A surface topography measurement method and device, electronic equipment and storage medium

Abstract

The present disclosure relates to the technical field of optical three-dimensional profile measurement, and particularly relates to a method and device for measuring surface profile of a to-be-measured surface, an electronic device and a storage medium. The method for measuring surface profile of the to-be-measured surface comprises: splitting a light beam emitted by a light source to form measurement light and reference light, the measurement light reaching the to-be-measured surface and being reflected by the to-be-measured surface, the reference light reaching a mirror surface and being reflected by the mirror surface, the reflected measurement light and the reflected reference light being combined to generate an interference image; adjusting a relative optical path difference between the measurement light and the reference light, so that the relative optical path difference changes within a preset scanning range; performing phase compensation on the measurement light and / or the reference light to reduce the density of time phase shift interference fringes in the interference image; collecting interference images at different times, and determining the height distribution of the to-be-measured surface according to the interference image sequence. The process uses a phase compensation method to reduce the density of time phase shift interference fringes formed after the measurement light and the reference light are combined.

Description

Technical Field

[0001] This disclosure relates to the field of optical three-dimensional topography measurement technology, and in particular to a method and apparatus for measuring the topography of a surface under test, an electronic device, and a storage medium. Background Technology

[0002] Precision micro / nano fabrication capabilities are a crucial component of advanced manufacturing. Fabrication accuracy impacts the performance of devices such as microelectromechanical systems (MEMS), thin-film devices, and microlens arrays. While production quality can be reflected through functional testing, directly obtaining the three-dimensional surface morphology of the devices for quantitative evaluation is more valuable. Rapid and high-precision morphology characterization will ensure quality traceability and production efficiency in micro / nano fabrication.

[0003] Coherent scanning interferometry (CSI) is one of the most common 3D topography measurement devices used for nanoscale non-contact measurements of micro and nano devices. This type of interferometer uses low-coherence light as a light source and typically determines the height of points on a surface by scanning one interference arm to find the distance where the optical path difference between the two arms is zero (corresponding to the position with the highest contrast of the interference fringes). CSI employs a full-field measurement method, using array detectors such as charge-coupled devices (CCDs). The measurement requires capturing all the details of the interference signal within a single scan cycle to accurately reconstruct the topography. As the measurement range increases, a large number of measurement frames are required, leading to longer measurement times and greater data processing demands. Summary of the Invention

[0004] In view of this, this disclosure proposes a technical solution for measuring the morphology of the surface to be measured.

[0005] According to one aspect of this disclosure, a method for measuring the topography of a surface to be measured is provided, wherein a light beam emitted from a light source is split into a measurement beam and a reference beam, the measurement beam reaches the surface to be measured and is reflected by the surface to be measured, the reference beam reaches the surface of a mirror and is reflected by the surface of the mirror, and the reflected measurement beam and the reflected reference beam are combined to generate an interference image.

[0006] Adjust the relative optical path difference between the measuring light and the reference light so that the relative optical path difference varies within a preset scanning range;

[0007] Phase compensation is performed on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image;

[0008] The height distribution of the surface under test is determined by the sequence of interference images acquired when the relative optical path difference changes within a preset scanning range.

[0009] In one possible implementation, the light source is low-coherence light, and the phase compensation of the measurement light and / or the reference light to reduce the density of time-shifted interference fringes in the interference image includes:

[0010] The measurement light outputs a phase compensation function to compensate for the phase of the measurement light.

[0011] and / or

[0012] A phase compensation is output to the reference light to perform phase compensation on the reference light.

[0013] In one possible implementation, adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes:

[0014] Adjust the length of the measuring arm through which the measuring light passes and / or the reference arm through which the reference light passes to adjust the relative optical path difference.

[0015] In one possible implementation, when adjusting the optical path difference, the compensation phase is proportional to the amount of change in the length.

[0016] In one possible implementation, the light source is a pulsed laser, and the splitting of the beam emitted by the light source to form a measurement beam and a reference beam includes:

[0017] The pulsed laser is controlled to emit a laser pulse at preset time intervals;

[0018] The laser pulse is split into a measurement beam and a reference beam;

[0019] Adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes:

[0020] According to the time interval, an initial optical path difference is set between the measurement light formed by splitting the same laser pulse and the reference light, so that the measurement light of each pulse interferes with the reference light of the Mth pulse after each pulse, where M is a positive integer;

[0021] The time interval is adjusted so that the relative optical path difference varies within a preset scanning range.

[0022] In one possible implementation, the phase compensation of the measurement light and / or the reference light to reduce the density of time-shifted interference fringes in the interferometric image includes:

[0023] Different modulation phases are applied to the measurement light and the reference light.

[0024] In one possible implementation, splitting the light beam emitted by the light source to form a measurement beam and a reference beam includes:

[0025] The beam emitted by the light source is polarized and split into measurement beam and reference beam;

[0026] The reflected measurement light and the reflected reference light are combined to generate an interference image, including:

[0027] The reflected measurement light and the reflected reference light are analyzed to produce an interference image.

[0028] According to another aspect of this disclosure, a surface morphology measuring device is provided, comprising:

[0029] An interference module is used to split the light beam emitted by the light source into a measurement beam and a reference beam. The measurement beam reaches the surface to be measured and is reflected by the surface to be measured. The reference beam reaches the surface of the mirror and is reflected by the surface of the mirror. The reflected measurement beam and the reflected reference beam are combined to generate an interference image.

