Measuring device, measuring system and measuring method

Abstract

The embodiment of the invention provides a measurement device, a measurement system and a measurement method, relates to the technical field of measurement, and solves the problem of low measurement precision of the measurement device. According to the specific scheme, the measuring device comprises a first interferometer and a displacement table which are arranged in a spaced mode in the first direction, and a second interferometer and the displacement table which are arranged in a spaced mode in the second direction. The sum of the number of first optical axes of the first interferometer and the number of second optical axes of the second interferometer is larger than the number of degrees of freedom of the displacement table. The first redundant optical axis is used for testing a to-be-tested object arranged on the displacement table in the second direction, and the rest first optical axes and the multiple second optical axes are used for movement of the servo displacement table in multiple degrees of freedom. The second redundant optical axis is used for testing a to-be-tested object arranged on the displacement table in the first direction, and the other second optical axes and the multiple first optical axes are used for movement of the servo displacement table in multiple degrees of freedom. The embodiment of the invention is used for the process of measuring the to-be-tested object by the measuring device.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of measurement technology, and in particular, to a measurement device, a measurement system, and a measurement method. Background Art

[0002] At present, the commonly used displacement measurement equipment in semiconductor manufacturing and testing equipment is the laser interferometer, which has the characteristics of non-contact, high precision and high sensitivity, and can achieve nanometer-level displacement measurement. The laser interferometer measures the displacement by identifying the Doppler shift caused by the movement of the long reflector on the precision translation stage. Therefore, the measurement range of the laser interferometer is related to the size of the long reflector, and the measurement accuracy of the laser interferometer is related to the surface shape of the long reflector.

[0003] However, compared with small-sized plane mirrors, the processing accuracy of large-sized and special-shaped long strip reflectors is difficult to guarantee, and the surface accuracy of large-sized and special-shaped long strip reflectors is also difficult to test and calibrate, which reduces the measurement accuracy of the laser interferometer. Summary of the invention

[0004] The embodiments of the present application provide a measuring device, a measuring system and a measuring method, which solve the problem of low measurement accuracy of the measuring device.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application adopts the following technical solution.

[0006] In a first aspect, an embodiment of the present application provides a measuring device, which includes: a displacement stage, a first interferometer and a second interferometer. The first interferometer is arranged at intervals from the displacement stage along a first direction, and the second interferometer is arranged at intervals from the displacement stage along a second direction, and the first direction and the second direction are perpendicular. The first interferometer is configured to generate a plurality of first optical axes, and the second interferometer is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the displacement stage. One of the plurality of first optical axes is a first redundant optical axis, and the first redundant optical axis is used to test an object to be tested arranged along the second direction on the displacement stage, and the first optical axis and the plurality of second optical axes other than the first redundant optical axis in the plurality of first optical axes are used to servo the displacement stage to move along the plurality of degrees of freedom. One of the plurality of second optical axes is a second redundant optical axis, and the second redundant optical axis is used to test an object to be tested arranged along the first direction on the displacement stage, and the second optical axis and the plurality of first optical axes other than the second redundant optical axis in the plurality of second optical axes are used to servo the displacement stage to move along the plurality of degrees of freedom.

[0007] Therefore, the measuring device provided in the embodiment of the present application can realize accurate control of the movement of the displacement stage and improve the measurement accuracy of the measuring device by jointly servoing the displacement stage along multiple degrees of freedom through the first optical axis of the first interferometer and the second optical axis of the second interferometer. In addition, the sum of the number of the first optical axis and the second optical axis is greater than the number of degrees of freedom of the displacement stage, that is, the first optical axis or the second optical axis may include a redundant optical axis, and the object to be tested may be measured through the redundant optical axis. Thus, accurate measurement of the object to be tested on the displacement stage with multiple degrees of freedom can be achieved.

[0008] In a possible design, the degrees of freedom of the translation stage include a first direction, a second direction, and a third direction, and the third direction is perpendicular to the first direction and the second direction. The plurality of first optical axes are used to servo the translation stage to move along the first direction. The displacement values ​​of the second optical axes other than the second redundant optical axis used to servo the translation stage along the second direction and the third direction are 0.

[0009] In this design, in a three-dimensional coordinate system, if the object to be tested is set along the first direction along the translation stage, the first optical axis and the second optical axis can be used to jointly servo-control the translation stage to move along the first direction, and the displacement values ​​of the jointly servoed translation stage along other directions are 0. In this way, accurate measurement of the object to be tested on the translation stage with multiple degrees of freedom can be achieved.

[0010] In a possible design, the degrees of freedom of the translation stage further include a fourth direction, a fifth direction, and a sixth direction, wherein the fourth direction is a direction in which the translation stage rotates around the first direction, the fifth direction is a direction in which the translation stage rotates around the second direction, and the sixth direction is a direction in which the translation stage rotates around the third direction. The plurality of first optical axes are also used to serve the displacement values ​​of the translation stage in the fifth direction and the sixth direction to be 0. The second optical axes among the plurality of second optical axes, except the second redundant optical axis, are also used to serve the displacement value of the translation stage in the fourth direction to be 0.

[0011] In this design, for a multi-degree-of-freedom translation stage, if the object to be tested is set along the translation stage in a first direction, the translation stage can be controlled to move in the first direction by the first optical axis and the second optical axis, and the displacement values ​​of the translation stage in other directions can be 0. In this way, accurate measurement of the object to be tested on the multi-degree-of-freedom translation stage can be achieved.

[0012] In a possible design, the degrees of freedom of the translation stage include a first direction, a second direction, and a third direction, and the third direction is perpendicular to the first direction and the second direction. A plurality of second optical axes are used to serve the translation stage so that the displacement value along the third direction is 0, and the translation stage moves along the second direction. A first optical axis other than the first redundant optical axis among the plurality of first optical axes is used to serve the translation stage so that the displacement value along the first direction is 0.

[0013] In a possible design, the degrees of freedom of the translation stage further include a fourth direction, a fifth direction, and a sixth direction, wherein the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction. The plurality of second optical axes are also used to keep the displacement values ​​of the servo translation stage in the fourth direction and the sixth direction to be 0. The first optical axes other than the first redundant optical axis among the plurality of first optical axes are also used to keep the displacement value of the servo translation stage in the fifth direction to be 0.

[0014] In this design, for a multi-degree-of-freedom translation stage, if the object to be tested is set along the second direction of the translation stage, the first optical axis and the second optical axis can be used to jointly servo-control the translation stage to move in the second direction, and the displacement values ​​of the jointly servoed translation stage in other directions are 0. In this way, accurate measurement of the object to be tested on the multi-degree-of-freedom translation stage can be achieved.

[0015] In a possible design, at least two first optical axes are spaced apart in the first direction, and at least two first optical axes are spaced apart in the third direction. At least two second optical axes are spaced apart in the second direction, and at least two first optical axes are spaced apart in the third direction.

[0016] In this design, by placing the at least three first optical axes or the at least three second optical axes not on the same horizontal line, redundant optical axes can be generated in the at least three first optical axes or the at least three second optical axes, so as to achieve accurate measurement of the object to be tested.

[0017] In a second aspect, an embodiment of the present application provides a measurement system, which includes: a displacement stage, a first interferometer, a second interferometer, a first reflector, and a second reflector. The first interferometer is arranged at intervals with the displacement stage along a first direction, and the second interferometer is arranged at intervals with the displacement stage along a second direction, and the first direction and the second direction are perpendicular. The first reflector is arranged on a first supporting surface of the displacement stage along the second direction, and the second reflector is arranged on a second supporting surface of the displacement stage along the first direction. The first interferometer is configured to generate a plurality of first optical axes, and the second interferometer is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the displacement stage. One of the plurality of first optical axes is a first redundant optical axis, and the first redundant optical axis is used to test the first reflector, and the first optical axis and the plurality of second optical axes other than the first redundant optical axis in the plurality of first optical axes are used to servo the displacement stage along the movement of the plurality of degrees of freedom. One of the plurality of second optical axes is a second redundant optical axis, and the second redundant optical axis is used to test the second reflector, and the second optical axis and the plurality of first optical axes other than the second redundant optical axis in the plurality of second optical axes are used to servo the displacement stage along the movement of the plurality of degrees of freedom.

[0018] Therefore, the measurement system provided in the embodiment of the present application can realize precise control of the movement of the translation stage and improve the measurement accuracy of the measurement system by jointly servoing the movement of the translation stage along multiple degrees of freedom through the first optical axis of the first interferometer and the second optical axis of the second interferometer. In addition, the first redundant optical axis can be used to test the first reflector, and the second redundant optical axis can be used to test the second reflector, so that the precise measurement of the first reflector and the second reflector on the translation stage with multiple degrees of freedom can be realized.

