CN114690579A - Calibration device and calibration method for vertical scaling error and photoetching equipment - Google Patents

Calibration device and calibration method for vertical scaling error and photoetching equipment Download PDF

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Publication number
CN114690579A
CN114690579A CN202011630468.0A CN202011630468A CN114690579A CN 114690579 A CN114690579 A CN 114690579A CN 202011630468 A CN202011630468 A CN 202011630468A CN 114690579 A CN114690579 A CN 114690579A
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China
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alignment
measurement
vertical
height
preset position
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CN202011630468.0A
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Chinese (zh)
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张静静
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Shanghai Micro Electronics Equipment Co Ltd
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Shanghai Micro Electronics Equipment Co Ltd
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Priority to CN202011630468.0A priority Critical patent/CN114690579A/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
    • G03F7/7085—Detection arrangement, e.g. detectors of apparatus alignment possibly mounted on wafers, exposure dose, photo-cleaning flux, stray light, thermal load
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70691—Handling of masks or workpieces
    • G03F7/70716—Stages

Abstract

The embodiment of the invention discloses a calibration device and a calibration method for vertical scaling errors and photoetching equipment, wherein the calibration device comprises a tool structure, a first measurement module and a fitting calculation module; the tool structure is arranged in the workpiece table; the step surfaces of the alignment steps of the tool structure have a height difference, and the step surface of each alignment step is provided with an alignment mark; the first measurement module aligns the alignment mark of the alignment step in the alignment measurement area and feeds back an alignment measurement signal to the fitting calculation module; and the fitting calculation module acquires height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is positioned at each preset position, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines the vertical scaling error of the vertical measurement device. According to the embodiment of the invention, the measurement accuracy of the vertical height of the workpiece platform by the vertical measurement device can be improved.

Description

Calibration device and calibration method for vertical scaling error and photoetching equipment
Technical Field
The embodiment of the invention relates to the technical field of semiconductor device preparation, in particular to a calibration device and a calibration method for vertical scaling errors and photoetching equipment.
Background
A work stage for carrying a process sheet of a semiconductor device is generally disposed in a manufacturing apparatus of the semiconductor device, and the semiconductor device is driven to move between stations, for example, after the work stage for carrying the process sheet in a photolithography apparatus is exposed at an exposure station, the process sheet is driven to move to a development station for development, etc., so as to implement an automated process of the semiconductor device.
At present, a laser interferometer is generally arranged in a lithography apparatus as a workpiece stage measurement system, but because both an optical path and a reflecting mirror of the laser interferometer have installation errors, when the laser interferometer with the installation errors is adopted to measure a workpiece stage, a positioning error exists in a measurement result. These errors will cause errors in the mutual coupling between the various degrees of freedom of the motion stage measured by the measurement system, as well as errors in the scaling of the horizontal (X, Y) and vertical (Z) positions. In the prior art, only the rotation and inclination errors of the laser interferometer are generally calibrated, and the device and the method for calibrating the scaling error of the vertical position of the laser interferometer are not provided. However, when there is a large error in the vertical position measured by the laser interferometer, the quality of the semiconductor device manufactured by the lithographic apparatus is also affected.
Disclosure of Invention
In view of the above problems, embodiments of the present invention provide a calibration apparatus and a calibration method for vertical scaling errors, and a lithographic apparatus, so as to calibrate the vertical scaling errors of a vertical measurement apparatus, thereby improving the measurement accuracy of the vertical measurement apparatus.
In a first aspect, an embodiment of the present invention provides a calibration apparatus for a vertical scaling error, configured to calibrate a vertical scaling error of a vertical measurement apparatus, where the vertical measurement apparatus is configured to measure a height of a workpiece stage in a first direction, and the first direction is a direction perpendicular to a substrate placement surface of the workpiece stage; the calibration device includes: the device comprises a tool structure, a first measurement module and a fitting calculation module;
the tool structure is arranged in the workpiece table; the tool structure comprises a plurality of alignment steps, and in the first direction, the step surfaces of any two alignment steps have a height difference; the step surface of each alignment step is provided with an alignment mark; the workpiece table sequentially moves to each preset position in a preset sequence, so that the alignment marks of the alignment steps are sequentially located in the alignment measurement area of the first measurement module in the preset sequence;
the first measurement module is used for aligning the alignment mark of the alignment step in the alignment measurement region and feeding back an alignment measurement signal to the fitting calculation module;
the fitting calculation module is used for acquiring height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performing fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determining a vertical scaling error of the vertical measurement device.
In a second aspect, an embodiment of the present invention further provides a method for calibrating a vertical scaling error, which is performed by using the calibration apparatus for a vertical scaling error, and is used for calibrating a vertical scaling error of a vertical measurement apparatus, where the method for calibrating includes:
the workpiece table sequentially moves to each preset position in a preset sequence, so that the alignment marks of the alignment steps are sequentially positioned in the alignment measurement area of the first measurement module in the preset sequence;
the first measurement module aligns alignment marks of the alignment steps in the alignment measurement area and feeds back alignment measurement signals to the fitting calculation module;
and the fitting calculation module acquires the height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines the vertical scaling error of the vertical measurement device.
In a third aspect, an embodiment of the present invention further provides a lithographic apparatus, including: at least one workpiece table and at least one station;
the workpiece stage comprises a substrate placement surface; the substrate placing surface is used for placing a substrate to be treated; the workpiece table drives the substrate to be processed to move between the stations;
each station is provided with at least one vertical measuring device; the vertical measuring device is used for measuring the height of a workpiece table at the station of the vertical measuring device in a first direction; the first direction is a direction perpendicular to the base placement surface;
the lithographic apparatus further comprises a calibration device for the vertical scaling error.
According to the calibration device and the calibration method for the vertical scaling error and the photoetching equipment, provided by the embodiment of the invention, the tool structure is arranged in the workpiece table and comprises a plurality of alignment steps, alignment marks are arranged on the step surfaces of the alignment steps, and the step surfaces of any two alignment steps have a height difference; the workpiece table can move to each preset position in sequence according to a preset sequence, so that the alignment marks of the alignment steps can be sequentially positioned in the alignment measurement area of the first measurement module in the preset sequence, at the moment, the first measurement module can be adopted to align the alignment marks of the alignment steps positioned in the alignment measurement area, and feeds back corresponding alignment measurement signals to the fitting calculation module, so that the fitting calculation module can obtain the alignment measurement signals fed back by the first measurement module according to the height measurement data measured by the vertical measurement device when the workpiece table is at the preset position, fitting out the vertical scaling error of the vertical measuring device by a preset fitting formula so as to obtain the vertical height of the workpiece platform, the vertical measuring device can calibrate the height measured by the vertical measuring device according to the determined vertical scaling error, therefore, the accuracy of the height of the workpiece platform measured by the vertical measuring device in the first direction is improved. Meanwhile, when the calibration device for the vertical scaling error is applied to the photoetching equipment, the vertical scaling error of the vertical measuring device in the photoetching equipment can be calibrated, so that the production yield of the semiconductor device prepared by the photoetching equipment can be improved.
