CN113624156A

CN113624156A - Measurement system and method

Info

Publication number: CN113624156A
Application number: CN202010380355.3A
Authority: CN
Inventors: 陈鲁; 杨乐; 马研忠; 张威; 李小辉
Original assignee: Skyverse Ltd
Current assignee: Skyverse Ltd
Priority date: 2020-05-09
Filing date: 2020-05-09
Publication date: 2021-11-09
Also published as: TWI783228B; TW202144733A; TW202305317A

Abstract

The present disclosure provides a measuring system and a method, relating to the technical field of measurement, wherein the measuring system comprises: a light source configured to generate an original light beam, wherein the original light beam returned from a measured area of a measured object is a return light beam; an optical assembly configured to obtain a light beam to be processed according to the return light beam, wherein at least part of the light beam to be processed is a first light beam; first detection means configured to obtain first detection information from the first light beam; a moving device configured to relatively move the optical assembly and the object to be measured in an optical axis direction of the optical assembly; and the processing system is configured to determine the actual distance between the optical assembly and the fixed plane of the measured object at each first moment according to the first detection information at each first moment in a plurality of first moments.

Description

Measurement system and method

Technical Field

The present disclosure relates to the field of measurement technologies, and in particular, to a measurement system and method.

Background

In the field of integrated circuit manufacturing, in order to improve the yield of products, the three-dimensional shape of a wafer needs to be measured to check whether the process of wafer manufacturing meets the standard. The three-dimensional shape measurement mode based on the white light interference technology is widely used in the field of integrated circuit detection due to the characteristics of no contact, rapidness, high precision and the like.

The white light interference technology takes white light with short coherence length as a light source, and can locate the surface morphology of a measured object through the peak value of interference signal intensity.

Disclosure of Invention

According to an aspect of an embodiment of the present disclosure, there is provided a measurement system including: a light source configured to generate an original light beam, wherein the original light beam returning from a measured area of a measured object forms a return light beam; an optical assembly configured to obtain a light beam to be processed according to the return light beam, wherein at least part of the light beam to be processed is a first light beam; first detection means configured to obtain first detection information from the first light beam; a moving device configured to relatively move the optical assembly and the object to be measured in an optical axis direction of the optical assembly; and the processing system is configured to determine the actual distance between the optical assembly and the fixed plane of the measured object at each first moment according to the first detection information at each first moment in a plurality of first moments.

In some embodiments, the optical assembly comprises: a first beam splitter configured to split the original beam into a reference beam and an object beam incident on the measured area, wherein the object beam returning from the measured area to the optical assembly forms the return beam; and a reference mirror configured to propagate the reference beam along a preset trajectory to obtain a pre-interference beam, wherein the pre-interference beam and the return beam interfere to obtain the beam to be processed; the first detection information includes an intensity of light of a predetermined wavelength in the beam to be processed.

In some embodiments, the processing system being configured to determine the actual distance between the optical assembly and the fixed plane of the object under test at each first time instant comprises: controlling the moving device to relatively move the optical assembly and the object to be measured along the optical axis direction so as to have a plurality of preset distances between the optical assembly and the fixed plane at a plurality of second moments; acquiring the first detection information at each of the plurality of second moments; and determining the actual distance between the optical component and the fixed plane at each first time instant according to the plurality of predetermined distances and the plurality of first detection information at each second time instant.

In some embodiments, the processing system is configured to determine, from the plurality of predetermined distances and the plurality of first detection information at each second time instant, an actual distance between the optical assembly and the fixed plane at each first time instant comprises: performing linear processing on each preset distance in the plurality of preset distances to obtain a movement parameter; fitting a function to be fitted by taking the difference between the movement parameter and the parameter to be solved at each second moment as an independent variable and the first detection information at each second moment as a dependent variable to obtain a fitting function; and determining an actual distance between the optical component and the fixed plane at each first time instant according to the fitted function and the first detection information at the plurality of first time instants.

In some embodiments, the optical assembly comprises: a first beam splitter configured to split the original beam into a reference beam and an object beam incident on the measured area, wherein the object beam returning from the measured area to the optical assembly forms the return beam; and a reference mirror configured to propagate the reference beam along a preset trajectory to obtain a pre-interference beam, wherein the pre-interference beam and the return beam interfere to obtain the beam to be processed; the first detection information comprises the intensity of light with a preset wavelength in the light beam to be processed; the function to be fitted is: i ═ a + cos r (x-x)₀) + B, wherein said linear processing comprises multiplying by 2 Π/λ, r ═ 1; or, the linear processing comprises multiplying by 1, r 2 Π/λ, λ being the wavelength of the light of the predetermined wavelength; the processing system is configured to take the difference between the movement parameter and the parameter to be obtained at each second time as an independent variable at each second timeFitting the to-be-fitted function by taking the carved first detection information as a dependent variable to obtain a fitted function comprises the following steps: fitting the function to be fitted by taking the movement parameter at each second moment as x in the function to be fitted and taking the intensity of the light with the preset wavelength at each second moment as I in the function to be fitted to obtain A and the parameter x to be solved₀And B, thereby obtaining the fitting function; determining an actual distance between the optical assembly and the fixed plane at each first time instant according to the fitted function and the first detection information at the plurality of first time instants comprises: taking the intensity of the light with the preset wavelength at each first moment as I in the fitting function, and calculating x in the fitting function as the movement parameter at each first moment; and determining the actual distance between the optical component and the fixed plane at each first moment according to the movement parameters at each first moment.

In some embodiments, the reference mirror is configured to propagate the reference beam along a preset trajectory by reflecting the reference beam to obtain a pre-interference beam; the reference mirror and the first light splitter are both half-transmitting and half-reflecting mirrors, and are arranged in parallel; alternatively, the reference mirror is a mirror.

In some embodiments, the first detection device comprises: one of a grating and a filter; and a light intensity detector.

In some embodiments, the measurement system further comprises: the first diaphragm is configured to block a part, which has an included angle larger than a first preset included angle, between the light beam to be processed and the central axis of the light beam to be processed from entering the first detection device.

In some embodiments, the measurement system further comprises: a second detection device configured to obtain second detection information according to a second light beam, the second light beam being a part of the return light beam or a part of the light beam to be processed, the second detection information being indicative of a relative distance between the optical component and the region under test in an optical axis direction of the optical component; the processing system is further configured to acquire a first moment when the second detection information is preset detection information as a characteristic moment; acquiring the actual distance between the optical assembly and the fixed plane at the characteristic moment; and determining the height information of the measured area according to the actual distance between the optical assembly and the fixed plane at the characteristic moment.

