Temperature correction method and device for infrared thermal imager used in pattern forming device

Abstract

The present invention discloses an infrared thermal imager temperature correction method and device for a pattern forming device, which relates to the field of photolithography technology and is used to solve the problem of inaccurate temperature testing of a pattern forming device by an infrared thermal imager. The method comprises: using an infrared thermal imager to obtain first temperature distribution data of the pattern forming device in a working state; obtaining second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data; calculating a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data; and correcting the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix.

Description

Technical Field

[0001] The present disclosure relates to the field of photolithography technology, and in particular to a temperature correction method and device for an infrared thermal imager used in a pattern forming device. Background Art

[0002] The pattern forming device (such as a mask) is an indispensable component of the photolithography process. The pattern forming device carries the design pattern. Light passes through the pattern forming device and projects the design pattern onto the photoresist. In the actual photolithography process, temperature changes will cause deformation of the pattern forming device and affect the effect of the exposure process. Therefore, it is necessary to test the temperature of the pattern forming device. The traditional contact temperature measurement method requires the sensor to be attached to the surface of the pattern forming device, which is bound to affect the accuracy of the exposure pattern. In addition, due to space limitations, non-contact measurement methods are currently mainly used to perform real-time temperature testing using infrared thermal imagers.

[0003] However, since the substrate of the pattern forming device is generally made of glass, and the mask layer pattern is formed by chrome plating, and the emissivities of the glass and chrome layers are different, and the pattern line width of the pattern forming device is at the nanometer level, when using an infrared thermal imager to test the surface temperature of the pattern forming device, it is impossible to accurately distinguish the pattern area on the pattern forming device and set different emissivities, which leads to inaccurate temperature test results. Summary of the invention

[0004] In view of the above technical problems, the present disclosure provides an infrared thermal imager temperature correction method for a pattern forming device, which is used to at least partially solve the problem of inaccurate temperature testing of the pattern forming device by an infrared thermal imager.

[0005] Based on this, the first aspect of the present disclosure provides an infrared thermal imager temperature correction method for a pattern forming device, comprising: using an infrared thermal imager to obtain first temperature distribution data of the pattern forming device in a working state; obtaining second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data; calculating a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data; and correcting the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix.

[0006] According to an embodiment of the present disclosure, obtaining second temperature distribution data of the pattern forming device includes: simulating the temperature distribution of the pattern forming device using finite element analysis to obtain second temperature distribution data; or measuring the temperature distribution of the pattern forming device in a non-working state using a contact measurement method to obtain second temperature distribution data.

[0007] According to an embodiment of the present disclosure, a transformation matrix between a temperature value corresponding to first temperature distribution data and a temperature value corresponding to second temperature distribution data is calculated, including: determining a target area of ​​a pattern forming device; obtaining third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and obtaining fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; fitting the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data within the target area; for each point in the target area, calculating a transformation value corresponding to the point according to a first temperature value of the point in the third temperature distribution data and a second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to all points in the target area constitute a transformation matrix.

[0008] According to an embodiment of the present disclosure, calculating a transformation matrix between a temperature value corresponding to first temperature distribution data and a temperature value corresponding to second temperature distribution data also includes: determining a target area of ​​a pattern forming device; obtaining third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and obtaining fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; fitting the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area; fitting the third temperature distribution data to obtain a second continuous temperature curve of the third temperature distribution data in the target area; for each point in the target area, calculating a transformation value corresponding to the point according to the third temperature value of the point in the second continuous temperature curve and the second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to all points in the target area constitute a transformation matrix.

[0009] According to an embodiment of the present disclosure, calculating a transformation matrix between a temperature value corresponding to first temperature distribution data and a temperature value corresponding to second temperature distribution data also includes: determining a target area of ​​a pattern forming device; obtaining third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and obtaining fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; for each point in the target area, calculating a transformation value corresponding to the point according to a first temperature value of the point in the third temperature distribution data and a fourth temperature value of the point in the fourth temperature distribution data, wherein the transformation values ​​corresponding to all points in the target area constitute a transformation matrix.

[0010] According to an embodiment of the present disclosure, calculating a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data includes:

[0011] k i =(T obj_i 4 -T refl 4 ) / (T test_i 4-T refl 4 )

[0012] Calculate the transformation value corresponding to each point in the target area of ​​the pattern forming device. The transformation values ​​corresponding to all points in the target area form a transformation matrix, where i is the sequence number of the point in the target area, k i is the transformation value corresponding to the i-th point, T test_i is the first temperature value corresponding to the i-th point, T obj_i is the second temperature value corresponding to the i-th point, T refl is the temperature value of the radiation source around the pattern forming device.

