Vertical measurement method based on pupil surface modulation, focusing and leveling system and exposure device

Abstract

The present invention provides a vertical measurement method, a focusing and leveling system and an exposure device based on pupil modulation. The focusing and leveling system adds a first pupil modulation element in the projection component, and adds a second pupil modulation element complementary to the first pupil modulation element in the first detection component. The second pupil modulation element achieves a filtering effect on the surface pattern of the object to be measured through energy distribution modulation and optical phase modulation of the pupil surface. The first pupil modulation element and the second pupil modulation element increase the wave aberration through optical phase modulation of the pupil surface, reduce the contrast of the surface pattern of the object to be measured, and weaken the influence of the surface pattern of the object to be measured on the energy distribution; and the first pupil modulation element and the second pupil modulation element reduce the uneven energy distribution of the measuring beam caused by the reflectivity through energy distribution modulation, thereby reducing the vertical measurement error, improving the vertical measurement accuracy, and ensuring a better imaging transmission effect from the projection component to the first detection component.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography equipment, and in particular to a vertical measurement method based on pupil surface modulation, a focusing and leveling system and an exposure device. Background Art

[0002] The focusing and leveling subsystem is one of the core subsystems of the lithography machine. It is mainly used for online measurement of the vertical height of the surface of the object to be measured and for surface topography scanning measurement. During the exposure process, there is a pattern distribution on the surface of the object to be measured based on multiple exposures, and the reflectivity of different pattern positions is different. This difference will cause a large error in the vertical measurement result. Summary of the invention

[0003] The purpose of the present invention is to provide a vertical measurement method based on pupil modulation, a focusing and leveling system and an exposure device to solve the problem that the vertical measurement result has large errors due to the difference in reflectivity at different pattern positions on the surface of the object being measured.

[0004] In order to solve the above technical problems, the present invention provides a focusing and leveling system, comprising an illumination component, a projection component, a first detection component, a relay component and a second detection component;

[0005] The projection assembly is provided with a first pupil surface modulation element, and the first detection assembly is provided with a second pupil surface modulation element complementary to the first pupil surface modulation element;

[0006] The lighting assembly is used to provide a measurement light beam;

[0007] The first pupil surface modulation element is used to modulate the measuring light beam into a measuring light beam with a non-ideal wave surface with an aberration, and the measuring light beam with a non-ideal wave surface with an aberration is irradiated to the surface of the object to be measured and reflected;

[0008] The second pupil modulation element is used to restore the measuring light beam reflected by the surface of the measured object into a measuring light beam having an ideal plane wave and filtering out pattern information of the surface of the measured object;

[0009] The second detection component is used to receive the ideal plane wave after passing through the relay component and filter out the measurement light beam of the pattern information on the surface of the object to be measured, so as to obtain a vertical height signal of the surface of the object to be measured.

[0010] Optionally, the first pupil surface modulation element is located at the optical pupil surface of the projection light path, the second pupil surface modulation element is located at the optical pupil surface of the detection light path, and the first pupil surface modulation element and the second pupil surface modulation element are placed in a substantially mirror image;

[0011] The first pupil surface modulation element and the second pupil surface modulation element have complementary modulation capabilities, and the second pupil surface modulation element modulates pupil surface energy distribution or optical phase distribution to filter out pattern information on the surface of the object to be measured.

[0012] Optionally, the first pupil surface modulation element is a spiral phase plate or a wavefront encoder; the second pupil surface modulation element is a spiral phase plate or a wavefront encoder.

[0013] Optionally, the projection component is further provided with a first defocus compensation element, and the first detection component is provided with a second defocus compensation element complementary to the first defocus compensation element, the first defocus compensation element and the second defocus compensation element are placed in a roughly mirror image, the first defocus compensation element and the second defocus compensation element have complementary modulation capabilities, and the second defocus compensation element adjusts spherical aberration to perform focal plane compensation to filter out pattern information on the surface of the object to be measured.

