Calibration device and calibration method for vertical scaling error, and lithography equipment

Abstract

An embodiment of the present invention discloses a calibration device and calibration method for vertical scaling error, and a lithography apparatus. The calibration device includes a tooling structure, a first measurement module, and a fitting calculation module; the tooling structure is disposed on the workpiece table; there is a height difference between the step surfaces of the respective alignment steps of the tooling structure, and an alignment mark is provided on the step surface of each alignment step; the first measurement module aligns with the alignment mark of the alignment step located within its alignment measurement area and feeds back an alignment measurement signal to the fitting calculation module; when the workpiece table is at each preset position, the fitting calculation module correspondingly obtains the height measurement data of the workpiece table measured by the vertical measurement device, and performs fitting calculation according to each height measurement data and each alignment measurement signal with a preset fitting formula to determine the vertical scaling error of the vertical measurement device. The embodiment of the present invention can improve the measurement accuracy of the vertical height of the workpiece table by the vertical measurement device.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of semiconductor device manufacturing, and in particular, to a calibration device and method for vertical scaling error, and a lithography apparatus. Background Art

[0002] In semiconductor device manufacturing equipment, a workpiece table for carrying a process wafer of a semiconductor device is usually provided, and the semiconductor device is driven to move between various stations. For example, in a lithography apparatus, the workpiece table for carrying the process wafer can drive the process wafer to move to a development station for development after exposure at an exposure station, etc., to achieve an automated manufacturing process of semiconductor devices.

[0003] Currently, a laser interferometer is usually provided in a lithography apparatus as its workpiece table measurement system. However, due to installation errors in the optical path and mirrors of the laser interferometer, when the workpiece table is measured using a laser interferometer with installation errors, the measurement results will have positioning errors. These errors will cause mutual coupling errors between the degrees of freedom of the moving stage measured by the measurement system, as well as scaling errors in the horizontal (X, Y) and vertical (Z) positions. In the prior art, usually only the errors of rotation and tilt of the laser interferometer are calibrated, and there is no device and method for calibrating the scaling error of the vertical position of the laser interferometer. However, when there are large errors in the vertical position measured by the laser interferometer, it will also affect the quality of semiconductor devices manufactured by the lithography apparatus. Summary of the Invention

[0004] In view of the above problems, embodiments of the present invention provide a calibration device and method for vertical scaling error, and a lithography apparatus, to calibrate the vertical scaling error of a vertical measurement device, thereby improving the measurement accuracy of the vertical measurement device.

[0005] In a first aspect, an embodiment of the present invention provides a calibration device for vertical scaling error, which is used to calibrate the vertical scaling error of a vertical measurement device. The vertical measurement device is used to measure the height of a workpiece table in a first direction, and the first direction is perpendicular to the base placement surface of the workpiece table. The calibration device includes: a tooling structure, a first measurement module, and a fitting calculation module;

[0006] The tooling structure is arranged in the workpiece table; the tooling structure includes a plurality of alignment steps, and there is a height difference between the step surfaces of any two alignment steps in the first direction; the step surface of each alignment step is provided with an alignment mark; wherein, the workpiece table moves to each preset position in a preset order, so that the alignment marks of each alignment step are sequentially located in the alignment measurement area of the first measurement module in the preset order;

[0007] The first measurement module is configured to align the alignment marks of the alignment steps located within the alignment measurement area and feedback an alignment measurement signal to the fitting calculation module;

[0008] The fitting calculation module is configured to, when the workpiece stage is located at each of the preset positions, obtain the height measurement data of the workpiece stage measured by the vertical measurement device one by one, and perform fitting calculation according to each of the height measurement data and each of the alignment measurement signals with a preset fitting formula to determine the vertical scaling error of the vertical measurement device.

[0009] In a second aspect, an embodiment of the present invention further provides a calibration method for vertical scaling error, which is executed by the above-described calibration device for vertical scaling error and is used to calibrate the vertical scaling error of the vertical measurement device. The calibration method includes:

[0010] The workpiece stage moves to each preset position in a preset order, so that the alignment marks of each of the alignment steps are located in the alignment measurement area of the first measurement module in the preset order;

[0011] The first measurement module aligns the alignment marks of the alignment steps located within the alignment measurement area and feedbacks an alignment measurement signal to the fitting calculation module;

[0012] The fitting calculation module, when the workpiece stage is located at each of the preset positions, obtains the height measurement data of the workpiece stage measured by the vertical measurement device one by one, and performs fitting calculation according to each of the height measurement data and each of the alignment measurement signals with a preset fitting formula to determine the vertical scaling error of the vertical measurement device.

[0013] In a third aspect, an embodiment of the present invention further provides a lithography apparatus, including: at least one workpiece stage and at least one working station;

[0014] The workpiece stage includes a substrate placement surface; the substrate placement surface is used to place a substrate to be processed; the workpiece stage drives the substrate to be processed to move between the working stations;

[0015] Each of the working stations is provided with at least one vertical measurement device; the vertical measurement device is used to measure the height of the workpiece stage at the corresponding working station in a first direction; the first direction is perpendicular to the substrate placement surface;

[0016] The lithography apparatus further includes the above-described calibration device for vertical scaling error.

[0017] The calibration device and calibration method for vertical scaling error, and the lithography equipment provided by the embodiments of the present invention set a tooling structure on the workpiece stage. The tooling structure includes multiple alignment steps. Alignment marks are arranged on the step surfaces of each alignment step, and there is a height difference between the step surfaces of any two alignment steps. The workpiece stage can move to each preset position in a preset order, so that the alignment marks of each alignment step can be located in the alignment measurement area of the first measurement module in a preset order. At this time, the first measurement module can align the alignment marks of the alignment step located in its alignment measurement area and feedback the corresponding alignment measurement signal to the fitting calculation module, so that the fitting calculation module can, according to the height measurement data measured by the vertical measurement device when the workpiece stage is located at the preset position and the alignment measurement signal feedback by the first measurement module, use a preset fitting formula to fit out the vertical scaling error of the vertical measurement device. When measuring the vertical height of the workpiece stage, the vertical measurement device can calibrate the measured height according to the determined vertical scaling error, thereby improving the accuracy of the height of the workpiece stage measured by the vertical measurement device in the first direction. At the same time, when the calibration device for vertical scaling error is applied to a lithography equipment, it can calibrate the vertical scaling error of the vertical measurement device in the lithography equipment, thereby improving the production yield of semiconductor devices prepared by using the lithography equipment. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of a vertical measurement device in the related art;

[0019] Figure 2 is a structural block diagram of a calibration device for vertical scaling error provided by an embodiment of the present invention;

[0020] Figure 3 is a schematic structural diagram of a tooling structure provided by an embodiment of the present invention;

[0021] Figure 4 is a schematic structural diagram of another tooling structure provided by an embodiment of the present invention;

[0022] Figure 5 is a schematic structural diagram of another tooling structure provided by an embodiment of the present invention;

[0023] Figure 6 is a schematic top view structural diagram of a workpiece stage provided by an embodiment of the present invention;

[0024] Figure 7 is along Figure 6 a schematic cross-sectional structural diagram of the A-A' section in

[0025] Figure 8 is a schematic top view structural diagram of another workpiece stage provided by an embodiment of the present invention;