Drawings
FIG. 1 is a schematic view of a vertical measuring device according to the related art;
FIG. 2 is a block diagram of a calibration apparatus for vertical scaling errors according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a tooling structure according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of another tooling structure provided in an embodiment of the present invention;
FIG. 5 is a schematic structural diagram of another tooling structure provided in an embodiment of the present invention;
fig. 6 is a schematic top view of a workpiece stage according to an embodiment of the present invention;
FIG. 7 is a schematic cross-sectional view taken along section A-A' of FIG. 6;
FIG. 8 is a schematic top view of a workpiece stage according to an embodiment of the present invention;
FIG. 9 is a schematic cross-sectional view taken along section B-B' of FIG. 8;
FIG. 10 is a schematic top view of a workpiece stage according to an embodiment of the present invention;
FIG. 11 is a schematic structural diagram of another tooling structure provided in an embodiment of the present invention;
FIG. 12 is a flow chart of a method for calibrating vertical scaling error according to an embodiment of the present invention;
FIG. 13 is a detailed flow chart of the fitting calculation module for determining vertical scaling error according to the embodiment of the present invention;
FIG. 14 is a detailed flowchart of another embodiment of the fitting calculation module for determining vertical scaling error;
FIG. 15 is a schematic diagram of a lithographic apparatus according to an embodiment of the invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
The embodiment of the invention provides a calibration device for vertical scaling errors, which is used for calibrating the vertical scaling errors of a vertical measurement device, wherein the vertical measurement device can be a device used for measuring the vertical position of a workpiece table in photoetching equipment, and can be an interferometer. For example, fig. 1 is a schematic structural diagram of a vertical measuring device in the related art. As shown in fig. 1, when the vertical measuring device 40 is an interferometer, the vertical measuring device 40 can measure the distance between the workpiece stage 50 and the mounting substrate 60 by using a corresponding interference principle, and determine the height of the workpiece stage 50 in the first direction Z according to the distance; wherein the first direction Z is a direction perpendicular to the substrate mounting surface 501 of the workpiece stage 50. However, due to the problems of installation error of the vertical measuring device 40, etc., the vertical measuring device 40 has a certain vertical scaling error in the first direction Z, so that the determined height of the workpiece stage 50 in the first direction Z and the actual height of the workpiece stage 50 in the first direction Z have a large error, the measured height is inaccurate, and the lithography quality of the lithographic apparatus on the substrate to be processed carried on the workpiece stage 50 is affected.
In order to solve the above technical problem, an embodiment of the present invention provides a calibration apparatus for a vertical scaling error, fig. 2 is a block diagram of a structure of the calibration apparatus for a vertical scaling error provided in the embodiment of the present invention, and fig. 3 is a schematic structural diagram of a tool structure provided in the embodiment of the present invention. Referring to fig. 2 and 3, the calibration apparatus 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 table 50; the tool structure 30 comprises a plurality of alignment steps 30, and in the first direction Z, a height difference exists between step surfaces of any two alignment steps (31, 32, …, 3i +1, … and 3 n); the step surface of each alignment step (31, 32, …, 3i +1, …, 3n) is provided with an alignment mark 301; the workpiece stage 50 sequentially moves to predetermined positions in a predetermined sequence, so that the alignment marks 301 of the alignment steps (31, 32, …, 3i +1, …, 3n) are sequentially located in the alignment measurement region of the first measurement module 10 in the predetermined sequence. The first measurement module 10 can align the alignment mark 301 of the alignment step in the alignment measurement region thereof, and feed back the alignment measurement signal to the fitting calculation module; the fitting calculation module 20 can obtain the height measurement data of the workpiece stage 50 measured by the vertical measurement device 40 in a one-to-one correspondence manner when the workpiece stage 50 is located at each preset position, perform fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determine the vertical scaling error of the vertical measurement device 40.
Since the alignment mark 301 is disposed on the step surface of each alignment step (31, 32, …, 3i +1, …, 3n), the alignment measurement signal fed back by the first measurement module 10 when aligning the alignment mark 301 located in the alignment measurement area may be a signal that can indicate the height of the step surface of the alignment step to which the alignment mark belongs, compared with the reference surface of the first measurement module 10.
For example, the sequential movement of the workpiece stage 50 to the preset positions in the preset sequence may be: the workpiece table 50 sequentially moves to a first preset position, a second preset position, …, an i-th preset position, an i + 1-th preset position, … and an n-th preset position, so that the alignment mark 301 of the alignment step 31, the alignment marks 301 and … of the alignment step 32, the alignment mark 301 of the alignment step 3i, the alignment marks 301 and … of the alignment step 3i +1 and the alignment mark 301 of the alignment step 3n are sequentially located in the alignment measurement area of the first measurement module 10; for example, when the workpiece stage 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; …, respectively; when the workpiece table 50 moves to the ith 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 stage 50 moves to the (i + 1) th preset position, the alignment mark 301 of the alignment step 3i +1 may be located in the alignment measurement area of the first measurement module 10; by analogy, when the workpiece stage 50 moves to the nth 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. The alignment measurement area of the first measurement module 10 may be, for example, an area where the first measurement module 10 can perform alignment measurement or an area where a reference surface of the first measurement module 10 is located, and the first measurement module 10 may measure that a height value of a step surface of a registration step to which the registration mark located on the reference surface belongs is zero.
When the workpiece stage 50 is at the first predetermined position, the fitting calculation module 20 obtains the vertical measurement device40 measured height measurement data of the workpiece table 50 at a first predetermined position; at this time, the alignment mark 301 of the alignment step 31 disposed in the workpiece stage 50 is located in the alignment measurement area of the first measurement module 10, so that the first measurement module 10 can align with the alignment mark 301 of the alignment step 31, and feed back an alignment measurement signal capable of indicating the height of the step surface of the alignment step 31 to the fitting calculation module 20, so that the fitting calculation module 20 obtains the height measurement data and the alignment measurement signal when the workpiece stage 50 is at the first preset position. Correspondingly, when the workpiece table 50 is at the second preset position, the fitting calculation module 20 may obtain a height measurement data of the workpiece table 50 at the second preset position, which is measured by the vertical measurement device 40; at this time, the alignment mark 301 of the alignment step 32 disposed in the workpiece stage 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 feed back an alignment measurement signal capable of indicating the height of the step surface of the alignment step 32 to the fitting calculation module 20, so that the fitting calculation module 20 obtains the height measurement data and the alignment measurement signal when the workpiece stage 50 is at 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 and the height difference between the corresponding step surfaces of the two alignment steps have a linear relationship, for example, the height measurement data when the workpiece stage 50 is at the i +1 th preset position and the height measurement data when the workpiece stage 50 is at the i th preset position are Fi+1-FiAnd 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 Hii+1Then there is Fi+1-Fi＝S*Hii+1+ b, where S is the vertical scaling error of the vertical measuring device 40 and b is a first constant; alternatively, the height measurement data has a linear relationship with the alignment measurement signal, i.e. Ri＝S*Fi+ b ', where S is the vertical scaling error of the vertical measurement device 40 and b' is a second constant.