[0014] Optionally, the first defocus compensation element and the second defocus compensation element are wedge plate sets.

[0015] Optionally, the first defocus compensation element includes a wedge plate group with different thicknesses, and the second defocus compensation element includes a wedge plate group with different thicknesses. The second defocus compensation element realizes different spherical aberrations through the different thicknesses of the wedge plate groups, and an adjustment amount of the second defocus compensation element is greater than an adjustment amount of the second pupil surface modulation element.

[0016] Based on the same inventive concept, the present invention also provides a vertical measurement method of an exposure device based on pupil modulation, comprising the following steps:

[0017] According to the workpiece process, confirm the pattern distribution on the surface of the object to be measured;

[0018] Calculating an optimal pupil modulation amount according to the pattern distribution on the surface of the object being measured;

[0019] Selecting a pupil modulation scheme, and adjusting the first pupil modulation element and the second pupil modulation element;

[0020] The illumination assembly emits a measurement light beam;

[0021] The measuring beam is modulated by a first pupil surface modulation element in the projection assembly into a measuring beam with a non-ideal wavefront having an aberration.

[0022] The measuring light beam with the non-ideal wavefront having an aberration is irradiated onto the surface of the object to be measured and is reflected;

[0023] The measuring light beam reflected by the surface of the measured object is restored to a measuring light beam having an ideal plane wave and filtering out pattern information of the surface of the measured object through the second pupil surface modulation element of the first detection assembly;

[0024] The measuring light beam having an ideal plane wave and filtering out the pattern information on the surface of the object to be measured is received by the second detection component after passing through the relay component to obtain a vertical height signal of the surface of the object to be measured;

[0025] The vertical height signal is solved by a calculation unit to obtain the vertical height of the surface of the object to be measured.

[0026] Optionally, after the measuring beam is modulated by the first pupil surface modulation element into a measuring beam with a non-ideal wavefront having an aberration,

[0027] The measuring light beam with the non-ideal wavefront with aberration is first incident on the first defocus compensation element and then irradiated onto the surface of the object to be measured.

[0028] The measuring light beam reflected by the surface of the object to be measured is first incident on the second defocus compensation element in the first detection component to preliminarily filter out the measuring light beam of the pattern information on the surface of the object to be measured, and then incident on the second pupil surface modulation element to restore it to a measuring light beam with an ideal plane wave and filter out the pattern information on the surface of the object to be measured again.

[0029] Optionally, the first pupil surface modulation element and the second pupil surface modulation element have complementary modulation capabilities, and the first defocus compensation element and the second defocus compensation element have complementary modulation capabilities.

[0030] Based on the same inventive concept, the present invention also provides an exposure device, comprising any of the focusing and leveling systems described above.

[0031] In the focusing and leveling system provided by the present invention, a first pupil surface modulation element is added to the projection component, and a second pupil surface modulation element complementary to the first pupil surface modulation element is added to the first detection component, and the second pupil surface modulation element realizes a filtering effect on the surface pattern of the object to be measured through energy distribution modulation and optical phase modulation, wherein the first pupil surface modulation element and the second pupil surface modulation element increase the wave aberration through optical phase modulation, reduce the contrast of the surface pattern of the object to be measured, and weaken the influence of the surface pattern of the object to be measured on the energy distribution, and the first pupil surface modulation element and the second pupil surface modulation element reduce the uneven energy distribution of the measuring light beam caused by the reflectivity through energy distribution modulation, thereby reducing the vertical measurement error, improving the vertical measurement accuracy, and ensuring a better imaging transmission effect from the projection component to the first detection component. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0033] Figure 1It is a schematic diagram of the structure of a focusing and leveling system according to an embodiment of the present invention.

[0034] Figure 2 It is a schematic diagram of pupil modulation and compensation principle of an embodiment of the present invention.

[0035] Figure 3a to Figure 3f It is a schematic diagram of pupil modulation and compensation effect according to an embodiment of the present invention.