[0026] Figure 9 is along Figure 8 a schematic cross-sectional structure diagram of the B-B' cross-section in

[0027] Figure 10 is a top view structure diagram of another workpiece stage provided by an embodiment of the present invention;

[0028] Figure 11 is a structure diagram of another tooling structure provided by an embodiment of the present invention;

[0029] Figure 12 is a flowchart of a method for calibrating the vertical scaling error provided by an embodiment of the present invention;

[0030] Figure 13 is a specific flowchart of a fitting calculation module for determining the vertical scaling error provided by an embodiment of the present invention;

[0031] Figure 14 is a specific flowchart of another fitting calculation module for determining the vertical scaling error provided by an embodiment of the present invention;

[0032] Figure 15 is a structure diagram of a lithography apparatus provided by an embodiment of the present invention. Detailed implementation manners

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0034] An embodiment of the present invention provides a calibration device for vertical scaling error, which is used to calibrate the vertical scaling error of a vertical measurement device. The vertical measurement device can be a device for measuring the vertical position of a workpiece stage in a lithography apparatus, and the vertical measurement device can be, for example, an interferometer. Exemplarily, Figure 1 is a structure diagram of a vertical measurement device in the related art. As Figure 1As shown, when the vertical measurement device 40 is an interferometer, the vertical measurement device 40 can measure the distance between the workpiece stage 50 and the mounting substrate 60 through the corresponding interference principle, and determine the height of the workpiece stage 50 in the first direction Z based on this distance; wherein, the first direction Z is the direction perpendicular to the base placement surface 501 of the workpiece stage 50. However, due to problems such as the installation error of the vertical measurement device 40, the vertical measurement device 40 has a certain vertical scaling error in the first direction Z, resulting in a large error between the height of the workpiece stage 50 determined in the first direction Z and the actual height of the workpiece stage 50 in the first direction Z, making the measured height inaccurate, and further affecting the lithography quality of the substrate to be processed carried on the workpiece stage 50 by the lithography equipment.

[0035] To solve the above technical problems, an embodiment of the present invention provides a calibration device for vertical scaling error. Figure 2 It is a structural block diagram of a calibration device for vertical scaling error provided by an embodiment of the present invention. Figure 3 It is a schematic structural diagram of a tooling structure provided by an embodiment of the present invention. Combining Figure 2 and Figure 3 As shown, the calibration device 100 for vertical scaling error includes a tooling structure 30, a first measurement module 10, and a fitting calculation module 20; the tooling structure 30 is disposed in the workpiece stage 50; the tooling structure 30 includes a plurality of alignment steps, and in the first direction Z, there is a height difference between the step surfaces of any two alignment steps (31, 32,..., 3i, 3i + 1,..., 3n); an alignment mark 301 is provided on the step surface of each alignment step (31, 32,..., 3i, 3i + 1,..., 3n); the workpiece stage 50 moves to each preset position in a preset order, so that the alignment marks 301 of each alignment step (31, 32,..., 3i, 3i + 1,..., 3n) are sequentially located in the alignment measurement area of the first measurement module 10 in a preset order. The first measurement module 10 can align the alignment mark 301 of the alignment step located in its alignment measurement area and feedback an alignment measurement signal to the fitting calculation module; the fitting calculation module 20 can, when the workpiece stage 50 is located at each preset position, obtain the height measurement data of the workpiece stage 50 measured by the vertical measurement device 40 one by one, and perform fitting calculation according to each height measurement data and each alignment measurement signal with a preset fitting formula to determine the vertical scaling error of the vertical measurement device 40.

[0036] Wherein, since the alignment mark 301 is provided on the step surface of each alignment step (31, 32,..., 3i, 3i + 1,..., 3n), the alignment measurement signal fed back by the first measurement module 10 when aligning the alignment mark 301 located in its alignment measurement area can be a signal that can represent the height of the step surface of the alignment step to which the alignment mark belongs compared to the reference surface of the first measurement module 10.

[0037] Exemplarily, the workpiece table 50 moving to each preset position in a preset order may be as follows: the workpiece table 50 moves to the first preset position, the second preset position, …, the i-th preset position, the (i + 1)-th preset position, …, the n-th preset position in sequence, so that the alignment marks 301 of the alignment step 31, the alignment marks 301 of the alignment step 32, …, the alignment marks 301 of the alignment step 3i, the alignment marks 301 of the alignment step 3(i + 1), …, the alignment marks 301 of the alignment step 3n are successively located in the alignment measurement area of the first measurement module 10; for example, when the workpiece table 50 moves to the first preset position, the alignment mark 301 of the alignment step 31 may be located in the alignment measurement area of the first measurement module 10; when the workpiece table 50 moves to the second preset position, the alignment mark 301 of the alignment step 32 may be located in the alignment measurement area of the first measurement module 10; …; when the workpiece table 50 moves to the i-th preset position, the alignment mark 301 of the alignment step 3i may be located in the alignment measurement area of the first measurement module 10; when the workpiece table 50 moves to the (i + 1)-th preset position, the alignment mark 301 of the alignment step 3(i + 1) may be located in the alignment measurement area of the first measurement module 10; and so on, when the workpiece table 50 moves to the n-th preset position, the alignment mark 301 of the alignment step 3n may be located in the alignment measurement area of the first measurement module 10. Among them, the alignment measurement area of the first measurement module 10 may be, for example, the area where the first measurement module 10 can perform alignment measurement or the area where the reference plane of the first measurement module 10 is located, and the first measurement module 10 will measure that the height value of the step surface of the alignment step to which the alignment mark located on its reference plane belongs is zero.

[0038] When the worktable 50 is in the first preset position, the fitting calculation module 20 acquires the height measurement data of the worktable 50 measured by the vertical measurement device 40 when the worktable 50 is in the first preset position; at this time, the alignment mark 301 of the alignment step 31 provided in the worktable 50 is located in the alignment measurement area of the first measurement module 10, so that the first measurement module 10 can align the alignment mark 301 of the alignment step 31 and feedback an alignment measurement signal indicating the height of the step surface of the alignment step 31 to the fitting calculation module 20, enabling the fitting calculation module 20 to obtain the height measurement data and the alignment measurement signal of the worktable 50 when the worktable 50 is in the first preset position. Correspondingly, when the worktable 50 is in the second preset position, the fitting calculation module 20 acquires a height measurement data of the worktable 50 measured by the vertical measurement device 40 when the worktable 50 is in the second preset position; at this time, the alignment mark 301 of the alignment step 32 provided in the worktable 50 is located in the alignment measurement area of the first measurement module 10, so that the first measurement module 10 can align the alignment mark 301 of the alignment step 32 and feedback an alignment measurement signal indicating the height of the step surface of the alignment step 32 to the fitting calculation module 20, enabling the fitting calculation module 20 to obtain the height measurement data and the alignment measurement signal of the worktable 50 when the worktable 50 is in the second preset position. By analogy, the fitting calculation module 20 can obtain n pairs of height measurement data and alignment measurement signals, and the difference between the two height measurement data has a linear relationship with the height difference between the step surfaces of the corresponding two alignment steps. For example, the height measurement data of the worktable 50 when it is in the (i + 1)-th preset position and the height measurement data of the worktable 50 when it is in the i-th preset position are F i+1 -F i , and the height difference between the step surface of the (i + 1)-th alignment step 3i + 1 and the step surface of the i-th alignment step 3i is H ii+1 , then there is F i+1 -F i =S*H ii+1 +b, where S is the vertical scaling error of the vertical measurement device 40 and b is the first constant; or, there is a linear relationship between the height measurement data and the alignment measurement signal, that is, R i =S*F i +b', where S is the vertical scaling error of the vertical measurement device 40 and b' is the second constant.

