Dark-field confocal microscopy measurement device based on vortex interferometry

Abstract

The present application discloses a dark field confocal microscopy measurement device based on vortex interferometry, which relates to the field of optical precision measurement technology. The vortex light generation module is used to generate vortex light of a predetermined order. The vortex light interference module is used to separate the vortex light into reference light and imaging light. The imaging light is used to illuminate the scanning position of the sample to be measured to obtain the sample reflected light at the scanning position, and the reference light and the sample reflected light are made to overlap and interfere to obtain interference light. The light spot of the interference light is petal-shaped. The rotation demodulation module is used to rotationally demodulate the interference light to obtain the amplitude and phase information of the scanning position, thereby characterizing the amplitude and phase information of the defect and realizing the detection of phase-type defects.

Description

Technical Field

[0001] The present application relates to the field of optical precision measurement technology, and in particular to a dark-field confocal microscopic measurement device based on vortex interferometry. Background Art

[0002] Interlayer defects (such as holes and stacking faults) in semiconductor three-dimensional integrated circuits can easily lead to a decrease in the electrical performance and lifespan of the three-dimensional integrated circuits. Accurate detection of interlayer defects can ensure the product yield of the three-dimensional integrated circuits.

[0003] Confocal microscopy, due to its three-dimensional tomography capabilities, can be used for nondestructive testing of defects in three-dimensional integrated circuits. Dark-field confocal microscopy, with its advantages of excellent optical tomography, high imaging resolution, and high imaging contrast due to a dark background, has become an important tool for nondestructive testing of defects in three-dimensional integrated circuits. However, traditional optical dark-field confocal microscopy has a low response rate to tiny defects. Furthermore, it is difficult to detect phase-type defects (such as bubbles and stacking faults), unable to obtain phase information, and thus lacks accuracy in defect determination. Summary of the Invention

[0004] The purpose of this application is to provide a dark-field confocal microscopy measurement device based on vortex interferometry, which can characterize the amplitude and phase information of defects and realize the detection of phase-type defects.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] The present application provides a dark-field confocal microscopy measurement device based on vortex interferometry, which includes:

[0007] A vortex light generating module, used to generate vortex light of a predetermined order;

[0008] A vortex light interference module is configured to separate the vortex light into reference light and imaging light, use the imaging light to illuminate a scanning position of a sample to be tested, obtain sample reflected light at the scanning position, and cause the reference light and the sample reflected light to overlap and interfere to obtain interference light; the sample to be tested is a three-dimensional integrated circuit; the reference light and the sample reflected light have opposite orders; and the interference light spot is petal-shaped;

[0009] The rotation demodulation module is used to rotationally demodulate the interference light to obtain the amplitude and phase information of the scanning position.

[0010] Optionally, the vortex light generating module includes: a fiber laser, a fiber collimating beam expander and a spiral phase plate arranged in sequence according to the propagation direction of light; the spiral phase plate is used to modulate the output light of the fiber collimating beam expander to obtain vortex light of a predetermined order.

[0011] Optionally, the vortex light interference module includes:

[0012] a first non-polarization beam splitter, configured to split the vortex light into a reference light and an imaging light;

[0013] a second non-polarizing beam splitter, configured to direct the imaging light into a sample scanning unit;

[0014] The sample scanning unit is configured to illuminate a scanning position of the sample to be measured with the imaging light, obtain sample reflected light at the scanning position, and transmit the sample reflected light to the second non-polarizing beam splitter;

[0015] a reference light processing unit, configured to perform multiple reflections on the reference light and allow the outgoing light after the multiple reflections to be incident on the second non-polarization beam splitter;

[0016] The second non-polarization beam splitter is further used to cause the reference light and the sample reflected light to overlap and interfere with each other to obtain interference light.

[0017] Optionally, the sample scanning unit includes: an objective lens.

[0018] Optionally, the reference light processing unit includes: a first reflector, an adjustable optical attenuator and a second reflector arranged in sequence according to the propagation direction of the light.