[0013] According to an embodiment of the present disclosure, correcting the temperature distribution data to be corrected by the pattern forming device according to the transformation matrix includes:

[0014]

[0015] Calculate the corrected temperature value corresponding to the fifth temperature value in the temperature distribution data to be corrected for each point in the target area, where T′ obj_i is the corrected temperature value corresponding to the i-th point, T′ test_i is the fifth temperature value corresponding to the i-th point.

[0016] According to an embodiment of the present disclosure, a linear interpolation method is used to fit the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

[0017] According to an embodiment of the present disclosure, the method further includes: visualizing the temperature values ​​corresponding to the first temperature distribution data and the temperature values ​​corresponding to the second temperature distribution data, converting the first temperature distribution data into a first image, and converting the second temperature distribution data into a second image.

[0018] The second aspect of the present disclosure provides an infrared thermal imager temperature correction device for a pattern forming device, comprising: a first acquisition module, used to use an infrared thermal imager to acquire first temperature distribution data of the pattern forming device in a working state; a second acquisition module, used to acquire second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data; a calculation module, used to calculate a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data; and a correction module, used to correct the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix.

[0019] The infrared thermal imager temperature correction method and device for a pattern forming device provided by the embodiments of the present disclosure at least have the following beneficial effects:

[0020] The temperature distribution data of the pattern forming device is obtained as reference data through simulation or direct measurement, and the transformation matrix between the reference data and the temperature value corresponding to the temperature distribution data of the pattern forming device photographed by the infrared thermal imager is calculated as the correction reference. The temperature distribution data of the pattern forming device photographed by the infrared thermal imager at any time can be corrected based on the correction reference, which solves the technical problem of inaccurate temperature test of the infrared thermal imager due to the inability to set different emissivity for fine pattern areas.

[0021] Furthermore, the temperature correction accuracy can be guaranteed by reasonably designing the transformation matrix and the specific calculation method of correcting the temperature distribution data to be corrected.

[0022] Furthermore, by setting multiple fitting methods for the reference data and the temperature distribution data of the pattern forming device photographed by the infrared thermal imager, and then calculating the transformation matrix according to the fitted temperature data to correct the temperature, it can be applicable to the infrared thermal imager temperature test correction of different distribution temperature fields in the target area.

[0023] In addition, by visualizing the reference data and the temperature distribution data of the pattern forming device captured by the infrared thermal imager, the temperature correction process and results can be easily and intuitively observed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0025] Figure 1 A flow chart of a method for temperature correction of an infrared thermal imager for a pattern forming device provided in an embodiment of the present disclosure is schematically shown.

[0026] Figure 2 A flow chart of a method for calculating a transformation matrix provided by an embodiment of the present disclosure is schematically shown.

[0027] Figure 3 A flow chart of a method for calculating a transformation matrix provided in another embodiment of the present disclosure is schematically shown.

[0028] Figure 4 A flow chart of a method for calculating a transformation matrix provided in yet another embodiment of the present disclosure is schematically shown.

[0029] Figure 5 The flowchart of the coordinate transformation method provided by the embodiment of the present disclosure is schematically shown.

[0030] Fig. 6A The visualization diagram corresponding to the temperature field before the coordinate translation transformation provided by the embodiment of the present disclosure is schematically shown.

[0031] Figure 6BThe diagram schematically shows a visualization diagram corresponding to the temperature field after the coordinate translation transformation provided by an embodiment of the present disclosure.

[0032] Figure 6C The diagram schematically shows a visualization diagram corresponding to the temperature field after the coordinate scaling transformation provided by an embodiment of the present disclosure.

[0033] Fig.6D The diagram schematically shows a visualization diagram corresponding to the temperature field before the coordinate rotation transformation provided by an embodiment of the present disclosure.

[0034] Fig. 6E The diagram schematically shows a visualization diagram corresponding to the temperature field after the coordinate rotation transformation provided by an embodiment of the present disclosure.

[0035] Fig. 7A A visualized image of the temperature field measured by the infrared thermal imager before correction provided by an embodiment of the present disclosure is schematically shown.

[0036] Figure 7B The visualized image of the temperature field measured by the infrared thermal imager after correction provided by the embodiment of the present disclosure is schematically shown.