[0039] In this way, the fitting calculation module 20 can, based on the alignment measurement signal fed back by the first measurement module 10, perform fitting calculations according to the obtained n pairs of height measurement data, the alignment measurement signal, and a preset fitting formula, determine the vertical scaling error of the height of the worktable 50 measured by the vertical measurement device 40 in the first direction Z, and provide this vertical scaling error to the vertical measurement device 40. So that when the vertical measurement device 40 subsequently measures the height of the position of the worktable 50 in the first direction Z, it can compensate the measured height according to this vertical scaling error, and thus can improve the measurement accuracy of the height of the worktable 50 in the first direction Z by the vertical measurement device 40. Among them, the preset fitting formula is a relational expression between the difference between height measurement data and the height difference between the step surfaces of the alignment steps or a relational expression between height measurement data and the alignment measurement signal. At the same time, for the accuracy of the calculation results, each height measurement data obtained by the fitting calculation module 30 can be the average value of multiple height measurement values of the current position of the worktable 50 measured by the vertical measurement device 40.

[0040] Optionally, continuing to refer to Figure 2 and Figure 3 , when multiple alignment steps 30 include a first alignment step 31, a second alignment step 32,..., an nth alignment step 3n, the height difference H ii+1 between the step surface of the ith alignment step 3i and the step surface of the (i + 1)th alignment step 3i+1 is a fixed value H; where n≥2, 1≤i<n, and both n and i are positive integers. At this time, the height difference H 12 between the step surface of the first alignment step 31 and the step surface of the second alignment step 32, the height difference between the step surface of the second alignment step 32 and the step surface of the third alignment step (not shown in the figure),..., and the height difference between the step surface of the (n - 1)th alignment step (not shown in the figure) and the step surface of the nth alignment step 3n are all fixed values H.

[0041] Among them, when the height difference H 12 between the step surface of the first alignment step 31 and the step surface of the second alignment step 32, the height difference between the step surface of the second alignment step 32 and the step surface of the third alignment step (not shown in the figure),..., and the height difference between the step surface of the (n - 1)th alignment step (not shown in the figure) and the step surface of the nth alignment step 3n are all fixed values H, the first alignment step 31, the second alignment step 32,..., the nth alignment step 3n can be arranged in sequence and distributed in a stepped manner.

[0042] Exemplarily, for better illustration of the form in which the alignment adjustments in the tooling structure are arranged in sequence and distributed in a stepped manner, such as Figure 4As shown, taking the fixture structure including five alignment steps as an example, the first alignment step 31, the second alignment step 32, the third alignment step 33, the fourth alignment step 34, and the fifth alignment step 35 are arranged in sequence and distributed in a stepped manner. At this time, the step surface of the second alignment step 32 is higher than the step surface of the first alignment step 31 by H 12 , the step surface of the third alignment step 33 is higher than the step surface of the second alignment step 32 by H 23 , the step surface of the fourth alignment step 34 is higher than the step surface of the third alignment step 33 by H 34 , the step surface of the fifth alignment step 35 is higher than the step surface of the fourth alignment step 34 by H 45 . Among them, H 12 , H 23 , H 34 and H 45 are all fixed values H.

[0043] It should be noted that Figure 3 and Figure 4 are only exemplary drawings of the embodiments of the present invention. Figure 3 It shows that the fixture structure 30 includes n alignment steps, where n can be any positive integer greater than or equal to 2, and in the first direction, the height difference between the step surfaces of any two adjacent alignment steps is equal, that is, the first alignment step 31, the second alignment step 32,..., the i-th alignment step 3i, the (i + 1)-th alignment step 3i + 1,..., the n-th alignment step 3n are adjacent in sequence; while in the embodiments of the present invention, the arrangement manners of the first alignment step 31, the second alignment step 32,..., the i-th alignment step 3i, the (i + 1)-th alignment step 3i + 1,..., the n-th alignment step 3n can also be other manners. On the premise that there is a height difference between the step surfaces of the alignment steps in the fixture structure, the setting manners of the alignment steps in the fixture structure in the embodiments of the present invention are not specifically limited.

[0044] Exemplarily, as Figure 5 shown, taking the fixture structure including five alignment steps as an example, the height difference H 12 between the step surface of the first alignment step 31 and the step surface of the second alignment step 32 is a fixed value H, but the first alignment step 31 and the second alignment step 32 are not adjacent; the height difference H 23 between the step surface of the second alignment step 32 and the step surface of the third alignment step 33 is a fixed value H, and the second alignment step 32 and the third alignment step 33 are not adjacent; the height difference H 34 between the step surface of the third alignment step 33 and the step surface of the fourth alignment step 34 is a fixed value H, but the third alignment step 33 and the fourth alignment step 34 are not adjacent; the height difference H 45is a fixed value H, but the third alignment step 33 and the fourth alignment step 34 are not adjacent.

[0045] It should be noted that Figure 4 and Figure 5 both take the tooling structure including five alignment steps as an example to exemplarily illustrate the technical solutions of the embodiments of the present invention; while in the embodiments of the present invention, the number of alignment steps in the tooling structure can be set according to actual situations, which is related to the accuracy of the finally determined vertical scaling error and the size of the area on the workpiece table available for setting the tooling structure. The embodiments of the present invention do not specifically limit the number of alignment steps provided in the tooling structure.

[0046] For the convenience of description, without specific instructions, the embodiments of the present invention all take Figure 4 the arrangement mode of each alignment step shown therein as an example to exemplarily illustrate the technical solutions of the embodiments of the present invention.

[0047] Optionally, the base placement surface of the workpiece table may include a tooling structure setting area and a base placement area, and the tooling structure setting area may be located on at least one side of the base placement area; wherein, the tooling structure setting area can be used to set the tooling structure, and the base placement area can be used to place the base to be processed. At this time, the tooling structure setting area can be located on one side of the base placement area, or the tooling structure setting area can surround the base placement area, etc. Without affecting the original design of the workpiece table, the embodiments of the present invention do not specifically limit the positional relationship between the tooling structure setting area and the base placement area.

[0048] Correspondingly, the tooling structure can be directly set on the surface of the base placement surface of the workpiece table, so that the alignment steps provided in the tooling structure setting area will form corresponding convex structures protruding from the base placement surface; or, corresponding grooves can be provided in the tooling structure setting area of the base placement surface, and each alignment step of the tooling structure can be set in the grooves. At this time, there will be no protrusions on the base placement surface of the workpiece table. Compared with the protruding situation, setting the tooling structure in the workpiece table will not affect the maximum displacement amount of the workpiece table in the first direction. In the embodiments of the present invention, without affecting the normal movement of the workpiece table and the original design of the workpiece table, the embodiments of the present invention do not specifically limit the setting method of the tooling structure in the workpiece table.