[0019] Optionally, the sample scanning unit further includes: a three-dimensional translation stage; the sample to be tested is located on the three-dimensional translation stage; the three-dimensional translation stage is used to drive the sample to be tested to move and adjust the scanning position of the sample to be tested.

[0020] Optionally, the rotation demodulation module includes: a signal generator, a chopper driver, a lock-in amplifier, and a third non-polarization beam splitter, a chopper, a focusing lens, a pinhole, and a photodetector arranged in sequence according to the propagation direction of the light;

[0021] The signal generator is signal-connected to the chopper driver and the lock-in amplifier respectively; the signal generator is used to transmit control signals to the chopper driver and the lock-in amplifier;

[0022] The chopper driver is used to drive the chopper to rotate based on the control signal; the chopper is used to chop the transmitted light of the third non-polarization beam splitter to obtain chop light;

[0023] The lock-in amplifier is connected to the photodetector signal; the lock-in amplifier is used to use the electrical signal output by the photodetector as an input signal and the control signal as a reference signal to demodulate the input signal to obtain the amplitude and phase information of the scanning position.

[0024] Optionally, a phase distribution is loaded on the spiral phase plate, and the phase distribution is:

[0025]

[0026] Wherein, i is the imaginary unit; m is the predetermined order; is the plane angular coordinate of the spiral phase plate.

[0027] Optionally, the chopper drive is a rotating motor.

[0028] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0029] The present application provides a dark field confocal microscopy measurement device based on vortex interferometry, wherein a vortex light generation module is used to generate vortex light of a predetermined order, a vortex light interference module is used to divide the vortex light into a reference light and an imaging light, and the imaging light is used to illuminate the scanning position of the sample to be measured to obtain the sample reflected light at the scanning position, and the reference light and the sample reflected light are caused to overlap and interfere to obtain interference light, the interference light spot is petal-shaped, and the rotational demodulation module is used to rotationally demodulate the interference light to obtain the amplitude and phase information of the scanning position. When there is a defect at the scanning position, amplitude modulation and phase modulation are generated on the imaging light, the phase modulation causes the symmetry axis of the interference light with the petal-shaped spot to rotate, and the amplitude modulation causes the relative intensity of the light and dark of the interference light with the petal-shaped spot to change. Subsequent demodulation by the rotational demodulation module can realize the simultaneous detection of the amplitude (i.e., absorptivity) and phase (i.e., height and refractive index, etc.) of the defect, thereby characterizing the amplitude and phase information of the defect and realizing the detection of phase-type defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 This is a schematic structural diagram of the dark-field confocal microscopy measurement device based on vortex interferometry provided in Example 1 of the present application.

[0032] Explanation of symbols:

[0033] 1-fiber laser; 2-fiber collimating beam expander; 3-spiral phase plate; 4-first non-polarizing beam splitter; 5-first reflector; 6-adjustable optical attenuator; 7-second reflector; 8-second non-polarizing beam splitter; 9-objective lens; 10-sample to be measured; 11-three-dimensional translation stage; 12-third non-polarizing beam splitter; 13-chopper; 14-chopper driver; 15-focusing lens; 16-pinhole; 17-photodetector; 18-phase-locked amplifier; 19-signal generator. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] Example 1

[0036] This embodiment provides a dark field confocal microscopy measurement device based on vortex interferometry, such as Figure 1 As shown, the dark field confocal microscopy measurement device based on vortex interferometry includes:

[0037] The vortex light generating module is used to generate vortex light of a predetermined order.

[0038] The vortex light interferometer module is used to separate the vortex light into reference light and imaging light. The imaging light is used to illuminate the scanning position of the sample 10 to obtain the sample reflected light at the scanning position. The reference light and the sample reflected light are then superimposed and interfered to produce interference light. In the case of a three-dimensional integrated circuit, the reference light and the sample reflected light are of opposite orders, resulting in a petal-shaped interference light spot.

[0039] The rotation demodulation module is used to rotationally demodulate the interference light to obtain the amplitude and phase information of the scanning position.

[0040] In this embodiment, the vortex light generating module is used to generate vortex light of a predetermined order, and the vortex light is subsequently used to illuminate the sample 10 to be tested, so it can be called vortex illumination light.