Thus, the fitting calculation module 20 can perform fitting calculation based on the alignment measurement signal fed back by the first measurement module 10 according to the obtained n pairs of height measurement data, the alignment measurement signal and the preset fitting formula, determine a vertical scaling error of the height of the workpiece stage 50 in the first direction Z measured by the vertical measurement device 40, and provide the 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 workpiece stage 50 in the first direction Z, the measured height can be compensated according to the vertical scaling error, and the measurement accuracy of the vertical measurement device 40 on the height of the workpiece stage 50 in the first direction Z can be further improved. The preset fitting formula is a relational expression of a difference value between the height measurement data and a height difference between step surfaces of the alignment steps or a relational expression between the height measurement data and the alignment measurement signals. Meanwhile, for the purpose of calculating the accuracy of the result, each height measurement data obtained by the fitting calculation module 30 may be an average value of a plurality of height measurement values of the current position of the workpiece stage 50 measured by the vertical measurement device 40.
Optionally, with continuing reference to fig. 2 and 3, when the plurality of alignment steps 30 includes the first alignment step 31, the second alignment step 32, … and the nth alignment step 3n, the height difference H between the step surface of the ith alignment step 3i and the step surface of the (i + 1) th alignment step 3i +1ii+1Is a fixed value H; wherein n is more than or equal to 2, and i is more than or equal to 1<n, and n and i are positive integers. At this time, a height difference H between the step surface of the first registration step 31 and the step surface of the second registration step 3212The 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 fixed values H.
Wherein, when the height difference H between the step surface of the first contraposition step 31 and the step surface of the second contraposition step 3212…, and the height difference between the step surface of the n-1 st alignment step (not shown) 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 steps 3n may be arranged in sequence and distributed in a step shape.
For better illustration of the manner in which the alignment adjustments in the tooling structure are sequentially arranged and distributed in a stepped manner, as shown in fig. 4, taking the tooling 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 sequentially arranged and distributed in a stepped manner. At this time, the step surface of the second registration step 32 is higher than the step surface of the first registration step 31 by H12The step surface of the third alignment step 33 is higher than that of the second alignment step 32 by H23The step surface of the fourth alignment step 34 is higher than the step surface of the third alignment step 33 by H34The step surface of the fifth alignment step 35 is higher than the step surface of the fourth alignment step 34 by H45. Wherein H12、H23、H34And H45Are all fixed values H.
It should be noted that fig. 3 and fig. 4 are only exemplary drawings of an embodiment of the present invention, and fig. 3 shows that the tool structure 30 includes n alignment steps, n may 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 ith alignment step 3i, the (i + 1) th alignment step 3i +1, …, and the nth alignment step 3n are sequentially adjacent; in the embodiment of the present invention, the arrangement manner 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, …, and the n-th alignment step 3n may be other manners, and on the premise that a height difference exists between step surfaces of each alignment step in the tool structure, the arrangement manner of each alignment step in the tool structure in the embodiment of the present invention is not particularly limited.
For example, as shown in fig. 5, taking the example that the tooling structure includes five alignment steps, the height difference H between the step surface of the first alignment step 31 and the step surface of the second alignment step 3212A fixed value H, but the first alignment step 31 and the second alignment step 32 are not adjacent; between the step surface of the second alignment step 32 and the step surface of the third alignment step 33Height difference H23Is a fixed value H, and the second alignment step 32 is not adjacent to the third alignment step 33; the height difference H between the step surface of the third alignment step 33 and the step surface of the fourth alignment step 3434A fixed value H, but the third alignment step 33 and the fourth alignment step 34 are not adjacent; the height difference H between the step surface of the fourth alignment step 34 and the step surface of the fifth alignment step 3545Is a fixed value H, but the third alignment step 33 and the fourth alignment step 34 are not adjacent.
It should be noted that, in both fig. 4 and fig. 5, a tool structure including five alignment steps is taken as an example to exemplarily describe the technical solution of the embodiment of the present invention; the number of the alignment steps in the tool structure in the embodiment of the present invention may be set according to actual conditions, and is related to the accuracy of the finally determined vertical scaling error and the size of the area in the workpiece table that can be used for setting the tool structure.
For convenience of description, without specific explanation, the embodiments of the present invention take the arrangement of each alignment step shown in fig. 4 as an example, and exemplarily explain the technical solution of the embodiments of the present invention.
Optionally, the substrate placing surface of the workpiece table may include a tooling structure setting area and a substrate placing area, and the tooling structure setting area may be located on at least one side of the substrate placing area; wherein, frock structure setting zone can be used to set up the frock structure, and the basement is placed the district and can be used to place the pending basement. At this time, the tool structure setting area may be located on one side of the substrate placing area, or the tool structure setting area may surround the substrate placing area, and the like, and on the premise of not affecting the original design of the workpiece table, the embodiment of the present invention does not specifically limit the position relationship between the tool structure setting area and the substrate placing area.
Correspondingly, the tool structure can be directly arranged on the surface of the substrate placing surface of the workpiece table, so that the alignment step arranged in the tool structure setting area can form a corresponding convex structure which protrudes out of the substrate placing surface; or, a corresponding groove may be provided in the tooling structure setting area of the substrate placing surface, and each alignment step of the tooling structure is provided in the groove, so that the substrate placing surface of the workpiece table does not have a protrusion, and compared with the protrusion, the maximum displacement of the workpiece table in the first direction is not affected after the tooling structure is provided in the workpiece table. In the embodiment of the invention, on the premise of not influencing the normal movement of the workpiece table and the original design of the workpiece table, the arrangement mode of the tooling structure in the workpiece table is not specifically limited.
Fig. 6 is a schematic top view of a workpiece stage according to an embodiment of the present invention, and fig. 7 is a schematic cross-sectional view taken along a-a' of fig. 6. As shown in fig. 6 and 7 in conjunction, the substrate placement face 501 of the workpiece stage 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 being usable to dispose sensors and the like. The non-substrate placing area 5012 may include a tooling structure setting area 5021, the tooling structure setting area 5021 is located on one side of the substrate placing area 5011, the tooling structure setting area 5021 is provided with a groove 5001, and alignment steps (31, 32, 33, 34 and 35) of the tooling structure are all arranged in the groove 5021. At this time, the prepared tooling structure may be installed into the groove 5021, or each alignment step (31, 32, 33, 34 and 35) of the tooling structure may be formed by directly forming a corresponding step structure on the groove bottom when the groove 5001 is formed, and providing a corresponding alignment mark on the step surface of each step structure.