[0019] In a possible design, the degrees of freedom of the translation stage include a first direction, a second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction. The measurement system also includes a first 45° reflector and a third reflector, the first 45° reflector is arranged on the second support surface of the translation stage along the first direction, the third reflector is arranged with a spacing from the translation stage along the third direction, and the first 45° reflector and the third reflector are arranged opposite to each other along the third direction. At least one second optical axis among the plurality of second optical axes is used to servo the translation stage to move along the third direction through the first 45° reflector.

[0020] In this design, the measurement system can realize the movement of the servo translation stage along the third direction through the first 45° reflector, thereby realizing precise control of the movement of the translation stage along multiple degrees of freedom.

[0021] In a possible design, one of the plurality of second optical axes is a third redundant optical axis. The third redundant optical axis is used to test the first 45° reflector.

[0022] In this design, the first 45° reflector can be tested through the third redundant optical axis in the measurement system, thereby achieving accurate measurement of the first 45° reflector.

[0023] In a possible design, the degrees of freedom of the translation stage further include a fourth direction, a fifth direction, and a sixth direction, the fourth direction being the direction in which the translation stage rotates around the first direction, the fifth direction being the direction in which the translation stage rotates around the second direction, and the sixth direction being the direction in which the translation stage rotates around the third direction. The second optical axes other than the third redundant optical axis among the plurality of second optical axes are used to serve the translation stage so that the displacement values ​​along the second direction, the third direction, the fourth direction, and the sixth direction are 0. The plurality of first optical axes are used to serve the translation stage so that the displacement value along the fifth direction is 0.

[0024] In this design, the measurement system can move along the first direction by the first optical axis and the second optical axis jointly servoing the translation stage, and the displacement value of the jointly servoing translation stage along other directions is 0. Thus, accurate measurement of the object to be tested on the translation stage with multiple degrees of freedom can be achieved.

[0025] In a possible design, the degrees of freedom of the translation stage include a first direction, a second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction. The measurement system also includes a second 45° reflector and a fourth reflector, the second 45° reflector is arranged on the first support surface of the translation stage along the second direction, the fourth reflector is arranged spaced apart from the translation stage along the third direction, and the second 45° reflector and the fourth reflector are arranged opposite to each other along the third direction. At least one first optical axis among the plurality of first optical axes is used to servo the movement of the translation stage along the third direction through the second 45° reflector.

[0026] In a possible design, one of the plurality of first optical axes is a fourth redundant optical axis. The fourth redundant optical axis is used to test the second 45° reflector.

[0027] In this design, the second 45° reflector can be tested in the measurement system through the fourth redundant optical axis, thereby achieving accurate measurement of the second 45° reflector.

[0028] In a possible design, the degrees of freedom of the translation stage further include a fourth direction, a fifth direction, and a sixth direction, the fourth direction being the direction in which the translation stage rotates around the first direction, the fifth direction being the direction in which the translation stage rotates around the second direction, and the sixth direction being the direction in which the translation stage rotates around the third direction. The first optical axes among the plurality of first optical axes, except the fourth redundant optical axis, are used to serve the translation stage so that the displacement values ​​along the first direction, the fifth direction, and the sixth direction are 0. The plurality of second optical axes are used to serve the translation stage so that the displacement values ​​along the third direction and the fourth direction are 0.

[0029] In this design, the measurement system can move along the second direction by the first optical axis and the second optical axis jointly servoing the translation stage, and the displacement value of the jointly servoing translation stage along other directions is 0. Thus, accurate measurement of the object to be tested on the translation stage with multiple degrees of freedom can be achieved.

[0030] In a possible design, the degrees of freedom of the displacement stage include a first direction, a second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction. The measurement system also includes a first 45° reflector and a third reflector, and a second 45° reflector and a fourth reflector. The first 45° reflector is arranged on the second supporting surface of the displacement stage along the first direction, the third reflector is arranged with the displacement stage at intervals along the third direction, and the first 45° reflector and the third reflector are arranged relative to each other along the third direction. The second 45° reflector is arranged on the first supporting surface of the displacement stage along the second direction, the fourth reflector is arranged with the displacement stage at intervals along the third direction, and the second 45° reflector and the fourth reflector are arranged relative to each other along the third direction. One of the plurality of second optical axes is a fifth redundant optical axis, and the fifth redundant optical axis is used to test the third reflector through the first 45° reflector. The plurality of first optical axes are used to serve the displacement values ​​of the displacement stage along the first direction and the third direction to be 0. The second optical axes other than the fifth redundant optical axis among the plurality of second optical axes are used to serve the displacement stage to move along the second direction.

[0031] In this design, the third reflector can be tested through the fifth redundant optical axis in the measurement system, thereby achieving accurate measurement of the third reflector.

[0032] In a possible design, the degrees of freedom of the translation stage further include a fourth direction, a fifth direction, and a sixth direction, wherein the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction. The plurality of first optical axes are also used to keep the displacement values ​​of the servo translation stage in the fifth direction and the sixth direction to be 0. The second optical axes other than the fifth redundant optical axis among the plurality of second optical axes are also used to keep the displacement values ​​of the servo translation stage in the fourth direction to be 0.

[0033] In this design, the measurement system can move along the second direction by the first optical axis and the second optical axis jointly servoing the translation stage, and the displacement value of the jointly servoing translation stage along other directions is 0. Thus, accurate measurement of the object to be tested on the translation stage with multiple degrees of freedom can be achieved.

[0034] In a third aspect, an embodiment of the present application provides a measurement method, which is applied to the measurement system of the second aspect, and the method includes: controlling the first redundant optical axis to test the first reflector, and controlling the movement of the first optical axis other than the first redundant optical axis among multiple first optical axes and multiple second optical axis servo translation stages along multiple degrees of freedom; and / or, controlling the second redundant optical axis to test the second reflector, and controlling the movement of the second optical axis other than the second redundant optical axis among multiple second optical axes and multiple first optical axis servo translation stages along multiple degrees of freedom.

[0035] The beneficial effects of the third aspect can refer to the description of the second aspect.

[0036] In a possible design, the method further includes: controlling at least one of the plurality of second optical axes to move along a third direction via the first 45° reflector servo translation stage, and controlling the third redundant optical axis to test the first 45° reflector.

[0037] In a possible design, the method further includes: controlling the second optical axes except the third redundant optical axis among the plurality of second optical axes, and the displacement values ​​of the servo translation stage along the second direction, the third direction, the fourth direction and the sixth direction are 0. Controlling the plurality of first optical axis servo translation stages to move along the first direction, and the displacement value of the servo translation stage along the fifth direction is 0.

[0038] In a possible design, the method further includes: controlling at least one first optical axis among the plurality of first optical axes to move along a third direction via a second 45° reflector servo translation stage, and controlling a fourth redundant optical axis to test the second 45° reflector.

[0039] In a possible design, the method further includes: controlling the first optical axes except the fourth redundant optical axis among the plurality of first optical axes, and the displacement values ​​of the servo translation stage along the first direction, the fifth direction and the sixth direction are 0. Controlling the plurality of second optical axis servo translation stages to move along the second direction, and the displacement values ​​of the servo translation stage along the third direction and the fourth direction are 0.

[0040] In a possible design, the method further includes: controlling the fifth redundant optical axis to test the third reflector through the first 45° reflector. Controlling the displacement values ​​of the plurality of first optical axis servo translation stages along the first direction and the third direction to be 0. Controlling the second optical axis servo translation stages of the plurality of second optical axes except the fifth redundant optical axis to move along the second direction.

[0041] In a possible design, the method further includes: controlling the displacement values ​​of the plurality of first optical axis servo translation stages along the fifth direction and the sixth direction to be 0. Controlling the second optical axes among the plurality of second optical axes except the fifth redundant optical axis to also set the displacement value of the servo translation stage along the fourth direction to be 0.

[0042] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, including computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the measurement method in any of the above aspects and any possible implementation methods.

[0043] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product runs on a computer or a processor, the computer or the processor executes the measurement method in any of the above aspects and any possible implementation methods.

[0044] It can be understood that any of the measuring devices, measuring systems, computer-readable storage media or computer program products provided above can be applied to the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods and will not be repeated here.