[0041] Specifically, the vortex light generating module includes: a fiber laser 1, a fiber collimating beam expander 2 and a spiral phase plate 3 arranged in sequence according to the propagation direction of the light.

[0042] The optical fiber laser 1 is used to output coherent laser light in the visible light band, that is, the wavelength of the laser light output by the optical fiber laser 1 is in the visible light band.

[0043] The fiber collimator and beam expander 2 is used to collimate and expand the coherent laser light output by the fiber laser 1 to generate parallel light.

[0044] The spiral phase plate 3 is used to modulate the output light (ie, parallel light) of the optical fiber collimating beam expander 2 to obtain vortex light of a predetermined order.

[0045] The wavelength of the spiral phase plate 3 is designed to match the wavelength of the coherent laser output by the fiber laser 1, and a phase distribution is applied to the spiral phase plate 3 so that the spiral phase plate 3 modulates the parallel light and outputs a fixed single-order vortex light. As an example, the order m of the vortex light can be selected as 1, 2, 3, 4, or 5. The phase distribution applied to the spiral phase plate 3 is:

[0046]

[0047] Where i is the imaginary unit, m is a predetermined order, which is an integer ranging from 1 to 5; is the plane angular coordinate of the spiral phase plate 3.

[0048] Based on the above structure of the vortex light generating module, the fiber laser 1 outputs coherent laser light in the visible light band, the coherent laser light is incident on the fiber collimator and expander 2, parallel light is generated by the fiber collimator and expander 2, the parallel light is incident on the spiral phase plate 3, and vortex light is output by the spiral phase plate 3.

[0049] In this embodiment, the vortex light interference module is used to divide the vortex light into reference light and imaging light, and use the imaging light to illuminate the scanning position of the sample to be tested 10 to obtain the sample reflected light at the scanning position, and make the reference light and the sample reflected light overlap and interfere to obtain interference light, and the interference light spot is petal-shaped.

[0050] Specifically, reference light and imaging light are generated by beam splitting, and the imaging light is focused on the scanning position of the sample 10 to be tested, so as to scan the scanning position of the sample 10 to obtain sample reflected light. The difference in the number of reflections of the reference light and the sample reflected light in the optical path makes the order of the reference light and the sample reflected light opposite, so that the reference light and the sample reflected light overlap and interfere, thereby generating petal-shaped interference light. The vortex light interference module includes:

[0051] The first non-polarization beam splitter 4 is used to split the vortex light into reference light and imaging light. Specifically, the vortex light is split to obtain reflected light and transmitted light. The reflected light is the reference light, and the transmitted light is the imaging light.

[0052] The second non-polarization beam splitter 8 is used to allow the imaging light to be incident on the sample scanning unit, specifically to transmit the imaging light to the sample scanning unit.

[0053] The sample scanning unit, also known as a vortex illumination confocal unit, is used to illuminate the scanning position of the sample 10 to be tested with imaging light, obtain sample reflected light at the scanning position, and direct the sample reflected light into the second non-polarizing beam splitter 8. The sample reflected light contains information about the sample 10 to be tested and the defect, and is therefore called signal return light.

[0054] Among them, the sample scanning unit includes: an objective lens 9, which is used to focus the imaging light to the scanning position of the sample to be tested 10, so as to use the imaging light to illuminate the scanning position of the sample to be tested 10, and obtain the sample reflected light at the scanning position. The sample reflected light passes through the objective lens 9 and is incident on the second non-polarizing beam splitter 8.

[0055] The reference light processing unit is used to reflect the reference light multiple times and make the outgoing light after the multiple reflections incident on the second non-polarization beam splitter 8 .

[0056] Among them, the reference light processing unit includes: a first reflector 5, an adjustable optical attenuator 6 and a second reflector 7 arranged in sequence according to the propagation direction of the light. The first reflector 5 is used to reflect the reference light to the adjustable optical attenuator 6. The adjustable optical attenuator 6 is used to adjust the intensity of the reflected light of the first reflector 5 so that the intensity of the reference light is the same as the intensity of the reflected light of the sample. The second reflector 7 is used to reflect the outgoing light of the adjustable optical attenuator 6 to the second non-polarizing beam splitter 8.

