Device and method for super-resolution imaging or defect detection of nano pattern

Abstract

The invention discloses a device and a method for super-resolution imaging or defect detection of a nano pattern. The device comprises a light source, a polarizing film, a first lens, a first proportional beam splitter, a first objective lens, a second lens, a third lens, a second proportional beam splitter, a phase modulator, a fourth lens and a detector, the designed phase pattern on the phase modulator coincides with the rotational symmetry center of the nano pattern on the to-be-tested sample, and the symmetry axis of the designed phase pattern coincides with the symmetry axis azimuth angle of the nano pattern on the to-be-tested sample; the polarizing film, the first lens, the first objective lens, the second lens, the third lens, the phase modulation device, the fourth lens and the detector meet conjugate arrangement of adjacent devices. The technical problem that in the prior art, the imaging contrast ratio and the imaging resolution ratio of bright field imaging are insufficient is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of integrated circuit nanostructure imaging or defect detection, and more particularly relates to a device and method for super-resolution imaging or defect detection of a nano-pattern. BACKGROUND

[0002] In the field of nanotechnology and precision manufacturing, there is an increasing demand for non-destructive detection of sub-wavelength scale structures. Traditional optical microscopy techniques are usually limited to a resolution of about half the wavelength of the illuminating light (about 200-300 nm) due to the Abbe diffraction limit, which severely restricts their application in semiconductor manufacturing, biomedical detection and other fields. The current technical routes for improving the resolution of optical microscopy mainly have the following limitations. Fluorescence super-resolution microscopy can achieve nanoscale resolution, but this technique must rely on fluorescent labeling, which not only increases the complexity of sample preparation, but also may introduce phototoxicity problems. In the application scenarios of semiconductor wafer defect detection and integrated circuit fault analysis, the sample usually cannot be labeled with fluorescence. Although interference scattering microscopy can achieve non-labeled detection, its detection sensitivity is highly dependent on the reflectivity of the substrate, which greatly limits its applicability in industrial detection. In addition, this method has limited ability to detect local defects in dense pattern backgrounds, and it is difficult to meet the detection requirements of 10-50 nm level defects in modern semiconductor manufacturing. Although near-field optical microscopy breaks the diffraction limit, its detection range is limited to the near-field region of the sample surface (<100 nm), which cannot achieve large field detection, and the scanning imaging method leads to slow detection speed, which is difficult to meet the efficiency requirements of industrial online detection. The current point spread function regulation technology improves the resolution by modulating the point spread function, but generally has the problems of low signal utilization and high background noise. More importantly, these methods do not fully consider the symmetry characteristics of the sample itself, resulting in insufficient specificity of structure defect recognition, which is prone to misjudgment in actual application. In summary, the current technology cannot meet the technical requirements of high resolution, high contrast, non-destructive and large field of view at the same time. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides a device and method for super-resolution imaging or defect detection of a nano-pattern, which aims to solve the technical problems of insufficient imaging contrast and imaging resolution of the current bright-field imaging scheme while retaining the advantages of non-destructive and large field of view of an optical microscope.