[0030] The scanning module is used to adjust the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range;

[0031] A phase compensation module is used to perform phase compensation on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image;

[0032] The height distribution determination module is used to determine the height distribution of the surface under test based on the sequence of interference images acquired when the relative optical path difference changes within a preset scanning range.

[0033] In one possible implementation, the light source is low-coherence light, and the phase compensation module is used for:

[0034] The measurement light outputs a phase compensation function to compensate for the phase of the measurement light.

[0035] and / or

[0036] A phase compensation is output to the reference light to perform phase compensation on the reference light.

[0037] In one possible implementation, the scanning module is configured to:

[0038] Adjust the length of the measuring arm through which the measuring light passes and / or the reference arm through which the reference light passes to adjust the relative optical path difference.

[0039] In one possible implementation, when adjusting the optical path difference, the compensation phase is proportional to the amount of change in the length.

[0040] In one possible implementation, the light source is a pulsed laser, and the interference module is used for:

[0041] The pulsed laser is controlled to emit a laser pulse at preset time intervals;

[0042] The laser pulse is split into a measurement beam and a reference beam;

[0043] The scanning module is used for:

[0044] According to the time interval, an initial optical path difference is set between the measurement light formed by splitting the same laser pulse and the reference light, so that the measurement light of each pulse interferes with the reference light of the Mth pulse after each pulse, where M is a positive integer;

[0045] The time interval is adjusted so that the relative optical path difference varies within a preset scanning range.

[0046] In one possible implementation, the phase compensation module is used for:

[0047] Different modulation phases are applied to the measurement light and the reference light.

[0048] In one possible implementation, the interference module is used for:

[0049] The beam emitted by the light source is polarized and split into measurement beam and reference beam;

[0050] The reflected measurement light and the reflected reference light are combined to generate an interference image, including:

[0051] The reflected measurement light and the reflected reference light are analyzed to produce an interference image.

[0052] According to another aspect of this disclosure, an electronic device is provided, comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to implement the above-described method when executing instructions stored in the memory.

[0053] According to another aspect of this disclosure, a non-volatile computer-readable storage medium is provided that stores computer program instructions thereon, wherein the computer program instructions, when executed by a processor, implement the above-described method.

[0054] According to another aspect of this disclosure, a computer program product is provided, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code, wherein when the computer-readable code is run in a processor of an electronic device, the processor in the electronic device performs the above-described method.

[0055] In this embodiment, coherent scanning is performed by adjusting the optical path difference between the measurement light and the reference light. Simultaneously, phase compensation is applied to the measurement light and / or reference light obtained by splitting the light emitted from the light source. Based on the interference image sequence acquired during the scanning process, the height distribution of the surface under test is determined. This process utilizes phase compensation to reduce the density of the time-shifted interference fringes formed after the measurement light and reference light are combined. This reduces interference signal details while maintaining measurement accuracy, increases scanning speed, and consequently reduces the impact of environmental disturbances on the measurement results, thereby improving the robustness of the surface topography measurement process.

[0056] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0057] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0058] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0059] Figure 1 A flowchart is shown for a method of measuring the morphology of a surface under test according to an embodiment of the present disclosure.

[0060] Figure 2 A schematic diagram illustrating the principle of a phase compensation method according to an embodiment of the present disclosure is shown.

[0061] Figure 3 A flowchart illustrating a method for measuring the morphology of a surface under test according to an application example of this disclosure is shown.

[0062] Figure 4 A schematic diagram of a coherent scanning interferometer according to an application example of this disclosure is shown.

[0063] Figure 5 A flowchart illustrating a method for measuring the morphology of a surface under test according to an application example of this disclosure is shown.

[0064] Figure 6 A schematic diagram of a coherent scanning interferometer according to an application example of this disclosure is shown.

[0065] Figure 7A block diagram of a surface topography measuring apparatus according to an embodiment of the present disclosure is shown.

[0066] Figure 8 A block diagram of an electronic device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0067] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0068] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0069] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0070] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0071] Figure 1 A flowchart illustrating a method for measuring the topography of a surface under test according to an embodiment of the present disclosure is shown. This method can be applied to a surface topography measuring device, which can be a terminal device, a server, or other processing equipment. The terminal device can be a user equipment (UE), mobile device, user terminal, terminal, cellular phone, cordless phone, personal digital assistant (PDA), handheld device, computing device, vehicle-mounted device, wearable device, etc.

[0072] In some possible implementations, the method for measuring the topography of the surface under test can be implemented by a processor calling computer-readable instructions stored in memory.

[0073] like Figure 1As shown, the method for measuring the morphology of the surface to be measured may include:

[0074] In step S11, the light beam emitted by the light source is split into a measurement beam and a reference beam. The measurement beam reaches the surface to be measured and is reflected by the surface to be measured. The reference beam reaches the surface of the mirror and is reflected by the surface of the mirror. The reflected measurement beam and the reflected reference beam are combined to generate an interference image.

[0075] The light source can be low-coherence light. In one example, the light source may include, but is not limited to, halogen lamps, LEDs, pulsed lasers, etc. This disclosure does not limit the specific type of light source, and it can be selected according to the actual situation.

[0076] After the light source emits a beam, the beam is split into two parts: a measurement beam and a reference beam. The measurement beam travels through a measurement arm to the surface under test, while the reference beam travels through a reference arm to the surface of a reflecting mirror. The measurement beam reflected by the surface under test and the reference beam reflected by the reflecting mirror interfere with each other, producing an interference pattern.