In some embodiments, the second detecting device is configured to obtain the second detection information from the second light beam including: obtaining a detection image according to the second light beam; and obtaining the second detection information from the detection image, the second detection information including at least one of a light intensity of the second light beam and a contrast of the detection image.

In some embodiments, the measurement system further comprises: a second beam splitter configured to split the return beam or the beam to be processed to obtain the second beam.

In some embodiments, the optical assembly further comprises: a first lens configured to collect the return beam, the first beam formed by at least a portion of the return beam collected by the first lens; alternatively, the first lens is configured to collect the light beam to be processed, the first light beam being formed by at least part of the light beam to be processed collected by the first lens.

In some embodiments, when the first lens is configured to collect the return beam, the second beam splitter is configured to split the return beam collected by the first lens to form the second beam and a third beam, the optical assembly is configured to derive the beam to be processed from the third beam; when the first lens is configured to collect the light beam to be processed, the second beam splitter is configured to split the light beam to be processed collected by the first lens to form the first light beam and the second light beam.

In some embodiments, the optical assembly further comprises: a second lens configured to collect the second light beam.

In some embodiments, the second beam splitter is configured to split the return beam to obtain the second beam, and the second lens makes a central axis of the second beam parallel to the moving direction of the optical assembly; the second optical splitter is fixedly connected with the optical assembly.

In some embodiments, the optical assembly is configured to move relative to the second beam splitter.

In some embodiments, the second beam splitter is configured to split the return beam to obtain the second beam; the optical assembly includes a lens configured to collect the return beam and propagate the return beam to the second beam splitter, or the lens is configured to collect the second beam; the measurement system further comprises: and the second diaphragm is configured to block a part of the second light beam, which has an included angle with the central axis of the second light beam larger than a second preset included angle, from entering the second detection device, and the second diaphragm and the second detection device are both conjugated with the focal plane of the lens.

In some embodiments, the original beam comprises a first original beam and a second original beam; the light source includes: a first sub-light source configured to generate the first original light beam, and a second sub-light source configured to generate the second original light beam; the return beams include a first return beam and a second return beam, the first return beam being the first original beam returned from the area under test, the second return beam being the second original beam returned from the area under test; the optical assembly includes: a first optical assembly configured to form the beam to be processed from the first return beam, the first beam being the beam to be processed, and a second optical assembly configured to collect the second return beam, the second beam being the second return beam, the first and second optical assemblies being fixedly connected.

In some embodiments, the first optical assembly is further configured to collect the first raw beam and to direct the first raw beam to the area under test; the first optical assembly includes: a dispersion prism configured to focus light of different wavelengths in the first original light beam to different positions of an optical axis of the first optical component.

In some embodiments, the measurement system further comprises: a data acquisition system configured to issue a synchronization trigger signal at each first time; the first detection device is configured to obtain the first detection information from the first light beam in response to the synchronization trigger signal; the second detection device is configured to derive the second detection information from the second light beam in response to the synchronization trigger signal.

In some embodiments, the second detection information comprises a light intensity of the second light beam; the light intensity of the second light beam at the characteristic time is larger than the light intensity of the second light beam at any one of the plurality of first times other than the characteristic time.

In some embodiments, the area under test comprises at least one sub-area, the detection image comprises at least one pixel corresponding to the at least one sub-area, each pixel being configured to acquire the second light beam of one sub-area; the second detection information comprises the light intensity of a second light beam formed by each sub-area, wherein at the characteristic time of any sub-area, the gray-scale value of a pixel of the sub-area is larger than that at any one first time except the characteristic time in the plurality of first times; the processing system is configured to determine height information of the measured area from the actual distance between the optical assembly and the fixed plane at the characteristic moment in time, including: and determining the height information of each subarea according to the actual distance between the optical assembly and the fixed plane at the characteristic moment of each subarea, thereby obtaining the height information of the measured area.

According to another aspect of the embodiments of the present disclosure, there is provided a measurement method including: the light source generates an original light beam, wherein the original light beam returning from a detected area of a detected object is a return light beam; the optical assembly obtains a light beam to be processed according to the return light beam, and at least part of the light beam to be processed is a first light beam; obtaining first detection information according to the first light beam; relatively moving the optical assembly and the object to be measured along the optical axis direction of the optical assembly; and determining an actual distance between the optical component and the fixed plane at each of the first moments according to the first detection information at each of the plurality of first moments.

In some embodiments, determining the actual distance between the optical assembly and the object under test at each first time instant comprises: relatively moving the optical assembly and the object to be measured along the optical axis direction to enable the optical assembly and the fixed plane to have a plurality of expected preset distances at a plurality of second moments; acquiring the first detection information at each of the plurality of second moments; and determining the actual distance between the optical component and the fixed plane at each first time instant according to the plurality of predetermined distances and the plurality of first detection information at each second time instant.

In some embodiments, determining the actual distance between the optical assembly and the fixed plane at each first time instant from the plurality of predetermined distances and the plurality of first detection information at each second time instant comprises: performing linear processing on each preset distance in the plurality of preset distances to obtain a movement parameter; fitting a function to be fitted by taking the difference between the movement parameter and the parameter to be solved at each second moment as an independent variable and the first detection information at each second moment as a dependent variable to obtain a fitting function; and determining an actual distance between the optical component and the fixed plane at each first time instant according to the fitted function and the first detection information at the plurality of first time instants.

In some embodiments, the optical assembly includes a first beam splitter and a mirror, the measurement method further comprising: the first beam splitter divides the original beam into a reference beam and an object beam incident to the measured areaWherein the object beam returning to the optical assembly from the region under test is the return beam; and the reference mirror enables the reference beam to propagate along a preset track to obtain a pre-interference beam, wherein the pre-interference beam interferes with the return beam to obtain the beam to be processed; the first detection information comprises the intensity of light with a preset wavelength in the light beam to be processed; the function to be fitted is: i ═ a + cos r (x-x)₀) + B, wherein said linear processing comprises multiplying by 2 Π/λ, r ═ 1; or, the linear processing comprises multiplying by 1, r 2 Π/λ, λ being the wavelength of the light of the predetermined wavelength; fitting the to-be-fitted function by taking the difference between the movement parameter and the parameter to be solved at each second moment as an independent variable and the first detection information at each second moment as a dependent variable to obtain the fitted function comprises the following steps: fitting the function to be fitted by taking the movement parameter at each second moment as x in the function to be fitted and taking the intensity of the light with the preset wavelength at each second moment as I in the function to be fitted to obtain A and the parameter x to be solved₀And B, thereby obtaining the fitting function; determining an actual distance between the optical assembly and the fixed plane at each first time instant according to the fitted function and the first detection information at the plurality of first time instants comprises: taking the intensity of the light with the preset wavelength at each first moment as I in the fitting function, and calculating x in the fitting function as the movement parameter at each first moment; and determining the actual distance between the optical component and the fixed plane at each first moment according to the movement parameters at each first moment.