[0004] To achieve the above-mentioned purpose, according to one aspect of the present application, a device for super-resolution imaging or defect detection of a nano-pattern is provided, which comprises a light source, a polarizer, a first lens, a first ratio beam splitter, a first objective lens, a second lens, a third lens, a second ratio beam splitter, a phase modulation device, a fourth lens and a detector. The polarizer, the first lens and the first objective are coaxially and parallelly arranged in sequence, and the first proportional beam splitter is arranged between the first lens and the first objective; the second lens and the third lens are coaxially and parallelly arranged; the phase modulation device, the fourth lens and the detector are coaxially and parallelly arranged in sequence; the second proportional beam splitter is arranged between the phase modulation device and the fourth lens; The polarizer is used for polarizing the collimated light emitted from the light source and then emitting the collimated light to the first lens; the first lens is used for focusing the light emitted from the polarizer to the first objective; the first objective is used for transmitting the light to the sample to be measured; the first proportional beam splitter is used for reflecting the light reflected from the sample to be measured to the second lens; the second lens is used for focusing the reflected light to the third lens; the third lens is used for focusing the reflected light to the second proportional beam splitter; the second proportional beam splitter is used for reflecting the light to the phase modulation device; the phase modulation device is used for modulating the phase distribution of the light field according to the designed phase pattern; the fourth lens is used for receiving the phase pattern incident from the phase modulation device and transmitting the phase pattern to the detector; and the detector is used for super-resolution imaging or defect detection of the nano pattern on the sample to be measured. The designed phase pattern on the phase modulation device and the rotationally symmetric center of the nano pattern on the sample to be measured coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nano pattern on the sample to be measured coincide with each other; the polarizer, the first lens, the first objective satisfy the coaxial arrangement between adjacent devices; the first objective and the second lens are coaxially arranged; the second lens and the third lens are coaxially arranged; the third lens and the phase modulation device are coaxially arranged; and the phase modulation device, the fourth lens and the detector satisfy the coaxial arrangement between adjacent devices.

[0005] In the present application, the coaxial arrangement refers to that the back focal plane of a subsequent optical device coincides with the front focal plane of a previous optical device along the direction of light propagation; and the rotationally symmetric center refers to the only geometric point around which a nano structure set is rotated by a specific angle to coincide with itself.

[0006] According to another aspect of the present application, a nano pattern super-resolution imaging or defect detection device is provided, which comprises a light source, a polarizer, a first lens, a first proportional beam splitter, a first objective, a second lens, a third lens, a phase modulation device, a fourth lens and a detector. The polarizer, the first lens and the first objective are coaxially and parallelly arranged in sequence, and the first proportional beam splitter is arranged between the first lens and the first objective; the second lens, the third lens, the phase modulation device, the fourth lens and the detector are coaxially and parallelly arranged in sequence. The polarizer is used to polarize the collimated light emitted from the light source and then emit the polarized light to the first lens; the first lens is used to focus the light emitted from the polarizer to the first objective; the first objective is used to transmit the light to the sample to be measured; the first ratio beam splitter is used to reflect the light reflected from the sample to be measured to the second lens; the second lens is used to focus the reflected light to the third lens; the third lens is used to focus the reflected light to the phase modulation device; the phase modulation device is used to modulate the phase distribution of the light field according to the designed phase pattern, and transmit to the fourth lens; the detector is used to receive the light emitted from the fourth lens for nanometer pattern super-resolution imaging or defect detection. The designed phase pattern on the phase modulation device and the rotationally symmetric center of the nanometer pattern on the sample to be measured coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nanometer pattern on the sample to be measured coincide with each other; the polarizer, the first lens, and the first objective satisfy the conjugate arrangement between adjacent devices; the first objective and the second lens are arranged in a conjugate manner; the second lens, the third lens, the phase modulation device, the fourth lens, and the detector satisfy the conjugate arrangement between adjacent devices.

[0007] According to another aspect of the present application, a nanometer pattern super-resolution imaging or defect detection device is provided, comprising a light source, a polarizer, a first lens, a first objective, a second lens, a third lens, a second ratio beam splitter, a phase modulation device, a fourth lens, a second objective, and a detector. The polarizer, the first lens, the first objective, the second objective, the second lens, and the third lens are coaxially and parallel arranged in sequence; the phase modulation device, the fourth lens, and the detector are coaxially and parallel arranged in sequence; the second ratio beam splitter is arranged between the phase modulation device and the fourth lens. The polarizer is used to polarize the collimated light emitted from the light source and then emit the polarized light to the first lens; the first lens is used to focus the light emitted from the polarizer to the first objective; the first objective is used to transmit the light to the sample to be measured; the second objective is used to receive the light transmitted from the sample to be measured and transmit to the second lens; the second lens is used to focus the light to the third lens; the third lens is used to focus the reflected light to the second ratio beam splitter; the second ratio beam splitter is used to reflect the light to the phase modulation device; the phase modulation device is used to modulate the phase distribution of the light field according to the designed phase pattern; the fourth lens is used to receive the phase pattern incident from the phase modulation device and transmit to the detector; the detector is used for super-resolution imaging or defect detection of the nanometer pattern on the sample to be measured. The designed phase pattern on the phase modulation device and the rotationally symmetric center of the nano-pattern on the sample to be tested coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nano-pattern on the sample to be tested coincide with each other; the polarization plate, the first lens, the first objective lens, the second objective lens, the second lens, and the third lens satisfy the conjugate setting between adjacent devices; the phase modulation device, the fourth lens, and the detector satisfy the conjugate setting between adjacent devices.