[0036] Figure 4 It is a flow chart of a vertical measurement method of an exposure device based on pupil modulation according to an embodiment of the present invention.

[0037] In the attached figure:

[0038] 101-light source; 102-illumination mirror group; 103-projection slit; 104-front projection group; 105-scanning galvanometer; 106-first pupil modulation element; 107-rear projection group; 108-first defocus compensation element; 109-measured object; 110-second defocus compensation element; 111-front detection group; 112-second pupil modulation element; 113-reflector; 114-rear detection group; 115-detection slit; 116-relay component; 117-second detection component. DETAILED DESCRIPTION

[0039] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0040] As used in the present invention, the singular forms "one", "an" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include one or at least two of the features. In addition, as used in the present invention, an element is arranged on another element, which usually only indicates that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, an element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Figure 1 FIG. 1 is a schematic diagram of the structure of the focusing and leveling system according to an embodiment of the present invention. Figure 1 As shown, this embodiment provides a focusing and leveling system, including an illumination component, a projection component, a first detection component, a relay component and a second detection component.

[0042] The lighting assembly comprises a light source 101 and a lighting lens assembly 102 in sequence, wherein the light source 101 is used to provide a measuring light beam and the lighting lens assembly 102 is used to adjust the measuring light beam emitted by the light source 101 into a uniform measuring light beam.

[0043] The projection assembly includes a projection slit 103, a projection front group 104, a scanning reflection unit 105, a first pupil surface modulation element 106, a projection back group 107 and a first defocus compensation element 108 in sequence. The illumination mirror group 102 illuminates the projection slit 103 in a Kohler illumination scheme. The projection slit 103 is used to form the measurement beam into a measurement beam of a desired shape. The projection front group 104 is used to adjust the measurement beam into a uniform measurement beam. The uniform measurement beam is irradiated onto the scanning galvanometer 105, and the scanning galvanometer 105 is used to perform energy modulation on the measurement beam. The energy-modulated measurement beam enters the first pupil surface modulation element 106, and the first pupil surface modulation element 106 is used to debug the image quality of the projection optical path. Specifically, the first pupil surface modulation element 106 is used to modulate the measurement beam into a non-ideal wavefront with aberrations. The measurement beam with a non-ideal wavefront with aberration is incident on the first defocus compensation element 108. The first defocus compensation element 108 realizes focal plane compensation through a wedge plate group of different thicknesses. It has a similar function to the first pupil surface modulation element 106. The wedge plate groups of different thicknesses can realize different spherical aberration terms. The adjustment amount of the first defocus compensation element 108 is generally much greater than the phase compensation of the first pupil surface modulation element 106, which can realize relatively rough image quality compensation with a large compensation amount. After the measurement beam passes through the first defocus compensation element 108 to compensate the focal plane, it is imaged on the surface of the object to be measured 109. The surface of the object to be measured 109 contains pattern information of the corresponding process.

[0044] The first detection assembly includes a second defocus compensation element 110, a detection front group 111, a second pupil surface modulation element 112, a reflector 113, a detection rear group 114 and a detection slit 115. The measurement beam with the non-ideal wavefront with aberration reflected by the surface of the measured object 109 is first incident on the second defocus compensation element 110, and the second defocus compensation element 110 is used to preliminarily filter out the pattern information on the surface of the measured object 109. The measurement beam with the non-ideal wavefront with aberration is then incident on the second pupil surface modulation element 112, and the second pupil surface modulation element 112 is used to restore the measurement beam with the non-ideal wavefront with aberration to an ideal plane wave and filter out the measurement beam of the pattern information on the surface of the measured object 109 again. The second detection assembly 117 is used to receive the measurement beam of the ideal plane wave and the pattern information on the surface of the measured object after passing through the relay assembly 116, so as to obtain the vertical height signal of the surface of the measured object. The second detection assembly 117 is, for example, a detector. The relay component 116 can focus the light to the second detection component 117 by adjusting the focal length of the lens. The second detection component 117 collects the detection signal and measures the vertical height signal of the surface of the object to be measured 109. The vertical height of the surface of the object to be measured is obtained by solving the vertical height signal through the calculation unit.