[0037] Figure 8 The infrared thermal imager temperature correction device for a pattern forming device provided in an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0039] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0040] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0041] In the description of the present disclosure, it is necessary to understand that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the subsystem or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0042] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. The shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship. In addition, in the claims, any reference symbol between brackets shall not be construed as a limitation to the claims.

[0043] Similarly, in order to simplify the present disclosure and help understand one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] Figure 1 A flow chart of a method for temperature correction of an infrared thermal imager for a pattern forming device provided in an embodiment of the present disclosure is schematically shown.

[0046] like Figure 1 As shown, the infrared thermal imager temperature correction method may include, for example, operations S101 to S104.

[0047] In operation S101, an infrared thermal imager is used to obtain first temperature distribution data of a pattern forming device in a working state.

[0048] In operation S102, second temperature distribution data of the pattern forming device is acquired, wherein the second temperature distribution data is used as reference data.

[0049] In operation S103, a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data is calculated.

[0050] In operation S104, the temperature distribution data to be corrected of the pattern forming device is corrected according to the transformation matrix.

[0051] In one embodiment of the present disclosure, there are multiple ways to obtain the second temperature distribution data of the pattern forming device, for example, it may include: using finite element analysis to simulate the temperature distribution of the pattern forming device to obtain the second temperature distribution data. Alternatively, a contact measurement method is used to measure the precise temperature distribution of the pattern forming device in a non-working state to obtain the second temperature distribution data. The contact measurement method may be, for example, measurement by a temperature sensor such as a thermocouple, which is not specifically limited by the present disclosure. The pattern forming device may refer to a mask, for example.

[0052] In one embodiment of the present disclosure, since the temperature distribution of the pattern forming device photographed by infrared thermal imaging is not continuous but a number of discrete temperature points, the temperature distribution of the pattern forming device simulated by finite element analysis is also not continuous but a number of discrete temperature points. Therefore, the transformation matrix can be directly calculated based on the obtained discrete first temperature distribution data and second temperature distribution data, or the first temperature distribution data and / or the second temperature distribution data can be fitted, and then the transformation matrix can be calculated based on the continuous temperature distribution data obtained after fitting. The following takes the mask as an example to introduce in detail the different calculation methods of the transformation matrix.

[0053] Figure 2 A flow chart of a method for calculating a transformation matrix provided by an embodiment of the present disclosure is schematically shown.

[0054] like Figure 2 As shown, the calculation method directly calculates the transformation matrix according to the acquired first temperature distribution data and second temperature distribution data, and for example may include operations S201 to S203.

[0055] In operation S201 , a target area of ​​a pattern forming device is determined.

[0056] The target area can be selected according to the actual application requirements. Taking the mask as an example, the entire upper surface of the mask is selected as the target area in this embodiment. In general, the area for simulating the temperature distribution of the mask using finite element analysis or the area measured using the contact measurement method is the entire upper surface of the mask. The area captured by the infrared thermal imager is larger, including the entire upper surface of the mask and the area outside. In other words, the first temperature distribution data includes not only the temperature distribution of the entire upper surface of the mask, but also the temperature distribution of the area outside the entire upper surface of the mask, while the second temperature distribution data can only include the temperature distribution of the entire upper surface of the mask.

[0057] In operation S202, third temperature distribution data corresponding to the first temperature distribution data target region is acquired, and fourth temperature distribution data corresponding to the second temperature distribution data target region is acquired.

[0058] When the target area is determined to be the entire upper surface of the mask, the fourth temperature distribution data may be the same as the second temperature distribution data, and the third temperature distribution data may be the temperature distribution data corresponding to the entire upper surface of the mask in the first temperature distribution data, excluding the temperature distribution data corresponding to the area outside the entire upper surface.

[0059] In operation S203, for each point in the target area, a transformation value corresponding to the point is calculated based on the first temperature value of the point in the third temperature distribution data and the fourth temperature value of the point in the fourth temperature distribution data, wherein the transformation values ​​corresponding to the points in the target area constitute a transformation matrix.

[0060] For example, if the target area includes n points, a transformation value is calculated for each point, and n transformation values ​​can be obtained for the n points, thereby forming a transformation matrix.