[0008] According to another aspect of the present application, a nano-pattern super-resolution imaging or defect detection device is provided, comprising a light source, a polarization plate, a first lens, a first objective lens, a second lens, a third lens, a phase modulation device, a fourth lens, a second objective lens, and a detector. The polarization plate, the first lens, the first objective lens, the second objective lens, the second lens, the third lens, the phase modulation device, the fourth lens, and the detector are coaxially and parallelly arranged in sequence. The polarization plate is used for polarizing the collimated light emitted from the light source and then emitting the collimated light to the first lens; the first lens is used for focusing the light emitted from the polarization plate to the first objective lens; the first objective lens is used for transmitting the light to the sample to be tested; the second objective lens is used for receiving the light transmitted from the sample to be tested and transmitting the light to the second lens; the second lens is used for focusing the light to the third lens; the third lens is used for focusing the reflected light to the phase modulation device; the phase modulation device is used for modulating the phase distribution of the light field incident thereon according to the designed phase pattern; the fourth lens is used for receiving the phase pattern incident from the phase modulation device and transmitting the phase pattern to the detector; and the detector is used for super-resolution imaging or defect detection of the nano-pattern on the sample to be tested. The designed phase pattern on the phase modulation device and the rotationally symmetric center of the nano-pattern on the sample to be tested coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nano-pattern on the sample to be tested coincide with each other; the polarization plate, the first lens, the first objective lens, the second objective lens, the second lens, the third lens, the phase modulation device, the fourth lens, and the detector satisfy the conjugate setting between adjacent devices.

[0009] Preferably, the light source and the polarization plate further comprise a speckle-eliminating assembly.

[0010] Preferably, the speckle-eliminating assembly comprises a fifth lens, a rotating diffuser, and a sixth lens arranged in sequence.

[0011] Preferably, the phase modulation device is arranged on a displacement stage, which is used for adjusting the spatial position and the azimuth angle of the phase modulation device.

[0012] According to another aspect of the present application, a method for nanometer pattern super-resolution imaging or defect detection by the nanometer pattern super-resolution imaging or defect detection device is provided, and the method specifically comprises the following steps: (1) selecting a sample to be measured, and determining a center of rotational symmetry and a symmetry axis of a nanometer pattern on the sample to be measured; (2) inserting a designed phase pattern on a phase modulation device, so that the designed phase pattern and the center of rotational symmetry of the nanometer pattern on the sample to be measured coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nanometer pattern on the sample to be measured coincide with each other; (3) turning on a light source, so that the nanometer pattern on the sample to be measured is imaged to a detector after modulation, and the detector captures a spatial image of the nanometer pattern, thereby completing nanometer pattern super-resolution imaging or defect detection.

[0013] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects: 1. In the present application, the designed phase pattern on the phase modulation device and the center of rotational symmetry of the nanometer pattern on the sample to be measured coincide with each other, and the symmetry axis of the designed phase pattern and the azimuth angle of the symmetry axis of the nanometer pattern on the sample to be measured coincide with each other. The symmetry of the nanometer pattern is used as basic information for reconstruction, so that the frequency domain scattering field of the nanometer pattern is converted from a symmetric state to an anti-symmetric state, thereby directly breaking through the optical diffraction limit in a general wide-field microscope, and realizing high-contrast and high-resolution imaging of sub-wavelength scale, periodic or symmetric nanostructures.