[0057] The second non-polarizing beam splitter 8 is also used to make the reference light and the sample reflected light overlap and interfere to obtain interference light. Specifically, the second non-polarizing beam splitter 8 is used to split the reference light and the sample reflected light respectively, so that the transmitted light of the reference light and the reflected light of the sample reflected light overlap and interfere to obtain interference light.

[0058] Based on the above structure of the vortex light interference module, the vortex light is divided into two beams by the first non-polarizing beam splitter 4, the reflected light enters the reference path, and the transmitted light enters the imaging path, that is, the first non-polarizing beam splitter 4 divides the light path into two paths: the reflected light path and the transmitted light path, the reflected light path is the reference path, and the transmitted light path is the imaging path, the reference path includes a reference light processing unit, and the imaging path includes a second non-polarizing beam splitter 8 and a sample scanning unit.

[0059] The vortex light in the reference path is reflected by the first non-polarizing beam splitter 4 to the first reflector 5, and then reflected by the first reflector 5 to the adjustable optical attenuator 6. After the light intensity is adjusted by the adjustable optical attenuator 6, it is incident on the second reflector 7, reflected by the second reflector 7 to the second non-polarizing beam splitter 8, and transmitted to the subsequent optical path through the second non-polarizing beam splitter 8. That is, the vortex light in the reference path is reflected by the first non-polarizing beam splitter 4, the first reflector 5 and the second reflector 7, and undergoes three reflections in total. The order of the reference light becomes -m order.

[0060] The vortex light in the imaging path is transmitted through the first non-polarizing beam splitter 4 to the second non-polarizing beam splitter 8, and then transmitted through the second non-polarizing beam splitter 8 to the objective lens 9. The objective lens 9 focuses on the scanning position of the sample to be measured 10 to obtain the sample reflected light. The sample reflected light is transmitted through the objective lens 9 to the second non-polarizing beam splitter 8, and then reflected through the second non-polarizing beam splitter 8 to the subsequent optical path. The sample reflected light is reflected by the sample to be measured 10 and the second non-polarizing beam splitter 8, and undergoes two reflections in total. The order of the sample reflected light is still m.

[0061] By setting up the reference path and imaging path, the optical path difference between the reference light and the sample reflected light is less than the coherence length of the light source, ensuring that interference light can be generated subsequently. At the same time, the sample reflected light is collected by the objective lens 9 and then reflected by the second non-polarizing beam splitter 8 to the subsequent optical path. The intensity of the reference light in the reference path is adjusted by the adjustable optical attenuator 6 to the same intensity as the sample reflected light in the imaging path. It is then transmitted by the second non-polarizing beam splitter 8 to the subsequent optical path. The two beams of light (i.e., the reference light and the sample reflected light) overlap and interfere in the subsequent optical path, producing a petal-shaped light spot with 2|m| petals.

[0062] In order to achieve position control of the sample to be tested 10, the sample scanning unit also includes: a three-dimensional displacement stage 11, on which the sample to be tested 10 is located. The three-dimensional displacement stage 11 is used to drive the sample to be tested 10 to move and adjust the scanning position of the sample to be tested 10 so that any position of the sample to be tested 10 can be scanned.

[0063] In this embodiment, the rotational demodulation module is used to rotationally demodulate the interference light, demodulate the optical path difference between the two light beams (i.e., the reference light and the sample reflected light) brought by the sample 10 to be tested and the change in the relative intensity of light and dark, restore the amplitude and phase information of the sample 10 to be tested, and obtain the amplitude and phase information of the scanning position.

[0064] Specifically, the rotation demodulation module includes: a signal generator 19, a chopper driver 14, a phase-locked amplifier 18, and a third non-polarization beam splitter 12, a chopper 13, a focusing lens 15, a pinhole 16 and a photodetector 17 arranged in sequence according to the propagation direction of the light.