[0045] These and other aspects of the present application will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of a measurement device using a direct measurement method provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of the structure of another measurement device using a direct measurement method provided in an embodiment of the present application;

[0048] Figure 3 A schematic diagram of the structure of a measuring device using an indirect measurement method provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of the structure of another measuring device using an indirect measurement method provided in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the structure of a measuring device provided in an embodiment of the present application;

[0051] Figure 6 A schematic diagram of a process for testing a first reflector and a second reflector provided in an embodiment of the present application;

[0052] Figure 7 A schematic diagram of the structure of a measurement system provided in an embodiment of the present application;

[0053] Figure 8 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application;

[0054] Fig. 9 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application;

[0055] Fig.10 A schematic diagram of a process for testing a first 45° reflector and a second 45° reflector provided in an embodiment of the present application;

[0056] Fig.11 A schematic diagram of a process for testing a third reflector provided in an embodiment of the present application;

[0057] Fig.12 A flow chart of a measurement method provided in an embodiment of the present application;

[0058] Fig.13 A schematic diagram of the composition of a measuring device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] For ease of understanding, some examples of concepts related to the embodiments of the present application are provided for reference, as shown below:

[0060] Doppler effect: The frequency or phase of the signal received when the source and the device under test are in relative motion is different from the frequency or phase of the signal received when the source and the device under test are stationary. If the source and the device under test move toward each other, the frequency of the received signal increases, and if the source and the device under test move in the opposite direction, the frequency of the received signal decreases.

[0061] Surface shape: The accuracy of the component surface, which can be expressed by local aperture, peak and valley (PV) and transmitted wavefront.

[0062] Servo: An automatic control system in which the position, orientation and state output of an object can change with any change in the input quantity.

[0063] Degree of freedom: The number of dimensions of a random vector, that is, the minimum number of unit vectors required to fully describe a random vector. In an example, a translation stage usually includes six degrees of freedom, namely: translational freedom in the X direction, translational freedom in the Y direction, translational freedom in the Z direction, rotational freedom around the X axis, rotational freedom around the Y axis, and rotational freedom around the Z axis.

[0064] Laser interferometer is a precision measuring instrument that uses the interference measurement principle and laser as the length reference to accurately measure the position accuracy (positioning accuracy and re-reading positioning accuracy, etc.) and geometric accuracy (pitch and yaw angles, straightness and verticality, etc.) of CNC equipment.

[0065] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0066] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0067] At present, in order to test the surface accuracy of the mirror, a direct measurement method is proposed, such as Figure 1 As shown, Figure 1 A schematic diagram of the structure of a measurement device using a direct measurement method provided in an embodiment of the present application. Figure 1 An interferometer, a reflector to be tested and a computer are shown in the figure, wherein the reflector to be tested is fixed on a test table by a measuring mechanical fixture, the reference mirror in the interferometer is positioned exactly to the mirror surface of the reflector to be tested, the interferometer and the computer are connected in communication, and the display interface of the computer can display the picture taken by the interferometer. In the direct measurement method, an interferometer is used to directly take a picture of the reflector to be tested, and the surface features of the reflector to be tested are displayed through the display interface of the computer, and the surface features include the highest position and the lowest position of the reflector to be tested. Therefore, the surface accuracy of the reflector to be tested can be characterized by the distance between the highest position and the lowest position of the reflector to be tested.

[0068] However, this direct measurement method requires specific measurement mechanical equipment to support the measurement process, which increases the measurement difficulty. In addition, the measurement accuracy is limited by the surface accuracy of the reference mirror of the interferometer, as well as the equipment size and measurement scheme, making it difficult to measure the reflector to be tested fixed on the translation stage frame.

[0069] In addition, another direct measurement method has been proposed, such as Figure 2 As shown, Figure 2 A schematic diagram of the structure of another measurement device using a direct measurement method provided in an embodiment of the present application. Figure 2, laser interferometer, beam splitter, beam splitter prism, computer, position sensor 1, position sensor 2, reflector and mirror to be tested are shown. Wherein, the output end of the laser interferometer is connected to the input end of the computer in communication, and the position result of the test is transmitted to the computer in real time when the measuring device is tested. The beam splitter is fixed on a two-dimensional adjustment frame (pitch adjustment and tilt adjustment), and the beam splitter prism is also fixed on a two-dimensional adjustment frame (pitch adjustment and tilt adjustment). In addition, position sensor 1 and position sensor 2 are also fixed on a two-dimensional adjustment frame (up and down adjustment and left and right adjustment), and the output ends of position sensor 1 and position sensor 2 are connected to the computer in communication, respectively, and the position result is transmitted to the computer in real time during the test. The reflector is fixed on a two-dimensional adjustment frame, and the input end of the reflector is connected to the output end of the computer in communication, and the computer transmits the attitude adjustment signal to the reflector in real time during the test. Thus, by moving the mirror to be tested along the moving direction, the surface shape accuracy of the mirror to be tested can be tested.

[0070] However, this direct measurement method also requires specific measurement mechanical equipment to support the measurement process, which increases the measurement difficulty. Moreover, this direct measurement method does not take into account the error caused by the movement of the mirror to be tested, and is not applicable to the measurement of the surface accuracy of the reflector on a multi-degree-of-freedom translation stage.

[0071] Besides this, an indirect measurement method is proposed, e.g. Figure 3 As shown, Figure 3 A schematic diagram of the structure of a measuring device using an indirect measurement method provided in an embodiment of the present application. Figure 3 , a first interferometer, a second interferometer and a reflector to be tested are shown, wherein the reflector to be tested includes a first mirror surface and a second mirror surface. When the reflector to be tested moves along the X direction, the second interferometer can test the surface shape accuracy of the second mirror surface, and when the reflector to be tested moves along the Y direction, the first interferometer can test the surface shape accuracy of the first mirror surface, thereby completing the measurement of the surface shape accuracy of the reflector to be tested.

[0072] However, in the indirect measurement method, the optical axis of the interferometer cannot servo the movement of the translation stage, and the movement of the translation stage may result in low surface accuracy. In addition, the indirect measurement method is not applicable to the measurement of the surface accuracy of the reflector on the translation stage with multiple degrees of freedom.

[0073] In addition to the above methods, an indirect measurement method is also proposed, such as Figure 4 As shown, Figure 4 A schematic diagram of the structure of a measuring device using an indirect measurement method provided for the implementation of the present application. Figure 4The first optical axis, the second optical axis, the third optical axis and the fourth optical axis of the displacement stage and the interferometer are shown in FIG. The displacement stage can step or scan in the X direction and the Y direction, the first optical axis and the second optical axis are used to measure the Y position of the displacement stage and perform servo control, and the third optical axis and the fourth optical axis are used to measure the X position of the displacement stage and perform servo control. In the measuring device, when the displacement stage scans along the X direction, the positions of the third optical axis and the fourth optical axis relative to the displacement stage remain fixed, so the rotation degree Rzx of the displacement stage measured by the third optical axis and the fourth optical axis is a constant value, that is, the scanning of the displacement stage along the X direction does not affect Rzx. Thus, the surface shape accuracy of the plane reflector surface arranged along the X direction on the displacement stage can be measured by the first optical axis and the second optical axis. In addition, the surface shape accuracy of the plane reflector surface arranged along the Y direction of the displacement stage can also be set based on the same principle.

[0074] However, in this indirect measurement method, the translation stage can only achieve movement in the X and Y directions, and cannot achieve movement with more than two degrees of freedom. In addition, this direct measurement method can only be used to test plane mirrors, and cannot test mirrors of other shapes or other positions.

[0075] Therefore, an embodiment of the present application provides a measuring device, which can achieve precise control of the movement of the displacement stage by servo-translating the displacement stage along multiple degrees of freedom through the optical axis of the interferometer, thereby improving the measurement accuracy of the measuring device. In addition, the number of optical axes of the interferometer is greater than the number of degrees of freedom of the displacement stage, that is, the optical axis of the interferometer includes redundant optical axes, and the surface accuracy of the object to be tested can be measured through the redundant optical axes. Therefore, accurate measurement of the object to be tested on the displacement stage with multiple degrees of freedom can be achieved.

[0076] For ease of understanding, the measuring device provided in the embodiments of the present application is further described below.

[0077] like Figure 5 As shown, Figure 5 A schematic diagram of the structure of a measuring device provided in an embodiment of the present application. The measuring device 50 includes a displacement stage 51, a first interferometer 52 and a second interferometer 53. The first interferometer 52 is spaced apart from the displacement stage 51 along a first direction, and the second interferometer 53 is spaced apart from the displacement stage 51 along a second direction, and the first direction and the second direction are perpendicular. The first interferometer 52 is configured to generate a plurality of first optical axes, and the second interferometer 53 is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the displacement stage 51. The number of degrees of freedom of the displacement stage 51 should be greater than or equal to 3.