[0049] Exemplarily, Figure 6 is a schematic top view structure diagram of a workpiece table provided by an embodiment of the present invention, Figure 7 is Figure 6 a schematic cross-sectional structure diagram of a cross-section along A-A' in Figure 6 and Figure 7As shown, the substrate placement surface 501 of the workpiece table 50 includes a substrate placement area 5011 and a non-substrate placement area 5012 surrounding the substrate placement area 5011. The non-substrate placement area 5012 can be used to set sensors and the like. The non-substrate placement area 5012 may include a tooling structure setting area 5021. The tooling structure setting area 5021 is located on one side of the substrate placement area 5011, and a groove 5001 is provided in the tooling structure setting area 5021. The alignment steps (31, 32, 33, 34, and 35) of the tooling structure are all provided in the groove 5021. At this time, the prepared tooling structure can be installed into the groove 5021, or the corresponding step structure can be directly formed at the bottom of the groove when forming the groove 5001, and the corresponding alignment marks can be set on the step surfaces of each step structure, so as to form the alignment steps (31, 32, 33, 34, and 35) of the tooling structure.

[0050] Exemplarily, Figure 8 is a top view structural schematic diagram of another workpiece table provided by an embodiment of the present invention. Figure 9 is along Figure 8 a cross-sectional structural schematic diagram of the B-B' section in Figure 8 and Figure 9 in Figure 6 and Figure 7 the same parts as in Figure 6 and Figure 7 can be referred to the above description of Figure 8 and Figure 9 will not be elaborated here. Only the differences between Figure 6 and Figure 7 and Figure 8 and Figure 9 are exemplarily described. As shown in combination with

[0051] Among them, as Figure 8 shown, when multiple grooves 5001 are provided in the tooling structure setting area 5021, the multiple grooves 5001 are all located on the same side of the substrate placement area 5011. At this time, the multiple grooves 5001 are arranged in a line along the second direction X, and the second direction X is a direction parallel to the step surface of the alignment step. Or, as Figure 10As shown, when there are multiple grooves 5001 provided in the tooling structure setting area 5021, the multiple grooves 5001 can be arranged around the base placement area 5011.

[0052] Optionally, Figure 11 is a schematic structural diagram of another tooling structure provided by an embodiment of the present invention. Combining Figure 2 and Figure 11 As shown, the first measurement module 10 may include an alignment light source emitting unit 110 and a plurality of optoelectronic signal measurement units (121, 122, 123, 124, 125); each optoelectronic signal measurement unit (121, 122, 123, 124, 125) is disposed on the back surface of each alignment step (31, 32, 33, 34, 35) in a one-to-one correspondence, and this back surface is opposite to the step surface. Among them, the alignment light source emitting unit 110 is used to provide an alignment light source to its focal plane; the optoelectronic signal measurement unit (121, 122, 123, 124, 125) is used to receive the alignment light beam of the alignment light source when the alignment mark on the corresponding alignment step is in the focal plane of the alignment light source emitting unit 110, and convert the alignment light beam into an alignment measurement signal and feedback it to the fitting calculation module 20.

[0053] Among them, the focal plane of the alignment light source emitting unit can be used as the reference plane of the first measurement module. When the alignment mark of the alignment step is located in the focal plane of the alignment light source emitting unit, it can be considered that the alignment measurement signal fed back by the optoelectronic signal measurement unit disposed on the back surface of the alignment step indicates that the step surface of the alignment step is located at the reference position, that is, the height of the step surface of the alignment step in the first direction is zero. At the same time, the alignment marks provided on the step surfaces of each alignment step can be, for example, strip-shaped hollow structures, or other markers for alignment. The embodiments of the present invention do not make specific limitations in this regard. Correspondingly, the size of each alignment step is related to the size of the alignment mark and the optoelectronic signal measurement unit provided thereon, that is, the size of the alignment step should meet the setting requirements of the alignment mark 301 and the optoelectronic signal measurement unit.

[0054] Exemplarily, continuing to refer in combination with Figure 2 and Figure 11, when the worktable moves to the first preset position, the alignment mark 301 of the first alignment step 31 provided in the worktable will be located on the focal plane of the alignment light source emitting unit 110, so that the optoelectronic signal measuring unit 121 provided on the back surface of the first alignment step 31 can receive the alignment light source emitted by the alignment light source emitting unit 110, and after photoelectric conversion of the alignment light source, it is converted into an alignment measurement signal that can be processed by the fitting calculation module 20. This alignment measurement signal can reflect that the height value of the step surface of the first alignment step 31 in the first direction Z is zero; at this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measuring device 40 when the worktable is at the first preset position, and calculate the average value of this set of height values as the height measurement data F1 when the worktable is at the first preset position. When the worktable moves to the second preset position, the alignment mark 301 of the second alignment step 32 provided in the worktable will be located on the focal plane of the alignment light source emitting unit 110, so that the optoelectronic signal measuring unit 122 provided on the back surface of the second alignment step 32 can receive the alignment light source emitted by the alignment light source emitting unit 110, and after photoelectric conversion of the alignment light source, it is converted into an alignment measurement signal that can be processed by the fitting calculation module 20. This alignment measurement signal can reflect that the height value of the step surface of the second alignment step 32 in the first direction Z is zero; at this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measuring device 40 when the worktable is at the second preset position, and calculate the average value of this set of height values as the height measurement data F2 when the worktable is at the second preset position. By analogy, the height measurement data F3 when the worktable is at the third preset position corresponding to the alignment mark 301 of the third alignment step 33 being on the focal plane, the height measurement data F4 when the worktable is at the fourth preset position corresponding to the alignment mark 301 of the fourth alignment step 34 being on the focal plane, and the height measurement data F5 when the worktable is at the fifth preset position corresponding to the alignment mark 301 of the fifth alignment step 35 being on the focal plane can be obtained in sequence.

[0055] After the first measurement module 10 is installed and fixed, it can be considered that the horizontal position and the vertical position of the focal plane of its alignment light source emitting unit 110 remain unchanged, and when the height difference between the step surfaces of two adjacent alignment steps is known, the height measurement data F i corresponding to the alignment mark 301 of the i-th alignment step being on the focal plane and the height measurement data F i+1 corresponding to the alignment mark 301 of the (i + 1)-th alignment step being on the focal plane can be obtained. There is the following relationship between them:

[0056] F i+1 -F i = S * H ii+1+b (Equation 1)

[0057] Wherein, H ii+1 is the height difference between the step surface of the i-th alignment step and the step surface of the i+1-th alignment step, S is the vertical scaling error of the vertical measuring device, and b is the first constant related to the difference between the installation height of the first measurement module and the installation height of the vertical measuring device. Therefore, Equation 1 can be used as the preset fitting formula, and F can be calculated based on the height measurement data i+1 –F i , and the alignment measurement signal fed back by each optoelectronic signal measurement unit is used to obtain the value corresponding to F i+1 –F i of H ii+1 , and with F i+1 –F i and H ii+1 as parameters for linear fitting, the corresponding vertical scaling error can be calculated by fitting, and this vertical scaling error is provided to the vertical measuring device 40 to calibrate the measured height of the workpiece table by the vertical measuring device 40, so as to improve the accuracy of the height of the workpiece table measured by the vertical measuring device 40.