[0065] The signal generator 19 is respectively connected to the chopper driver 14 and the phase-locked amplifier 18. The signal generator 19 is used to transmit a control signal to the chopper driver 14 and the phase-locked amplifier 18. The control signal can be a periodic square wave signal or a periodic sine wave signal with a frequency of f and a duty cycle of 50%. The control signal can be a microwave signal.

[0066] The chopper driver 14 may be a rotary motor, which may be referred to as a chopper-driven rotary motor. The chopper driver 14 is configured to drive the chopper 13 to rotate based on a control signal.

[0067] The third non-polarization beam splitter 12 is used to split the interference light to obtain reflected light and transmitted light, and the transmitted light is incident on the chopper 13 .

[0068] The chopper 13 is used to chop the transmitted light from the third non-polarizing beam splitter 12 to produce chopped light. The cross-section of the chopper 13 is composed of multiple centrally symmetrical sectors, each of which is a high-reflection region or a low-reflection region. The high-reflection region has a greater reflectivity for the light beam than the low-reflection region. The high-reflection and low-reflection regions are arranged in an alternating pattern. Interference light incident on the cross-section of the chopper 13 near an edge can be completely covered by a sector. The chopper 13 is controlled by a rotating motor based on a control signal from a signal generator 19, with a chopping frequency of f. The interference light generated after the interference passes through the third non-polarizing beam splitter 12 and is chopped by the chopper 13 to produce chopped light.

[0069] The chopped light is incident on the third non-polarization beam splitter 12 , which is used to split the chopped light into reflected light and transmitted light. The reflected light enters the focusing lens 15 .

[0070] The focusing lens 15 is used to focus the reflected light of the third non-polarization beam splitter 12 to obtain focused light, and then direct the focused light into the pinhole 16 .

[0071] The pinhole 16 is used to allow the collected light to enter the photodetector 17 .

[0072] The photodetector 17 is used to perform photoelectric conversion on the light emitted from the pinhole 16 to obtain an electrical signal.

[0073] The lock-in amplifier 18 is signal-connected to the photodetector 17. The lock-in amplifier 18 uses the electrical signal output by the photodetector 17 as its input signal and the control signal as its reference signal. It then demodulates the input signal to obtain amplitude and phase information of the scanning position. The time constant of the lock-in amplifier 18 is set to be greater than or equal to 2 / f.

[0074] Based on the above structure of the rotary demodulation module, the interference light is transmitted through the third non-polarizing beam splitter 12 to the chopper 13, and is chopped by the chopper 13. The light reflected back by the chopper 13 (i.e., the chopped light) is reflected by the third non-polarizing beam splitter 12, focused by the focusing lens 15 to the pinhole 16, and the light intensity is recorded by the photodetector 17. The electrical signal output by the photodetector 17 is connected to the phase-locked amplifier 18 as the input signal, and the control signal of the signal generator 19 is connected to the phase-locked amplifier 18 as the reference signal. The phase-locked amplifier 18 demodulates at a frequency f and records the amplitude and phase of the input signal.

[0075] This embodiment provides a dark-field confocal microscopy measurement device based on vortex interferometry, which includes a vortex light generation module, a vortex light interference module, and a rotational demodulation module. Petal-shaped light spots are generated by interfering vortex lights of opposite orders, effectively realizing the detection of phase-type defects such as bubbles and stacking faults, and the system sensitivity is improved through phase-locked amplification detection to achieve nanoscale defect detection.

[0076] In this embodiment, the working process of the dark field confocal microscopy measurement device based on vortex interferometry is as follows:

[0077] (1) Fiber laser 1 outputs coherent laser light in the visible light band. The coherent laser light is incident on fiber collimator and beam expander 2, and parallel light is generated by fiber collimator and beam expander 2. The parallel light is incident on spiral phase plate 3, and vortex light is output.