[0061] According to the embodiments of the present disclosure, by directly calculating the transformation matrix with discrete temperature points, the amount of data to be corrected is reduced, thereby making the temperature correction speed the fastest. However, since the interval of discrete temperatures of the pattern forming device photographed by the infrared thermal imager is smaller than the interval of discrete temperatures of the pattern forming device simulated using finite element analysis, some temperature points do not have a correction reference, and the accuracy of temperature calibration is low. This method of correcting the temperature measured by the infrared thermal imager under the same coordinates based on the simulated discrete temperature is suitable for the low-order distribution of the temperature field in the target area (the low-order distribution of the temperature field can refer to the temperature change along the coordinate direction is relatively smooth, will not fluctuate, and will not have multiple peaks). In this scenario, an infrared thermal imager with lower pixels can be selected. The target area data points collected are small, the corresponding finite element simulation grid is larger, and the data points are also small. The reference data temperature value corresponding to each point of the infrared thermal imager can be found for correction.

[0062] Figure 3 A flow chart of a method for calculating a transformation matrix provided in another embodiment of the present disclosure is schematically shown.

[0063] like Figure 3 As shown, the calculation method calculates the transformation matrix according to the acquired first temperature distribution data and the fitted second temperature distribution data, and may include, for example, operations S301 to S304.

[0064] In operation S301 , a target area of ​​a pattern forming device is determined.

[0065] The target area can be selected according to the actual application requirements. In this embodiment, the entire upper surface of the mask is selected as the target area. In general, the area where the temperature distribution of the mask is simulated using finite element analysis or the area measured using the contact measurement method is the entire upper surface of the mask. The area captured by the infrared thermal imager is larger, including the entire upper surface of the mask and the area outside. In other words, the first temperature distribution data includes not only the temperature distribution of the entire upper surface of the mask, but also the temperature distribution of the area outside the entire upper surface of the mask, while the second temperature distribution data can only include the temperature distribution of the entire upper surface of the mask.

[0066] In operation S302, third temperature distribution data corresponding to the first temperature distribution data target region is acquired, and fourth temperature distribution data corresponding to the second temperature distribution data target region is acquired.

[0067] When the target area is determined to be the entire upper surface of the mask, the fourth temperature distribution data may be the same as the second temperature distribution data, and the third temperature distribution data may be the temperature distribution data corresponding to the entire upper surface of the mask in the first temperature distribution data, excluding the temperature distribution data corresponding to the area outside the entire upper surface.

[0068] In operation S303, the fourth temperature distribution data is fitted to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

[0069] In the embodiment of the present disclosure, since the temperature corresponding to the fourth temperature distribution data is a discrete temperature point, a linear interpolation method can be used to fit the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

[0070] In operation S304, for each point in the target area, a transformation value corresponding to the point is calculated based on the first temperature value of the point in the third temperature distribution data and the second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to the points in the target area constitute a transformation matrix.

[0071] According to the embodiment of the present disclosure, the simulated discrete temperature points are fitted into a continuous temperature curve, which is used as a reference to correct the discrete temperature points measured by the discrete infrared thermal imager. At this time, all the infrared thermal imager temperature points have a correction reference, so that the correction accuracy is better than that of Figure 2 The method shown is improved, but the correction speed is reduced due to the fitting of the simulated temperature. This method of fitting the simulated discrete temperature points into a continuous temperature curve for correction is suitable for high-order distribution of temperature field (high-order distribution of temperature field can refer to large temperature changes along the coordinate direction, which may fluctuate and have multiple peaks). In this scenario, a high-pixel thermal imager can be selected to collect a large number of data points for correction.

[0072] Figure 4 A flow chart of a method for calculating a transformation matrix provided in yet another embodiment of the present disclosure is schematically shown.

[0073] like Figure 4 As shown, the calculation method calculates the transformation matrix according to the fitted first temperature distribution data and the fitted second temperature distribution data, and may include, for example, operations S401 to S405.

[0074] In operation S401 , a target area of ​​a pattern forming device is determined.

[0075] The target area can be selected according to the actual application requirements. In this embodiment, the entire upper surface of the mask is selected as the target area. In general, the area where the temperature distribution of the mask is simulated using finite element analysis or the area measured using the contact measurement method is the entire upper surface of the mask. The area captured by the infrared thermal imager is larger, including the entire upper surface of the mask and the area outside. In other words, the first temperature distribution data includes not only the temperature distribution of the entire upper surface of the mask, but also the temperature distribution of the area outside the entire upper surface of the mask, while the second temperature distribution data can only include the temperature distribution of the entire upper surface of the mask.

[0076] In operation S402, third temperature distribution data corresponding to the first temperature distribution data target region is acquired, and fourth temperature distribution data corresponding to the second temperature distribution data target region is acquired.

