, device, or component. The program code contained on the computer-readable storage medium can be transmitted by any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0128] The above computer-readable storage medium can be included in a lithography apparatus of a mask; or can exist separately and not be assembled into the lithography apparatus of the mask.

[0129] The above computer-readable storage medium carries one or more programs. When the one or more programs are executed by the lithography apparatus of the mask, the lithography apparatus of the mask is caused to: obtain the exposure pattern of the mask; input the exposure pattern into a position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model, where the position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient; correct the initial motion data of the lithography machine for lithographing the mask based on the position correction data to obtain the corrected motion data of the lithography machine, and control the lithography machine to lithograph the mask based on the corrected motion data.

[0130] Computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The above-mentioned programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN: Local Area Network) or a wide area network (WAN: Wide Area Network), or it can be connected to an external computer (for example, by connecting through the Internet using an Internet service provider).

[0131] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and this module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order from that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0132] The modules described in the embodiments of this application can be implemented in software or in hardware. Among them, the name of the module does not constitute a limitation on the unit itself in some cases.

[0133] The readable storage medium provided by this application is a computer-readable storage medium. The computer-readable storage medium stores computer-readable program instructions (i.e., computer programs) for performing the above-mentioned photolithography method of the mask, which can solve the technical problem that the current method for reducing the position accuracy deviation is restricted by physical limitations, cost, and technical feasibility, resulting in a low effect of reducing the position accuracy deviation. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by this application are the same as those of the photolithography method of the mask provided in the above embodiments, and will not be elaborated here.

[0134] The present application also provides a computer program product, including a computer program, which implements the steps of the lithography method of the mask as described above when executed by a processor.

[0135] The computer program product provided by the present application can solve the technical problem that the current method for reducing the position accuracy deviation is restricted by physical limitations, cost, and technical feasibility, resulting in a low effect of reducing the position accuracy deviation. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as those of the lithography method of the mask provided by the above embodiments, and will not be elaborated herein.

[0136] The above are only partial embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural transformation made by using the content of the specification and drawings of the present application under the technical concept of the present application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A photolithography method for a mask, characterized in that, The method described includes: Obtaining the exposure pattern of the mask; Inputting the exposure pattern into a position deviation correction model to obtain position correction data of the mask after being corrected by the position deviation model. The position deviation correction model is built based on a thermal diffusion algorithm corrected by a load rate correction coefficient and a position correction coefficient. Wherein, the load rate is the ratio of the area with patterns in a preset area to the total area; Among them, the step of inputting the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model includes: Inputting the exposure pattern into the position deviation correction model, and based on the thermal diffusion correction algorithm in the position deviation correction model, determining the temperature fluctuation map of each pattern area on the mask; Based on the thermal expansion algorithm in the position deviation correction model, converting the temperature fluctuation degree into a position deviation map, so that the position deviation model outputs the position correction data of the mask based on the position deviation map; Based on the position correction data, correcting the initial motion data of the lithography machine for lithographing the mask to obtain the corrected motion data of the lithography machine, and controlling the lithography machine to lithograph the mask based on the corrected motion data.

2. The method according to claim 1, characterized in that, Before the step of obtaining the exposure pattern of the mask includes: Obtaining the actual position deviation of each sample measurement target on the sample mask and the theoretical position deviation obtained based on a preset thermal expansion algorithm; Based on the actual position deviation and the theoretical position deviation, determining the load rate correction coefficient and the position correction coefficient of the sample mask; Based on the load rate correction coefficient and the position correction coefficient, correcting the thermal diffusion algorithm to obtain a thermal diffusion correction algorithm; Building a position deviation correction model according to the thermal diffusion correction algorithm and the thermal expansion algorithm.

3. The method according to claim 2, wherein The step of determining the load rate correction coefficient and the position correction coefficient of the sample mask based on the actual position deviation and the theoretical position deviation includes: Converting the deviation value between the actual position deviation and the theoretical position deviation into a heat deviation; Based on the heat deviation, determining the load rate correction coefficient during lithography of the sample mask; Under the condition that the load rate is determined, modifying the position difference between the auxiliary pattern and the measurement target marked on the sample mask to obtain the actual position deviation of each modification, and obtaining the corresponding theoretical position deviation; Based on the actual position deviation of each modification and the corresponding theoretical position deviation, determining the position correction coefficient corresponding to each load rate.

4. The method according to claim 2, wherein The step of obtaining the actual position deviation of each sample measurement target on the sample mask includes: Obtaining the initial position accuracy when exposing the sample measurement target and the blank auxiliary pattern on the sample mask, and obtaining the deviation position accuracy between the sample measurement target and the sample auxiliary pattern with a load rate; Taking the difference between the initial position accuracy and the deviation position accuracy to obtain the actual position deviation of each sample measurement target.

5. The method according to claim 1, wherein The step of inputting the exposure pattern into the position deviation correction model, and based on the thermal diffusion correction algorithm in the position deviation correction model, determining the temperature fluctuation map of each pattern area on the mask includes: Input the exposure pattern into the position deviation correction model to identify the graphic structures of each graphic region in the exposure pattern; Based on the thermal diffusion correction algorithm corresponding to the graphic structure, determine the temperature fluctuations of each graphic region; According to each of the temperature fluctuations, determine the temperature fluctuation map of each graphic region on the mask; 6. A lithographic apparatus for a mask, characterized in that, The device includes: An acquisition module for acquiring the exposure pattern of the mask; A data determination module for inputting the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model. The position deviation correction model is built based on the thermal diffusion algorithm corrected by the load rate correction coefficient and the position correction coefficient. Wherein, the load rate is the ratio of the area of the graphic region in the preset region to the total area. The step of inputting the exposure pattern into the position deviation correction model to obtain the position correction data of the mask after being corrected by the position deviation model includes: inputting the exposure pattern into the position deviation correction model, based on the thermal diffusion correction algorithm in the position deviation correction model, determine the temperature fluctuation map of each graphic region on the mask, based on the thermal expansion algorithm in the position deviation correction model, convert the temperature fluctuation degree into a position deviation map, so that the position deviation model outputs the position correction data of the mask based on the position deviation map; A correction module for correcting the initial motion data of the lithography machine for lithographing the mask based on the position correction data to obtain the corrected motion data of the lithography machine, and controlling the lithography machine to lithograph the mask based on the corrected motion data; 7. A lithographic apparatus for a photomask, characterized in that The device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. The computer program is configured to implement the steps of the lithography method of the mask according to any one of claims 1 to 5; 8. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by the processor, it implements the steps of the lithography method of the mask according to any one of claims 1 to 5; 9. A computer program product, characterized in that, The computer program product includes a computer program. When the computer program is executed by the processor, it implements the steps of the lithography method of the mask according to any one of claims 1 to 5.

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