[0058] It should be noted that the above fitting calculation formula and the process of determining the vertical scaling error of the vertical measuring device are only exemplary methods of the embodiments of the present invention, and are not specific limitations on the embodiments of the present invention; on the premise that the vertical scaling error of the vertical measuring device can be obtained through the vertical scaling error calibration device provided by the embodiments of the present invention, the embodiments of the present invention do not specifically limit the fitting calculation formula and the specific process of determining the vertical scaling error of the vertical measuring device.

[0059] Exemplarily, continue to combine and refer to Figure 2 and Figure 11, when the workpiece table is located at the first preset position, the first alignment step 31 can be located within the alignment measurement area of the first measurement module, but it may not be in the focal plane of the alignment light source emitting unit 110 in the first measurement module 10; at this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measurement device 40 when the workpiece table is at the first preset position, and calculate the average value of this set of height values as the height measurement data F1 when the workpiece table is at the first preset position; then the workpiece table continues to move until the alignment mark 301 of the first alignment step 31 is in the focal plane of the alignment light source emitting unit 110, and the optoelectronic signal measurement unit 121 provided on the back of the first alignment step 31 feeds back the alignment measurement signal generated during the alignment of the alignment mark 301 of the first alignment step 31. This alignment measurement signal can represent the height difference between the step surface height of the first alignment step 31 when the workpiece table is at the first preset position and the step surface height of the first alignment step 31 when the alignment mark 301 of the first alignment step 31 is in the focal plane of the alignment light source emitting unit 110; and for the accuracy of calculation, multiple alignment measurement signals can be fed back to the data processor 20, and the data processor 20 can calculate the average value of these multiple alignment measurement signals as the height difference between the step surface height of the first alignment step 31 when the workpiece table is at the first preset position and the step surface height of the first alignment step 31 when the first alignment step 31 is in the focal plane of the alignment light source emitting unit 110, that is, and regard this height difference as the alignment height difference R1 of the first alignment step 31. Similarly, when the workpiece table is located at the second preset position, the second alignment step 32 can be located within the alignment measurement area of the first measurement module, but it may not be in the focal plane of the alignment light source emitting unit 110 in the first measurement module 10; at this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measurement device 40 when the workpiece table is at the second preset position, and calculate the average value of this set of height values as the height measurement data F2 when the workpiece table is at the second preset position; then the workpiece table continues to move until the alignment mark 301 of the second alignment step 32 is in the focal plane of the alignment light source emitting unit 110, and the optoelectronic signal measurement unit 122 provided on the back of the second alignment step 32 feeds back the alignment measurement signal generated during the alignment of the alignment mark 301 of the second alignment step 32. This alignment measurement signal can represent the height difference between the step surface height of the second alignment step 32 when the workpiece table is at the second preset position and the step surface height of the second alignment step 32 when the alignment mark 301 of the second alignment step 32 is in the focal plane of the alignment light source emitting unit 110; similarly, multiple alignment measurement signals can be fed back to the data processor 20, and the data processor 20 can calculate the average value of these multiple alignment measurement signals as the alignment height difference R2 of the second alignment step 32.And so on, the height measurement data F3 of the vertical measurement device 40 and the alignment height difference R3 of the third alignment step 33, the height measurement data F4 of the vertical measurement device 40 and the alignment height difference R4 of the fourth alignment step 34, and the height measurement data F5 of the vertical measurement device 40 and the alignment height difference R5 of the fifth alignment step 35 can be obtained respectively when the worktable is at the third preset position, the fourth preset position, and the fifth preset position.

[0060] After the first measurement module 10 is installed and fixed, it can also be considered that the position of the focal plane of the alignment light source emitting unit 110 remains unchanged, and the alignment height difference R of the i-th alignment step can be obtained i and the height measurement data F of the vertical measurement device 40 when the worktable is at the i-th preset position i have the following relationship:

[0061] R i = S * F i + b' (Equation 2)

[0062] where S is the vertical scaling error of the vertical measurement device, and b' is the second constant related to the difference between the installation height of the first measurement module and the installation height of the vertical measurement device. Accordingly, Equation 2 can be used as the preset fitting formula, and with R i and F i as parameters for linear fitting, the corresponding vertical scaling error S can be calculated by fitting, and the vertical scaling error S is provided to the vertical measurement device 40 to calibrate the measured height of the worktable by the vertical measurement device 40, thereby improving the accuracy of the height of the worktable measured by the vertical measurement device 40.

[0063] An embodiment of the present invention also provides a calibration method for vertical scaling error. This calibration method can be executed by the calibration device for vertical scaling error provided in the embodiment of the present invention, and is used to calibrate the vertical scaling error of the vertical measurement device. Figure 12 is a flowchart of a calibration method for vertical scaling error provided in an embodiment of the present invention. As Figure 12 shown, this calibration method includes:

[0064] S100. The worktable moves to each preset position in a preset order, so that the alignment marks of each alignment step are sequentially located in the alignment measurement area of the first measurement module;

[0065] S200. The first measurement module aligns with the alignment mark of the alignment step located in the alignment measurement area and feeds back an alignment measurement signal to the fitting calculation module;

[0066] When the workpiece stage is at each preset position, the fitting calculation module correspondingly obtains the height measurement data of the workpiece stage measured by the vertical measurement device, and performs fitting calculation according to each height measurement data and each alignment measurement signal with a preset fitting formula to determine the vertical scaling error of the vertical measurement device.

[0067] Specifically, each preset position corresponds one-to-one to each alignment step of the tooling structure. That is, when the workpiece stage moves to a preset position, the alignment step corresponding to this preset position will be in the alignment measurement area of the first measurement module; at this time, the fitting calculation module will obtain a height measurement data of the workpiece stage when it is at this preset position measured by the vertical measurement device, and the first measurement module will align the alignment mark of the alignment step corresponding to this preset position and feedback the corresponding alignment measurement signal to the fitting calculation module. In this way, the workpiece stage can move to each preset position in turn, and the fitting calculation module can successively obtain the height measurement data of the workpiece stage when it is at each preset position measured by the vertical measurement device; correspondingly, the workpiece stage can move to each preset position in turn, and the first measurement module can also align the alignment marks of each alignment step located in its alignment measurement area in turn and feedback the alignment measurement signals when aligning the alignment marks of each alignment step in turn. The fitting calculation module can perform fitting calculation based on the alignment measurement signals fed back by the first measurement module, according to the obtained height measurement data, alignment measurement signals and the preset fitting formula, determine the vertical scaling error of the vertical measurement device, and provide this vertical scaling error to the vertical measurement device, so that when the vertical measurement device measures the height of the workpiece stage in the first direction at a subsequent position, it can compensate the measured height according to this vertical scaling error, thereby improving the measurement accuracy of the vertical measurement device for the height of the workpiece stage in the first direction. Among them, the alignment measurement area of the first measurement module can be the area where the first measurement module 10 can perform alignment measurement or the area where the reference plane of the first measurement module 10 is located, and the first measurement module 10 will measure that the height value of the step surface of the alignment step to which the alignment mark located on its reference plane belongs is zero.