In some embodiments, the measurement method further comprises: obtaining second detection information according to a second light beam, wherein the second light beam is a part of the return light beam or a part of the light beam to be processed, and the second detection information represents the relative position between the optical assembly and the detected area; acquiring a first moment when the second detection information is preset detection information as a characteristic moment; acquiring the actual distance between the optical assembly and the fixed plane at the characteristic moment; and determining the height information of the measured area according to the actual distance between the optical assembly and the fixed plane at the characteristic moment.

In some embodiments, obtaining the second detection information from the second beam comprises: obtaining a detection image according to the second light beam; and obtaining the second detection information from the detection image, the second detection information including at least one of a light intensity of the second light beam and a contrast of the detection image.

In some embodiments, the measurement method further comprises: and acquiring the appearance of the measured object according to the height information of the plurality of measured areas relative to the same reference plane.

Other features, aspects, and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure, in which:

FIG. 1 is a schematic block diagram of a measurement system according to some embodiments of the present disclosure;

FIG. 2 is a schematic block diagram of a measurement system according to further embodiments of the present disclosure;

FIG. 3 is a schematic block diagram of a measurement system according to further embodiments of the present disclosure;

FIG. 4 is a schematic flow chart diagram for determining an actual distance between an optical assembly and a fixed plane of an object under test at each first time instant according to some implementations of the present disclosure;

FIG. 5 illustrates one particular implementation of step 406 in FIG. 4;

FIG. 6 is a schematic block diagram of a measurement system according to further embodiments of the present disclosure;

FIG. 7 is a schematic structural diagram of a measurement system according to further embodiments of the present disclosure;

FIG. 8 is a schematic structural diagram of a measurement system according to further embodiments of the present disclosure;

FIG. 9 is a schematic flow diagram of a measurement method according to some embodiments of the present disclosure;

FIG. 10 is a schematic flow chart diagram of a measurement method according to further embodiments of the present disclosure.

It should be understood that the dimensions of the various parts shown in the figures are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific component is described as being located between a first component and a second component, there may or may not be intervening components between the specific component and the first component or the second component. When it is described that a specific component is connected to other components, the specific component may be directly connected to the other components without having an intervening component, or may be directly connected to the other components without having an intervening component.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

The inventor has noted that when the optical component and the object to be measured are driven to move relatively, due to factors such as movement errors, vibration of the measurement system, and environmental vibration, it is desirable that the predetermined distance between the optical component and the fixed plane of the object to be measured is often different from the actual distance between the optical component and the fixed plane of the object to be measured. Therefore, measuring the height information of the measured object according to the predetermined distance will result in inaccurate measurement results.

In view of this, the embodiments of the present disclosure provide the following technical solutions.

FIG. 1 is a schematic block diagram of a measurement system according to some embodiments of the present disclosure.

As shown in fig. 1, the measurement system may include a light source 101, an optical assembly 102, a first detection device 103, a mobile device 104, and a processing system 105.

The light source 101 is configured to generate a primary light beam. In some embodiments, the original light beam may be a broad spectrum light beam, such as one or a combination of white light, infrared light, and ultraviolet light. Here, the original beam returned from the measured area of the measured object a (e.g., a wafer or the like) is a return beam.

In some embodiments, the original light beam generated by the light source 101 may be directly incident on the object a to be measured. In other embodiments, referring to fig. 1, the primary light beam generated by the light source 101 may be incident on the object a to be measured via the optical assembly 102. For example, the original light beam generated by the light source 101 may be shaped by the shaping mirror group 201 and then incident on the beam splitter 202, and then reflected by the beam splitter 202 and incident on the optical assembly 102, and further incident on the object a to be measured via the optical assembly 102. For example, the shaping mirror group 201 may perform shaping operations such as collimation and filtering on the original light beam generated by the light source 101.

The optical assembly 102 is configured to derive a beam to be processed from the return beam. Here, at least part of the beam to be processed is the first beam.

In some embodiments, the optical assembly 102 may be an interference objective. In this case, the beam to be processed may be an interference beam. In other embodiments, the optical assembly 102 may be a confocal objective. In this case, the light beam to be processed may be a return light beam returned from the object a to be measured. The optical assembly 102 is configured to split the original beam into a reference beam and an object beam incident on the measured area, wherein the object beam returning from the measured area to the optical assembly forms a return beam, and the optical assembly 102 is further configured to interfere the reference beam with the return beam.

For example, the optical assembly 102 includes a first beam splitter 112 and a reference mirror 122, the first beam splitter 112 being configured to split the original beam into a reference beam and an object beam incident on a measured area of the measured object a; the reference mirror 122 is configured to propagate the reference beam along a preset trajectory to obtain a pre-interference beam, wherein the pre-interference beam and the return beam interfere to obtain a beam to be processed.

In one embodiment, the first beam splitter 112 is configured to split the original beam into a reference beam and an object beam incident on a measured area of the measured object a. Here, the object beam returned from the measured area of the measured object a to the optical assembly 102 is a return beam. The reference mirror 122 is configured to propagate the reference beam along a preset trajectory by reflecting the reference beam to obtain a pre-interference beam. Here, the pre-interference beam and the return beam interfere to obtain a beam to be processed. For example, the reference mirror 122 and the first beam splitter 112 are both half mirrors, and the reference mirror 122 and the first beam splitter 112 are disposed in parallel. However, the disclosed embodiments are not limited thereto. For example, in other embodiments, the reference mirror 122 may be a mirror (e.g., the embodiment shown in FIG. 6).

In other embodiments, the reference mirror 122 is configured to refract or diffract the reference beam to obtain the pre-interference beam. The reference mirror 122 is, for example, a refractive element or a diffractive element.

The first detection means 103 is configured to derive first detection information from the first light beam. In some embodiments, the beam to be processed is an interference beam resulting from interference of the reflected beam and the return beam. In this case, the first detection information may include the intensity of light of a predetermined wavelength in the beam to be processed. For example, the light beam to be processed includes light of a plurality of wavelengths. The light of the predetermined wavelength may be light of any one of a plurality of wavelengths.

The moving device 104 is configured to move the optical assembly 102 and the object a to be measured relatively in the optical axis direction of the optical assembly 102.