[0078] For example, in a plane rectangular coordinate system, the first direction may be an X direction, and the second direction may be a Y direction. The degrees of freedom of the translation stage 51 may include the first direction and the second direction, that is, the translation stage 51 may move along the first direction, the translation stage 51 may also move along the second direction, and in addition, the translation stage 51 may also move along other directions.

[0079] In addition, the first interferometer 52 and the second interferometer 53 may be multi-axis laser interferometers, which may generate multiple optical axes. The first interferometer 52 may generate multiple first optical axes, and the second interferometer 53 may generate multiple second optical axes, wherein: Figure 5 3. Three first optical axes (X1, X2 and X3) generated by the first interferometer 52 are shown, and four second optical axes (Y1, Y2, Y3 and Z1) generated by the second interferometer 53 are shown.

[0080] Among them, one of the multiple first optical axes is a first redundant optical axis, the first redundant optical axis is used to test the object to be tested arranged along the second direction on the translation stage 51, and the first optical axis and multiple second optical axes except the first redundant optical axis among the multiple first optical axes are used to servo the movement of the translation stage 51 along multiple degrees of freedom.

[0081] For example, see Figure 5 , the three first optical axes may include a first redundant optical axis, that is, X1 may be the first redundant optical axis, X2 may also be the first redundant optical axis, and X3 may also be the first redundant optical axis. In one example, assuming that X1 is the first redundant optical axis, X2 and X3 may cooperate with a plurality of second optical axes to servo-control the displacement stage 51 to move along the Y direction, and the displacement value of the servo-controlled displacement stage 51 along the X direction is 0. Therefore, in the process of the displacement stage 51 moving along the Y direction, X1 may scan the object to be tested set along the Y direction on the displacement stage 51, that is, X1 may complete the test of the object to be tested. The principle of testing the remaining first optical axes as the first redundant optical axes is the same as that of X1, and will not be repeated here.

[0082] Correspondingly, one of the multiple second optical axes is a second redundant optical axis, the second redundant optical axis is used to test the object to be tested which is arranged along the first direction on the translation stage 51, and the second optical axes other than the second redundant optical axis among the multiple second optical axes and the multiple first optical axes are used to servo the movement of the translation stage 51 along multiple degrees of freedom.

[0083] For example, see Figure 5, the four second optical axes include a second redundant optical axis, that is, Y1 can be the second redundant optical axis, Y2 can also be the second redundant optical axis, Y3 can also be the second redundant optical axis, and Z1 can also be the second redundant optical axis. In an example, assuming that Y1 is the second redundant optical axis, Y2, Y3 and Z1 can cooperate with multiple first optical axes to servo-control the displacement stage 51 to move along the X direction, and the displacement value of the servo-controlled displacement stage 51 along the Y direction is 0. Therefore, in the process of the displacement stage 51 moving along the X direction, Y1 can scan the object to be tested set along the X direction on the displacement stage 51, that is, Y1 can complete the test of the object to be tested. The principle of testing the remaining second optical axes as the second redundant optical axes is the same as that of Y1, which will not be repeated here.

[0084] Therefore, compared with Figures 1 to 4 The measuring device 50 provided in the embodiment of the present application can realize accurate control of the movement of the translation stage and improve the measurement accuracy of the measuring device by using the first optical axis of the first interferometer 52 and the second optical axis of the second interferometer 53 to jointly servo the movement of the translation stage along multiple degrees of freedom. In addition, the sum of the number of the first optical axis and the second optical axis is greater than the number of degrees of freedom of the translation stage, that is, the first optical axis or the second optical axis may include a redundant optical axis, and the object to be tested may be measured through the redundant optical axis. In this way, accurate measurement of the object to be tested on the translation stage with multiple degrees of freedom can be achieved.

[0085] Optionally, the degrees of freedom of the translation stage 51 include a first direction, a second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction. The plurality of first optical axes are used to servo the translation stage 51 to move along the first direction. The displacement values ​​of the second optical axes other than the second redundant optical axis used to servo the translation stage 51 along the second direction and the third direction are 0. The second redundant optical axis is used to test the object to be tested that is arranged along the first direction on the translation stage 51.

[0086] Exemplarily, in a three-dimensional coordinate system, the first direction may be an X direction, the second direction may be a Y direction, and the third direction may be a Z direction. That is, if the object to be tested is arranged along the X direction on the test displacement stage 51, the displacement stage 51 may be servo-controlled to move along the X direction through a plurality of first optical axes, and the displacement values ​​of the servo-controlled displacement stage 51 along the Y direction and the Z direction may be 0 through the second optical axis other than the second redundant optical axis, that is, if the object to be tested is arranged along the first direction on the test displacement stage 51, the displacement values ​​of the servo-controlled displacement stage 51 along other directions except the first direction are all 0.

[0087] At this time, the second redundant optical axis can scan the object to be tested, wherein the object to be tested can be a strip reflector. Specifically, the second redundant optical axis of the second interferometer 53 scans the starting position to the end position of the strip reflector, thereby obtaining the surface data of the strip reflector. Then, the surface data can be processed by interpolation, and the surface data can be subtracted from the interpolated surface result to obtain the surface residual, and finally the surface residual can be filtered to obtain the final surface data of the strip reflector.

[0088] Wherein, at least two first optical axes are arranged at intervals in the first direction, and at least two first optical axes are arranged at intervals in the third direction.

[0089] Continue to view Figure 5 , the first optical axis can be set as follows: X1 and X2 are on the same horizontal line, and X3 is located below X1 and X2, that is, the three first optical axes are not on the same horizontal line. If X1 and X2 are on the same horizontal line, it can be considered that X1 and X2 are equal. If X1 is used to servo the movement of the translation stage 51, then X2 can be used as the first redundant optical axis. If X2 is used to servo the movement of the translation stage 51, then X1 can be used as the first redundant optical axis.

[0090] Optionally, the degrees of freedom of the translation stage 51 further include a fourth direction, a fifth direction, and a sixth direction, wherein the fourth direction is the direction in which the translation stage 51 rotates around the first direction, the fifth direction is the direction in which the translation stage 51 rotates around the second direction, and the sixth direction is the direction in which the translation stage 51 rotates around the third direction. That is, the fourth direction may be the direction in which the translation stage 51 rotates around the X direction, namely, Rx, the fifth direction may be the direction in which the translation stage 51 rotates around the Y direction, namely, Ry, and the sixth direction may be the direction in which the translation stage 51 rotates around the Z direction, namely, Rz.

[0091] The first optical axes are also used to keep the displacement values ​​of the servo stage 51 along the fifth and sixth directions to be 0. The second optical axes other than the second redundant optical axis among the second optical axes are also used to keep the displacement values ​​of the servo stage 51 along the fourth direction to be 0.

[0092] That is, if the translation stage can move along six degrees of freedom, if one wants to test an object to be tested arranged along a first direction, the displacement values ​​of the servo translation stage 51 along directions other than the first direction can be made 0 by cooperating with multiple first optical axes and multiple second optical axes, thereby achieving precise control of the translation stage 51. Then, the object to be tested can be tested through the second redundant optical axis to obtain the surface accuracy of the object to be tested.

[0093] Optionally, in the three-dimensional coordinate system, the displacement values ​​of the plurality of second optical axes used to servo the translation stage 51 along the third direction are 0, and the servo translation stage 51 moves along the second direction. The displacement values ​​of the first optical axes other than the first redundant optical axis used to servo the translation stage 51 along the first direction are 0.

[0094] That is, if the object to be tested is set along the Y direction on the test displacement stage 51, the displacement stage 51 can be moved along the Y direction by the multiple second optical axes. In addition, the displacement values ​​of the servo-controlled displacement stage 51 along the X direction and the Z direction can be 0 by the first optical axis except the first redundant optical axis. That is, if the object to be tested is tested along the second direction on the test displacement stage 51, the displacement values ​​of the servo-controlled displacement stage 51 along the directions other than the second direction are all 0.

[0095] Wherein, at least two second optical axes are arranged at intervals in the second direction, and at least two second optical axes are arranged at intervals in the third direction.

[0096] Continue to view Figure 5 , the second optical axis can be set as follows: Y1 and Y2 are on the same horizontal line, and Y3 is located below Y1 and Y2, that is, the three second optical axes are not on the same horizontal line. In addition, Z1 can be located below Y1, Y2 and Y3. If Y1 and Y2 are on the same horizontal line, it can be considered that Y1 and Y2 are equivalent. If Y1 is used to servo the movement of the translation stage 51, Y2 can be used as the second redundant optical axis. If Y2 is used to servo the movement of the translation stage 51, Y1 can be used as the second redundant optical axis.