[0077] In step S12, the relative optical path difference between the measuring light and the reference light is adjusted so that the relative optical path difference varies within a preset scanning range.

[0078] Specifically, coherent scanning can be achieved by adjusting the relative optical path difference between the measuring light and the reference light, allowing the relative optical path difference to vary within a preset scanning range. The preset scanning range can be set according to the surface morphology of the sample being measured. This disclosure does not specifically limit the method for obtaining the preset scanning range; it can be selected based on actual conditions.

[0079] In step S13, phase compensation is performed on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image.

[0080] Coherent scanning is a full-field measurement method. During the measurement of the surface morphology, it requires capturing all the details of the interference signal within a single scan cycle to find the interference fringes with the highest contrast and precisely locate the constructive interference point where the optical path difference between the scanning and measurement beams is zero. The fluctuations in light intensity received by each pixel of the detector over time are called time-shifted interference fringes. This process requires a large number of measurement frames, resulting in longer measurement times and greater data processing pressure.

[0081] At the same level of accuracy, reducing the number of frames required for a single measurement will improve the measurement speed of a coherent scanning interferometer and reduce the impact of environmental disturbances on the measurement results. In one example, while varying the relative optical path difference within a preset scanning range, a dynamic compensation phase can be applied to the interference optical path to reduce the density of interference fringes in the interference image. This reduces the detail of the captured interference signal, decreases the number of measurement frames, and allows for faster coherent scanning, thus reducing the impact of environmental disturbances on the measurement results. Simultaneously, since the position with the highest contrast of the interference fringes remains unchanged during coherent scanning, the measurement accuracy level is maintained at the same level. The phase compensation can be performed on the measurement light, the reference light, or both simultaneously. The specific implementation method of phase compensation can be flexibly chosen according to the actual situation, as detailed in subsequent disclosed embodiments, and will not be elaborated here.

[0082] In one example, steps S12 and S13 can be performed synchronously, that is, phase compensation is performed while the phase optical path difference changes.

[0083] In step S14, the height distribution of the surface under test is determined based on the interference image sequence acquired when the relative optical path difference changes within a preset scanning range.

[0084] The interference image sequence refers to interference images acquired at different times. Specifically, interference images can be acquired during the coherent scanning process in step S12. When the optical path difference between the measurement light and the reference light is zero, the light intensity of the time-shifted interference fringes reaches an extreme value, achieving optimal interference. The height information of the corresponding pixel can be obtained based on the optical path difference between the measurement light and the reference light at this time. The set of heights of all corresponding pixel points represents the topographic distribution of the surface under test. In one example, the surface under test can be imaged onto the camera's image plane, allowing the camera to continuously acquire interference patterns during the scanning process and output them to a data acquisition card. The data acquisition card then saves the continuous interference patterns output by the camera to the interference image processing device.

[0085] In this embodiment, coherent scanning is performed by adjusting the optical path difference between the measurement light and the reference light. Simultaneously, phase compensation is applied to the measurement light and / or reference light obtained by splitting the light emitted from the light source. Based on the interference image sequence acquired during the scanning process, the height distribution of the surface under test is determined. This process utilizes phase compensation to reduce the density of the time-shifted interference fringes formed after the measurement light and reference light are combined. This reduces interference signal details while maintaining measurement accuracy, increases scanning speed, and consequently reduces the impact of environmental disturbances on the measurement results, thereby improving the robustness of the surface topography measurement process.

[0086] Since coherent scanning interferometers are divided into two different types, mechanically scanned and non-mechanically scanned, the corresponding method for phase compensation of the measurement light and / or the reference light is also adjusted according to the type of coherent scanning interferometer.

[0087] During mechanical scanning, phase compensation can be performed by directly compensating the phase of the light output using devices such as phase compensators. In one possible implementation, the light source is low-coherence light, and the phase compensation of the measurement light and / or the reference light to reduce the density of time-shifted interference fringes in the interference image includes:

[0088] The measurement light outputs a phase compensation function to compensate for the phase of the measurement light.

[0089] and / or

[0090] A phase compensation is output to the reference light to perform phase compensation on the reference light.

[0091] Specifically, a phase compensator can be used to compensate the phase output of the measurement light and / or reference light, thereby reducing the density of the time-shifted interference fringes after the measurement and reference lights are combined. The density of the time-shifted interference fringes can be arbitrarily adjusted by the phase compensator. This disclosure does not specifically limit the adjustment range of the interference signal fringe density; it can be selected as needed. The phase compensator used for phase compensation can include, but is not limited to, piezoelectric actuators, liquid crystal phase delay devices, electro-optic phase modulators, and acousto-optic frequency shifters.

[0092] Furthermore, adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes:

[0093] Adjust the length of the measuring arm through which the measuring light passes and / or the reference arm through which the reference light passes to adjust the relative optical path difference.

[0094] This disclosure describes the adjustment of the optical path difference between the measurement beam and the reference beam in a coherent scanning interferometer employing mechanical scanning. Specifically, since the measurement beam passes through a measurement arm and the reference beam passes through a reference arm, the optical path difference between the measurement beam and the reference beam can be adjusted by adjusting the length of the measurement arm and / or the reference arm. During this process, the length of the reference arm can be adjusted, the length of the measurement arm can be adjusted, or the lengths of both the reference arm and the measurement arm can be adjusted simultaneously. This disclosure does not specifically limit the method for implementing the optical path difference between the measurement beam and the reference beam in a coherent scanning interferometer employing mechanical scanning; the appropriate method can be selected based on the actual situation.