[0068] Correspondingly, when the alignment steps include the first alignment step, the second alignment step,..., the nth alignment step, and the height difference between the ith alignment step and the (i + 1)th alignment step is a fixed value H, and each preset position is the first preset position, the second preset position,..., the nth preset position respectively, the difference between two height measurement data has a linear relationship with the height difference between the step surfaces of the corresponding two alignment steps. For example, the height measurement data of the workpiece stage when it is at the (i + 1)th position and the height measurement data of the workpiece stage when it is at the ith preset position are F i+1 -F i , and the height difference between the step surface of the (i + 1)th alignment step and the step surface of the ith alignment step is H ii+1 , then there is Fi+1 -F i = S * H ii+1 + b, where S is the vertical scaling error of the vertical measurement device and b is the first constant; alternatively, there is a linear relationship between the height measurement data and the alignment measurement signal, that is, R i = S * F i + b', where S is the vertical scaling error of the vertical measurement device and b' is the second constant. At the same time, for the accuracy of the calculation result, each height measurement data obtained by the fitting calculation module can be the average value of multiple height measurement values of the position where the current workpiece stage is located measured by the vertical measurement device.

[0069] Optionally, when the alignment steps include the first alignment step, the second alignment step,..., the nth alignment step, and the height difference between the ith alignment step and the (i + 1)th alignment step is a fixed value H, and the preset positions are the first preset position, the second preset position,..., the nth preset position respectively, it can be considered that the difference between two height measurement data has a linear relationship with the height difference between the corresponding step surfaces of the two alignment steps; at this time, the alignment measurement area of the first measurement module is the area where the reference surface of the first measurement module is located; where n ≥ 2, 1 ≤ i ≤ n, and both n and i are positive integers. Figure 13 is a specific flowchart of a fitting calculation module for determining the vertical scaling error provided by an embodiment of the present invention. As Figure 13 described, the method for the processing module to determine the vertical scaling error includes:

[0070] S11. When receiving the alignment measurement signal fed back when the first measurement module aligns with the alignment mark of the ith alignment step, determine that the workpiece stage is located at the ith preset position;

[0071] S12. Obtain the height measurement data of the workpiece stage measured by the vertical measurement device when the workpiece stage is located at the ith preset position; where the height measurement data includes multiple height measurement values of the workpiece stage when it is located at the current preset position;

[0072] S13. Calculate the average value of each height measurement value in the height measurement data of the workpiece stage when the workpiece stage is located at the ith preset position, and use the average value of each height measurement value in the height measurement data as the vertical height of the workpiece stage when it is located at the ith preset position;

[0073] S14. Loop through S11, S12, and S13 until the vertical heights of the workpiece stage when it is located at each preset position are obtained;

[0074] S15. According to the fitting formula |F i+1 – F iPerform fitting calculation according to |=S*H + b to determine the vertical scaling error S of the vertical measurement device; where, is the average value of multiple height measurement values when the worktable is at the i-th preset position measured by the vertical measurement device, F i+1 is the average value of multiple height measurement values when the worktable is at the (i + 1)-th preset position measured by the vertical measurement device; b is the first constant.

[0075] Exemplarily, continue to combine Figure 2 and Figure 3 As shown, when the worktable 50 moves to the first preset position, the alignment mark 301 of the first alignment step 31 provided in the worktable 50 will be within the alignment measurement area of the first measurement module 10, that is, the height value of the step surface of the first alignment step 31 measured by the first measurement module is zero; at this time, the fitting calculation module 20 will obtain a set of height measurement values of the worktable 50 at the first preset position measured by the vertical measurement device 40, and calculate the average value of this set of height measurement values as the vertical height F1 of the worktable 50 at the first preset position. When the worktable 50 moves to the second preset position, the alignment mark 301 of the second alignment step 32 provided in the worktable 50 will be within the alignment measurement area of the first measurement module 10, that is, the height of the step surface of the second alignment step 32 measured by the first measurement module is zero; at this time, the fitting calculation module 20 will obtain a set of height measurement values of the worktable 50 at the second preset position measured by the vertical measurement device 40, and calculate the average value of this set of height measurement values as the vertical height F2 of the worktable 50 at the second preset position. And so on, until the vertical height F1 of the worktable 50 at the first preset position, the vertical height F2 at the second preset position,..., the vertical height F i at the i-th preset position, the vertical height F i+1 at the (i + 1)-th preset position,..., and the vertical height F n at the n-th preset position are obtained, that is, n vertical heights corresponding to n preset positions are obtained.

[0076] Since after the first measurement module 10 is installed and fixed, it can be considered that the position of the focal plane of the alignment light source emitting unit 110 remains unchanged, and when the height difference between the step surfaces of two adjacent alignment steps is a fixed value H, it can be known that the vertical height F i of the worktable 50 at the i-th preset position corresponding to when the alignment mark 301 of the i-th alignment step 3i is within the alignment measurement area and the vertical height F i+1 of the worktable 50 at the (i + 1)-th preset position corresponding to when the alignment mark 301 of the (i + 1)-th alignment step is within the alignment measurement area have the following relationship:

[0077] F i+1 - F i= S * H + b (Equation 3)

[0078] Where S is the vertical scaling error of the vertical measurement device, and b is the first constant related to the difference between the installation height of the first measurement module and the installation height of the vertical measurement device. Therefore, Equation 3 is used as the preset fitting formula, and F is calculated based on the vertical height of the worktable 50 at each preset position i+1 –F i and, with F i+1 –F i and H as parameters for linear fitting, the corresponding vertical scaling error S can be calculated by fitting, and the vertical scaling error S is provided to the vertical measurement device 40, so that the vertical measurement device 40 calibrates the measured height of the worktable, thereby improving the accuracy of the height of the worktable measured by the vertical measurement device 40

[0079] Optionally, when multiple alignment steps include the first alignment step, the second alignment step,..., the nth alignment step, and the preset positions are the first preset position, the second preset position,..., the nth preset position respectively, it can be considered that there is a linear relationship between the height measurement data and the alignment measurement signal. At this time, the alignment measurement area of the first measurement module is the area where the first measurement module can perform alignment measurement. Correspondingly Figure 14 is a specific flowchart of another method for the fitting calculation module to determine the vertical scaling error provided by the embodiment of the present invention. As Figure 14 shown, the method for the processing module to determine the vertical scaling error may include

[0080] S21. When the worktable is at the ith preset position, obtain the height measurement data F i ' of the worktable measured by the vertical measurement device when the worktable is at the ith preset position; where the height measurement data F i ' is the height measurement value of the worktable when it is at the current preset position

[0081] S22. Obtain the alignment measurement signal R i generated by the first measurement module during the process of the worktable moving from the ith preset position to the alignment mark of the ith alignment step by the first measurement module; where the alignment measurement signal is the displacement of the worktable in the first direction when the worktable moves from the current preset position to the alignment mark of the alignment step by the first measurement module

[0082] S23. Loop through S21 and S22 until the height measurement data of the worktable measured by the vertical measurement device at each preset position is obtained, and the alignment measurement signal generated during the process of the first measurement module aligning the alignment marks of each alignment step is obtained

[0083] S24. According to the fitting formula R i = S * Fi Perform fitting calculations to determine the vertical scaling error S of the vertical measurement device; where b' is the second constant.