[0014] 2. In the present application, the adjacent devices are arranged in a conjugate manner between the polarizer, the first lens, the first objective lens, the second lens, the third lens, the phase modulation device, the fourth lens and the detector, so as to ensure that only low-frequency components exist in the frequency domain of the illumination field, that is, the sample is under wide-field illumination, and to ensure that the phase modulation device is accurately located at the Fourier plane of the system, so that the phase pattern modulation device directly modifies the frequency domain scattering field of the sample. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a schematic diagram of a principle light path of nanometer pattern super-resolution imaging and defect detection according to Embodiment 1 of the present application.

[0016] Figure 2 FIG. 3 is a schematic diagram of a target nanometer pattern used in Embodiment 1 of the present application.

[0017] Figure 3 FIG. 4 is a designed phase pattern corresponding to the target nanometer pattern in Embodiment 1 of the present application.

[0018] Figure 4 FIG. 5 is an initial Fourier far-field amplitude and phase of the target nanometer pattern in Embodiment 1 of the present application.

[0019] Figure 5 is the designed phase pattern modulated Fourier far field amplitude and phase of the target nano-pattern in embodiment 1 of the present application.

[0020] Figure 6 is the aerial image of the target nano-pattern in embodiment 1 of the present application.

[0021] Figure 7 is the schematic diagram of the target nano-pattern used in embodiment 5 of the present application.

[0022] Figure 8 is the initial Fourier far field amplitude and phase of the target nano-pattern in embodiment 5 of the present application.

[0023] Figure 9 is the designed phase pattern modulated Fourier far field amplitude and phase of the target nano-pattern in embodiment 5 of the present application.

[0024] Figure 10 is the aerial image of the target nano-pattern in embodiment 5 of the present application.

[0025] Figure 11 is the schematic diagram of the nano-pattern super-resolution imaging or defect detection device provided by embodiment 2 of the present application.

[0026] Figure 12 is the schematic diagram of the nano-pattern super-resolution imaging or defect detection device provided by embodiment 3 of the present application.

[0027] Figure 13 is the schematic diagram of the nano-pattern super-resolution imaging or defect detection device provided by embodiment 4 of the present application.

[0028] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein: 200, light source; 201, fifth lens; 202, rotating scattering sheet; 203, sixth lens; 204, polarizing sheet; 205, first lens; 206, first ratio beam splitter; 207, first objective lens; 208, sample to be measured; 209, second lens; 210, third lens; 211, second ratio beam splitter; 212, phase modulation device; 213, fourth lens; 214, detector; 215, second objective lens. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0030] Example 1 A nanopattern super-resolution imaging or defect detection device, when both the sample 208 and the phase modulation device 212 are opaque devices, such as Figure 1 As shown, it includes a light source 200, a polarizer 204, a first lens 205, a first proportional beam splitter 206, a first objective lens 207, a second lens 209, a third lens 210, a second proportional beam splitter 211, a phase modulation device 212, a fourth lens 213, and a detector 214. The polarizer 204, the first lens 205, and the first objective lens 207 are arranged coaxially and parallel in sequence. The first proportional beam splitter 206 is disposed between the first lens 205 and the first objective lens 207. The second lens 209 and the third lens 210 are arranged coaxially and parallel in sequence. The phase modulation device 212, the fourth lens 213, and the detector 214 are arranged coaxially and parallel in sequence. The second proportional beam splitter 211 is disposed between the phase modulation device 212 and the fourth lens 213. The light source 200 and the polarizer 204 are also provided with a speckle reduction assembly, which includes a fifth lens 201, a rotating scattering plate 202, and a sixth lens 203 arranged in sequence.