[0097] Optionally, if the translation stage 51 can move along six degrees of freedom, the plurality of second optical axes are also used to servo the translation stage to a displacement value of 0 along the fourth direction and the sixth direction. The first optical axes except the first redundant optical axis among the plurality of first optical axes are also used to servo the translation stage to a displacement value of 0 along the fifth direction.

[0098] That is to say, if the object to be tested is set along the second direction, the displacement values ​​of the servo stage 51 along directions other than the second direction can be made 0 by cooperating with the multiple first optical axes and the multiple second optical axes, thereby achieving precise control of the stage 51. Then, the object to be tested is tested through the first redundant optical axis to test the surface accuracy of the object to be tested.

[0099] In one example, assuming that the first interferometer 52 includes three first optical axes (X1, X2, and X3), the second interferometer 53 includes four second optical axes (Y1, Y2, Y3, and Z1), and the translation stage can move along six degrees of freedom (X, Y, Z, Rx, Ry, and Rz). The object to be tested arranged along the X direction is the second reflector, and the object to be tested arranged along the Y direction is the first reflector. Figure 6 As shown, Figure 6 A schematic diagram of a process for testing a first reflector and a second reflector provided in an embodiment of the present application. Figure 6(a) in the figure shows a flow chart of the test of the first reflector, and the process of testing the first reflector includes: (1) using Y1, Y2 and Y3 to serve the degrees of freedom Y, Rz and Rx; (2) using X1 and X2 to serve the degrees of freedom X and Ry; (3) using Z1 to serve the degree of freedom Z; (4) moving the translation stage along the Y direction, and assigning 0 to the displacement values ​​of other degrees of freedom; (5) reading the reading of X3 to obtain the surface shape related data of the first reflector; (6) solving the reading of X3 to obtain the surface shape accuracy of the first reflector.

[0100] Figure 6 (b) in the figure shows a flow chart of the second reflector test, and the process of testing the second reflector includes: (1) using X1, X2 and X3 to serve the degrees of freedom X, Rz and Ry; (2) using Y1 and Y2 to serve the degrees of freedom Y and Rx; (3) using Z1 to serve the degree of freedom Z; (4) moving the translation stage along the X direction, and assigning 0 to the displacement values ​​of other degrees of freedom; (5) reading the reading of Y3 to obtain the surface shape related data of the second reflector; (6) solving the reading of Y3 to obtain the surface shape accuracy of the second reflector.

[0101] Based on the above-mentioned measuring device, the embodiment of the present application also provides a measuring system, which can be applied to complete equipment suitable for the translation stage, such as a photolithography machine, an etching machine, and high-precision semiconductor detection equipment. Figure 7 As shown, Figure 7 A schematic diagram of the structure of a measurement system provided in an embodiment of the present application. The measurement system 70 includes a displacement stage 51, a first interferometer 52, a second interferometer 53, a first reflector 71 and a second reflector 72. The first interferometer 52 is spaced apart from the displacement stage 51 along the first direction, and the second interferometer 53 is spaced apart from the displacement stage 51 along the second direction, and the first direction and the second direction are perpendicular. The first reflector 71 is disposed on a first supporting surface along the second direction on the displacement stage 51, and the second reflector 72 is disposed on a second supporting surface along the first direction on the displacement stage 51. The first interferometer 52 is configured to generate a plurality of first optical axes, and the second interferometer 53 is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the displacement stage 51.

[0102] Exemplarily, in a plane rectangular coordinate system, the first direction may be the X direction, and the second direction may be the Y direction. The degrees of freedom of the displacement stage 51 may include the first direction and the second direction, that is, the displacement stage 51 may move along the first direction, and the displacement stage 51 may also move along the second direction. In addition, the displacement stage 51 may also move along other directions. In addition, the displacement stage 51 may drive the movement of the first reflector 71 and the second reflector 72 when moving. The position of the first optical axis of the first interferometer 52 is arranged relative to the first reflector 71, and the position of the second optical axis of the second interferometer 53 is arranged relative to the second reflector 72. That is, the laser emitted from the first optical axis of the first interferometer 52 may be irradiated onto the first reflector 71, and the laser emitted from the second optical axis of the second interferometer 53 may be irradiated onto the second reflector 72.

[0103] Among them, one of the multiple first optical axes is a first redundant optical axis, the first redundant optical axis is used to test the first reflector 71, and the first optical axis and multiple second optical axes other than the first redundant optical axis are used to servo the movement of the translation stage along multiple degrees of freedom.

[0104] For example, see Figure 7 , Figure 7 , three first optical axes (X1, X2, and X3) generated by the first interferometer 52 are shown, and four second optical axes (Y1, Y2, Y3, and Z1) generated by the second interferometer 53 are shown. The three first optical axes include a first redundant optical axis, that is, X1 can be the first redundant optical axis, X2 can also be the first redundant optical axis, and X3 can also be the first redundant optical axis. In an example, assuming that X1 is the first redundant optical axis, X2 and X3 can cooperate with multiple second optical axes to servo-control the displacement stage 51 to move along the Y direction, and the displacement value of the servo-controlled displacement stage 51 along the X direction is 0. Therefore, in the process of the displacement stage 51 moving along the Y direction, X1 can scan the first reflector 71, that is, X1 can complete the test of the first reflector 71. The principle of testing the remaining first optical axes as the first redundant optical axes is the same as that of X1, which will not be repeated here.

[0105] Among them, one of the multiple second optical axes is a second redundant optical axis, the second redundant optical axis is used to test the second reflector 72, and the second optical axes other than the second redundant optical axis and the multiple first optical axes are used to servo the movement of the translation stage 51 along multiple degrees of freedom.

[0106] For example, see Figure 7, the four second optical axes include a second redundant optical axis, that is, Y1 can be the second redundant optical axis, Y2 can be the second redundant optical axis, Y3 can be the second redundant optical axis, and Z1 can be the second redundant optical axis. In one example, assuming that Y1 is the second redundant optical axis, Y2 and Y3 can cooperate with multiple first optical axes to servo-control the displacement stage 51 to move along the X direction, and the displacement value of the servo-controlled displacement stage 51 along the Y direction is 0. Therefore, in the process of the displacement stage 51 moving along the X direction, Y1 can scan the second reflector 72 set along the X direction on the displacement stage 51, that is, Y1 can complete the test of the second reflector 72. The principle of testing the remaining second optical axes as the second redundant optical axes is the same as that of Y1, which will not be repeated here.

[0107] In addition, the first reflector 71 is the object to be tested arranged along the second direction of the displacement stage 51, and the second reflector 72 is the object to be tested arranged along the first direction of the displacement stage 51. Specifically, the test of the first reflector 71 and the second reflector 72 can refer to the relevant description of the above-mentioned measuring device 50, which will not be repeated here.

[0108] Optionally, the degrees of freedom of the translation stage 51 include a first direction, a second direction and a third direction. Figure 8 As shown, Figure 8 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application. The measurement system 70 also includes a first 45° reflector 73 and a third reflector 74. The first 45° reflector 73 is arranged on the second support surface of the displacement stage 51 along the first direction, and the third reflector 74 is arranged spaced apart from the displacement stage 51 along the third direction. The first 45° reflector 73 and the third reflector 74 are arranged opposite to each other along the third direction. The angle between the mirror surface of the first 45° reflector 73 and the third direction is 45°, and the angle between the mirror surface of the third reflector 74 and the third direction is 90°.

[0109] At least one of the plurality of second optical axes is used to drive the servo translation stage 51 to move along the third direction via the first 45° reflecting mirror 73 .

[0110] For example, Figure 8 , multiple second optical axes (Y1, Y2, Y3 and Z1) are shown, wherein Y1, Y2 and Y3 are arranged opposite to the second reflector 72, and Z1 is arranged opposite to the first 45° reflector 73. That is, the lasers emitted by Y1, Y2 and Y3 are irradiated on the mirror surface of the second reflector 72, and the lasers emitted by Z1 are irradiated on the first 45° reflector 73, and then reflected by the first 45° reflector 73 to the third reflector 74.

[0111] Optionally, one of the multiple second optical axes is a third redundant optical axis, and the third redundant optical axis is used to test the first 45° reflector 73 .

[0112] Exemplarily, the plurality of first optical axes can servo the translation stage 51 to move along the first direction, and the second optical axes except the third redundant optical axis among the plurality of second optical axes can servo the translation stage 51 to move along the second direction and the third direction with a displacement value of 0. Thus, the third redundant optical axis can scan and test the first 45° reflector 73, thereby implementing the test of the first 45° reflector 73.