For example, the moving device 104 may move the optical assembly 102 relative to the object a to be measured along the optical axis direction of the optical assembly 102 under the control of the processing system 105. For another example, the moving device 104 may move the object a to be measured relative to the optical assembly 102 along the optical axis direction of the optical assembly 102 under the control of the processing system 105. Here, the optical axis direction of the optical component 102 may be understood as a central axis direction of the return light beam entering the optical component 102, for example, a direction indicated by a double-headed arrow in fig. 1. In some embodiments, mobile device 104 may be a phase shifter.

Moving in the optical axis direction of the optical component 102 relative to the object a to be measured means that the moving direction of the optical component 102 and the object a to be measured has a component in the optical axis direction of the optical component 102 as long as the moving direction of the optical component 102 and the object a to be measured is not perpendicular to the optical axis direction of the optical component 102.

The processing system 105 is configured to determine an actual distance between the optical assembly 102 and the fixed plane of the object a to be measured at each of the first moments in time based on the first detection information at each of the plurality of first moments in time. Here, the fixing plane of the object a to be measured may be a plane determined by an arbitrary area of the surface of the object a to be measured. In other words, an arbitrary plane of the object a to be measured can be used as the fixed plane of the object a to be measured.

It will be appreciated that at different first moments in time, the actual distance between the optical assembly 102 and the fixed plane of the object a to be measured is different. For example, the processing system 105 may subsequently determine the height information of the area under test from the actual distance between the optical assembly 102 and the fixed plane of the object under test a at each first time instant.

The processing system 105 may be a computer or other processing capable device. In some embodiments, the processing system 105 may include a memory and a processor coupled to the memory, and the processor may perform various operations based on instructions stored on the memory, for example, determining the actual distance between the optical assembly 102 and the fixed plane of the object a under test at each first time instant and the operations mentioned below. The memory may include, for example, system memory, fixed non-volatile storage media, and the like. The system memory may store, for example, an operating system, application programs, a Boot Loader (Boot Loader), and other programs.

In the above embodiment, the optical assembly 102 obtains the light beam to be processed from the return light beam, and the first detection device 103 obtains the first detection information from at least a part of the light beam to be processed (i.e., the first light beam). The processing system 105 determines an actual distance between the optical assembly 102 and the fixed plane of the object a at each of the first moments according to the first detection information at each of the plurality of first moments. In this way, the actual distance between the optical assembly 102 and the fixed plane of the object a to be measured at each first time can be obtained by using the first detection information at a plurality of first times. Subsequent operations can be performed more accurately based on the actual distance between the optical assembly 102 and the fixed plane of the object a to be measured at each first time, for example, height information of the area to be measured of the object a to be measured and the like can be determined more accurately.

In some embodiments, referring to fig. 1, the measurement system may further include a second detection device 106. The second detection means 106 is configured to derive second detection information from the second light beam. Here, the second beam is a part of the beam to be processed. For example, the measurement system further comprises a second beam splitter 107 configured to split the light beam to be processed to obtain a second light beam. For example, the light beam to be processed transmitted through the second beam splitter 107 is the first light beam, and the light beam to be processed reflected by the second beam splitter 107 is the second light beam, or vice versa. In other embodiments, the second beam may be part of the return beam. In this case, the second beam splitter 107 is configured to split the return beam to obtain the second beam. This will be described later in connection with other embodiments, such as the embodiment shown in fig. 6.

The second detection information can represent the relative distance between the optical assembly 102 and the measured area of the measured object a along the optical axis direction of the optical assembly, that is, the second detection information changes with the change of the relative distance; the relative distance between the optical assembly 102 and the measured area of the measured object a can be obtained from the second detection information.

In some embodiments, the second detection device 106 may obtain a detection image (e.g., an interference image or an image of the measured area of the measured object a) according to the second light beam, and further obtain second detection information according to the detection image. The second detection means 106 may be, for example, a camera, a video camera, etc. In other embodiments, the second detection device 106 may be a single photodiode or photomultiplier tube.

Here, the second detection information may include at least one of an intensity of the second light beam and a contrast of the detection image. For example, the second detection information may include the light intensity of the second light beam. For another example, the second detection information may include a contrast of a detection image obtained from the second light beam. For another example, the second detection information may include the light intensity of the second light beam and the contrast of the detected image.

The processing system 105 is further configured to obtain a first time when the second detection information is the preset detection information as the characteristic time; acquiring the actual distance between the optical assembly 102 and the fixed plane of the measured object A at the characteristic moment; and determining the height information of the measured area according to the actual distance between the optical assembly 102 and the fixed plane of the measured object A at the characteristic moment.

In some embodiments, the second detection information may include an intensity of the second light beam. The light intensity of the second light beam at the characteristic time is larger than the light intensity of the second light beam at any one of the plurality of first times other than the characteristic time. In other words, the light intensity of the second light beam at the characteristic instant is maximal. For example, at a characteristic time, the optical path of the reference beam is equal to the optical path of the object beam. For another example, at the characteristic time, the distance between the optical assembly 102 and the measured area of the measured object a is equal to the focal length of the optical assembly 102.

The distance between the optical assembly 102 and different measured regions is the same for different measured regions at the characteristic time. Therefore, the actual distance between the optical element 102 and the fixed plane of the object a at the characteristic time can reflect the height of the measured area. For example, for the measured area a1, the actual distance between the optical component 102 and the fixed plane of the measured object a at the characteristic moment is h 1; for the measured area a2, the actual distance between the optical element 102 at the characteristic moment and the fixed plane of the measured object a is h 2. The difference between h1 and h2 is the height difference between the measured area A1 and the measured area A2.

In some embodiments, the region under test comprises at least one sub-region and the detection image comprises at least one pixel corresponding to the at least one sub-region. For example, the region under test includes a plurality of sub-regions, and the detection image includes a plurality of pixels in one-to-one correspondence with the plurality of sub-regions. The second detection information may include the light intensity of the second light beam acquired by each pixel. In this case, the detection information is preset to the maximum gradation value of the pixel. The characteristic time is the first time when the gray value is maximum. Each pixel has a characteristic instant, i.e. each sub-region corresponds to a characteristic instant. At the characteristic time of each sub-region, the gray-scale value of the pixel corresponding to the sub-region is larger than the gray-scale value of the pixel at any one of the first times except the characteristic time. In other words, for a pixel, the gray-scale value of the pixel at the characteristic time is the largest.

In other embodiments, the preset detection information is a value at which a mean value or a sum value of gray-scale values of the plurality of pixels is maximum; the characteristic time is a first time when the average or sum of the gray-scale values of the plurality of pixels is maximum.