[0031] The polarizer 204 is used to polarize the collimated light emitted from the light source 200 and direct it to the first lens 205; the first lens 205 is used to focus the light emitted from the polarizer 204 onto the first objective lens 207; the first objective lens 207 is used to transmit the light incident on it to the sample 208 under test; the first proportional beam splitter 206 is used to reflect the light reflected from the sample 208 under test to the second lens 209; the second lens 209 is used to focus the reflected light incident on it onto the third lens 210; the third lens 210... Mirror 210 is used to focus the reflected light incident upon it onto the second proportional beam splitter 211; the second proportional beam splitter 211 is used to reflect the light incident upon it onto the phase modulation device 212; the phase modulation device 212 is used to modulate the phase distribution of the light field incident upon it to form a phase pattern; the fourth lens 213 is used to receive the phase pattern incident from the phase modulation device 212 and transmit it to the detector 214; the detector 214 is used for super-resolution imaging or defect detection of the nanopattern on the sample 208 under test. The phase pattern on the phase modulation device 212 coincides with the center of rotation symmetry of the nano-pattern on the sample 208, and the symmetry axis of the phase pattern coincides with the azimuth angle of the symmetry axis of the nano-pattern on the sample 208; the adjacent devices are coaxially arranged between the polarizer 204, the first lens 205 and the first objective 207; the first objective 207 and the second lens 209 are coaxially arranged; the second lens 209 and the third lens 210 are coaxially arranged; the third lens 210 and the phase modulation device 212 are coaxially arranged; the adjacent devices are coaxially arranged between the phase modulation device 212, the fourth lens 213 and the detector 214.

[0032] Working principle: the light source 200 generates a coherent illumination beam; the illumination beam is converged on the rotating scattering plate 202 through the lens 201; the scattered beam generated by the rotating scattering plate 202 is collected and collimated by the lens 203; the high-speed rotating rotating scattering plate 202 can generate a dynamic changing speckle light field to suppress the coherent illumination speckle; the collimated illumination beam is incident on the first lens 205 by controlling the polarization state of the illumination light field by the polarizer 204; the illumination beam passes through the first lens 205 and the first proportional beam splitter 206 in turn, and is converged on the back focal plane of the first objective 207, that is, the first Fourier plane; the converged illumination beam generates a wide-field collimated illumination beam on the surface of the sample 208 after passing through the first objective 207; the first objective 207 collects the scattered imaging light field of the sample 208 in the reflection direction and forms a first frequency domain scattered light field; the first proportional beam splitter 206 partially reflects the imaging beam and propagates to the second lens 209 and the third lens 210 in turn; the second proportional beam splitter 211 partially reflects the imaging beam from the third lens 210 to the plane where the phase modulation device 212 is located, that is, the second Fourier plane, and forms a second frequency domain scattered light field; the phase modulation device 212 modulates the phase distribution of the incident light field to form a phase pattern; the phase pattern is reflected by the phase modulation device 212 and passes through the second proportional beam splitter 211 and the fourth lens 213 in turn, and finally forms a spatial image on the detector 214; the detector captures the spatial image of the sample, thereby realizing the super-resolution imaging or defect detection of the nano-pattern of the sample.

[0033] The method for performing nano-pattern super-resolution imaging by using the nano-pattern super-resolution imaging or defect detection device of the embodiment includes the following steps: (1) Select a target nano-pattern, which should contain any number of isolated nano-structures; the target nano-pattern selected in the embodiment includes four structure regions as shown in Figure 2 The target nano-pattern is placed at the center of the system imaging field to achieve optimal high-resolution and high-contrast imaging effect.

[0034] (2) Determine the symmetry properties of the target nano-pattern and find all the symmetry axes, which should not coincide with the structure region of the target nano-pattern, as shown in Figure 2 .

[0035] (3) Design a phase pattern matching the symmetry of the target nano-pattern. The phase pattern is designed according to the symmetry axes of the target nano-pattern obtained in step (2), so that the center of rotational symmetry of the target nano-pattern and the center of rotational symmetry of the designed phase pattern coincide with each other, and the symmetry axes of the designed phase pattern coincide with the azimuthal angles of the symmetry axes of the target nano-pattern, as shown in Figure 3 .