[0113] Optionally, if the translation stage 51 can move along six degrees of freedom, the second optical axes except the third redundant optical axis among the plurality of second optical axes are used to serve the translation stage 51 so that the displacement values ​​along the second direction, the third direction, the fourth direction and the sixth direction are 0. The plurality of first optical axes are used to serve the translation stage so that the displacement value along the first direction and the translation stage 51 are used to serve the translation stage 51 so that the displacement value along the fifth direction is 0.

[0114] That is, if the translation stage can move along 6 degrees of freedom, if the first 45° reflector 73 is to be tested, since the first 45° reflector 73 is arranged along the first direction, the displacement values ​​of the servo translation stage 51 along directions other than the first direction can be coordinated by multiple first optical axes and multiple second optical axes to be 0, thereby achieving precise control of the translation stage 51. Then, the first 45° reflector 73 is tested through the third redundant optical axis to obtain the surface accuracy of the first 45° reflector 73.

[0115] Optional, such as Fig. 9 As shown, Fig. 9 A schematic diagram of the structure of another measurement system provided in an embodiment of the present application. The measurement system 70 also includes: a second 45° reflector 75 and a fourth reflector 76, wherein the second 45° reflector 75 is disposed on the first support surface along the second direction of the displacement stage 51, and the fourth reflector 76 is disposed spaced apart from the displacement stage 51 along the third direction, and the second 45° reflector 75 and the fourth reflector 76 are disposed opposite to each other along the third direction. The angle between the mirror surface of the second 45° reflector 75 and the third direction is 45°, and the angle between the mirror surface of the fourth reflector 76 and the third direction is 90°.

[0116] At least one of the plurality of first optical axes is used to servo the translation stage 51 to move along the third direction via the second 45° reflection mirror 75 .

[0117] For example, Fig. 9 , multiple first optical axes (X1, X2, X3, Z3 and Z4) are shown, wherein X1, X2 and X3 are arranged opposite to the first reflector 71, and Z3 and Z4 are arranged opposite to the second 45° reflector 75. That is, the lasers emitted from X1, X2 and X3 are irradiated on the mirror surface of the first reflector 71, and the lasers emitted from Z1 and Z2 are irradiated on the second 45° reflector 75, and then reflected by the second 45° reflector 75 to the fourth reflector 76.

[0118] in addition, Fig. 9 A plurality of second optical axes (Y1, Y2, Y3, Z1 and Z2) are also shown, wherein Y1, Y2 and Y3 are arranged opposite to the second reflector 72, and Z1 is arranged opposite to the first 45° reflector 73. That is, the lasers emitted by Y1, Y2 and Y3 are irradiated on the mirror surface of the second reflector 72, and the lasers emitted by Z1 and Z2 are irradiated on the first 45° reflector 73, and then reflected by the first 45° reflector 73 to the third reflector 74.

[0119] Optionally, one of the multiple first optical axes is a fourth redundant optical axis, and the fourth redundant optical axis is used to test the second 45° reflector 75 .

[0120] Exemplarily, the plurality of second optical axes can servo the translation stage 51 to move along the second direction, and the first optical axes except the fourth redundant optical axis among the plurality of first optical axes can servo the translation stage 51 to move along the first direction and the third direction with a displacement value of 0. Thus, the fourth redundant optical axis can scan and test the second 45° reflector 75, thereby implementing the test of the second 45° reflector 75.

[0121] Optionally, if the translation stage 51 can move along six degrees of freedom, the first optical axes among the plurality of first optical axes, except the fourth redundant optical axis, are used to serve the displacement values ​​of the translation stage 51 along the first direction, the fifth direction, and the sixth direction to be 0. The plurality of second optical axes are used to serve the translation stage 51 to move along the second direction, and the displacement values ​​of the translation stage 51 along the third direction and the fourth direction to be 0.

[0122] That is, if the translation stage can move along 6 degrees of freedom, if the second 45° reflector 75 is to be tested, since the second 45° reflector 75 is arranged along the second direction, the displacement values ​​of the servo translation stage 51 along directions other than the second direction can be made 0 by cooperating with the multiple first optical axes and the multiple second optical axes, thereby achieving precise control of the translation stage 51. Then, the second 45° reflector 75 is tested through the fourth redundant optical axis to obtain the surface accuracy of the second 45° reflector 75.

[0123] Therefore, assuming that the first interferometer includes five first optical axes (X1, X2, X3, Z3 and Z4), and the second interferometer includes five second optical axes (Y1, Y2, Y3, Z1 and Z2), the translation stage can move along six degrees of freedom (X, Y, Z, Rx, Ry, Rz). Fig.10 As shown, Fig.10 A schematic diagram of a process for testing a first 45° reflector and a second 45° reflector provided in an embodiment of the present application. Fig.10(a) shows a flow chart of the first 45° reflector. The process of testing the first 45° reflector includes: (1) using X1, X2 and X3 to serve the degrees of freedom X, Rz and Ry; (2) Y1, Y2 and Y3 to serve the degrees of freedom Y, Rz and Rx; (3) using Z1 to serve the degree of freedom Z; (4) moving the translation stage along the X direction, and assigning 0 to other degrees of freedom; (5) reading the reading of Z2 to obtain the surface shape related data of the first 45° reflector; (6) solving the reading of Z2 to obtain the surface shape accuracy of the first 45° reflector.

[0124] in addition, Fig.10 (b) in the figure shows a flow chart of the second 45° reflector. The process of testing the 45° reflector includes: (1) using X1, X2 and X3 to serve the degrees of freedom X, Rz and Ry; (2) using Y1, Y2 and Y3 to serve the degrees of freedom Y, Rz and Rx; (3) using Z1 to serve the degree of freedom Z; (4) moving the translation stage along the Y direction and assigning 0 to other degrees of freedom; (5) reading the reading of Z4 to obtain the surface shape related data of the second 45° reflector; (6) solving the reading of Z4 to obtain the surface shape accuracy of the second 45° reflector.

[0125] Optional, continue to see Fig. 9 At least one of the multiple second optical axes is used to servo the translation stage 51 to move along the second direction, and one of the multiple second optical axes is a fifth redundant optical axis, which is used to test the third reflector 74 through the first 45° reflector 73.

[0126] Exemplarily, the plurality of second optical axes can servo the translation stage 51 to move along the second direction, and the plurality of first optical axes can servo the translation stage 51 to move along the first direction and the third direction with a displacement value of 0. Thus, the fifth redundant optical axis can scan the third reflector 74 through the first 45° reflector to implement the test of the third reflector 74.

[0127] Optionally, if the translation stage 51 can move along six degrees of freedom, the plurality of first optical axes are also used to servo the translation stage 51 so that the displacement values ​​along the fifth direction and the sixth direction are 0. The second optical axes except the fifth redundant optical axis among the plurality of second optical axes are also used to servo the translation stage 51 so that the displacement value along the fourth direction is 0.

[0128] Specifically, assuming that the first interferometer includes five first optical axes (X1, X2, X3, Z3, and Z4), the second interferometer includes five second optical axes (Y1, Y2, Y3, Z1, and Z2), and the translation stage can move along six degrees of freedom (X, Y, Z, Rx, Ry, and Rz). Fig.11 As shown, Fig.11A schematic diagram of a process for testing a third reflector provided in an embodiment of the present application. The process for testing the third reflector may include: (1) using X1, X2 and X3 to serve the degrees of freedom X, Rz and Ry; (2) using Y1, Y2 and Y3 to serve the degrees of freedom Y, Rz and Rx; (3) using Z3 (or Z4) to serve the degree of freedom Z; (4) moving the translation stage along the Y direction, and assigning 0 to other degrees of freedom; (5) reading the reading of Z1 (or Z2) to obtain the surface shape related data of the third reflector; (6) solving the reading of Z1 (or Z2) to obtain the surface shape accuracy of the third reflector. It can be understood that the reading of Z1 (or Z2) is the coupling result of the third reflector and the first 45° reflector.

[0129] Based on the above principle of testing the third reflector, the fourth reflector can be tested, which will not be described in detail here.

[0130] In summary, the measurement system 70 provided in the embodiment of the present application can realize the test of the long reflector and the 45° reflector at different positions, thereby obtaining the surface shape data of all the reflector surfaces of the translation stage 51. When using the measurement system 70, compensation can be performed based on the surface shape data, thereby improving the measurement accuracy of the measurement system 70.

[0131] Based on the above-mentioned measurement system 70, the embodiment of the present application further provides a measurement method, which can be applied to different systems or devices, such as an execution device, which can be a terminal, such as a mobile terminal, a tablet computer, a laptop computer, an AR device, a VR device, a vehicle terminal, etc., and can also be a server, etc. The execution device is configured with an input / output (I / O) interface for data interaction with the measurement device.