[0045] In the focusing and leveling system based on energy detection, when performing vertical measurement, the difference in reflectivity at different positions in the pattern on the surface of the object to be measured is coupled into the result of energy detection, thereby affecting and causing vertical measurement errors. Through a filtering scheme, the pattern of a specific period can be filtered to improve the measurement accuracy, that is, the pattern information on the surface of the object to be measured 109 is first preliminarily filtered out by the second defocus compensation element 110, and then the pattern information on the surface of the object to be measured 109 is filtered out again after being incident on the second pupil surface modulation element 112. This solves the problem that the surface of the object to be measured that has been exposed multiple times has pattern distribution and the reflectivity at different pattern positions is different, and this difference will cause a large error in the vertical measurement result, and solves the problem of pattern process adaptability in the vertical measurement of the focusing and leveling system.

[0046] Figure 2 1 is a diagram showing the principle of pupil modulation and compensation according to an embodiment of the present invention. Figure 2 As shown, the first pupil surface modulation element 106 is located at the optical pupil surface of the projection optical path, and the second pupil surface modulation element 112 is located at the optical pupil surface of the detection optical path. The second pupil surface modulation element 112 is placed in a mirror image with the first pupil surface modulation element 106, and has a complementary effect on the regulation of the wavefront. For example, an ideal plane wave becomes a non-ideal wavefront with aberration after being modulated by the pupil surface of the first pupil surface modulation element 106. The measuring beam irradiated on the surface of the measured object 109 is modulated by the first pupil surface modulation element 106, and the measuring beam reflected by the measured object 109 is restored to an ideal plane wave after passing through the complementary second pupil surface modulation element 112. Therefore, the complementary optical path can realize a relatively complete transmission of the measuring beam information, but the pattern information on the surface of the measured object 109 can be filtered out by the second pupil surface modulation element 112. The second pupil surface modulation element 112 modulates the pupil surface energy distribution or the optical phase distribution to filter out the pattern information on the surface of the measured object 19. Specifically, the first pupil surface modulation element 106 and the second pupil surface modulation element 112 introduce optical wave aberration, and the wave aberration becomes larger after the measuring light beam is modulated by the pupil surface, resulting in blurred imaging, that is, reduced contrast, and the filtered pattern information on the surface of the object 19 to be measured weakens the influence of the pattern information on the surface of the object 19 to be measured on the energy distribution by reducing the contrast of the pattern information, thereby reducing the vertical measurement error. The first pupil surface modulation element 106 and the second pupil surface modulation element 112 are, for example, a spiral phase plate and a wavefront encoder, wherein the wavefront encoder is a micro-mirror array. The surface of the spiral phase plate is, for example, composed of a structure with 64 step distributions, and the equivalent optical path change of each step is 2π / 64×λ, and the two spiral phase plates are roughly placed in a mirror image with a complementary optical path difference. Of course, the surface of the spiral phase plate can also be composed of structures with other numbers of step distributions, which is not limited in this embodiment.