Illustratively, fig. 8 is a schematic top view of a further workpiece stage according to an embodiment of the present invention, and fig. 9 is a schematic cross-sectional view taken along a section B-B' in fig. 8. The same points in fig. 8 and 9 as those in fig. 6 and 7 may refer to the description of fig. 6 and 7, which is not repeated herein, and here, only the differences in fig. 8 and 9 from fig. 6 and 7 are exemplarily described. As shown in fig. 8 and 9, a plurality of independent grooves 5001 are provided in the tool structure setting region 5021 of the workpiece stage 50, so that each alignment step (31, 32, 33, 34, 35) of the tool structure is disposed in each groove 5001 in a one-to-one correspondence. At this time, each alignment step of the tooling structure needs to be separately prepared, and each prepared alignment step is correspondingly arranged in each groove 5001 one by one; alternatively, when the grooves 5001 are provided, the depth of each groove 5001 may be set according to the height of the step surface of the alignment step provided in the groove 5001, so that each groove 5001 should have a different depth.
As shown in fig. 8, when the fixture structure setting area 5021 is provided with a plurality of grooves 5001, the grooves 5001 are located on the same side of the substrate placing area 5011, and at this time, the grooves 5001 are arranged in a straight line along a second direction X, and the second direction X is parallel to the step surface of the alignment step. Alternatively, as shown in fig. 10, when the tooling structure setting area 5021 is provided with a plurality of grooves 5001, the plurality of grooves 5001 may be provided around the substrate placement area 5011.
Optionally, fig. 11 is a schematic structural diagram of another tooling structure provided in an embodiment of the present invention. As shown in fig. 2 and 11, the first measurement module 10 may include an alignment light source emitting unit 110 and a plurality of photoelectric signal measurement units (121, 122, 123, 124, 125); the photoelectric signal measuring units (121, 122, 123, 124, 125) are arranged on the back surfaces of the alignment steps (31, 32, 33, 34, 35) in a one-to-one correspondence manner, and the back surfaces are opposite to the step surfaces. The alignment light source emitting unit 110 is used for providing an alignment light source to a focal plane thereof; the photoelectric signal measuring units (121, 122, 123, 124, 125) are configured to receive alignment light beams of the alignment light source when the alignment marks of the alignment steps corresponding thereto are located on the focal plane of the alignment light source emitting unit 110, convert the alignment light beams into alignment measurement signals, and feed the alignment measurement signals back to the fitting calculation module 20.
When the alignment mark of the alignment step is located on the focal plane of the alignment light source exit 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 shows 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. Meanwhile, the alignment marks arranged on the step surfaces of each alignment step may be, for example, strip-shaped hollow structures, or other marks for alignment, which is not specifically limited in this embodiment of the present invention. Accordingly, the size of each alignment step is related to the size of the alignment mark and the photoelectric signal measuring unit disposed thereon, i.e. the size of the alignment step should satisfy the requirements set for the alignment mark 301 and the photoelectric signal measuring unit.
For example, with continuing reference to fig. 2 and fig. 11, when the workpiece stage moves to the first preset position, the alignment mark 301 of the first alignment step 31 disposed in the workpiece stage is located on the focal plane of the alignment light source emission unit 110, so that the photoelectric signal measurement unit 121 disposed on the back of the first alignment step 31 can receive the alignment light source emitted from the alignment light source emission unit 110, perform photoelectric conversion on the alignment light source, and convert the alignment light source into an alignment measurement signal that can be processed by the fitting calculation module 20, where the 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 obtains the height values of the workpiece stage at the first preset position measured by the set of vertical measurement devices 40, and calculates the average value of the height values as the height measurement data F of the workpiece stage at the first preset position1. When the workpiece stage moves to the second preset position, the alignment mark 301 of the second alignment step 32 disposed in the workpiece stage is located on the focal plane of the alignment light source emitting unit 110, so that the photoelectric signal measuring unit 122 disposed on the back of the second alignment step 32 can receive the alignment light source emitted by the alignment light source emitting unit 110, and convert the alignment light source into an alignment measurement signal which can be processed by the fitting calculation module 20 after performing photoelectric conversion, and the 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 obtains the height values of the workpiece stage at the second preset position measured by the set of vertical measurement devices 40, and calculates the average value of the height values as the height measurement data F of the workpiece stage at the second preset position2. By analogy, the height measurement data F of the workpiece stage at the third preset position corresponding to the position alignment mark 301 of the third position alignment step 33 at the focal plane can be obtained in sequence3And the fourth pairHeight measurement data F of the corresponding workpiece stage at the fourth preset position when the alignment mark 301 of the position step 34 is at the focal plane4And height measurement data F when the stage corresponding to the position of the alignment mark 301 of the fifth alignment stage 35 is at the fifth preset position5。
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 the first measurement module aligned with the light source emitting unit 110 are kept unchanged, and when the height difference between the step surfaces of two adjacent alignment steps is known, the height measurement data F of the workpiece stage at the ith preset position corresponding to the position where the alignment mark 301 of the ith alignment step is located at the focal plane can be obtainediAnd height measurement data F when the workpiece stage corresponding to the i +1 th alignment step when the alignment mark 301 is at the focal plane is at the i +1 th preset positioni+1Have the following relationship between:
Fi+1-Fi＝S*Hii+1+ b (type one)
Wherein Hii+1The height difference between the step surface of the ith alignment step and the step surface of the (i + 1) th alignment step is obtained, S is a vertical scaling error of the vertical measuring device, and b is a first constant related to the difference between the installation height of the first measuring module and the installation height of the vertical measuring device. Therefore, the formula I can be used as a preset fitting formula, and F is obtained by calculation according to height measurement datai+1–FiAnd obtaining and F from alignment measurement signals fed back from the respective photoelectric signal measurement unitsi+1–FiCorresponding to Hii+1And with Fi+1–FiAnd Hii+1And performing linear fitting on the parameters, namely fitting and calculating corresponding vertical scaling errors, and providing the vertical scaling errors for the vertical measuring device 40, so that the vertical measuring device 40 calibrates the measurement height of the workpiece table, and the accuracy of the height of the workpiece table measured by the vertical measuring device 40 can be improved.
It should be noted that the fitting calculation formula and the process of determining the vertical scaling error of the vertical measurement device are only exemplary methods according to 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 calibration device for the vertical scaling error provided by the embodiment of the invention, the embodiment of the invention does not specifically limit the fitting calculation formula and the specific process for determining the vertical scaling error of the vertical measuring device.