[0132] like Fig.12 As shown, Fig.12 A flow chart of a measurement method provided in an embodiment of the present application. The measurement method includes the following process:

[0133] S1201, executing a device to control a first redundant optical axis to test a first reflector, and to control the movement of a first optical axis other than the first redundant optical axis among a plurality of first optical axes and a plurality of second optical axis servo translation stages along a plurality of degrees of freedom.

[0134] Therefore, the embodiment of the present application can servo-control the movement of the translation stage along multiple degrees of freedom through the first optical axis and multiple second optical axes other than the first redundant optical axis, so as to achieve precise control of the translation stage and improve the measurement accuracy. In addition, the first reflector can also be tested through the first redundant optical axis. For specific testing methods, please refer to Figure 6 The flowchart shown in (a).

[0135] S1202, the device controls the second redundant optical axis to test the second reflector, and controls the movement of the second optical axes other than the second redundant optical axis among the multiple second optical axes and the multiple first optical axis servo translation stages along multiple degrees of freedom.

[0136] Therefore, the embodiment of the present application can servo-control the movement of the translation stage along multiple degrees of freedom through the second optical axis other than the second redundant optical axis and multiple first optical axes to achieve precise control of the translation stage and improve measurement accuracy. In addition, the second reflector can also be tested through the second redundant optical axis. For specific test methods, please refer to Figure 6 The flowchart shown in (b).

[0137] Optionally, in the three-dimensional coordinate system, the method may further include: executing a device to control at least one of the plurality of second optical axes to move along a third direction via the first 45° reflector servo translation stage, and executing a device to control a third redundant optical axis to test the first 45° reflector.

[0138] Optionally, if the translation stage can move along six degrees of freedom, the method may further include: the execution device controls the second optical axes except the third redundant optical axis among the plurality of second optical axes, and the displacement values ​​of the servo translation stage along the second direction, the third direction, the fourth direction and the sixth direction are 0. And the plurality of first optical axis servo translation stages are controlled to move along the first direction, and the displacement value of the servo translation stage along the fifth direction is 0. For specific test methods, please refer to Fig.10 The flowchart shown in (a).

[0139] Optionally, in the three-dimensional coordinate system, the method may further include: executing a device to control at least one of the plurality of first optical axes to move along a third direction through a second 45° reflector servo translation stage, and controlling a fourth redundant optical axis to test the second 45° reflector.

[0140] Optionally, if the translation stage can move along six degrees of freedom, the method may further include: the execution device controls the first optical axis except the fourth redundant optical axis among the multiple first optical axes, and the displacement values ​​of the servo translation stage along the first direction, the fifth direction and the sixth direction are 0. And the multiple second optical axis servo translation stages are controlled to move along the second direction, and the displacement values ​​of the servo translation stage along the third direction and the fourth direction are 0. For specific test methods, please refer to Fig.10 The flowchart shown in (b).

[0141] Optionally, in the three-dimensional coordinate system, the method may further include: executing a device to control the fifth redundant optical axis to test the third reflector through the first 45° reflector, controlling the displacement values ​​of the plurality of first optical axis servo displacement stages along the first direction and the third direction to be 0, and controlling the second optical axis servo displacement stages of the plurality of second optical axes except the fifth redundant optical axis to move along the second direction.

[0142] Optionally, if the translation stage can move along six degrees of freedom, the method may further include: executing the device to control the displacement values ​​of the plurality of first optical axes to servo the translation stage along the fifth direction and the sixth direction to be 0. And controlling the second optical axes other than the fifth redundant optical axis among the plurality of second optical axes to servo the translation stage along the fourth direction to be 0. For specific test methods, see Fig.11 The flowchart shown in .

[0143] It is understandable that in order to implement the above functions, the electronic device includes hardware and / or software modules corresponding to the execution of each function. In combination with the algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application in combination with the embodiments, but such implementation should not be considered to be beyond the scope of the present application.

[0144] In this embodiment, the electronic device can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0145] In the case of dividing each functional module into corresponding functional modules, Fig.13 A possible schematic diagram of the composition of the measuring device 1300 involved in the above embodiment is shown. Fig.13 As shown, the measuring device 1300 may include: a first control unit 1301 and a second control unit 1302 .

[0146] The first control unit 1301 may be used to support the measuring device 1300 to execute the above-mentioned step S1201 and / or other processes of the technology described herein.

[0147] The second control unit 1302 may be used to support the measuring device 1300 to execute the above-mentioned step S1202 and / or other processes of the technology described herein.

[0148] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0149] The measuring device 1300 provided in this embodiment is used to execute the above antenna gain adjustment method, and thus can achieve the same effect as the above implementation method.

[0150] In the case of using an integrated unit, the measuring device 1300 may include a processing module, a storage module and a communication module. The processing module may be used to control and manage the actions of the measuring device 1300, for example, it may be used to support the measuring device 1300 to execute the steps executed by the first control unit 1301 and the second control unit 1302. The storage module may be used to support the measuring device 1300 to store program codes and data, etc. The communication module may be used to support the communication between the measuring device 1300 and other devices, for example, communication with a wireless access device.

[0151] Among them, the processing module can be a processor or a controller. It can implement or execute various exemplary logic boxes, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module can be a memory. The communication module can specifically be a device that interacts with other electronic devices, such as a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip, etc.

[0152] The embodiment of the present application also provides an electronic device, including one or more processors and one or more memories. The one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program codes, and the computer program codes include computer instructions. When the one or more processors execute the computer instructions, the electronic device executes the above-mentioned related method steps to implement the measurement method in the above-mentioned embodiment.

[0153] An embodiment of the present application further provides a computer storage medium, in which computer instructions are stored. When the computer instructions are executed on an electronic device, the electronic device executes the above-mentioned related method steps to implement the measurement method in the above-mentioned embodiment.

[0154] The embodiments of the present application further provide a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the measurement method executed by the electronic device in the above-mentioned embodiments.

[0155] In addition, an embodiment of the present application also provides a device, which can specifically be a chip, component or module, and the device may include a connected processor and memory; wherein the memory is used to store computer-executable instructions, and when the device is running, the processor can execute the computer-executable instructions stored in the memory so that the chip executes the measurement method performed by the electronic device in the above-mentioned method embodiments.

[0156] Among them, the measuring device, measuring system, computer storage medium, computer program product or chip provided in this embodiment are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0157] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0158] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0159] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0160] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0161] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium, including several instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0162] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A measuring device, characterized in that: The measuring device comprises: a translation stage, a first interferometer and a second interferometer; The first interferometer is spaced apart from the translation stage along a first direction, and the second interferometer is spaced apart from the translation stage along a second direction, and the first direction is perpendicular to the second direction; The first interferometer is configured to generate a plurality of first optical axes, and the second interferometer is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the translation stage; One of the plurality of first optical axes is a first redundant optical axis, the first redundant optical axis is used to test the object to be tested which is arranged on the translation stage along the second direction, and the first optical axis other than the first redundant optical axis among the plurality of first optical axes and the plurality of second optical axes are used to serve the movement of the translation stage along the plurality of degrees of freedom; One of the multiple second optical axes is a second redundant optical axis, and the second redundant optical axis is used to test the object to be tested which is arranged on the translation stage along the first direction. The second optical axes among the multiple second optical axes except the second redundant optical axis and the multiple first optical axes are used to serve the movement of the translation stage along the multiple degrees of freedom.

2. The device according to claim 1, characterized in that The degrees of freedom of the translation stage include the first direction, the second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction; The plurality of first optical axes are used to serve as a servo drive for the translation stage to move along the first direction; The second optical axes other than the second redundant optical axis among the plurality of second optical axes are used to serve the displacement values ​​of the translation stage along the second direction and the third direction to be 0.

3. The device according to claim 2, characterized in that The degrees of freedom of the translation stage further include a fourth direction, a fifth direction and a sixth direction, the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction; The plurality of first optical axes are further used to serve the displacement values ​​of the translation stage along the fifth direction and the sixth direction to be 0; The second optical axes other than the second redundant optical axis among the plurality of second optical axes are further used to serve to keep the displacement value of the translation stage along the fourth direction to be 0.

4. The device according to claim 1, characterized in that The degrees of freedom of the translation stage include the first direction, the second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction; The plurality of second optical axes are used to serve the displacement value of the translation stage along the third direction to be 0, and to serve the translation stage to move along the second direction; A first optical axis among the plurality of first optical axes except the first redundant optical axis is used to serve a displacement value of 0 for servoing the translation stage along the first direction.