[0036] The optimal phase difference value of the phase modulation amount on both sides of the phase discontinuous line in the designed phase pattern is π, so as to produce the optimal super-resolution imaging effect; the phase difference value in the range of 0.8π ~ 1.2π can also produce a better imaging effect.

[0037] (4) Load the designed phase pattern to the phase modulation device to modulate the second frequency domain leaf scattering field of the sample.

[0038] Under the normal incidence plane wave illumination condition generated by the target nano-pattern in the illumination light path, the scattering field will retain the set symmetry of the nano-pattern itself, that is, the sample scattering field pattern collected by the first objective 207 is still symmetric about the symmetry axis of the target nano-pattern in the first Fourier plane, as shown in Figure 4 . The 4f system composed of the second lens 209 and the third lens 210 is conjugate imaged to the second Fourier plane. The designed phase pattern is loaded to the phase modulation device 212, that is, the second Fourier plane, to form an applied phase pattern; the center of the applied phase pattern and the center of the sample scattering field pattern coincide with each other, and the symmetry axes of the designed phase pattern coincide with the azimuthal angles of the symmetry axes of the nano-pattern on the sample 208; the second frequency domain scattering field is then modulated by the phase pattern, and the third frequency domain scattering field is obtained; the amplitude of the third frequency domain scattering field does not change, but the phase of part of the region is inverted, losing the original symmetry, as shown in Figure 5 .

[0039] (5) The modulated light field is imaged to the image plane. The third frequency domain scattering field is directly imaged to the detector 214 after passing through the fourth lens 213, and the detector can capture the spatial image of the target nano-pattern, as shown in Figure 7 .

[0040] Figure 6 The left image in Figure 2 is the conventional microscope imaging result obtained without using the designed phase pattern, and cannot distinguish the four nanoparticles contained in the target nano-pattern in Figure 6The image on the right shows the imaging results obtained by using the proposed method with the designed phase pattern. Four-nanometer particles below the diffraction limit in the first target nanopattern can be directly observed. The background intensity of the unstructured region is significantly reduced, demonstrating improved resolution and imaging contrast.

[0041] Example 2 A nanopattern super-resolution imaging or defect detection device, when the sample 208 is an opaque device and the phase modulation device 212 is a transparent device, such as Figure 11 As shown, it includes a light source 200, a polarizer 204, a first lens 205, a first proportional beam splitter 206, a first objective lens 207, a second lens 209, a third lens 210, a phase modulation device 212, a fourth lens 213, and a detector 214. The polarizer 204, the first lens 205, and the first objective lens 207 are arranged coaxially and parallel in sequence, and the first proportional beam splitter 206 is disposed between the first lens 205 and the first objective lens 207; the second lens 209, the third lens 210, the phase modulation device 212, the fourth lens 213, and the detector 214 are arranged coaxially and parallel in sequence; the light source 200 and the polarizer 204 are also provided with a speckle reduction assembly, which includes a fifth lens 201, a rotating scattering plate 202, and a sixth lens 203 arranged in sequence.

[0042] The polarizer 204 is used to polarize the collimated light emitted from the light source 200 and direct it to the first lens 205; the first lens 205 is used to focus the light emitted from the polarizer 204 onto the first objective lens 207; the first objective lens 207 is used to transmit the light incident on it to the sample 208 under test; the first proportional beam splitter 206 is used to reflect the light reflected from the sample 208 under test to the second lens 209; the second lens 209 is used to focus the reflected light incident on it onto the third lens 210; the third lens 210 is used to focus the reflected light incident on it onto the phase modulation device 212; the phase modulation device 212 is used to modulate the phase distribution of the light field incident on it, forming a phase pattern, and transmitting it to the fourth lens 213; the detector 214 is used to receive the light emitted from the fourth lens 213 for nanopattern super-resolution imaging or defect detection. The phase pattern on the phase modulation device 212 coincides with the rotational symmetry center of the nanopattern on the sample under test 208, and the symmetry axis of the phase pattern coincides with the azimuth angle of the symmetry axis of the nanopattern on the sample under test; the polarizer 204, the first lens 205, and the first objective lens 207 are configured as conjugates between adjacent devices; the first objective lens 207 and the second lens 209 are configured as conjugates between each other; the second lens 209, the third lens 210, the phase modulation device 212, the fourth lens 213, and the detector 214 are configured as conjugates between adjacent devices.