[0077] When the target area is determined to be the entire upper surface of the mask, the fourth temperature distribution data may be the same as the second temperature distribution data, and the third temperature distribution data may be the temperature distribution data corresponding to the entire upper surface of the mask in the first temperature distribution data, excluding the temperature distribution data corresponding to the area outside the entire upper surface.

[0078] In operation S403, the fourth temperature distribution data is fitted to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

[0079] In the embodiment of the present disclosure, since the temperature corresponding to the fourth temperature distribution data is a discrete temperature point, the fourth temperature distribution data can be fitted using a linear interpolation method to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

[0080] In operation S404, the third temperature distribution data is fitted to obtain a second continuous temperature curve of the third temperature distribution data in the target area.

[0081] In the embodiment of the present disclosure, since the temperature corresponding to the third temperature distribution data is a discrete temperature point, the third temperature distribution data can also be fitted by linear interpolation to obtain a second continuous temperature curve of the third temperature distribution data in the target area.

[0082] In operation S405, for each point in the target area, a transformation value corresponding to the point is calculated according to the third temperature value of the point in the second continuous temperature curve and the second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to the points in the target area form a transformation matrix.

[0083] According to the embodiment of the present disclosure, the discrete temperature points of the simulation and the discrete temperature points photographed by the infrared thermal imager are fitted into a continuous temperature curve. At this time, the continuous infrared thermal imager temperature is corrected based on the continuous simulation temperature. Figure 2 and Figure 3 The method shown has the highest temperature correction accuracy, but because both the simulated temperature and the thermal imager temperature are fitted, the temperature correction speed is the slowest. This method of fitting the discrete temperature points of the simulation and the discrete temperature points captured by the infrared thermal imager into a continuous temperature curve for temperature correction is suitable for scenes with high-order distribution of the temperature field and low pixels of the infrared thermal imager that cannot collect a large number of data points. By fitting the temperature points of the infrared thermal imager, a large number of temperature point data can be obtained to improve accuracy.

[0084] In the embodiment of the present disclosure, based on Figure 2-Figure 4 Different calculation methods of the transformation matrix shown in the figure, for each point in the target area, the formula for calculating the transformation value corresponding to the point can be as follows:

[0085] according to

[0086] k i =(T obj_i 4 -T refl 4 ) / (T test_i 4 -T refl 4 )

[0087] Calculate the transformation value corresponding to each point in the target area of ​​the pattern forming device, i is the serial number of the point in the target area, k is i is the transformation value corresponding to the i-th point.

[0088] Among them, in the use of Figure 2 When the calculation method shown is used, T test_i is the first temperature value corresponding to the i-th point, T obj_i is the fourth temperature value corresponding to the i-th point. Figure 3 When the calculation method shown is used, T test_i is the first temperature value corresponding to the i-th point, T obj_i is the second temperature value corresponding to the i-th point. Figure 4 When the calculation method shown is used, T test_i is the third temperature value corresponding to the i-th point, T obj_i is the second temperature value corresponding to the i-th point.

[0089] Among them, T refl is the temperature value of the radiation source around the pattern forming device, which can be set to 22° C. in this embodiment, for example.

[0090] In the embodiment of the present disclosure, based on the calculated transformation value of each point in the target area, the method of correcting the temperature distribution data to be corrected by the pattern forming device according to the transformation matrix can be, for example, as follows:

[0091] according to

[0092]

[0093] Calculate the corrected temperature value corresponding to the fifth temperature value in the temperature distribution data to be corrected for each point in the target area, where T′ obj_i is the corrected temperature value corresponding to the i-th point, T′ test_i is the fifth temperature value corresponding to the i-th point. Based on this, the corrected temperature value corresponding to each point in the target area photographed by the infrared thermal imager at any time can be obtained.

[0094] In order to observe the temperature correction process and results more intuitively, in the embodiment of the present disclosure, the temperature value corresponding to the first temperature distribution data and the second temperature distribution data can also be visualized, the first temperature distribution data can be converted into a first image, and the second temperature distribution data can be converted into a second image. Then, the transformation matrix is ​​calculated based on the first image and the second image. The following is a specific example to illustrate the process of calculating and correcting the transformation matrix based on visualization:

[0095] For example, the emissivity of the infrared thermal imager is set to the emissivity of the glass, and the light intensity is 150 mW / cm 2The mask is illuminated with a UV light source for 15 minutes, and the temperature of the mask is monitored using an infrared thermal imager. In order to facilitate subsequent data analysis, the temperature measured by the infrared thermal imager and the reference temperature are exported. The exported data can be stored in an Excel spreadsheet or other types of files.