[0078] (2) The vortex light is divided into two paths by the first non-polarizing beam splitter 4, the reflected light path is the reference path, and the transmitted light path is the imaging path. The vortex light in the reference path is reflected by the first non-polarizing beam splitter 4 to the first reflector 5, and then reflected by the first reflector 5 to the adjustable optical attenuator 6. After the light intensity is adjusted by the adjustable optical attenuator 6, it is incident on the second reflector 7, and then reflected by the second reflector 7 to the second non-polarizing beam splitter 8. It is transmitted to the subsequent optical path through the second non-polarizing beam splitter 8. The reference light undergoes three reflections in total, and the order becomes -m order. The vortex light in the imaging path is transmitted by the first non-polarizing beam splitter 4 and the second non-polarizing beam splitter 8, and then enters the objective lens 9. It is focused on the scanning position of the sample to be tested 10 by the objective lens 9. The sample reflected light reflected by the scanning position of the sample to be tested 10 is collected by the objective lens 9, and then transmitted to the second non-polarizing beam splitter 8. It is reflected to the subsequent optical path through the second non-polarizing beam splitter 8. The sample reflected light undergoes two reflections in total, and the order is still m order. Adjusting the variable optical attenuator 6 ensures that the reference light intensity in the reference path is equal to the intensity of the sample reflected light in the imaging path. Adjusting the second reflector 7 ensures that the two beams (i.e., the reference light and the sample reflected light) completely overlap in the subsequent optical path, generating interference light. The 3D translation stage 11 is moved in three dimensions to achieve 3D microscopic measurement of the sample 10.

[0079] (3) The position of the chopper 13 is adjusted so that the interference light is located near the edge of the chopper 13 and can be completely covered by a certain sector-shaped area. The signal generator 19 outputs a control signal to control the rotary motor, driving the chopper 13 to rotate at the chopping frequency f. The interference light is transmitted to the chopper 13 through the third non-polarizing beam splitter 12. After being chopped by the chopper 13, the chopper light reflected back from the chopper 13 is reflected by the third non-polarizing beam splitter 12 to the focusing lens 15. The focusing lens 15 focuses on the pinhole 16, and the light intensity is recorded by the photodetector 17. The output signal of the photodetector 17 is connected to the phase-locked amplifier 18 as the input signal. The control signal of the signal generator 19 is connected to the phase-locked amplifier 18 as the reference signal. The phase-locked amplifier 18 demodulates at the frequency f and records the amplitude and phase of the input signal.

[0080] This embodiment realizes quantitative measurement of samples through the petal-shaped light spot generated by the interference of positive and negative order vortex light. The symmetry axis direction of the interference light with the petal-shaped light spot generated after vortex interference is highly sensitive to phase, which can realize high-sensitivity phase-type defect detection and quantitative phase recovery. The phase-locked amplification detection can perceive tiny intensity and phase changes, which can effectively improve the sensitivity of defect detection, thereby realizing quantitative phase measurement of samples and high-sensitivity defect detection.

[0081] The symmetry axis of the petal-shaped interference light is linearly related to the phase difference between the imaging path and the reference path, resulting in high phase sensitivity. When a defect exists in the spatial location of the focused light spot (i.e., the scanning position), the imaging light of the imaging path undergoes amplitude and phase modulation. Phase modulation causes the symmetry axis of the petal-shaped interference light to rotate, which can be quantitatively recovered through phase demodulation in the phase-locked amplification detection process. Amplitude modulation changes the relative intensity of the light and dark components of the petal-shaped interference light, which can be extracted through amplitude demodulation in the phase-locked amplification detection process. This allows for simultaneous detection of both the amplitude (i.e., absorptivity) and phase (i.e., height and refractive index, etc.) of defects, enabling the simultaneous acquisition of three-dimensional distribution information for phase-type defects such as nanoscale surface scratches, wear, interlayer bubbles, and stacking faults.

[0082] After vortex interference, a centrally symmetrical petal-shaped light spot is generated. During the chopping process of the chopper 13, the intensity of the reflected light shows periodic changes. The phase-locked amplifier 18 is used to detect the periodic intensity changes, which has the advantage of high sensitivity. Compared with the existing technology, the high phase sensitivity of vortex interference provides an innovative solution for precision measurement and detection, and has extremely high measurement sensitivity for interlayer defects of three-dimensional integrated circuits.