For example, with continued reference to fig. 2 and 11, when the workpiece stage is in the first preset position, the first alignment step 31 may be located within the alignment measurement area of the first measurement module, but it may not be located at the focal plane of the alignment light source exit unit 110 in the first measurement module 10; at this time, the fitting calculation module 20 obtains the height values of the workpiece stage at the first preset position measured by the set of vertical measurement devices 40, and calculates the average value of the height values as the height measurement data F of the workpiece stage at the first preset position1(ii) a Then, the workpiece stage continues to move until the alignment mark 301 of the first alignment step 31 is located on the focal plane of the alignment light source emission unit 110, and an alignment measurement signal generated in the process of aligning the alignment mark 301 of the first alignment step 31 is fed back by the photoelectric signal measurement unit 121 arranged on the back of the first alignment step 31, wherein the alignment measurement signal is capable of indicating a height difference between the height of the step plane of the first alignment step 31 when the workpiece stage is at the first preset position and the height of the step plane of the first alignment step 31 when the alignment mark 301 of the first alignment step 31 is located on the focal plane of the alignment light source emission unit 110; and for the accuracy of the calculation, a plurality of alignment measurement signals may be fed back to the data processor 20, and the data processor 20 may calculate an average value of the plurality of alignment measurement signals as a height difference between the height of the step surface of the first alignment step 31 when the workpiece stage is at the first preset position and the height of the step surface of the first alignment step 31 when the first alignment step 31 is at the focal plane of the alignment light source emission unit 110, that is, the height difference is regarded as the alignment height difference R of the first alignment step 311. Likewise, when the workpiece stage is in the second preset position, the second alignment step 32 may be located within the alignment measurement area of the first measurement module, but it may not be located in the alignment light source exit unit 1 in the first measurement module 1010, a focal plane; at this time, the fitting calculation module 20 obtains the height values of the workpiece stage at the second preset position measured by the set of vertical measurement devices 40, and calculates the average value of the height values as the height measurement data F of the workpiece stage at the second preset position2(ii) a Then, the workpiece stage continues to move until the alignment mark 301 of the second alignment step 32 is located on the focal plane of the alignment light source emission unit 110, and an alignment measurement signal generated in the process of aligning the alignment mark 301 of the second alignment step 32 is fed back by the photoelectric signal measurement unit 122 arranged on the back of the second alignment step 32, where the alignment measurement signal is a height difference that can represent the height of the step surface of the second alignment step 32 when the workpiece stage is at the second preset position and the height of the step surface of the second alignment step 32 when the alignment mark 301 of the second alignment step 32 is located on the focal plane of the alignment light source emission unit 110; similarly, a plurality of alignment measurement signals may be fed back to the data processor 20, and the data processor 20 may calculate an average of the plurality of alignment measurement signals as the alignment height difference R of the second alignment stage 322. By analogy, the height measurement data F of the vertical measurement device 40 when the workpiece table is at the third preset position can be obtained respectively3And the alignment height difference R of the third alignment step 333Height measurement data F of the vertical measuring device 40 when the workpiece table is at the fourth preset position4And a fourth alignment step 344And height measurement data F of the vertical measuring device 40 when the workpiece table is at a fifth predetermined position5And the alignment height difference R of the fifth alignment step 355。
After the first measurement module 10 is installed and fixed, the position of the focal plane of the first measurement module aligned with the light source exit unit 110 may be considered to remain unchanged, and the alignment height difference R of the ith alignment step may be obtainediHeight measurement data F of the vertical measuring device 40 at the ith predetermined position from the workpiece tableiHave the following relationship between:
Ri＝S*Fi+ b' (type two)
Wherein S is the vertical scaling error of the vertical measuring device, and b' is the error of the first measuring moduleAnd a second constant related to a difference between the mounting height of the vertical measuring device. Accordingly, the formula two can be used as the preset fitting formula, and R is usediAnd FiAnd performing linear fitting on the parameters, namely fitting and calculating a corresponding vertical scaling error S, and providing the vertical scaling error S for the vertical measuring device 40, so that the vertical measuring device 40 calibrates the measurement height of the workpiece table, and the accuracy of the height of the workpiece table measured by the vertical measuring device 40 can be improved.
The embodiment of the invention also provides a calibration method of the vertical scaling error, which can be executed by adopting the calibration device of the vertical scaling error provided by the embodiment of the invention and is used for calibrating the vertical scaling error of the vertical measuring device. FIG. 12 is a flowchart of a method for calibrating vertical scaling errors according to an embodiment of the present invention. As shown in fig. 12, the calibration method includes:
s100, sequentially moving the workpiece table to each preset position in a preset sequence, so that the alignment marks of each alignment step are sequentially positioned in an alignment measurement area of the first measurement module in the preset sequence;
s200, aligning the alignment mark of the alignment step in the alignment measurement area by the first measurement module, and feeding back an alignment measurement signal to the fitting calculation module;
s300, when the workpiece table is located at each preset position, the fitting calculation module correspondingly obtains height measurement data of the workpiece table measured by the vertical measurement device one by one, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines a vertical scaling error of the vertical measurement device.
Specifically, each preset position corresponds to each alignment step of the tool structure one by one, namely when the workpiece table moves to a preset position, the alignment step corresponding to the preset position is located in an alignment measurement area of the first measurement module; at this time, the fitting calculation module obtains height measurement data of the workpiece platform at the preset position, which is measured by the vertical measurement device, and the first measurement module aligns the alignment mark of the alignment step corresponding to the preset position and feeds back a corresponding alignment measurement signal to the fitting calculation module. Therefore, the workpiece table can move to each preset position in sequence, and the fitting calculation module can sequentially obtain height measurement data of the workpiece table at each preset position, which is measured by the vertical measurement device; correspondingly, the workpiece table can move to each preset position in sequence, and the first measurement module can also align the alignment marks of each alignment step in the alignment measurement area in sequence and feed back alignment measurement signals when the alignment marks of each alignment step are aligned in sequence. The fitting calculation module can perform fitting calculation according to the obtained height measurement data, the alignment measurement signals and a preset fitting formula by taking each alignment measurement signal fed back by the first measurement module as a reference, determine a vertical scaling error of the vertical measurement device, and provide the vertical scaling error for the vertical measurement device, so that when the vertical measurement device measures the height of the position of the workpiece table in the first direction in the follow-up process, the measured height can be compensated according to the vertical scaling error, and the measurement accuracy of the vertical measurement device on the height of the workpiece table in the first direction can be improved. The alignment measurement area of the first measurement module may be an area where the first measurement module 10 can perform alignment measurement or an area where a reference surface of the first measurement module 10 is located, and the first measurement module 10 may measure that a height value of a step surface of a registration step to which the registration mark located on the reference surface belongs is zero.