[0095] Figure 2 This is a schematic diagram illustrating the principle of the phase compensation method. Figure 2 Part (a) shows a mechanically scanned coherent scanning interferometer that adjusts the optical path difference between the reference light and the measurement light by adjusting the reference arm, and a phase compensator is placed in front of the mirror to compensate the phase of the reference light. Figure 2 Part (b) shows a schematic diagram of the phase compensator output and the interference signal before phase compensation of the reference light; Figure 2 Section (c) shows a schematic diagram of the phase compensator output and an interference signal diagram after phase compensation of the reference light. Through the analysis of... Figure 2 Part (b) of the middle and Figure 2 By comparing the interference signals in part (c) of the diagram, it can be seen that the phase compensation method can reduce the density of time-phase-shifted interference fringes, thereby allowing the coherent scanning interferometer to complete the measurement at a faster scanning speed, and the process does not lose too much signal-to-noise ratio.

[0096] Furthermore, in one example, when adjusting the optical path difference, the compensation phase is proportional to the amount of change in the length.

[0097] Specifically, for a coherent scanning interferometer, when using mechanical scanning to scan the length of a certain interferometer arm (measuring arm or reference arm), the formula for calculating the carrier phase of the interference signal (if present) is as follows:

[0098]

[0099] in, Let n be the carrier phase, n be the air refractive index, x be the displacement of the arm length, and λ0 be the center wavelength of the light source.

[0100] The phase compensator is used to adjust the above carrier phase. The period decreases, but the linear relationship between phase and displacement should still be maintained. Therefore, the compensation phase should satisfy formula (2).

[0101]

[0102] in, For carrier phase, To compensate for the phase.

[0103] Substituting formula (2) into formula (1), we get:

[0104]

[0105] As can be seen from formula (3), setting the compensation phase to be proportional to the displacement of the arm length of the measuring arm or reference arm (i.e., the change in the length of the arm) is beneficial to achieving phase compensation of the measuring light or reference light, reducing the density of time phase shift interference fringes, and thus achieving the goal of increasing the scanning speed.

[0106] Specifically, when adjusting the optical path difference between the measurement light and the reference light of a coherent scanning interferometer using mechanical scanning, a displacement sensor can be used to feed back the change in the interference length to the phase compensator in real time, and the phase compensator outputs the compensation phase according to a preset ratio.

[0107] In this embodiment, phase compensation is performed on the measurement light and / or reference light by directly outputting a compensated phase. This process achieves phase compensation for the interferometer arms of a coherent scanning interferometer using mechanical scanning, reducing the density of time-shifted interference fringes formed after the measurement and reference lights are combined. While maintaining measurement accuracy, it reduces interference signal details, increases scanning speed, and thus reduces the impact of environmental disturbances on the measurement results, improving the robustness of the surface topography measurement process.

[0108] In one possible implementation, the light source is a pulsed laser, and the splitting of the beam emitted by the light source to form a measurement beam and a reference beam includes:

[0109] The pulsed laser is controlled to emit a laser pulse at preset time intervals;

[0110] The laser pulse is split into a measurement beam and a reference beam;

[0111] Adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes:

[0112] According to the time interval, an initial optical path difference is set between the measurement light formed by splitting the same laser pulse and the reference light, so that the measurement light of each pulse interferes with the reference light of the Mth pulse after each pulse, where M is a positive integer;

[0113] The time interval is adjusted so that the relative optical path difference varies within a preset scanning range.

[0114] The pulsed laser is a frequency-tunable laser, and the laser emitter can be a femtosecond laser. Specifically, the time interval between adjacent laser pulses can be adjusted as needed to adjust the optical path distance (optical path distance = time interval × speed of light) between adjacent laser pulses, thereby achieving scanning between pulses. To better illustrate this disclosure and highlight its main points, the specific embodiments herein focus on adjusting the time interval. Those skilled in the art should understand that this disclosure can also be implemented for other adjustable objects such as the optical path distance.

[0115] The initial optical path difference is the optical path difference between the reference light and the measurement light that first generate interference. If, among the several measurement lights and several reference lights generated by several laser pulses emitted by the laser emitter, there exists a reference light and a measurement light whose optical path difference is exactly equal to M times the spatial interval (M is a positive integer), then the measurement light generated by each laser pulse will interfere with the reference light generated by the Mth laser pulse following that laser pulse. Under this premise, when the laser emitter repeatedly emits laser pulses, the time interval between adjacent laser pulses is continuously adjusted to change the optical path interval between adjacent laser pulses, thereby changing the relative optical path difference between the reference light and the measurement light that generate interference. This achieves relative scanning between laser pulses in a coherent scanning interferometer using non-mechanical scanning. Furthermore, based on the interference image sequence obtained from the above scanning process, the optical path difference at which the fringe contrast is highest can be obtained, and the height distribution information of the surface under test can be obtained from this optical path difference. Specifically, the spatial interval can be varied within a preset spatial interval range by precisely tuning the length of the laser resonant cavity to achieve relative scanning. This disclosure does not specifically limit the method of achieving relative scanning; it can be selected according to the actual situation.