[0047] The first defocus compensation element 108 and the second defocus compensation element 110 are also placed in a roughly mirrored manner, and also have a complementary effect on the regulation of the wavefront. The second defocus compensation element 110, the first defocus compensation element 108, the second pupil surface modulation element 112, and the first pupil surface modulation element 106 have similar functions, and the second defocus compensation element 110 can also filter out the pattern information on the surface of the object to be measured 109. The first defocus compensation element 108 and the second defocus compensation element 110 include a wedge plate group. The first defocus compensation element 108 includes a wedge plate group with different thicknesses and focal plane compensation is achieved through the different thicknesses of the wedge plate group. The second defocus compensation element 110 includes a wedge plate group with different thicknesses and focal plane compensation is achieved through the different thicknesses of the wedge plate group. The wedge plate group is, for example, a glass plate. Specifically, glass plates of different thicknesses can achieve different spherical aberration adjustments. Spherical aberration is a part of the aberration. Therefore, the first defocus compensation element 108 and the second defocus compensation element 110 also introduce optical wave aberration. After the measuring light beam passes through the focal plane compensation, the wave aberration becomes larger, resulting in blurred imaging, that is, reduced contrast. The filtered pattern information on the surface of the object 19 to be measured weakens the influence of the pattern information on the surface of the object 19 to be measured on the energy distribution by reducing the contrast of the pattern information, thereby reducing the vertical measurement error. However, the adjustment amount of the second defocus compensation element 110 is generally greater than the adjustment amount of the second pupil surface modulation element 112. Preferably, the adjustment amount of the second defocus compensation element 110 is much greater than the adjustment amount of the second pupil surface modulation element 112. The second defocus compensation element 110 can achieve relatively rough image quality compensation with a large compensation amount.

[0048] Figure 3a to Figure 3f It is a schematic diagram of pupil modulation and compensation effect according to an embodiment of the present invention. Figure 3a is the measurement spot shape emitted by the projection slit 103, Figure 3b The pattern distribution on the surface of the object 109 is assumed. Based on the imaging simulation results, the spot shape of the pattern period of 290 μm received by the detection slit 115 is as follows: Figure 3c The spot shape of the pattern period of 105um received by the detection slit 115 is as follows: Figure 3d , the vertical height error is calculated by calculating the energy passing through the detection slit 115, Figure 3e The pattern period is 290um, which is the simulation result. Figure 3f The pattern period is 105um, which is the simulation result. Figure 3e and Figure 3f The vertical axis is the error (Error), the unit is um, and the horizontal axis is the measurement beam position (Spot Position), the unit is um. Figure 3e and Figure 3fIt can be seen that by adding pupil modulation and defocus compensation, the vertical measurement error of the pattern with a pattern period of 290um is reduced from a maximum of 110nm to 60nm, and the vertical measurement error of the pattern with a pattern period of 105um is reduced from 100nm to 35nm. Therefore, adding pupil modulation and defocus compensation has obvious vertical error suppression results.

[0049] Figure 4 : is a flow chart of a vertical measurement method of an exposure device based on pupil modulation according to an embodiment of the present invention. Based on the same inventive concept, the present invention also provides a vertical measurement method based on pupil modulation, comprising:

[0050] Step S10, confirming the pattern distribution on the surface of the object to be measured according to the workpiece process;

[0051] Step S20, calculating the optimal pupil modulation amount according to the pattern distribution on the surface of the object to be measured;

[0052] Step S30, selecting a pupil modulation scheme and performing pupil modulation;

[0053] Step S40: the second detection component performs vertical height measurement and scanning imaging.