[0096] The temperature field data obtained by the infrared thermal imager and the finite element calculation are read by MATLAB software respectively, and the temperature field data obtained by the infrared thermal imager and the finite element calculation are converted into image pixels respectively. In the same coordinate system, the same area is intercepted as the target area, and the coordinate transformation is performed to make the position coordinates of the target area analyzed by the two methods coincide. That is, the coordinate transformation is used to make the position coordinates of the mask outline and mark in the finite element image and the thermal imager image coincide.

[0097] Figure 5 The flowchart of the coordinate transformation method provided by the embodiment of the present disclosure is schematically shown.

[0098] like Figure 5 As shown, the coordinate transformation method may include, for example, operations S501 to S504.

[0099] In operation S501, a first image corresponding to temperature distribution data captured by an infrared thermal imager before coordinate transformation and a second image corresponding to temperature distribution data simulated by a finite element method are acquired in the same coordinate system.

[0100] During the test, the chrome layer and glass on the mask are set to the same emissivity, for example, both are set to the glass emissivity of 0.9, and k = ε1 / ε2 is defined, where ε1 is the glass emissivity and ε2 is the chrome layer emissivity. In actual situations, the glass emissivity is a constant of 0.9, and the chrome layer has an unknown emissivity due to the different film thickness and distribution areas, and it is not a fixed value. Since the chrome layer emissivity is set to the glass emissivity, the temperature distribution data captured by the infrared thermal imager is inaccurate and needs to be corrected.

[0101] Fig. 6A The visualization diagram corresponding to the temperature field before the coordinate translation transformation provided by the embodiment of the present disclosure is schematically shown.

[0102] like Fig. 6A As shown, (x, y) is the position coordinate of each point in the target area, the area shown in the grid is the first image corresponding to the temperature distribution data taken by the infrared thermal imager; the black circular area is the second image corresponding to the temperature distribution data of the finite element simulation.

[0103] In operation S502, a translation transformation is performed on the image of the target area of ​​the infrared thermal imager.

[0104] In the embodiment of the present disclosure, the position coordinates of the center temperature point of the image of the target area of ​​the infrared thermal imager can be obtained, and the entire thermal imager temperature field can be translated as follows according to the position coordinates of the center temperature point. The translation transformation formula can be, for example,:

[0105]

[0106] Among them, a and b are the translation parameters in the x direction and y direction respectively, (x, y) is the coordinate of each point in the target area before translation, and (x1, y1) is the coordinate of each point in the target area after translation.

[0107] For example, if the position coordinates of the central temperature point are (81, 70), the translation parameter a can be -81 and b can be -70.

[0108] Figure 6B The diagram schematically shows a visualization diagram corresponding to the temperature field after the coordinate translation transformation provided by an embodiment of the present disclosure.

[0109] like Figure 6B As shown, the second image corresponding to the temperature distribution data of the finite element simulation and the first image corresponding to the temperature distribution data taken by the infrared thermal imager are basically aligned.

[0110] In operation S503, scaling transformation is performed on the visualized image after the translation transformation.

[0111] In the disclosed embodiment, due to the influence of the shooting angle, the temperature field position coordinate scaling transformation is nonlinear. To simplify the calculation, the temperature field is divided into two regions, A and B, and each region is scaled with different parameters to make the contour edge of the mask in the target area image of the thermal imager coincide with the edge of the mask in the target area image of the finite element simulation. The scaling transformation relationship can be in the following form:

[0112]

[0113] Among them, (x2, y2) is the coordinate of each point in the target area after scaling, and k1 and k2 are the scaling parameters in the x direction and y direction respectively.

[0114] For example, the scaling parameter k of region A 1A =0.32, k 2A = 0.469, the expansion parameter k of region B 1B =0.356, k 2B =0.403.

[0115] Figure 6C The visualization diagram corresponding to the temperature field after the telescopic transformation provided by the embodiment of the present disclosure is schematically shown.

[0116] like Figure 6CAs shown, the second image corresponding to the temperature distribution data of the finite element simulation and the first image corresponding to the temperature distribution data taken by the infrared thermal imager further tend to overlap.

[0117] In operation S504, a rotation transformation is performed on the scaled visualized image.