[0116] To ensure that among the several measurement beams and several reference beams generated by several laser pulses emitted by the aforementioned laser emitter, there exists an optical path difference between a reference beam and a measurement beam that is approximately equal to M times the spatial interval (M being a positive integer), an initial optical path difference other than the height of the surface under test can be generated using a long optical fiber. The initial optical path difference introduced by this long optical fiber is approximately M times the optical path interval. Specifically, an initial optical path difference can be generated between the reference beam and the measurement beam by adjusting the optical path of the measurement beam and / or the reference beam. This can be achieved by adjusting only the optical path of the measurement beam using a long optical fiber, adjusting only the optical path of the reference beam using a long optical fiber, or simultaneously adjusting the optical path of both the measurement beam and the reference beam, thus creating an initial optical path difference between the interfering measurement beam and the reference beam. This disclosure does not specifically limit the device used to generate the initial optical path difference other than the height of the surface under test; besides a long optical fiber, other devices capable of generating an initial optical path difference other than the height of the surface under test can be selected according to actual needs.

[0117] In one example, it can be based on the repetition frequency f of the laser emitter. r Precise control is achieved to control the optical path interval, thereby realizing the relative scanning between laser pulses. The optical path difference x can be expressed according to formula (4).

[0118]

[0119] Where x is the optical path difference, D0 is the initial optical path difference of the unequal-arm interferometer, c represents the speed of light in vacuum, M is a positive integer, and f r L is the repetition frequency of the laser emitter. pp This is the optical path interval.

[0120] In this embodiment, a time interval is set between adjacent laser pulses, and an initial optical path difference is set between the measurement light and the reference light formed by the same pulse according to the time interval. The time interval is adjusted so that the relative optical path difference varies within a preset scanning range. During the process of the relative optical path difference varying within the preset scanning range, the setting of the initial optical path difference causes interference between different pulses, while the adjustment of the time interval causes the optical path difference between the interfering measurement light and the reference light to change continuously. That is, this process realizes the relative scanning between laser pulses of a coherent scanning interferometer using a non-mechanical scanning method.

[0121] In one possible implementation, the phase compensation of the measurement light and / or the reference light to reduce the density of time-shifted interference fringes in the interferometric image includes:

[0122] Different modulation phases are applied to the measurement light and the reference light.

[0123] In this context, phase modulation refers to changing the phase of the measurement light or the reference light. Specifically, the method for phase modulation can be a modulation frequency. In one example, after splitting the laser pulse generated by the laser emitter into a measurement light and a reference light, different modulation frequencies can be applied to the measurement light and the reference light to generate a fixed heterodyne frequency between them. During the aforementioned scanning process, the carrier phase of the interference signal changes uniformly, and as can be seen from formula (5), the heterodyne frequency introduced by the modulation frequency, after being integrated over time, also exhibits a uniformly changing phase.

[0124]

[0125] Among them, f h For heterodyne frequency, To compensate for the phase, T is time.

[0126] By adjusting the heterodyne frequency to match the linear scan speed, the desired result can be achieved.

[0127]

[0128] Since the carrier phase of the interference signal is uniformly varied, and the heterodyne frequency introduced by the modulation frequency is integrated over time and exhibits a uniformly varied phase, it is equivalent to loading different modulation frequencies onto the measurement light and the reference light, which enables phase compensation for the measurement light and the reference light.

[0129] In this embodiment, phase compensation is achieved by applying different modulation phases to the measurement light and reference light generated by the laser pulse. This process realizes phase compensation of the interferometer arm of a coherent scanning interferometer using a non-mechanical scanning method, reduces the density of interference fringes formed after the measurement light and reference light are combined, thereby reducing interference signal details while maintaining measurement accuracy, increasing scanning speed, reducing the impact of environmental disturbances on the measurement results, and improving the robustness of the surface topography measurement process.

[0130] In one possible implementation, splitting the light emitted from the light source into a measurement beam and a reference beam includes:

[0131] The beam emitted by the light source is polarized and split into measurement beam and reference beam;

[0132] The reflected measurement light and the reflected reference light are combined to generate an interference image, including:

[0133] The reflected measurement light and the reflected reference light are analyzed to produce an interference image.

[0134] To ensure accurate identification of the central fringe, the acquired low-coherence interference signal must maintain a high signal-to-noise ratio. Therefore, to achieve accurate detection of the surface morphology under test, it is necessary to reduce the noise of the interference system. In one example, the noise of the interference system can be reduced and the sensitivity of the interference system improved by reducing the interference between the measurement light and the reference light that generate the interference. Specifically, the laser pulse emitted by the laser emitter can be polarized and split to form measurement light and reference light with orthogonal polarization directions. This reduces the mutual interference between the measurement light and the reference light when they travel the same optical path. Since the measurement light and the reference light do not interfere with each other, they can also be configured with non-equilateral arms. At the same time, a polarization analyzer is set up so that the measurement light reflected from the surface under test and the reference light reflected from the surface of the mirror can be superimposed on the same polarization axis, thereby satisfying the interference conditions and generating low-coherence interference fringes. To ensure that the low-coherence interference fringes have high contrast, in one example, the light intensities of the reference light and the measurement light can be made similar. This disclosure does not limit the specific method for achieving similar light intensities of the reference light and the measurement light, and the appropriate method can be selected according to the actual situation.