[0054] In step S30 and step S40, the focusing and leveling system is used to perform pupil modulation and vertical height measurement and scan imaging. Specifically, the light source 101 in the illumination assembly emits a measuring beam, and the illumination mirror group 102 in the illumination assembly adjusts the measuring beam emitted by the light source 101 into a uniform measuring beam. The illumination mirror group 102 illuminates the projection slit 103 in a Kohler illumination scheme, and the measuring beam generates a measuring beam of a desired shape through the projection slit 103. The projection front group 104 adjusts the measuring beam into a uniform measuring beam. The measuring beam is, for example, an ideal plane wave. In this embodiment, the ideal plane wave is a nearly ideal plane wave. The uniform measuring beam is irradiated onto the scanning galvanometer 105, and the scanning galvanometer 105 performs energy modulation on the measuring beam. The energy-modulated measuring beam enters the first pupil surface modulation element 106, and the first pupil surface modulation element 106 adjusts the image quality of the projection optical path. Specifically, the measuring beam becomes a measuring beam with a non-ideal wavefront with an aberration after the pupil surface modulation of the first pupil surface modulation element 106. The measurement beam with a non-ideal wavefront with an aberration is incident on the first defocus compensation element 108. The measurement beam with a non-ideal wavefront with an aberration is imaged on the surface of the object 109 after the focus is compensated by the first defocus compensation element 108. The surface of the object 109 contains pattern information of the corresponding process. The measurement beam reflected by the surface of the object 109 is first incident on the second defocus compensation element 110 to initially filter out the pattern information on the surface of the object 109, and then incident on the second pupil surface modulation element 112 to restore it to an ideal plane wave and filter out the pattern information on the surface of the object 109 again. The measurement beam is received by the second detection component 117 after passing through the relay component 116 to obtain the vertical height signal of the surface of the object; the vertical height signal is resolved by the calculation unit to obtain the vertical height of the surface of the object. The relay component 116 focuses the measurement beam on the second detection component 117 by adjusting the focal length of the lens to obtain the vertical height of the surface of the object 19. In the focusing and leveling system based on energy detection, when performing vertical measurement, the difference in reflectivity at different positions in the pattern on the surface of the object to be measured is coupled into the result of energy detection, thereby affecting and causing vertical measurement errors. Through a filtering scheme, the pattern of a specific period can be filtered to improve the measurement accuracy, that is, the pattern information on the surface of the object to be measured 109 is first preliminarily filtered out by the second defocus compensation element 110, and then the pattern information on the surface of the object to be measured 109 is filtered out again after being incident on the second pupil surface modulation element 112. This solves the problem that the surface of the object to be measured that has been exposed multiple times has pattern distribution and the reflectivity at different pattern positions is different, and this difference will cause a large error in the vertical measurement result, and solves the problem of pattern process adaptability in the vertical measurement of the focusing and leveling system.

[0055] This embodiment further provides an exposure device, comprising any of the focusing and leveling systems described above, and used to implement any of the vertical measurement methods based on pupil modulation described above.

[0056] In summary, it can be seen that in the vertical measurement method and focusing and leveling system of the exposure device based on pupil modulation provided in the embodiment of the present invention, a first pupil modulation element is added to the projection component, and a second pupil modulation element complementary to the first pupil modulation element is added to the first detection component, and the second pupil modulation element realizes a filtering effect on the surface pattern of the object to be measured through energy distribution modulation and optical phase modulation, wherein the first pupil modulation element and the second pupil modulation element increase the wave aberration through optical phase modulation, reduce the contrast of the surface pattern of the object to be measured, and weaken the influence of the surface pattern of the object to be measured on the energy distribution, and the first pupil modulation element and the second pupil modulation element reduce the uneven energy distribution of the measuring light beam caused by reflectivity through energy distribution modulation, thereby reducing the vertical measurement error, and at the same time ensuring a better imaging transmission effect from the projection component to the first detection component, thereby solving the problem of pattern process adaptability of vertical measurement of the exposure device and improving the accuracy of vertical measurement.

[0057] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A focusing and leveling system, characterized in that: It includes an illumination component, a projection component, a first detection component, a relay component, and a second detection component; The projection assembly is provided with a first pupil surface modulation element, the first detection assembly is provided with a second pupil surface modulation element complementary to the first pupil surface modulation element, the first pupil surface modulation element is located at the optical pupil surface of the projection light path, the second pupil surface modulation element is located at the optical pupil surface of the detection light path, the second pupil surface modulation element is mirror-placed with the first pupil surface modulation element, and has a complementary effect on the regulation of the wavefront; The lighting assembly is used to provide a measurement light beam; The first pupil surface modulation element is used to modulate the measuring light beam into a measuring light beam with a non-ideal wave surface with an aberration, and the measuring light beam with a non-ideal wave surface with an aberration is irradiated to the surface of the object to be measured and reflected; The second pupil modulation element is used to restore the measuring light beam reflected by the surface of the measured object into a measuring light beam having an ideal plane wave and filtering out pattern information of the surface of the measured object; The second detection component is used to receive the ideal plane wave after passing through the relay component and filter out the measurement light beam of the pattern information on the surface of the object to be measured, so as to obtain a vertical height signal of the surface of the object to be measured.