[0118] In the embodiment of the present disclosure, the role of the rotation transformation is to make the mark of the mask in the second image corresponding to the temperature distribution data of the finite element simulation coincide with the mark of the mask in the first image corresponding to the temperature distribution data taken by the infrared thermal imager. The rotation transformation relationship can be, for example, in the following form:

[0119]

[0120] Among them, (x3, y3) is the rotated coordinate of each point in the target area, and α is the rotation parameter of the temperature field position coordinate.

[0121] Fig.6D The diagram schematically shows a visualization diagram corresponding to the temperature field before the coordinate rotation transformation provided by an embodiment of the present disclosure. Fig. 6E The diagram schematically shows a visualization diagram corresponding to the temperature field after the coordinate rotation transformation provided by an embodiment of the present disclosure.

[0122] from Fig.6D and Fig. 6E It can be seen that, based on the above transformation operation, the edges and marks of the mask in the second image corresponding to the temperature distribution data of the finite element simulation coincide with the edges and marks of the mask in the first image corresponding to the temperature distribution data taken by the infrared thermal imager, respectively, so as to facilitate the correction of the temperature distribution data taken by the infrared thermal imager based on the temperature distribution data of the finite element simulation at the same position coordinates.

[0123] It should be noted that in the visualized image after coordinate transformation, each point in the target area can be marked as (x, y, T), where (x, y) is the position coordinate of the point, and T is the temperature value of the point with the position coordinate (x, y). In this way, the temperature distribution of each point in the target area can be intuitively observed.

[0124] In order to verify the advantages of the infrared thermal imager temperature correction method provided by the embodiment of the present disclosure, the infrared thermal imager image at time t=674s is corrected, and the results before and after correction are as follows:

[0125] Fig. 7A A visualized image of the temperature field measured by the infrared thermal imager before correction provided by an embodiment of the present disclosure is schematically shown. Figure 7B The visualized image of the temperature field measured by the infrared thermal imager after correction provided by the embodiment of the present disclosure is schematically shown.

[0126] See also Fig. 7A and Figure 7B , combined with the temperature data of the target area of ​​the pattern forming device, multiple feature points are selected from the target area for analysis, and the correction effect of the method is compared. The measured data of the correction of the feature points in the target area are shown in Table 1:

[0127] Table 1

[0128]

[0129] It can be seen from Table 1 that the point with the largest deviation in the measurement result is reduced from -10.59°C to -1.26°C, and the measurement error after correction is 12% of that before correction; the point with the position coordinates (0.32, -12.67) has the largest error after correction, which is only 27% of that before correction. This proves that this method is effective and can realize the correction of the temperature of the pattern forming device photographed by the infrared thermal imager.

[0130] Based on the same inventive concept, an embodiment of the present disclosure also provides a temperature correction method for an infrared thermal imager of a pattern forming device.

[0131] Figure 8 The infrared thermal imager temperature correction device for a pattern forming device provided in an embodiment of the present disclosure is schematically shown.

[0132] like Figure 8 As shown, the infrared thermal imager temperature correction device 800 for the pattern forming device may include, for example:

[0133] The first acquisition module 810 is used to use an infrared thermal imager to acquire first temperature distribution data of the pattern forming device in a working state.

[0134] The second acquisition module 820 is used to acquire second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data.

[0135] The calculation module 830 is used to calculate a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data.

[0136] The correction module 840 is used to correct the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix.

[0137] It should be noted that the infrared thermal imager temperature correction device part used for the pattern forming device in the embodiment of the present disclosure corresponds to the infrared thermal imager temperature correction method part used for the pattern forming device in the embodiment of the present disclosure, and their specific implementation details and the technical effects brought about are also the same, which will not be repeated here.

[0138] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for correcting the temperature of an infrared thermal imager used in a pattern forming device, characterized in that: include: Using an infrared thermal imager to obtain first temperature distribution data of the pattern forming device in a working state; acquiring second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data; Calculating a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data, comprising: determining a target area of ​​the pattern forming device; acquiring third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, acquiring fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; fitting the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area; for each point in the target area, calculating a transformation value corresponding to the point according to a first temperature value of the point in the third temperature distribution data and a second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to all points in the target area constitute the transformation matrix; the calculation of the transformation matrix between the temperature value corresponding to the first temperature distribution data and the temperature value corresponding to the second temperature distribution data also comprises: according to Calculate the transformation value corresponding to each point in the target area of ​​the pattern forming device, and the transformation values ​​corresponding to all points in the target area form the transformation matrix, where i is the sequence number of the point in the target area, k i is the transformation value corresponding to the i-th point, T test_i is the temperature value corresponding to the first temperature distribution data corresponding to the i-th point, T obj_i is the temperature value corresponding to the second temperature distribution data corresponding to the i-th point, T refl is the temperature value of the radiation source around the pattern forming device; The temperature distribution data to be corrected of the pattern forming device is corrected according to the transformation matrix.