[0135] In one example, a first polarization beam splitter and a second polarization beam splitter can be configured. The first polarization beam splitter splits the laser emitted by the laser emitter into a reference beam and a probe beam. After setting an initial optical path difference between the measurement beam and the reference beam, the reference beam and the beam to be measured are combined. The combined reference beam and probe beam then pass through the second polarization beam splitter, allowing the measurement beam and reference beam to reach the surface to be measured and the mirror surface, respectively. Since the polarization direction of the measurement beam reflected from the surface to be measured is perpendicular to the polarization direction of the measurement beam before reflection, and the polarization direction of the reference beam reflected from the mirror surface is perpendicular to the polarization direction of the reference beam before reflection, to ensure that the measurement beam reflected from the surface to be measured and the reference beam reflected from the mirror surface can pass smoothly through the second polarization beam splitter a second time, in one example, a quarter-wave plate can be placed before the measurement beam reflected from the surface to be measured and the reference beam reflected from the mirror surface enter the second polarization beam splitter. This changes the polarization direction of the measurement beam and the reference beam, allowing the reflected reference beam and the reflected measurement beam to pass smoothly through the second polarization beam splitter after passing through the quarter-wave plate, thus achieving beam combining and interference.

[0136] In this embodiment, the light beam emitted from the light source is polarized and split into a reference beam and a measurement beam with different polarization directions. The measurement beam reflected from the surface of the test point and the reference beam reflected from the surface of the mirror are analyzed to ensure that the polarization directions of the reference beam and the measurement beam are the same, resulting in low-coherence interference. This process ensures that the polarization directions of the measurement beam and the reference beam, which undergo low-coherence interference, are different before interference, reducing interference between them and ensuring a non-equilateral configuration between them. This is beneficial for interference imaging, thereby improving the contrast of the interference fringes and increasing the signal-to-noise ratio.

[0137] Application Scenario Example 1

[0138] Figure 3 A schematic diagram illustrating an application example according to this disclosure is shown, such as... Figure 3 As shown in the embodiments of this disclosure, a method for measuring the morphology of a surface to be measured is proposed. This method can realize the morphology measurement of the surface to be measured. Figure 4 A schematic diagram of a coherent scanning interferometer employing mechanical scanning using this measurement method is shown.

[0139] like Figure 3 As shown, the surface morphology measurement process can be roughly divided into four steps:

[0140] Step 1: Beam splitting of the light source. Specifically, the low-coherence light emitted by the light source is reflected by beam splitter 1 to the interference module. Inside the interference module, the beam is collimated by the objective lens and then split into two paths by beam splitter 2: the transmitted light is used as the measuring arm to illuminate the test point of the sample, and the reflected light is illuminated on the reflector by the phase compensator.

[0141] Step 2: Mechanical Scanning. Specifically, a scanning stage is used to perform a vertical scan of the entire interference module. Simultaneously, a displacement sensor feeds back the scanning distance to the phase compensator in real time. The phase compensator then outputs a phase compensation for the reflected light according to a preset ratio.

[0142] Step 3: Light source beam combining. Specifically, both the sample and the mirror are located at the focal plane of the objective lens. The reflected light formed on the surfaces of the two beams returns to beam splitter 2 and is combined. After passing through the objective lens and then through beam splitter 1, it is imaged onto the camera image plane by the eyepiece.

[0143] Step 4: Height Measurement. Specifically, acquire the phase-compensated interference image sequence captured by the camera, analyze the position of the highest contrast of the interference fringes in each time-phase-shifted interference signal pixel by pixel, determine the height of the corresponding point of the pixel, and then reconstruct the surface morphology of the entire field.

[0144] Application Scenario Example 2

[0145] Figure 5 A schematic diagram illustrating an application example according to this disclosure is shown, such as... Figure 5 As shown in the embodiments of this disclosure, a method for measuring the morphology of a surface to be measured is proposed. This method can achieve the measurement of the height of the surface to be measured. Figure 6 A schematic diagram of a coherent scanning interferometer based on scanning pulse time intervals using this measurement method is shown.

[0146] like Figure 7 As shown, the surface morphology measurement process can be roughly divided into four steps:

[0147] Step 1: Light Source Beam Splitting. Specifically, the light source is a laser emitter with an adjustable time interval. The emitted pulsed light is split into two orthogonally polarized paths by polarization beam splitter 1: one path is delayed by a long optical fiber, then frequency-shifted by acousto-optic frequency shifter 1 before entering the polarization beam combiner; the other path directly enters acousto-optic frequency shifter 2 for frequency shifting and then enters the polarization beam combiner. At this point, the combined light has different time delays and optical frequencies in different polarization states. The light output from the polarization beam combiner is coupled into space by an optical fiber collimator. This pair of orthogonally polarized lights is separated again at polarization beam splitter 2: the transmitted light serves as the reference arm, illuminating the reflector after passing through quarter-wave plate 1; the reflected light serves as the measurement arm, illuminating the test point of the sample after passing through quarter-wave plate 2. The function of the long optical fiber is to ensure that the optical path difference between the two interference arms of the interference module is approximately M times the optical path interval (M is a positive integer).

[0148] Step 2: Pulse Time Interval Scanning. Specifically, based on precise control of the laser emitter's repetition frequency, linear scanning of the spatial interval is achieved. Simultaneously with the linear scanning, a pair of slightly different modulation frequencies are applied to acousto-optic frequency shifters 1 and 2, causing the two interference arms of the interferometer to generate fixed heterodyne frequencies. Under linear scanning of the spatial interval, the carrier phase of the interference signal changes uniformly, and the heterodyne frequency introduced by the acousto-optic frequency shifters, after time integration, also exhibits a uniformly changing phase. Acousto-optic frequency shifters 1 and 2 together form a dynamic phase compensator. By adjusting the heterodyne frequency to match the linear scanning speed, phase compensation of the interference signal fringe frequencies can be achieved.