Correspondingly, when the alignment steps comprise a first alignment step, a second alignment step, … and an nth alignment step, 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 a first preset position, a second preset position, … and an nth preset position, the difference value of the two height measurement data has a linear relationship with the height difference of the step surfaces of the two corresponding alignment steps, for example, the height measurement data when the workpiece table is at the (i + 1) th position and the height measurement data when the workpiece table is at the (i) th preset position are Fi+1-FiAnd the height difference between the step surface of the i +1 th alignment step and the step surface of the i-th alignment step is Hii+1Then there is Fi+1-Fi＝S*Hii+1+ b, wherein S is verticalA vertical scaling error to the measurement device, b being a first constant; alternatively, the height measurement data has a linear relationship with the alignment measurement signal, i.e. Ri＝S*Fi+ b ', where S is the vertical scaling error of the vertical measurement device and b' is a second constant. Meanwhile, for the accuracy of the calculation result, each height measurement data acquired by the fitting calculation module may be an average value of a plurality of height measurement values of the current position of the workpiece stage measured by the vertical measurement device.
Optionally, when the alignment steps include a first alignment step, a second alignment step, …, and an nth alignment step, and a height difference between the ith alignment step and the (i + 1) th alignment step is a fixed value H, and each preset position is a first preset position, a second preset position, a …, and an nth preset position, it may be considered that a difference value of the two height measurement data and a height difference of step surfaces of the two corresponding alignment steps have a linear relationship; at the moment, the alignment measurement area of the first measurement module is the area where the reference surface of the first measurement module is located; wherein n is more than or equal to 2, i is more than or equal to 1 and less than or equal to n, and both n and i are positive integers. FIG. 13 is a flowchart illustrating a method for determining vertical scaling error by the fitting calculation module according to an embodiment of the present invention. As shown in fig. 13, the method for determining the vertical scaling error by the processing module includes:
s11, when an alignment measurement signal fed back when the first measurement module aligns with the alignment mark of the ith alignment step is received, determining that the workpiece table is located at the ith preset position;
s12, acquiring height measurement data of the workpiece platform at the ith preset position measured by the vertical measuring device; the height measurement data comprises a plurality of height measurement values when the workpiece table is located at a current preset position;
s13, calculating the average value of each height measurement value in the height measurement data when the workpiece platform is located at the ith preset position, and taking the average value of each height measurement value in the height measurement data as the vertical height of the workpiece platform when the workpiece platform is located at the ith preset position;
s14, circularly executing S11, S12 and S13 until the vertical height of the workpiece table at each preset position is obtained;
s15, fitting formula | Fi+1–FiPerforming fitting calculation to determine a vertical scaling error S of the vertical measuring device; wherein the average value of a plurality of height measurement values measured by the vertical measuring device when the workpiece table is at the ith preset position is Fi+1The average value of a plurality of height measurement values is obtained when the workpiece platform measured by the vertical measuring device is positioned at the (i + 1) th preset position; b is a first constant.
For example, as shown in fig. 2 and fig. 3, when the workpiece stage 50 moves to the first preset position, the alignment mark 301 of the first alignment step 31 disposed in the workpiece stage 50 is located in 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 obtains a set of height measurement values measured by the vertical measurement device 40 when the workpiece stage 50 is at the first predetermined position, and calculates an average value of the set of height measurement values as a vertical height F of the workpiece stage 50 when the workpiece stage 50 is at the first predetermined position1. When the workpiece table 50 moves to the second preset position, the alignment mark 301 of the second alignment step 32 disposed in the workpiece table 50 is located in 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 obtains the height measurement values of the workpiece stage 50 at the second predetermined position measured by the set of vertical measurement devices 40, and calculates an average value of the height measurement values as the vertical height F of the workpiece stage 50 at the second predetermined position2. And so on until the vertical height F of the workpiece table 50 at the first preset position is obtained1Vertical height F when located at second preset position2…, vertical height F at i-th preset positioniAnd a vertical height F at the i +1 th preset positioni+1…, and a vertical height F at the nth predetermined positionnNamely, n vertical heights corresponding to the n preset positions are obtained.
After the first measurement module 10 is fixed, the position of the focal plane aligned with the light source emitting unit 110 is not changed, and two adjacent measurement modules are adjacent to each otherWhen the height difference between the step surfaces of the respective alignment steps is a fixed value H, it is possible to know the vertical height F of the workpiece stage 50 located at the ith preset position corresponding to the alignment mark 301 of the ith alignment step 3i located at the alignment measurement regioniAnd a vertical height F when the workpiece table 50 corresponding to the alignment mark 301 of the (i + 1) th alignment step is positioned in the alignment measurement region is positioned at the (i + 1) th preset positioni+1Have the following relationship between:
Fi+1-Fih + b (three formula)
Wherein S is a vertical scaling error of the vertical measuring device, and b is a first constant related to a difference between the mounting height of the first measuring module and the mounting height of the vertical measuring device. Therefore, the formula III is used as a preset fitting formula, and F is obtained by calculating the vertical height of the workpiece table 50 at each preset positioni+1–FiAnd with Fi+1–FiAnd H is used for carrying out linear fitting on the parameters, namely, the corresponding vertical scaling error S can be calculated in a fitting mode, and the vertical scaling error S is provided for the vertical measuring device 40, so that the vertical measuring device 40 can calibrate the measurement height of the workpiece table, and the accuracy of the height of the workpiece table measured by the vertical measuring device 40 can be improved.
Optionally, when the plurality of alignment steps include a first alignment step, a second alignment step, …, and an nth alignment step, and each preset position is a first preset position, a second preset position, …, and an nth preset position, respectively, it may be considered that the height measurement data and the alignment measurement signal have a linear relationship, and at this time, the alignment measurement area of the first measurement module is an area where the first measurement module can perform alignment measurement. Accordingly, fig. 14 is a specific flowchart of another fitting calculation module for determining a vertical scaling error according to an embodiment of the present invention. As shown in fig. 14, the method for determining the vertical scaling error by the processing module may include:
s21, when the workpiece platform is located at the ith preset position, acquiring height measurement data F of the workpiece platform, which is measured by the vertical measuring device, when the workpiece platform is located at the ith preset positioni'; wherein the height measurement data FiFor the workpiece table to be in the current preset positionA height measurement of time;
s22, acquiring an alignment measurement signal R generated by the first measurement module in the process that the workpiece platform starts to move from the ith preset position to the alignment mark of the first measurement module aligned with the ith alignment stepi(ii) a The alignment measurement signal is the displacement of the workpiece table in the first direction when the workpiece table starts to move from the current preset position to the alignment mark of the first measurement module aligned with the alignment step;
s23, circularly executing S21 and S22 until height measurement data of the workpiece platform at each preset position are obtained, wherein the height measurement data are measured by the vertical measurement device, and alignment measurement signals generated in the process that the first measurement module aligns the alignment marks of each alignment step are obtained;
s24, fitting formula Ri＝S*Fi+ b' performing fitting calculation to determine a vertical scaling error S of the vertical measuring device; wherein b' is a second constant.