2. The focusing and leveling system according to claim 1, characterized in that: The first pupil surface modulation element and the second pupil surface modulation element have complementary modulation capabilities, and the second pupil surface modulation element modulates the energy distribution or optical phase distribution of the pupil surface to filter out the pattern information on the surface of the object to be measured.

3. The focusing and leveling system according to claim 1, characterized in that: The first pupil surface modulation element is a spiral phase plate or a wavefront encoder; the second pupil surface modulation element is a spiral phase plate or a wavefront encoder.

4. The focusing and leveling system according to claim 1, characterized in that: The projection component is also provided with a first defocus compensation element, and the first detection component is provided with a second defocus compensation element complementary to the first defocus compensation element. The first defocus compensation element and the second defocus compensation element are placed in a roughly mirror image manner, and the first defocus compensation element and the second defocus compensation element have complementary modulation capabilities. The second defocus compensation element adjusts spherical aberration to perform focal plane compensation to filter out pattern information on the surface of the object to be measured.

5. The focusing and leveling system according to claim 4, characterized in that: The first defocus compensation element and the second defocus compensation element are wedge plate sets.

6. The focusing and leveling system according to claim 5, characterized in that: The first defocus compensation element includes a wedge plate group with different thicknesses, and the second defocus compensation element includes a wedge plate group with different thicknesses. The second defocus compensation element realizes different spherical aberrations through the different thicknesses of the wedge plate groups to perform focal plane compensation to filter out pattern information on the surface of the object to be measured, and an adjustment amount of the second defocus compensation element is greater than an adjustment amount of the second pupil surface modulation element.

7. A vertical measurement method based on pupil modulation, characterized in that: The steps include: According to the workpiece process, confirm the pattern distribution on the surface of the object to be measured; Calculating an optimal pupil modulation amount according to the pattern distribution on the surface of the object being measured; Selecting a pupil modulation scheme, and adjusting the first pupil modulation element and the second pupil modulation element; The illumination assembly emits a measurement light beam; The measuring beam is modulated by the first pupil surface modulation element in the projection assembly into a measuring beam with a non-ideal wavefront having an aberration. The measuring light beam with the non-ideal wavefront having an aberration is irradiated onto the surface of the object to be measured and is reflected; The measuring light beam reflected by the surface of the measured object is restored to a measuring light beam having an ideal plane wave and filtering out pattern information of the surface of the measured object through the second pupil surface modulation element of the first detection assembly; The measuring light beam having an ideal plane wave and filtering out the pattern information on the surface of the object to be measured is received by the second detection component after passing through the relay component to obtain a vertical height signal of the surface of the object to be measured; The vertical height signal is solved by a calculation unit to obtain the vertical height of the surface of the object to be measured.

8. The vertical measurement method based on pupil modulation according to claim 7, characterized in that: After the measuring beam is modulated by the first pupil surface modulation element into a measuring beam with a non-ideal wavefront having an aberration, The measuring light beam with the non-ideal wavefront with aberration is first incident on the first defocus compensation element and then irradiated onto the surface of the object to be measured. The measuring light beam reflected by the surface of the object to be measured is first incident on the second defocus compensation element in the first detection component to preliminarily filter out the measuring light beam of the pattern information on the surface of the object to be measured, and then incident on the second pupil surface modulation element to restore it to a measuring light beam with an ideal plane wave and filter out the pattern information on the surface of the object to be measured again.

9. The vertical measurement method based on pupil modulation according to claim 8, characterized in that: The first pupil surface modulation element and the second pupil surface modulation element have complementary modulation capabilities, and the first defocus compensation element and the second defocus compensation element have complementary modulation capabilities.

10. An exposure device, characterized in that: The focusing and leveling system comprises the focusing and leveling system as described in any one of claims 1 to 6.

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