[0149] Step 3: Beam Combining. Specifically, the reflected light from the mirror and the sample passes through quarter-wave plate 1 and quarter-wave plate 2 respectively before entering polarization beam splitter 2. Since passing through two quarter-wave plates rotates the polarization state by 90 degrees, they pass through polarization beam splitter 2 in the form of reflection and transmission respectively, and then combine. The imaging mirror group images the surface of the sample's test point onto the camera's image plane. The combined beam output from polarization beam splitter 2, after passing through the imaging mirror group, is analyzed by the polarizer, allowing the two interference arms to interfere, and is recorded by the camera.

[0150] Step 4: Height Measurement. Specifically, based on the interference signal obtained by phase compensation from the fringe frequency acquired by the camera, when scanning the repetition frequency of the laser emitter, if the optical path difference is exactly equal to M times the spatial interval, each pulse of one arm of the interference arm will interfere with the Mth pulse that follows it. Based on the repetition frequency at this time, the height of the corresponding point of the pixel can be determined, thereby reconstructing the surface morphology of the entire field.

[0151] In this embodiment, coherent scanning is performed by adjusting the optical path difference between the measurement light and the reference light. Simultaneously, phase compensation is applied to the measurement light and / or reference light obtained by splitting the light emitted from the light source. Based on the interference image sequence acquired during the scanning process, the height distribution of the surface under test is determined. This process utilizes phase compensation to reduce the density of the time-shifted interference fringes formed after the measurement light and reference light are combined. This reduces interference signal details while maintaining measurement accuracy, increases scanning speed, and consequently reduces the impact of environmental disturbances on the measurement results, thereby improving the robustness of the surface topography measurement process.

[0152] It should be noted that the order of description of the above embodiments is not intended to limit the preferred order of embodiments in this application.

[0153] It should also be noted that the surface topography measurement method of the present disclosure can be used in Michelson type, Mirau type and other types of interference optical paths, and can also be applied to any other type of interference optical path. The present disclosure does not limit this.

[0154] The method for measuring the surface topography of the subject in this disclosure is not limited to the mechanical and non-mechanical phase compensation methods described above. Other phase compensation methods of any kind can also be applied, and this disclosure does not limit them.

[0155] It is understood that the various method embodiments mentioned above in this disclosure can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this disclosure will not elaborate further. Those skilled in the art will understand that in the above methods of specific implementation, the specific execution order of each step should be determined by its function and possible internal logic.

[0156] In addition, this disclosure also provides a surface morphology measuring device, electronic device, computer-readable storage medium, and program, all of which can be used to implement any of the surface morphology measuring methods provided in this disclosure. The corresponding technical solutions and descriptions are described in the corresponding section of the method and will not be repeated here.

[0157] Figure 7 A block diagram of a surface topography measuring apparatus according to an embodiment of the present disclosure is shown. The surface topography measuring apparatus can be a terminal device, a server, or other processing device. The terminal device can be a user equipment (UE), mobile device, user terminal, terminal, cellular phone, cordless phone, personal digital assistant (PDA), handheld device, computing device, vehicle-mounted device, wearable device, etc.

[0158] In some possible implementations, the surface topography measuring device can be implemented by a processor calling computer-readable instructions stored in memory.

[0159] like Figure 7 As shown, the surface topography measuring device 70 may include:

[0160] A surface morphology measuring device, comprising:

[0161] Interference module 71 is used to split the light beam emitted by the light source into a measurement light and a reference light. The measurement light reaches the surface to be measured and is reflected by the surface to be measured. The reference light reaches the surface of the mirror and is reflected by the surface of the mirror. The reflected measurement light and the reflected reference light are combined to generate an interference image.

[0162] The scanning module 72 is used to adjust the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range;

[0163] Phase compensation module 73 is used to perform phase compensation on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image;

[0164] The height distribution determination module 74 is used to determine the height distribution of the surface under test based on the interference image sequence acquired when the relative optical path difference changes within a preset scanning range.

[0165] In one possible implementation, the light source is low-coherence light, and the phase compensation module is used for:

[0166] The measurement light outputs a phase compensation function to compensate for the phase of the measurement light.

[0167] and / or

[0168] A phase compensation is output to the reference light to perform phase compensation on the reference light.

[0169] In one possible implementation, the scanning module is configured to:

[0170] Adjust the length of the measuring arm through which the measuring light passes and / or the reference arm through which the reference light passes to adjust the relative optical path difference.

[0171] In one possible implementation, when adjusting the optical path difference, the compensation phase is proportional to the amount of change in the length.

[0172] In one possible implementation, the light source is a pulsed laser, and the interference module is used for:

[0173] The pulsed laser is controlled to emit a laser pulse at preset time intervals;

[0174] The laser pulse is split into a measurement beam and a reference beam;

[0175] The scanning module is used for:

[0176] According to the time interval, an initial optical path difference is set between the measurement light formed by splitting the same laser pulse and the reference light, so that the measurement light of each pulse interferes with the reference light of the Mth pulse after each pulse, where M is a positive integer;

[0177] The time interval is adjusted so that the relative optical path difference varies within a preset scanning range.

[0178] In one possible implementation, the phase compensation module is used for:

[0179] Different modulation phases are applied to the measurement light and the reference light.

[0180] In one possible implementation, the interference module is used for:

[0181] The beam emitted by the light source is polarized and split into measurement beam and reference beam;

[0182] The reflected measurement light and the reflected reference light are combined to generate an interference image, including:

[0183] The reflected measurement light and the reflected reference light are analyzed to produce an interference image.