The processing system 105 is configured to determine the height information of the sub-area corresponding to each pixel, depending on the actual distance between the optical component 102 and the fixed plane at the characteristic moment. And obtaining the height information of the measured area after obtaining the height information of the sub-area corresponding to each pixel.

The actual distance between the optical component 102 and the fixed plane of the object a to be measured at the moment of the feature corresponding to the sub-area may correspond to the height of the sub-area. For example, for the sub-area a11 of the measured area a, the actual distance between the optical component 102 and the fixed plane of the measured object a at the time of the characterization is h 11; for sub-area a12 of the measured area a, the actual distance between the optical component 102 at the moment of the characterization and the fixed plane of the measured object a is h 12. The difference between h11 and h12 is the height difference between sub-region a11 and sub-region a 12.

In some embodiments, a plurality of measured areas of the measured object may be measured by the measuring system, so as to obtain height information of each measured area relative to the same reference plane. After the height information of each measured area relative to the same reference plane is obtained, the three-dimensional shape of the measured object can be obtained. For example, the height information of a plurality of measured areas can be spliced to obtain the three-dimensional appearance of the measured object.

In some embodiments, referring to fig. 1, the measurement system further comprises a data acquisition system 108 configured to issue a synchronization trigger signal at each of a plurality of first time instants. The first detection means 103 is configured to derive first detection information from the first light beam in response to the synchronization trigger signal. The second detection means 106 is configured to derive second detection information from the second light beam in response to the synchronization trigger signal. In this way, the first detecting device 103 can obtain a plurality of first detection information at the first time, and the second detecting device 106 can obtain a plurality of second detection information at the first time. The data collection system 108 can collect a plurality of first detection information at the first time from the first detection device 103 and a plurality of second detection information at the first time from the second detection device 106, and transmit the plurality of first detection information to the processing system 105.

Different implementations of the first detection means 103 will be described below with reference to fig. 2 and 3. It should be noted that, in the present specification, each embodiment is described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts in each embodiment may be referred to each other.

FIG. 2 is a schematic block diagram of a measurement system according to further embodiments of the present disclosure.

As shown in fig. 2, the first detection device 103 is a spectrometer. For example, the first detection device 103 may comprise a grating 113 and a light intensity detector 123 (e.g. a photodetector). The grating 113 is configured such that light of different wavelengths in the first light beam is incident on different areas of the light intensity detector 123, i.e. the grating 113 has a light splitting effect. The light intensity detector 123 is configured to detect light intensities of the plurality of wavelengths of light in the first light beam. The processing system 105 may perform subsequent analysis based on the intensity of the predetermined wavelength of light (i.e., the first detection information) of the plurality of wavelengths of light.

FIG. 3 is a schematic block diagram of a measurement system according to further embodiments of the present disclosure.

As shown in fig. 3, the first detecting means 103 may comprise a filter 113' and a light intensity detector 123. The filter 113' is configured such that light of a predetermined wavelength among the plurality of wavelengths of light in the first light beam reaches the light intensity detector 123, and light of other wavelengths among the plurality of wavelengths does not reach the light intensity detector 123. In other words, the filter segment 113' allows only light of a predetermined wavelength to pass therethrough. In this case, the light intensity detector 123 may directly detect the intensity of the light of the predetermined wavelength.

In some embodiments, referring to fig. 2 and 3, the measurement system may further include a first stop 109, such as an aperture stop. The first diaphragm 109 is configured to block a portion of the light beam to be processed having an angle with the central axis of the light beam to be processed larger than a first preset angle from entering the first detection device 103. In other words, the portion of the light beam to be processed, which has an angle smaller than or equal to the first predetermined angle with respect to the central axis of the light beam to be processed, can enter the first detecting device 103. It should be understood that the first preset included angle may be determined according to actual conditions. In this case, the first detecting device 103 does not need to detect the entire light beam to be processed, the adverse effect of light at the edge of the light beam to be processed is reduced, and the detection accuracy is improved.

Some specific implementations of the processing system determining the actual distance between the optical component and the fixed plane of the object to be measured at each first instant in time are described below in connection with fig. 4 and 5.

Fig. 4 is a schematic flow chart of determining an actual distance between an optical assembly and a fixed plane of an object under test at each first time instant according to some implementations of the present disclosure.

In step 402, the moving device is controlled to relatively move the optical component and the object to be measured in the optical axis direction so as to have a desired plurality of predetermined distances between the optical component and the fixed plane at a plurality of second moments.

Here, the plurality of second time instants may be the same as or different from the plurality of first time instants, or may be partially the same.

Controlling the moving device to relatively move the optical assembly and the object to be measured in the optical axis direction includes: one or a combination of moving the optical assembly with the moving device or moving the object under test with the moving device.

At step 404, first probe information at each of a plurality of second time instances is obtained.

In step 406, an actual distance between the optical assembly and the fixed plane of the object to be measured at each first time instant is determined based on the plurality of predetermined distances and the plurality of first detection information at each second time instant.

When the mobile device only moves the optical assembly, determining the actual distance between the optical assembly and the fixed plane of the object to be measured at each first time comprises determining the distance between the optical assembly and any one of the fixed planes at each first time; when the moving device only moves the object to be measured, determining the actual distance between the optical assembly and the fixed plane of the object to be measured at each first time comprises determining the distance between the optical assembly and any one of the fixed planes at each first time.

For example, step 406 may be implemented by steps 416-436 shown in FIG. 5.

In step 416, each of the plurality of predetermined distances is linearly processed to obtain a movement parameter. For example, each predetermined distance is multiplied by a constant to obtain a movement parameter.

In step 426, the difference between the motion parameter and the parameter to be obtained at each second time is used as an independent variable, and the first detection information at each second time is used as a dependent variable to fit the function to be fitted, so as to obtain a fitting function.

For example, the function to be fitted may include, for example, a trigonometric function expansion, a polynomial, a fourier expansion, and the like.

At step 436, the actual distance between the optical assembly and the fixed plane at each first time instant is determined based on the fitted function and the first detection information at the plurality of first time instants.

Some specific implementations of steps 416-436 will be described below by taking as an example the optical assembly 102 including the first beam splitter 112 and the reference mirror 122, and the function to be fitted is a trigonometric function. The functions of the first beam splitter 112 and the reference mirror 122 can refer to the above description, and are not described herein.