[0083] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A dark field confocal microscopy measurement device based on vortex interferometry, characterized in that: The dark field confocal microscopy measurement device based on vortex interferometry includes: A vortex light generating module, used to generate vortex light of a predetermined order; A vortex light interference module is configured to separate the vortex light into reference light and imaging light, utilize the imaging light to illuminate a scanning position of a sample to be tested, obtain sample reflected light at the scanning position, and cause the reference light and sample reflected light to overlap and interfere with each other to obtain interference light; the sample to be tested is a three-dimensional integrated circuit; the reference light and the sample reflected light have opposite orders; the interference light spot is petal-shaped; when a defect exists at the scanning position, amplitude modulation and phase modulation are generated on the imaging light; phase modulation causes the symmetry axis of the interference light with the petal-shaped spot to rotate, and amplitude modulation causes the relative intensity of light and dark in the interference light with the petal-shaped spot to change; A rotation demodulation module, configured to rotationally demodulate the interference light to obtain amplitude and phase information of the scanning position; The vortex light interference module includes: a first non-polarizing beam splitter, configured to split the vortex light into a reference light and an imaging light, transmit the imaging light to a second non-polarizing beam splitter, and reflect the reference light to a reference light processing unit; a second non-polarizing beam splitter, configured to direct the imaging light into a sample scanning unit; The sample scanning unit is configured to illuminate a scanning position of the sample to be measured with the imaging light, obtain sample reflected light at the scanning position, and transmit the sample reflected light to the second non-polarizing beam splitter; a reference light processing unit, configured to reflect the reference light multiple times and direct the outgoing light after the multiple reflections into the second non-polarizing beam splitter; the reference light processing unit comprising: a first reflector, an adjustable optical attenuator, and a second reflector, arranged in sequence according to the propagation direction of the light; The second non-polarization beam splitter is further used to transmit the reference light to the rotation demodulation module and reflect the sample reflected light to the rotation demodulation module, so that the transmitted light of the reference light and the reflected light of the sample reflected light overlap and interfere to obtain interference light; The rotary demodulation module includes: a signal generator, a chopper driver, a lock-in amplifier, and a third non-polarization beam splitter, a chopper, a focusing lens, a pinhole, and a photodetector arranged in sequence according to the propagation direction of the light; The signal generator is signal-connected to the chopper driver and the lock-in amplifier respectively; the signal generator is used to transmit control signals to the chopper driver and the lock-in amplifier; The chopper driver is configured to drive the chopper to rotate based on the control signal; the chopper is configured to chop the transmitted light of the third non-polarization beam splitter so that the light intensity varies periodically to obtain chop light; The lock-in amplifier is connected to the photodetector signal; the lock-in amplifier is used to use the electrical signal output by the photodetector as an input signal and the control signal as a reference signal to demodulate the input signal to obtain the amplitude and phase information of the scanning position.

2. The dark field confocal microscopy measurement device based on vortex interferometry according to claim 1, characterized in that: The vortex light generation module includes: a fiber laser, a fiber collimating beam expander and a spiral phase plate arranged in sequence according to the propagation direction of light; the spiral phase plate is used to modulate the output light of the fiber collimating beam expander to obtain vortex light of a predetermined order.

3. The dark field confocal microscopy measurement device based on vortex interferometry according to claim 1, characterized in that: The sample scanning unit includes an objective lens.

4. The dark field confocal microscopy measurement device based on vortex interferometry according to claim 1, characterized in that: The sample scanning unit further includes: a three-dimensional displacement stage; the sample to be tested is located on the three-dimensional displacement stage; the three-dimensional displacement stage is used to drive the sample to be tested to move and adjust the scanning position of the sample to be tested.

5. The dark field confocal microscopy measurement device based on vortex interferometry according to claim 2, characterized in that: The spiral phase plate is loaded with a phase distribution, and the phase distribution is: exp(imφ); Wherein, i is the imaginary unit; m is the predetermined order; φ is the plane angular coordinate of the spiral phase plate.

6. The dark field confocal microscopy measurement device based on vortex interferometry according to claim 1, characterized in that: The chopper drive is a rotating electric machine.

Images