[0184] This disclosure also proposes a computer-readable storage medium storing computer program instructions that, when executed by a processor, implement the above-described method. The computer-readable storage medium may be a non-volatile computer-readable storage medium.

[0185] This disclosure also proposes an electronic device, including: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to invoke the instructions stored in the memory to execute the above-described method.

[0186] This disclosure also provides a computer program product including computer-readable code, which, when executed on a device, causes a processor in the device to execute instructions for performing the measurement of the surface topography as provided in any of the above embodiments.

[0187] This disclosure also provides another computer program product for storing computer-readable instructions that, when executed, cause a computer to perform the operation of measuring the surface topography provided in any of the above embodiments.

[0188] Electronic devices can be provided as terminals, servers, or other forms of devices.

[0189] Figure 8 A block diagram of an electronic device 1900 according to an embodiment of the present disclosure is shown. For example, the electronic device 1900 may be provided as a server. (Refer to...) Figure 8 The electronic device 1900 includes a processing component 1922, which further includes one or more processors, and memory resources represented by memory 1932 for storing instructions, such as application programs, that can be executed by the processing component 1922. The application programs stored in memory 1932 may include one or more modules, each corresponding to a set of instructions. Furthermore, the processing component 1922 is configured to execute instructions to perform the methods described above.

[0190] Electronic device 1900 may also include a power supply component 1926 configured to perform power management of electronic device 1900, a wired or wireless network interface 1950 configured to connect electronic device 1900 to a network, and an input / output interface 1958. Electronic device 1900 can operate on an operating system, such as Windows Server, stored in memory 1932. TM Mac OS X TM Unix TM Linux TM FreeBSD TM Or similar.

[0191] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 1932 including computer program instructions that can be executed by a processing component 1922 of an electronic device 1900 to perform the above-described method.

[0192] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0193] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0194] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0195] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, Python, Java, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of this disclosure.

[0196] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0197] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0198] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0199] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0200] The computer program product can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0201] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for measuring the morphology of a surface to be measured, characterized in that, include: The light beam emitted by the light source is split into a measurement beam and a reference beam. The measurement beam reaches the surface to be measured and is reflected by the surface to be measured. The reference beam reaches the surface of the mirror and is reflected by the surface of the mirror. The reflected measurement beam and the reflected reference beam are combined to produce an interference image. Adjust the relative optical path difference between the measuring light and the reference light so that the relative optical path difference varies within a preset scanning range; Phase compensation is performed on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image; when adjusting the relative optical path difference, the compensation phase is proportional to the change in the length of the measurement arm and / or the reference arm; The height distribution of the surface under test is determined by the sequence of interference images acquired when the relative optical path difference changes within a preset scanning range.

2. The method according to claim 1, characterized in that, The light source is low-coherence light, and the phase compensation of the measurement light and / or the reference light to reduce the density of time-shifted interference fringes in the interference image includes: The measurement light outputs a phase compensation function to compensate for the phase of the measurement light. and / or A phase compensation is output to the reference light to perform phase compensation on the reference light.

3. The method according to claim 2, characterized in that, Adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes: Adjust the length of the measuring arm through which the measuring light passes and / or the reference arm through which the reference light passes to adjust the relative optical path difference.

4. The method according to claim 1, characterized in that, The light source is a pulsed laser, and the process of splitting the beam emitted by the light source to form a measurement beam and a reference beam includes: The pulsed laser is controlled to emit a laser pulse at preset time intervals; The laser pulse is split into a measurement beam and a reference beam; Adjusting the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range, includes: According to the time interval, an initial optical path difference is set between the measurement light formed by splitting the same laser pulse and the reference light, so that the measurement light of each pulse interferes with the reference light of the Mth pulse after each pulse, where M is a positive integer; The time interval is adjusted so that the relative optical path difference varies within a preset scanning range.

5. The method according to claim 1, characterized in that, The step of performing phase compensation on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image includes: Different compensation phases are applied to the measurement light and the reference light.

6. The method according to claim 5, characterized in that, The step of splitting the light beam emitted by the light source into a measurement beam and a reference beam includes: The beam emitted by the light source is polarized and split into measurement beam and reference beam; The reflected measurement light and the reflected reference light are combined to generate an interference image, including: The reflected measurement light and the reflected reference light are analyzed to produce an interference image.

7. A device for measuring the morphology of a surface to be measured, characterized in that, include: An interference module is used to split the light beam emitted by the light source into a measurement beam and a reference beam. The measurement beam reaches the surface to be measured and is reflected by the surface to be measured. The reference beam reaches the surface of the mirror and is reflected by the surface of the mirror. The reflected measurement beam and the reflected reference beam are combined to generate an interference image. The scanning module is used to adjust the relative optical path difference between the measuring light and the reference light, so that the relative optical path difference varies within a preset scanning range; A phase compensation module is used to perform phase compensation on the measurement light and / or the reference light to reduce the density of time-phase-shifted interference fringes in the interference image; When adjusting the relative optical path difference, the compensation phase is proportional to the change in the length of the measuring arm and / or the reference arm; The height distribution determination module is used to determine the height distribution of the surface under test based on the sequence of interference images acquired when the relative optical path difference changes within a preset scanning range.

8. An electronic device, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to implement the method of any one of claims 1 to 6 when executing instructions stored in the memory.

9. A non-volatile computer-readable storage medium storing computer program instructions thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method described in any one of claims 1 to 6.

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