2. The infrared thermal imager temperature correction method according to claim 1, characterized in that: The acquiring second temperature distribution data of the pattern forming device comprises: Using finite element analysis to simulate the temperature distribution of the pattern forming device to obtain the second temperature distribution data; or The temperature distribution of the pattern forming device in a non-working state is measured by a contact measurement method to obtain the second temperature distribution data.

3. The infrared thermal imager temperature correction method according to claim 1, characterized in that: The calculating of the transformation matrix between the temperature value corresponding to the first temperature distribution data and the temperature value corresponding to the second temperature distribution data also includes: determining a target area of ​​the patterning device; Acquire third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and acquire fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; Fitting the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area; Fitting the third temperature distribution data to obtain a second continuous temperature curve of the third temperature distribution data in the target area; For each point in the target area, the transformation value corresponding to the point is calculated based on the third temperature value of the point in the second continuous temperature curve and the second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to all points in the target area constitute the transformation matrix.

4. The infrared thermal imager temperature correction method according to claim 1, characterized in that: The calculating of the transformation matrix between the temperature value corresponding to the first temperature distribution data and the temperature value corresponding to the second temperature distribution data also includes: determining a target area of ​​the patterning device; Acquire third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and acquire fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; For each point in the target area, the transformation value corresponding to the point is calculated according to the first temperature value of the point in the third temperature distribution data and the fourth temperature value of the point in the fourth temperature distribution data, wherein the transformation values ​​corresponding to all points in the target area constitute the transformation matrix.

5. The infrared thermal imager temperature correction method according to claim 1, characterized in that: The correcting the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix comprises: according to Calculate the corrected temperature value corresponding to the fifth temperature value in the temperature distribution data to be corrected for each point in the target area, wherein: is the corrected temperature value corresponding to the i-th point, is the fifth temperature value corresponding to the i-th point.

6. The infrared thermal imager temperature correction method according to claim 1 or 3, characterized in that: The fourth temperature distribution data is fitted by a linear interpolation method to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area.

7. The infrared thermal imager temperature correction method according to claim 1, characterized in that: The method further comprises: The temperature value corresponding to the first temperature distribution data and the temperature value corresponding to the second temperature distribution data are visualized, the first temperature distribution data is converted into a first image, and the second temperature distribution data is converted into a second image.

8. An infrared thermal imager temperature correction device for a pattern forming device, characterized in that: include: A first acquisition module, used for acquiring first temperature distribution data of the pattern forming device in a working state by using an infrared thermal imager; A second acquisition module, used to acquire second temperature distribution data of the pattern forming device, wherein the second temperature distribution data is used as reference data; A calculation module, for calculating a transformation matrix between a temperature value corresponding to the first temperature distribution data and a temperature value corresponding to the second temperature distribution data, comprising: determining a target area of ​​the pattern forming device; obtaining third temperature distribution data corresponding to the target area of ​​the first temperature distribution data, and obtaining fourth temperature distribution data corresponding to the target area of ​​the second temperature distribution data; fitting the fourth temperature distribution data to obtain a first continuous temperature curve of the fourth temperature distribution data in the target area; for each point in the target area, calculating a transformation value corresponding to the point according to a first temperature value of the point in the third temperature distribution data and a second temperature value of the point in the first continuous temperature curve, wherein the transformation values ​​corresponding to all points in the target area constitute the transformation matrix; the calculation of the transformation matrix between the temperature value corresponding to the first temperature distribution data and the temperature value corresponding to the second temperature distribution data also comprises: according to Calculate the transformation value corresponding to each point in the target area of ​​the pattern forming device, and the transformation values ​​corresponding to all points in the target area form the transformation matrix, where i is the sequence number of the point in the target area, k i is the transformation value corresponding to the i-th point, T test_i is the temperature value corresponding to the first temperature distribution data corresponding to the i-th point, T obj_i is the temperature value corresponding to the second temperature distribution data corresponding to the i-th point, T refl is the temperature value of the radiation source around the pattern forming device; A correction module is used to correct the temperature distribution data to be corrected of the pattern forming device according to the transformation matrix.

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