For example, as shown in fig. 2 and fig. 3, the alignment measurement area may be an area that can be measured by the first measurement module 10, and when the first measurement module 10 aligns the alignment mark of the corresponding alignment step, the alignment mark of the alignment step should be on the reference surface of the first measurement module 10, that is, when the first measurement module 10 aligns the alignment mark of the alignment step, the first measurement module 10 measures that the height value of the step surface of the alignment step is zero. When the workpiece table 50 is located at the first preset position, the first alignment step 31 may be located in the alignment measurement area of the first measurement module 10, but the first measurement module 10 may not be aligned with the alignment mark of the first alignment step 31; at this time, the fitting calculation module 20 obtains the height values of the workpiece stage 50 at the first predetermined position measured by the set of vertical measuring devices 40, and calculates the average value of the height values as the obtained height measurement data F of the vertical measuring devices 401(ii) a Then, the workpiece table 50 will continue to move until the first measurement module 10 is aligned with the alignment mark 301 of the first alignment step 31, that is, the step surface of the first alignment step 31 to which the workpiece table 50 moves is located on the reference surface of the first measurement module 10; at this time, the first measurement module 10 feeds back the stage 50 from the first measurement moduleThe alignment measurement signal R generated by the first measurement module 10 starts from the preset position to the process that the first measurement module 10 aligns with the alignment mark 301 of the first alignment step 311As the displacement of the workpiece stage 50 in the first direction Z during the alignment of the alignment mark 301 in the first alignment stage 31 of the first measurement module 10. When the workpiece stage 50 is located at the second predetermined position, the second alignment step 32 may be located in the alignment measurement area of the first measurement module 10, but the first measurement module 10 may not be aligned with the alignment mark 301 of the second alignment step 32; at this time, the fitting calculation module 20 obtains the height values of the workpiece stage 50 at the second predetermined position measured by the set of vertical measuring devices 40, and calculates the average value of the height values as the obtained height measurement data F of the vertical measuring devices 402(ii) a Then, the workpiece table 50 will continue to move until the first measurement module 10 is aligned with the alignment mark 301 of the second alignment step 32, that is, the step surface of the second alignment step 32 to which the workpiece table 50 moves is located on the reference surface of the first measurement module 10; at this time, the first measurement module 10 feeds back the alignment measurement signal R generated by the first measurement module 10 from the second predetermined position to the alignment mark 301 of the second alignment step 32 in the process of aligning the first measurement module 10 with the alignment mark 50 of the workpiece stage 502As the displacement amount of the workpiece table 50 in the first direction Z during the alignment of the alignment mark 301 in the second alignment stage 32 by the first measurement module 10. And so on until obtaining the height measurement data F of the workpiece table 50 at the first preset position measured by the vertical measuring device 401Height measurement data F at a second predetermined position2…, height measurement data F at i-th preset positioniHeight measurement data F at i +1 th preset positioni+1… height measurement data F at n-th preset positionnAnd correspondingly obtaining an alignment measurement signal R generated by the first measurement module 10 in the process of aligning the alignment mark 301 in the first alignment stage 311An alignment measurement signal R generated during alignment of the alignment mark 301 in the second alignment stage 322…, alignment measurement signal R generated in the process of aligning the alignment mark 301 in the i-th alignment stage 3iiAn alignment measurement signal R generated in the process of aligning the alignment mark 301 in the (i + 1) th alignment stage 3i +1i+1…, alignment measurement signal R generated in the process of aligning the alignment mark 301 of the n-th alignment stage 3nn。
After the first measurement module 10 is installed and fixed, the height of the reference surface is also considered to be constant, and the alignment measurement signal R generated by the first measurement module in the process of aligning the alignment mark of the ith alignment step 3i can be obtainediHeight measurement data F of the stage 50 at the i-th predetermined positioni' have the following relationship:
Ri＝S*Fi'+ b' (type four)
Wherein S is a vertical scaling error of the vertical measuring device, and b' is a second constant related to a difference between the mounting height of the first measuring module and the mounting height of the vertical measuring device. Therefore, the formula four is used as a preset fitting formula, linear fitting is carried out by taking Ri and Fi' as parameters, and then the corresponding vertical scaling error S can be calculated in a fitting manner and provided to the vertical measuring device 40, so that the vertical measuring device 40 can calibrate the measurement height of the workpiece table, and the accuracy of the height of the workpiece table measured by the vertical measuring device 40 can be improved.
The embodiment of the present invention further provides a lithographic apparatus, which includes the calibration device for vertical scaling error provided in the embodiment of the present invention, and the calibration device for vertical scaling error can be used to execute the calibration method for vertical scaling error provided in the embodiment of the present invention, so that the lithographic apparatus has the technical features and beneficial effects of the calibration device for vertical scaling error provided in the embodiment of the present invention and the calibration method executed by the calibration device for vertical scaling error provided in the embodiment of the present invention, and the same points can refer to the above description of the calibration device for vertical scaling error and the calibration method provided in the embodiment of the present invention, and are not described herein again.
Illustratively, FIG. 15 is a schematic structural diagram of a lithographic apparatus according to an embodiment of the invention. As shown in fig. 15, the lithographic apparatus comprises at least one workpiece stage and at least one station, which may be, for example, two workpiece stages (51 and 52) and two stations (201 and 202), which may include an exposure station; each work head (51, 52) comprises a substrate placement surface 501; a substrate placing surface 501 of each work table (51, 52) for placing a substrate (71, 72) to be processed; the workpiece tables (51, 52) drive the substrates (71, 72) to be processed which are placed on the substrate placing 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 for measuring the height of a workpiece table at the station of the workpiece table in the first direction Z; the first direction Z is a direction perpendicular to the substrate placement surface 501. Correspondingly, the lithographic apparatus is further provided with a calibration device for vertical scaling errors, which is used to calibrate the vertical scaling errors of the vertical measurement device 40 at each station, and the specific process of the calibration device for vertical scaling errors in calibrating the vertical measurement device 40 at each station may be the same or different, which is not specifically limited in the embodiments of the present invention.
Therefore, when the calibration device of the vertical scaling error determines the vertical scaling error of the corresponding vertical measuring device, the determined vertical scaling error can be provided for the corresponding vertical measuring device, so that when the vertical measuring device measures the workpiece table at the station where the vertical measuring device is located, automatic compensation can be carried out according to the vertical scaling error, and the production yield of the semiconductor device prepared by the photoetching equipment can be improved.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims (12)

1. A calibration device for vertical scaling errors is used for calibrating vertical scaling errors of a vertical measurement device, and is characterized in that the vertical measurement device is used for measuring the height of a workpiece table in a first direction, and the first direction is a direction perpendicular to a base placing surface of the workpiece table; the calibration device includes: the device comprises a tool structure, a first measurement module and a fitting calculation module;
the tool structure is arranged in the workpiece table; the tool structure comprises a plurality of alignment steps, and in the first direction, the step surfaces of any two alignment steps have a height difference; the step surface of each alignment step is provided with an alignment mark; the workpiece table sequentially moves to each preset position in a preset sequence, so that the alignment marks of the alignment steps are sequentially located in the alignment measurement area of the first measurement module in the preset sequence;
the first measurement module is used for aligning the alignment mark of the alignment step in the alignment measurement area and feeding back an alignment measurement signal to the fitting calculation module;
the fitting calculation module is used for acquiring height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performing fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determining a vertical scaling error of the vertical measurement device.