[0084] Exemplarily, continue to combine Figure 2 and Figure 3As shown, the alignment measurement area can be the area that the first measurement module 10 can measure. When the first measurement module 10 aligns with the alignment mark of the corresponding alignment step, the alignment mark of the alignment step should be on the reference plane of the first measurement module 10. That is, when the first measurement module 10 aligns with the alignment mark of the alignment step, the first measurement module 10 will measure that the height value of the step surface of the alignment step is zero. When the workpiece table 50 is at the first preset position, the first alignment step 31 may be within the alignment measurement area of the first measurement module 10, but the first measurement module 10 may not have aligned with the alignment mark of the first alignment step 31 yet. At this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measurement device 40 when the workpiece table 50 is at the first preset position, and calculate the average value of this set of height values as the height measurement data F1 of the obtained vertical measurement device 40. Then the workpiece table 50 will continue to move until the first measurement module 10 aligns with the alignment mark 301 of the first alignment step 31, that is, the workpiece table 50 moves to a position where the step surface of the first alignment step 31 is on the reference plane of the first measurement module 10. At this time, the first measurement module 10 will feedback the alignment measurement signal R1 generated by the first measurement module 10 during the process from the first preset position to the alignment of the first measurement module 10 with the alignment mark 301 of the first alignment step 31, as the displacement amount of the workpiece table 50 in the first direction Z during the process of the first measurement module 10 aligning with the alignment mark 301 in the first alignment step 31. When the workpiece table 50 is at the second preset position, the second alignment step 32 may be within the alignment measurement area of the first measurement module 10, but the first measurement module 10 may not have aligned with the alignment mark 301 of the second alignment step 32 yet. At this time, the fitting calculation module 20 will obtain a set of height values measured by the vertical measurement device 40 when the workpiece table 50 is at the second preset position, and calculate the average value of this set of height values as the height measurement data F2 of the obtained vertical measurement device 40. Then the workpiece table 50 will continue to move until the first measurement module 10 aligns with the alignment mark 301 of the second alignment step 32, that is, the workpiece table 50 moves to a position where the step surface of the second alignment step 32 is on the reference plane of the first measurement module 10. At this time, the first measurement module 10 will feedback the alignment measurement signal R2 generated by the first measurement module 10 during the process from the second preset position to the alignment of the first measurement module 10 with the alignment mark 301 of the second alignment step 32, as the displacement amount of the workpiece table 50 in the first direction Z during the process of the first measurement module 10 aligning with the alignment mark 301 in the second alignment step 32. And so on, until the height measurement data F1 of the workpiece table 50 measured by the vertical measurement device 40 when it is at the first preset position, the height measurement data F2 when it is at the second preset position,..., the height measurement data F i when it is at the (i + 1)-th preset position are obtained. The height measurement data F i+1, …, the height measurement data F when located at the nth preset position n , and correspondingly obtained alignment measurement signals R1 generated during the process of the first measurement module 10 aligning with the alignment mark 301 in the first alignment step 31, alignment measurement signals R2 generated during the process of aligning with the alignment mark 301 in the second alignment step 32, …, alignment measurement signals R generated during the process of aligning with the alignment mark 301 in the ith alignment step 3i i , and alignment measurement signals R generated during the process of aligning with the alignment mark 301 in the (i + 1)th alignment step 3i+1 i+1 , …, alignment measurement signals R generated during the process of aligning with the alignment mark 301 in the nth alignment step 3n n .

[0085] After the first measurement module 10 is installed and fixed, it can also be considered that the height of the position where its reference plane is located remains unchanged. It is possible to obtain the alignment measurement signal R generated by the first measurement module during the process of aligning with the alignment mark of the ith alignment step 3i i and the height measurement data F when the workpiece table 50 is located at the ith preset position i ' have the following relationship:

[0086] R i = S * F i '+ b' (Equation 4)

[0087] where S is the vertical scaling error of the vertical measurement device, and b' is the second constant related to the difference between the installation height of the first measurement module and the installation height of the vertical measurement device. Therefore, using Equation 4 as the preset fitting formula and performing linear fitting with Ri and Fi' as parameters, the corresponding vertical scaling error S can be calculated by fitting, and this vertical scaling error S is provided to the vertical measurement device 40 to calibrate the measured height of the workpiece table by the vertical measurement device 40, thereby improving the accuracy of the height of the workpiece table measured by the vertical measurement device 40.

[0088] The embodiment of the present invention also provides a lithography apparatus, which includes the calibration device for vertical scaling error provided by the embodiment of the present invention. This calibration device for vertical scaling error can be used to execute the calibration method for vertical scaling error provided by the embodiment of the present invention. Therefore, this lithography apparatus has the technical features and beneficial effects of the calibration device for vertical scaling error provided by the embodiment of the present invention and the calibration method it executes. The same parts can refer to the description of the calibration device for vertical scaling error and the calibration method provided by the embodiment of the present invention above, and will not be repeated here.

[0089] Exemplarily, Figure 15 is a schematic structural diagram of a lithography apparatus provided by the embodiment of the present invention. As Figure 15As shown, the lithography apparatus includes at least one workpiece table and at least one station. For example, it may include two workpiece tables (51 and 52) and two stations (201 and 202), and one of the two stations may include an exposure station; each workpiece table (51, 52) includes a substrate placement surface 501; the substrate placement surfaces 501 of the workpiece tables (51, 52) are used to place substrates to be processed (71, 72); the workpiece tables (51, 52) drive the substrates to be processed (71, 72) placed on their substrate placement surfaces 501 to move between the stations (201 and 202); each station (201, 202) is provided with at least one vertical measuring device 40; the vertical measuring device 40 is used to measure the height of the workpiece table at the corresponding station in the first direction Z; the first direction Z is the direction perpendicular to the substrate placement surface 501. Correspondingly, a calibration device for vertical scaling error is also provided in the lithography apparatus, which is used to calibrate the vertical scaling error of the vertical measuring device 40 at each station, and the specific process of the calibration device for vertical scaling error calibrating the vertical scaling error of the vertical measuring device 40 at each station may be the same or different, and the embodiments of the present invention do not make specific limitations on this.

[0090] In this way, when the calibration device for vertical scaling error determines the vertical scaling error of the corresponding vertical measuring device, it can provide the determined vertical scaling error to the corresponding vertical measuring device, so that when the vertical measuring device measures the workpiece table at its corresponding station, it can automatically compensate according to the vertical scaling error, thereby improving the production yield of semiconductor devices prepared by using this lithography apparatus.