5. The device according to claim 4, characterized in that The degrees of freedom of the translation stage further include a fourth direction, a fifth direction and a sixth direction, the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction; The plurality of second optical axes are further used to serve the displacement value of the translation stage along the fourth direction and the sixth direction to be 0; The first optical axes other than the first redundant optical axis among the plurality of first optical axes are further used to serve to keep the displacement value of the translation stage along the fifth direction to be 0.

6. The device according to any one of claims 2 to 5, characterized in that: At least two of the first optical axes are arranged at intervals in the first direction, and at least two of the first optical axes are arranged at intervals in the third direction; At least two of the second optical axes are arranged at intervals in the second direction, and at least two of the first optical axes are arranged at intervals in the third direction.

7. A measurement system, characterized in that: The measuring system comprises: a translation stage, a first interferometer, a second interferometer, a first reflector and a second reflector; The first interferometer is spaced apart from the translation stage along a first direction, and the second interferometer is spaced apart from the translation stage along a second direction, and the first direction is perpendicular to the second direction; The first reflector is disposed on a first supporting surface of the translation platform along the second direction, and the second reflector is disposed on a second supporting surface of the translation platform along the first direction; The first interferometer is configured to generate a plurality of first optical axes, and the second interferometer is configured to generate a plurality of second optical axes, and the sum of the number of the first optical axes and the second optical axes is greater than the number of degrees of freedom of the translation stage; One of the plurality of first optical axes is a first redundant optical axis, the first redundant optical axis is used to test the first reflector, and the first optical axes other than the first redundant optical axis among the plurality of first optical axes and the plurality of second optical axes are used to serve the movement of the translation stage along the plurality of degrees of freedom; One of the plurality of second optical axes is a second redundant optical axis, the second redundant optical axis is used to test the second reflector, and the second optical axes other than the second redundant optical axis among the plurality of second optical axes and the plurality of first optical axes are used to serve the movement of the translation stage along the plurality of degrees of freedom.

8. The system according to claim 7, characterized in that The degrees of freedom of the translation stage include the first direction, the second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction; the measurement system further includes a first 45° reflector and a third reflector, the first 45° reflector is arranged on the second supporting surface of the translation stage along the first direction, the third reflector is arranged with a spacing from the translation stage along the third direction, and the first 45° reflector and the third reflector are arranged opposite to each other along the third direction; At least one of the plurality of second optical axes is used to serve as a servo drive for the translation stage to move along the third direction via the first 45° reflecting mirror.

9. The system according to claim 8, characterized in that One of the plurality of second optical axes is a third redundant optical axis; The third redundant optical axis is used to test the first 45° reflector.

10. The system according to claim 9, characterized in that The degrees of freedom of the translation stage further include a fourth direction, a fifth direction and a sixth direction, the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction; The second optical axes other than the third redundant optical axis among the plurality of second optical axes are used to serve the displacement values ​​of the translation stage along the second direction, the third direction, the fourth direction and the sixth direction to be 0; The plurality of first optical axes are used to serve the translation stage to move along the first direction, and the displacement value of serving the translation stage along the fifth direction is 0.

11. The system according to claim 7, characterized in that The degrees of freedom of the translation stage include the first direction, the second direction and a third direction, and the third direction is perpendicular to the first direction and the second direction; the measurement system further includes a second 45° reflector and a fourth reflector, the second 45° reflector is arranged on the first supporting surface of the translation stage along the second direction, the fourth reflector is arranged at a distance from the translation stage along the third direction, and the second 45° reflector and the fourth reflector are arranged opposite to each other along the third direction; At least one of the plurality of first optical axes is used to serve as a servo mechanism for the translation stage to move along the third direction via the second 45° reflecting mirror.

12. The system according to claim 11, characterized in that One of the plurality of first optical axes is a fourth redundant optical axis; The fourth redundant optical axis is used to test the second 45° reflector.

13. The system according to claim 12, characterized in that The degrees of freedom of the translation stage further include a fourth direction, a fifth direction and a sixth direction, the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction; A first optical axis among the plurality of first optical axes except the fourth redundant optical axis is used to serve the displacement value of the translation stage along the first direction, the fifth direction and the sixth direction to be 0; The plurality of second optical axes are used to serve the translation stage to move along the second direction, and the displacement values ​​of the translation stage along the third direction and the fourth direction are 0.

14. The system according to claim 7, characterized in that The degrees of freedom of the translation stage include the first direction, the second direction and a third direction, the third direction is perpendicular to the first direction and the second direction, the measurement system also includes a first 45° reflector and a third reflector, and a second 45° reflector and a fourth reflector; the first 45° reflector is arranged on the second supporting surface of the translation stage along the first direction, the third reflector is spaced apart from the translation stage along the third direction, and the first 45° reflector and the third reflector are arranged opposite to each other along the third direction; the second 45° reflector is arranged on the first supporting surface of the translation stage along the second direction, the fourth reflector is spaced apart from the translation stage along the third direction, and the second 45° reflector and the fourth reflector are arranged opposite to each other along the third direction; One of the plurality of second optical axes is a fifth redundant optical axis, and the fifth redundant optical axis is used to test the third reflector through the first 45° reflector; The plurality of first optical axes are used to serve as servo displacement values ​​of the translation stage along the first direction and the third direction to be 0; The second optical axes other than the fifth redundant optical axis among the plurality of second optical axes are used to serve as a servo drive for the translation stage to move along the second direction.

15. The system according to claim 14, characterized in that The degrees of freedom of the translation stage further include a fourth direction, a fifth direction and a sixth direction, the fourth direction is the direction in which the translation stage rotates around the first direction, the fifth direction is the direction in which the translation stage rotates around the second direction, and the sixth direction is the direction in which the translation stage rotates around the third direction; The plurality of first optical axes are further used to serve the displacement values ​​of the translation stage along the fifth direction and the sixth direction to be 0; The second optical axes other than the fifth redundant optical axis among the plurality of second optical axes are further used to serve to maintain a displacement value of the translation stage along the fourth direction to be 0.

16. A measurement method, characterized in that: The method is applied to the measurement system according to any one of claims 7 to 15, and the method comprises: Controlling the first redundant optical axis to test the first reflector, and controlling the movement of the first optical axis other than the first redundant optical axis and the plurality of second optical axis servo translation stages along the plurality of degrees of freedom; and / or, The second redundant optical axis is controlled to test the second reflecting mirror, and the second optical axes other than the second redundant optical axis among the plurality of second optical axes and the plurality of first optical axes are controlled to servo the movement of the translation stage along the plurality of degrees of freedom.

17. The method according to claim 16, characterized in that The method further comprises: Control at least one of the plurality of second optical axes to servo the translation stage along a third direction via a first 45° reflecting mirror; The third redundant optical axis is controlled to test the first 45° reflector.

18. The method according to claim 17, characterized in that The method further comprises: Controlling the second optical axes other than the third redundant optical axis among the plurality of second optical axes, and servoing the displacement values ​​of the translation stage along the second direction, the third direction, the fourth direction and the sixth direction to be 0; The plurality of first optical axes are controlled to servo the translation stage to move along the first direction, and a displacement value of the translation stage servoed along the fifth direction is 0.

19. The method according to claim 16, characterized in that The method further comprises: Controlling at least one of the plurality of first optical axes to servo the translation stage along the third direction through a second 45° reflecting mirror; The fourth redundant optical axis is controlled to test the second 45° reflector.

20. The method according to claim 19, characterized in that The method further comprises: Controlling the first optical axes other than the fourth redundant optical axis among the plurality of first optical axes, and servoing the displacement values ​​of the translation stage along the first direction, the fifth direction and the sixth direction to be 0; The plurality of second optical axes are controlled to servo the translation stage to move along the second direction, and the displacement values ​​of the translation stage servoed along the third direction and the fourth direction are controlled to be zero.

21. The method according to claim 16, characterized in that The method further comprises: Controlling the fifth redundant optical axis to test the third reflector through the first 45° reflector; Controlling the plurality of first optical axes to servo the displacement values ​​of the translation stage along the first direction and the third direction to be 0; The second optical axes other than the fifth redundant optical axis among the plurality of second optical axes are controlled to servo the translation stage to move along the second direction.

22. The method according to claim 21, characterized in that The method further comprises: Controlling the plurality of first optical axes to servo the displacement values ​​of the translation stage along the fifth direction and the sixth direction to be 0; Controlling the second optical axes other than the fifth redundant optical axis among the plurality of second optical axes is also used to servo the displacement value of the translation stage along the fourth direction to be 0.

23. A computer-readable storage medium, characterized in that: The method comprises computer instructions, which, when executed on an electronic device, cause the electronic device to execute the method according to any one of claims 16 to 22.

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