2. The calibration device according to claim 1, wherein the plurality of alignment steps comprises a first alignment step, a second alignment step, …, an nth alignment step, and a height difference between a step surface of the ith alignment step and a step surface of the (i + 1) th alignment step is a fixed value H; wherein n is more than or equal to 2, i is more than or equal to 1 and less than n, and both n and i are positive integers.
3. The calibration device as set forth in claim 2, wherein the first alignment step, the second alignment step, … and the nth alignment step are arranged in sequence and are distributed in a step shape.
4. The calibration device of claim 2, wherein the substrate placement surface comprises a tooling structure setting area and a substrate placement area; the tool structure setting area is positioned on at least one side of the substrate placing area;
the tool structure setting area is used for setting the tool structure, and the substrate placing area is used for placing a substrate to be processed.
5. The calibrating device according to claim 4, wherein the tool structure setting area is provided with a groove; each alignment step is arranged in the groove.
6. The calibration device according to claim 4, wherein the tooling structure setting area is provided with a plurality of independent grooves; the alignment steps are correspondingly arranged in the grooves one by one.
7. The alignment device of claim 6 wherein each of the recesses is arranged in series along the second direction; the second direction is parallel to the step surface;
alternatively, a plurality of the grooves may be provided around the substrate placement area.
8. The calibration device of claim 1, wherein the first measurement module comprises an alignment light source exit unit and a plurality of optoelectronic signal measurement units; each photoelectric signal measuring unit is arranged on the back surface of each alignment step in a one-to-one correspondence manner; the back surface is opposite to the step surface;
the alignment light source emergent unit is used for providing an alignment light source to a focal plane of the alignment light source emergent unit;
the photoelectric signal measuring unit is used for receiving the alignment light beam of the alignment light source when the alignment mark of the alignment step corresponding to the photoelectric signal measuring unit is positioned on the focal plane, converting the alignment light beam into an alignment measuring signal and feeding the alignment measuring signal back to the fitting calculation module.
9. A method for calibrating vertical scaling errors, which is performed by the calibration apparatus for vertical scaling errors according to any one of claims 1 to 8, and is used for calibrating vertical scaling errors of a vertical measurement apparatus, the method comprising:
the workpiece table sequentially moves to each preset position in a preset sequence, so that the alignment marks of the alignment steps are sequentially positioned in the alignment measurement area of the first measurement module in the preset sequence;
the first measurement module aligns alignment marks of the alignment steps in the alignment measurement area and feeds back alignment measurement signals to the fitting calculation module;
and the fitting calculation module acquires the height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines the vertical scaling error of the vertical measurement device.
10. The calibration method according to claim 9, wherein the plurality of alignment steps comprises a first alignment step, a second alignment step, …, and 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; wherein n is more than or equal to 2, i is more than or equal to 1 and less than or equal to n, and both n and i are positive integers;
each preset position is a first preset position, a second preset position, … and an nth preset position respectively;
the fitting calculation module obtains height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines a vertical scaling error of the vertical measurement device, and includes:
s11, when an alignment measurement signal fed back when the first measurement module aligns with the alignment mark of the ith alignment step is received, determining that the workpiece table is located at the ith preset position;
s12, acquiring height measurement data of the workpiece platform at the ith preset position measured by the vertical measuring device; the height measurement data comprises a plurality of height measurement values of the workpiece platform located at the current preset position;
s13, calculating the average value of each height measurement value in the height measurement data when the workpiece platform is located at the ith preset position, and taking the average value of each height measurement value in the height measurement data as the vertical height of the workpiece platform when the workpiece platform is located at the ith preset position;
s14, circularly executing S11, S12 and S13 until the vertical height of the workpiece table at each preset position is obtained;
s15, fitting formula | Fi+1–FiPerforming fitting calculation to determine a vertical scaling error S of the vertical measuring device; wherein, FiIs the average value of a plurality of height measurement values measured by the vertical measuring device when the workpiece platform is positioned at the ith preset position, Fi+1The average value of a plurality of height measurement values measured by the vertical measuring device when the workpiece platform is positioned at the (i + 1) th preset position is obtained; b is a first constant.
11. The calibration method according to claim 9, wherein the plurality of alignment steps comprises a first alignment step, a second alignment step, …, and 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; wherein n is more than or equal to 2, i is more than or equal to 1 and less than or equal to n, and both n and i are positive integers;
the preset positions are respectively a first preset position, a second preset position, … and an nth preset position;
the fitting calculation module acquires height measurement data of the workpiece table measured by the vertical measurement device in a one-to-one correspondence manner when the workpiece table is located at each preset position, performs fitting calculation according to each height measurement data and each alignment measurement signal by using a preset fitting formula, and determines a vertical scaling error of the vertical measurement device, and the fitting calculation module comprises:
s21, when the workpiece platform is located at the ith preset position, acquiring height measurement data F of the workpiece platform, which is measured by the vertical measuring device, when the workpiece platform is located at the ith preset positioni'; wherein the height measurement data Fi' is a height measurement value of the workpiece table at the current preset position;
s22, acquiring an alignment measurement signal R generated by the first measurement module in the process that the workpiece platform moves from the ith preset position to the alignment mark of the ith alignment step aligned by the first measurement modulei(ii) a The alignment measurement signal is the displacement of the workpiece stage in the first direction when the workpiece stage starts to move from the current preset position to the alignment mark aligned with the alignment step by the first measurement module;
s23, circularly executing S21 and S22 until height measurement data of the workpiece table at each preset position, which are measured by the vertical measuring device, are obtained, and obtaining an alignment measurement signal generated in the process that the first measuring module aligns the alignment mark of each alignment step;
s24, fitting formula Ri＝S*Fi'+ b' to perform fitting calculation to determine the vertical scaling error S of the vertical measuring device; wherein b' is a second constant.
12. A lithographic apparatus, comprising: at least one workpiece table and at least one station;
the workpiece stage comprises a substrate placement surface; the substrate placing surface is used for placing a substrate to be treated; the workpiece table drives the substrate to be processed to move between the stations;
each station is provided with at least one vertical measuring device; the vertical measuring device is used for measuring the height of a workpiece table at the station of the vertical measuring device in a first direction; the first direction is a direction perpendicular to the base placement surface;
the lithographic apparatus further comprises a calibration device for vertical scaling errors according to any of claims 1 to 8.
CN202011630468.0A 2020-12-31 2020-12-31 Calibration device and calibration method for vertical scaling error and photoetching equipment Pending CN114690579A (en)

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