In this implementation, the first detection information includes an intensity of light of a predetermined wavelength in the beam to be processed. The function to be fitted is: i ═ a + cos r (x-x)₀) + B. Where A is the amplitude of the intensity of light of a predetermined wavelength, x₀For the parameter to be determined, B is the average intensity of the light with the preset wavelength, r is 1 or 2 pi/lambda, and lambda is the wavelength of the light with the preset wavelength. In the case where the linear processing in step 416 is to multiply by 2 Π/λ, r is 1,the motion parameter is a phase shift quantity; in the case where the linear processing in step 416 is to multiply by 1, r is 2 Π/λ, and the movement parameter is equal to the predetermined distance.

For example, fitting the function to be fitted by using the movement parameter at each second time as x in the function to be fitted and using the intensity of the light with the predetermined wavelength at each second time as I in the function to be fitted to obtain A and the parameter x to be solved₀And B, thereby obtaining a fitting function.

For example, the intensities of the light with the predetermined wavelength at the plurality of second time points are respectively I₁、I₂、I₃…, the plurality of movement parameters at the second time points are x₀₁、x₀₂、x₀₃… are provided. With x₀₁、x₀₂、x₀₃… as x and I respectively₁、I₂、I₃… As I, fitting the above formula, for example, least squares fitting, can give A, x₀And B, obtaining a fitting function.

At yield A, x₀And B, obtaining a relational expression of the light intensity I of the light with the preset wavelength and the movement parameter x. And then, taking the intensity of the light with the preset wavelength at each first moment as I in the fitting function, and calculating x in the fitting function as the movement parameter at each first moment.

For example, the intensities I of a plurality of lights with predetermined wavelengths at a first time are measured₁’、I₂’、I₃' … substituting the fitting function to obtain multiple movement parameters x₁₁、x1₂、x₁₃…。

Then, the actual distance between the optical component and the fixed plane at each first time is determined according to the movement parameters at each first time.

For example, the actual distance between the optical element and the fixed plane at each first time is equal to the movement parameter at each first time. For another example, the actual distance between the optical element and the fixed plane at each first time is equal to the ratio of the movement parameter to 2 Π/λ at each first time.

The relationship between the light intensity of the light with the preset wavelength and the movement parameter accords with the above formula, so the above formula is the function to be fitted, the calculation process can be simplified, and the detection speed can be improved.

It should be noted that the processing system 105 can fit A, x corresponding to each measured area in the above manner when measuring each measured area₀And B, and then carrying out subsequent treatment. The actual distance between the optical assembly and the fixed plane at the first moment obtained in such a way is more accurate, so that more accurate height information of the measured area can be obtained.

It should be further noted that, when the function to be fitted is a trigonometric function expansion, a polynomial, or a fourier expansion, the function to be fitted may be subjected to trigonometric function fitting, polynomial fitting, or fourier series fitting.

FIG. 6 is a schematic diagram of a measurement system according to further embodiments of the present disclosure. FIG. 7 is a schematic diagram of a measurement system according to still further embodiments of the present disclosure.

Measurement systems according to some embodiments of the present disclosure are described below in conjunction with fig. 1-3, and 6-7. It should be noted that, in the following description, the functions of the same or similar components in different embodiments are not described in detail.

In some embodiments, the optical assembly 102 may include a first lens 132. The first lens 132 may be configured to collect the return beam or the beam to be processed. The following description is made in conjunction with various embodiments.

In some embodiments, referring to fig. 6, the optical assembly 102 further includes a first lens 132 configured to collect the return beam. In this case, the first light beam is formed by at least part of the return light beam collected by the first lens 132.

In some embodiments, referring to fig. 6, when the first lens 132 is configured to collect the return beam, the second beam splitter 107 is configured to split the return beam collected by the first lens 132 to form the second beam and the third beam. The optical assembly 102 is configured to derive a beam to be processed from the third beam. The second detection means 106 obtains second detection information from the second light beam. For example, the third light beam transmitted through the first beam splitter 112 interferes with the reflected light beam reflected by the first beam splitter 112 to obtain the light beam to be processed.

In some embodiments, referring to fig. 6, where the first lens 132 is configured to collect the return beam, the optical assembly 102 is configured to move relative to the second beam splitter 107. For example, in the case where the mobile device 104 moves the optical component 102, the second beam splitter 107 is relatively stationary.

In other embodiments, referring to fig. 1-3, and 7, the optical assembly 102 further includes a first lens 132 configured to collect the light beam to be processed. In this case, the first light beam is formed by the light beam to be processed collected by at least part of the first lens 132.

In some embodiments, referring to fig. 1-3, when the first lens 132 is configured to collect the light beam to be processed, the second beam splitter 107 is configured to split the light beam to be processed collected by the first lens 132 to form the first light beam and the second light beam. The first detection means 102 obtains first detection information from the first light beam and the second detection means 106 obtains second detection information from the second light beam. The optical assembly 102 is configured to move relative to the second beam splitter 107, for example, in the case where the mobile device 104 moves the optical assembly 102, the second beam splitter 107 is relatively stationary. In some embodiments, the light beam to be processed from the first lens 132 may be incident on the second beam splitter 107 after being transmitted by the beam splitter 202 and condensed by the condensing lens 203. Alternatively, the light beam to be processed from the first lens 132 may be incident on the second beam splitter 107 after being reflected by the beam splitter 202 and condensed by the condensing lens 203.

In some embodiments, referring to fig. 7, the optical assembly may further include a second lens 110 configured to collect the second light beam. In this case, the second beam splitter 107 is configured to split the return beam to obtain the second beam. For example, the second light beam may be reflected by the mirror 304 and collected by the second lens 110.

In some embodiments, referring to fig. 7, the second lens 110 makes the central axis of the second light beam parallel to the moving direction of the optical assembly 102, and the second beam splitter 107 is fixedly connected to the optical assembly 102. In this case, in the case where the optical assembly 102 moves, the second lens 110 and the second beam splitter 107 may move simultaneously.

In some embodiments, referring to fig. 6 or 7, the optical assembly includes a lens (e.g., lens 132 of fig. 6 or lens 110 of fig. 7) configured to collect the return light and propagate the return light to the second beam splitter 107, or the lens is configured to collect the second light beam. The second beam splitter 107 is configured to split the return beam to obtain a second beam. The measurement system may further comprise a second diaphragm 109 configured to block a portion of the second light beam having an angle with the central axis of the second light beam larger than a second preset angle from entering the second detection device 106. In other words, the portion of the second light beam having the included angle with the central axis of the second light beam smaller than or equal to the second predetermined included angle can enter the second detecting device 106. It should be understood that the second preset included angle may be determined according to actual conditions. Here, the second diaphragm 109 and the second detection device 106 are both conjugated to the focal plane of the lens 132 or the lens 110.