[0091] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, combinations with each other, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, it may include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A calibration device for vertical scaling error, which is used to calibrate the vertical scaling error of a vertical measurement device, and is characterized in that The vertical measurement device is used to measure the height of the worktable in a first direction, which is perpendicular to the base placement surface of the worktable; the calibration device includes: a tooling structure, a first measurement module, and a fitting calculation module; The tooling structure is arranged in the worktable; the tooling structure includes a plurality of alignment steps, and in the first direction, there is a height difference between the step surfaces of any two of the alignment steps; each step surface of the alignment step is provided with an alignment mark; wherein, the worktable moves to each preset position in a preset order, so that the alignment marks of each alignment step are located in the alignment measurement area of the first measurement module in the preset order; The first measurement module is used to align the alignment mark of the alignment step located in the alignment measurement area and feedback an alignment measurement signal to the fitting calculation module; The fitting calculation module is used to obtain the height measurement data of the worktable measured by the vertical measurement device one by one when the worktable is located at each preset position, and perform fitting calculation according to each height measurement data and each alignment measurement signal with a preset fitting formula to determine the vertical scaling error of the vertical measurement device; Wherein, the preset fitting formula is a linear fitting relationship between the difference between the height measurement data and the height difference between the step surfaces of the alignment steps or a linear fitting relationship between the height measurement data and the alignment measurement signal.

2. The calibration device according to claim 1, wherein, The plurality of alignment steps include a first alignment step, a second alignment step,..., an nth alignment step, and the height difference between the step surface of the ith alignment step and the step surface of the (i + 1)th alignment step is a fixed value H; wherein, n≥2, 1≤i<n, and both n and i are positive integers.

3. The calibration device according to claim 2, wherein, The first alignment step, the second alignment step,..., and the nth alignment step are arranged in sequence and distributed in a stepped shape.

4. The calibration device according to claim 2, characterized in that, The base placement surface includes a tooling structure setting area and a base placement area; the tooling structure setting area is located on at least one side of the base placement area; Wherein, the tooling structure setting area is used to set the tooling structure, and the base placement area is used to place the base to be processed.

5. The calibration device according to claim 4, characterized in that, The tooling structure setting area is provided with a groove; each alignment step is arranged in the groove.

6. The calibration device according to claim 4, characterized in that, The tooling structure setting area is provided with a plurality of independent grooves; each alignment step is arranged in each groove in a one-to-one correspondence.

7. The calibration device according to claim 6, characterized in that Each of the grooves is arranged in sequence in a second direction; wherein, the second direction is parallel to the step surface; Alternatively, a plurality of the grooves are arranged around the base placement area.

8. The calibration device according to claim 1, wherein The first measurement module includes an alignment light source emitting unit and a plurality of photoelectric signal measurement units; each photoelectric signal measurement unit is arranged on the back surface of each alignment step in a one-to-one correspondence; the back surface is opposite to the step surface; The alignment light source emitting unit is used to provide an alignment light source to its focal plane; The optoelectronic signal measurement unit is configured to receive the alignment beam of the alignment light source and convert the alignment beam into an alignment measurement signal for feedback to the fitting calculation module when the alignment mark of the corresponding alignment step is in the focal plane.

9. A calibration method for vertical scaling error, which is executed by the calibration device for vertical scaling error according to any one of claims 1 to 8 and is used to calibrate the vertical scaling error of a vertical measurement device, characterized in that, The calibration method includes: The workpiece stage moves to each preset position in a preset order, so that the alignment marks of the respective alignment steps are sequentially located in the alignment measurement area of the first measurement module in the preset order; The first measurement module aligns with the alignment mark of the alignment step located in the alignment measurement area and feeds back an alignment measurement signal to the fitting calculation module; When the workpiece stage is at each of the preset positions, the fitting calculation module correspondingly obtains the height measurement data of the workpiece stage measured by the vertical measurement device, and performs fitting calculation according to each of the height measurement data and each of the alignment measurement signals with a preset fitting formula to determine the vertical scaling error of the vertical measurement device.

10. The calibration method according to claim 9, characterized in that, The multiple alignment steps include a first alignment step, a second alignment step, …, an nth alignment step, and the height difference between the ith alignment step and the (i + 1)th alignment step is a fixed value H; where n≥2, 1≤i≤n, and both n and i are positive integers; The respective preset positions are a first preset position, a second preset position, …, an nth preset position; When the workpiece stage is at each of the preset positions, the fitting calculation module correspondingly obtains the height measurement data of the workpiece stage measured by the vertical measurement device, and performs fitting calculation according to each of the height measurement data and each of the alignment measurement signals with a preset fitting formula to determine the vertical scaling error of the vertical measurement device, including: S11. When receiving the alignment measurement signal fed back when the first measurement module aligns with the alignment mark of the ith alignment step, determine that the workpiece stage is at the ith preset position; S12. Obtain the height measurement data of the workpiece stage at the ith preset position measured by the vertical measurement device; where the height measurement data includes multiple height measurement values when the workpiece stage is at the current preset position; S13. Calculate the average value of each of the height measurement values in the height measurement data when the workpiece stage is at the ith preset position, and use the average value of each of the height measurement values in the height measurement data as the vertical height of the workpiece stage at the ith preset position; S14. Loop through S11, S12, and S13 until the vertical heights of the workpiece stage at each of the preset positions are obtained; S15. According to the fitting formula |F i+1 – F i | = S * H + b for fitting calculation to determine the vertical scaling error S of the vertical measuring device; where F i is the average of multiple height measurement values when the worktable measured by the vertical measuring device is at the i-th preset position, and F i+1 is the average of multiple height measurement values when the worktable measured by the vertical measuring device is at the (i + 1)-th preset position; b is a first constant.

11. The calibration method according to claim 9, wherein The multiple alignment steps include a first alignment step, a second alignment step, …, an nth alignment step, and the height difference between the ith alignment step and the (i + 1)th alignment step is a fixed value H; where n≥2, 1≤i≤n, and both n and i are positive integers; The respective preset positions are a first preset position, a second preset position, …, an nth preset position; When the workpiece table is at each of the preset positions, the fitting calculation module correspondingly obtains the height measurement data of the workpiece table measured by the vertical measurement device, and performs fitting calculation according to each of the height measurement data and each of the alignment measurement signals with a preset fitting formula to determine the vertical scaling error of the vertical measurement device, including: S21. When the worktable is at the i-th preset position, obtain the height measurement data F of the worktable measured by the vertical measurement device when the worktable is at the i-th preset position i '; where the height measurement data F i ' is the height measurement value of the worktable when it is at the current preset position S22. Obtain the alignment measurement signal R generated by the first measurement module during the process that the worktable moves from the i-th preset position to the alignment mark of the i-th alignment step by the first measurement module i ; wherein, the alignment measurement signal R i is the displacement of the worktable in the first direction when the worktable moves from the current preset position to the alignment mark of the alignment step by the first measurement module S23. Repeatedly execute S21 and S22 until the height measurement data of the workpiece table measured by the vertical measurement device at each of the preset positions is obtained, and the alignment measurement signals generated during the process of the first measurement module aligning the alignment marks of each of the alignment steps are obtained; S24. According to the fitting formula R i = S*F i '+b' for fitting calculation to determine the vertical scaling error S of the vertical measuring device; where b' is the second constant.

12. A lithographic apparatus, characterized in that, including: at least one workpiece table and at least one working station; The workpiece table includes a substrate placement surface; the substrate placement surface is used for placing a substrate to be processed; the workpiece table drives the substrate to be processed to move between the working stations; Each of the working stations is provided with at least one vertical measurement device; the vertical measurement device is used for measuring the height of the workpiece table at the corresponding working station in a first direction; the first direction is perpendicular to the substrate placement surface; The lithography apparatus further includes a calibration device for the vertical scaling error according to any one of claims 1 to 8.

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