Specifically, when the lens is configured to collect the return light and propagate the return light to the second beam splitter, i.e., the embodiment shown in fig. 6, the lens is the first lens 132; when the lens is configured to collect the second light beam, i.e., the embodiment shown in fig. 7, the lens is the second lens 110.

For example, referring to fig. 6, the second light beam is converged by the converging lens 301 and then enters the second diaphragm 109, the second light beam transmitted through the second diaphragm 109 enters the converging lens 302, and then the second light beam is converged by the converging lens 303 and then enters the second detection device 106.

For example, referring to fig. 7, the second light beam collected by the second lens 110 is reflected by the reflecting mirror 305 and then enters the converging lens 306, the second light beam is converged by the converging lens 306 and then enters the second diaphragm 109, the second light beam transmitted through the second diaphragm 109 enters the converging lens 307, and then enters the second detection device 106 after being converged by the converging lens 307.

The second detecting means 106 is an imaging means or a light intensity detecting member. The image forming apparatus includes: a camera or a video camera, and the light intensity detection part comprises a single photodiode or photoelectric multiplying light.

In the embodiment shown in fig. 6 and 7, when the second detection device 106 is an imaging device or a light intensity detection component, the second detection information includes the light intensity of the second light beam.

When the second detection device 106 is an imaging device, the second detection information includes: a detected image of the region under test. The second detection information includes one or more of a combination of light intensity of the second light beam, contrast of the detection image, and dispersion of the detection image.

When the second detection information is the degree of dispersion of the detected image, the degree of dispersion at the characteristic time is smaller than the degree of dispersion at any one of the first times except the characteristic time.

In the embodiments shown in fig. 1-3, 6 and 7, the first detection device 103 and the second detection device 106 detect the same measured area, and the actual distance determined according to the first detection information acquired by the first detection device 103 can represent the height of the measured area, so that the detection accuracy can be improved.

FIG. 8 is a schematic diagram of a measurement system according to further embodiments of the present disclosure.

As shown in fig. 8, the light source 101 includes a first sub light source 111 and a second sub light source 121. The first sub-light source 111 is configured to generate a first original light beam. The second sub-light sources 121 are configured to generate a second original light beam. In other words, the original light beam generated by the light source 101 includes a first original light beam and a second original light beam.

The return beam returned from the measured area of the measured object a includes a first return beam and a second return beam. The first return beam is a first original beam returned from the measured area of the measured object a. The second return beam is a second original beam returned from the measured area of the measured object a.

The optical assembly 102 comprises a first optical assembly 1021 and a second optical assembly 1022 which are fixedly connected. The first optical assembly 1021 is configured to form a beam to be processed from the first return beam. In this case, the first beam is the beam to be processed. The second optical assembly 1022 is configured to collect the second return beam. In this case, the second beam is the second return beam.

The first detection means 103 is configured to derive first detection information from the first light beam. The second detection means 106 is configured to derive second detection information from the second light beam.

In some embodiments, the first optical assembly 1021 is further configured to collect the first raw light beam and direct the first raw light beam to a measured area of the measured object a. The first optical component 1021 comprises a dispersing prism configured to focus light of different wavelengths in the first original light beam to different positions of the optical axis of the first optical component 1021.

The optical axis of the first optical element 1021 is the central axis of the first return beam.

In some embodiments, the second optical assembly 1022 is further configured to collect the second original beam and direct the second original beam to the area under test. The second optical component 1022 includes a dispersion prism configured to focus light of different wavelengths in the second original beam to different positions of the optical axis of the second optical component 1022. In other embodiments, the second optical assembly 1022 may include an interference objective lens configured to obtain the interference beam from the second return beam as the second beam.

In the embodiment shown in fig. 8, the first detection device 103 is a spectrometer.

The processing system 105 is configured to determine an actual distance between the optical assembly 102 and the fixed plane of the object a to be measured at each of the first moments in time based on the first detection information at each of the plurality of first moments in time, including: for a certain first moment, the light intensity of each wavelength in the first light beam at the first moment is obtained through the first detection device 103; and acquiring the actual distance at the first moment according to the wavelength corresponding to the light intensity with the maximum light intensity.

In some embodiments, the first optical component 1021 is an interferometric lens and the first detection device is a spectrometer; the first optical component 1021 is a single lens or a lens group, and the first detection device is a camera or a video camera. In another embodiment, the first optical component 1021 is a shaping lens configured to collect first raw light and emit the shaped first raw light toward an object, and cross sections of the shaped first raw light at different positions along an optical axis of the shaping lens have one or both of different shapes or sizes. Specifically, the cross section of the shaped first original light is a semicircular point, and arcs of the semicircular line on two sides of the point exceed different directions.

Fig. 9 is a flow diagram of a measurement method according to some embodiments of the present disclosure. The measurement method can be implemented based on the measurement system of any one of the above embodiments.

At step 902, a light source generates a raw light beam. Here, the original beam returned from the measured area of the measured object is a return beam. For example, the original light beam may include one or a combination of white light, ultraviolet light, and infrared light.

At step 904, the optical assembly derives a beam to be processed from the return beam. Here, at least part of the beam to be processed is the first beam.

For example, the optical assembly may comprise an interference objective or a confocal objective.

At step 906, first detection information is obtained from the first beam.

For example, the first detection means obtains first detection information from the first light beam. For example, the first detection information includes the light intensity of light of a predetermined wavelength in the light beam to be processed.

In step 908, the optical assembly and the object to be measured are relatively moved in the optical axis direction of the optical assembly.

For example, at least one of the optical assembly and the object to be measured is moved by controlling the moving device.

In step 910, an actual distance between the optical assembly and the fixed plane at each first time is determined according to the first detection information at each first time in the plurality of first times.

The implementation of step 910 may refer to the above description, and is not described herein again.

In the above embodiment, the actual distance between the optical assembly and the fixed plane of the object to be measured at each first time can be obtained by using the first detection information at the plurality of first times. Subsequent operations can be performed more accurately based on the actual distance between the optical assembly and the fixed plane of the object to be measured at each first time, for example, height information of the measured area of the object to be measured and the like can be determined more accurately.

In some embodiments, the measurement method of FIG. 9 further includes steps 912-918 of FIG. 10. FIG. 10 is a schematic flow chart diagram of a measurement method according to further embodiments of the present disclosure.

In step 912, second detection information is obtained from the second light beam, the second light beam being a portion of the return light beam or a portion of the light beam to be processed, the second detection information being indicative of a relative position between the optical assembly and the region under test.

For example, obtaining the second detection information from the second beam includes: obtaining a detection image according to the second light beam; and obtaining second detection information from the detection image, the second detection information including at least one of a light intensity of the second light beam and a contrast of the detection image.

In some embodiments, the second detection information comprises an intensity of the second light beam; the light intensity of the second light beam at the characteristic time is larger than the light intensity of the second light beam at any one of the plurality of first times other than the characteristic time.

In step 914, a first time when the second detection information is the preset detection information is obtained as the characteristic time.

At step 916, the actual distance between the optical component and the fixed plane at the time of the feature is obtained.

In step 918, height information of the measured area is determined according to the actual distance between the optical component and the fixed plane at the characteristic time.

In some embodiments, the measurement method further comprises: and acquiring the appearance of the object to be measured according to the height information of the plurality of measured areas relative to the same reference surface.

In some embodiments, obtaining the profile of the object to be measured according to the height information of the plurality of measured areas relative to the same reference plane includes: repeating the light source to generate an original light beam for each measured area; determining the height information of the measured area according to the actual distance between the optical assembly and the fixed surface at the characteristic moment; acquiring height information of each measured area relative to the same reference plane; and acquiring the appearance of the object to be measured according to the height information of each measured area relative to the same reference surface.

For example, the step of acquiring the height information of each measured area with respect to the same reference plane includes: repeating the steps 902 to 918 to obtain the height of each measured area relative to the initial reference plane; unifying the initial datum plane of each measured area to the same datum plane.

Thus, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

As will be appreciated by one skilled in the art, embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A measurement system, comprising:

a light source configured to generate an original light beam, wherein the original light beam returning from a measured area of a measured object forms a return light beam;

an optical assembly configured to obtain a light beam to be processed according to the return light beam, wherein at least part of the light beam to be processed is a first light beam;

first detection means configured to obtain first detection information from the first light beam;

a moving device configured to relatively move the optical assembly and the object to be measured in an optical axis direction of the optical assembly; and

a processing system configured to determine an actual distance between the optical assembly and a fixed plane of the object to be measured at each of a plurality of first moments in time based on the first detection information at each of the first moments in time.

2. The measurement system of claim 1, wherein the optical assembly comprises:

a first beam splitter configured to split the original beam into a reference beam and an object beam incident on the measured area, wherein the object beam returning from the measured area to the optical assembly forms the return beam; and

a reference mirror configured to propagate the reference beam along a preset trajectory to obtain a pre-interference beam, wherein the pre-interference beam and the return beam interfere to obtain the beam to be processed;

the first detection information includes an intensity of light of a predetermined wavelength in the beam to be processed.

3. The measurement system of claim 2,

the reference mirror is configured to make the reference beam propagate along a preset track to obtain a pre-interference beam by reflecting the reference beam;

the reference mirror and the first light splitter are both half-transmitting and half-reflecting mirrors, and are arranged in parallel;

alternatively, the reference mirror is a mirror.

4. The measurement system according to claim 1 or 2, further comprising:

a second detection device configured to obtain second detection information according to a second light beam, the second light beam being a part of the return light beam or a part of the light beam to be processed, the second detection information being indicative of a relative distance between the optical component and the region under test in an optical axis direction of the optical component;

the processing system is further configured to acquire a first moment when the second detection information is preset detection information as a characteristic moment; acquiring the actual distance between the optical assembly and the fixed plane at the characteristic moment;

and determining the height information of the measured area according to the actual distance between the optical assembly and the fixed plane at the characteristic moment.

5. The measurement system of claim 4, further comprising:

a second beam splitter configured to split the return beam or the beam to be processed to obtain the second beam.

6. The measurement system of claim 5, wherein the optical assembly further comprises:

a first lens configured to collect the return beam, the first beam formed by at least a portion of the return beam collected by the first lens; alternatively, the first lens is configured to collect the light beam to be processed, the first light beam being formed by at least part of the light beam to be processed collected by the first lens.

7. The measurement system of claim 6,

when the first lens is configured to collect the return beam, the second beam splitter is configured to split the return beam collected by the first lens to form the second beam and a third beam, and the optical assembly is configured to obtain the beam to be processed according to the third beam;

when the first lens is configured to collect the light beam to be processed, the second beam splitter is configured to split the light beam to be processed collected by the first lens to form the first light beam and the second light beam.

8. The measurement system of claim 6, wherein the optical assembly further comprises:

a second lens configured to collect the second light beam.

9. The measurement system of claim 8, wherein:

the second beam splitter is configured to split the return beam to obtain the second beam, and the second lens makes a central axis of the second beam parallel to the moving direction of the optical assembly;

the second optical splitter is fixedly connected with the optical assembly.

10. The measurement system of claim 7,

the optical assembly is configured to move relative to the second beam splitter.

11. The measurement system of claim 5,

the second beam splitter is configured to split the return beam to obtain the second beam;

the optical assembly includes a lens configured to collect the return beam and propagate the return beam to the second beam splitter, or the lens is configured to collect the second beam;

the measurement system further comprises:

and the second diaphragm is configured to block a part of the second light beam, which has an included angle with the central axis of the second light beam larger than a second preset included angle, from entering the second detection device, and the second diaphragm and the second detection device are both conjugated with the focal plane of the lens.

12. The measurement system of claim 4,

the original light beam comprises a first original light beam and a second original light beam;

the light source includes:

a first sub-light source configured to generate the first original light beam, and

a second sub-light source configured to generate the second original light beam;

the return beams include a first return beam and a second return beam, the first return beam being the first original beam returned from the area under test, the second return beam being the second original beam returned from the area under test;

the optical assembly includes:

a first optical assembly configured to form the beam to be processed from the first return beam, the first beam being the beam to be processed, an

A second optical assembly configured to collect the second return beam, the second beam being the second return beam, the first and second optical assemblies being fixedly connected.

13. A measuring method of a measuring system according to any one of claims 1 to 12, comprising:

the light source generates an original light beam, wherein the original light beam returning from a detected area of a detected object is a return light beam;

the optical assembly obtains a light beam to be processed according to the return light beam, and at least part of the light beam to be processed is a first light beam;

obtaining first detection information according to the first light beam;

relatively moving the optical assembly and the object to be measured along the optical axis direction of the optical assembly; and

determining an actual distance between the optical assembly and the fixed plane at each of the first moments according to the first detection information at each of the plurality of first moments.

14. The measurement method according to claim 13, further comprising:

the number of the detected areas is multiple;

the processing system is configured to repeat the light source generating the original light beam for each measured area to determine the height of the measured area based on the actual distance between the optical assembly and the fixed surface at the characteristic time

Information, namely acquiring height information of each measured area relative to the same reference plane;

and acquiring the appearance of the object to be measured according to the height information of each measured area relative to the same reference surface.