[0043] Working principle: The light source 200 generates a coherent illumination beam; the illumination beam is focused onto the rotating diffuser 202 by the lens 201; the scattered beam generated by the rotating diffuser 202 is collected and collimated by the lens 203; the high-speed rotating diffuser 202 can generate a dynamically changing speckle light field to suppress coherent illumination speckle; the collimated illumination beam is controlled by the polarizer 204 to be incident on the first lens 205; the illumination beam passes through the first lens 205 and the first proportional beam splitter 206 in sequence, and then converges on the back focal plane of the first objective lens 207, that is, the first Fourier plane; the converged illumination beam... A wide-field collimated illumination beam is generated on the surface of the sample 208 after passing through the first objective lens 207. The first objective lens 207 collects the scattered imaging light field in the reflection direction of the sample 208 and forms a first frequency domain scattered light field. The first proportional beam splitter 206 partially reflects the imaging beam and propagates it sequentially to the second lens 209 and the third lens 210. The imaging beam of the third lens 210 is focused onto the plane where the phase modulator 212 is located, that is, the second Fourier plane, and forms a second frequency domain scattered light field. The second frequency domain scattered light field and the first frequency domain scattered light field are conjugate to each other and satisfy the object-image relationship. The phase modulator 212 modulates the phase distribution of the light field incident on it to form a phase pattern. The phase pattern passes through the phase modulator 212 and is sequentially transmitted to the fourth lens 213 and the detector 214, and forms a spatial image on the detector 214. The detector captures the spatial image of the sample, thereby realizing super-resolution imaging or defect detection of the nanopattern of the sample.

[0044] Example 3 A nanopattern super-resolution imaging or defect detection device, when the sample 208 is a transparent device and the phase modulation device 212 is an opaque device, such as Figure 12 As shown, it includes a light source 200, a polarizer 204, a first lens 205, a first objective lens 207, a second lens 209, a third lens 210, a second proportional beam splitter 211, a phase modulation device 212, a fourth lens 213, a second objective lens 215, and a detector 214. The polarizer 204, the first lens 205, the first objective 207, the second objective 215, the second lens 209, and the third lens 210 are coaxially and in parallel arranged in sequence; the phase modulation device 212, the fourth lens 213, and the detector 214 are coaxially and in parallel arranged in sequence; the second proportional beam splitter 211 is arranged between the phase modulation device 212 and the fourth lens 213; the light source 200 and the polarizer 204 further comprise a speckle elimination assembly, which comprises a fifth lens 201, a rotating scattering plate 202, and a sixth lens 203 arranged in sequence.

[0045] The polarizer 204 is used for polarizing the collimated light emitted from the light source 200 and then emitting the collimated light to the first lens 205; the first lens 205 is used for focusing the light emitted from the polarizer 204 to the first objective 207; the first objective 207 is used for transmitting the light to the sample 208 to be measured; the second objective 215 is used for receiving the light transmitted from the sample 208 to be measured and then transmitting the light to the second lens 209; the second lens 209 is used for focusing the light to the third lens 210; the third lens 210 is used for focusing the reflected light to the second proportional beam splitter 211; the second proportional beam splitter 211 is used for reflecting the light to the phase modulation device 212; the phase modulation device 212 is used for modulating the phase distribution of the light field incident thereon to form a phase pattern; the fourth lens 213 is used for receiving the phase pattern incident from the phase modulation device 212 and then transmitting the phase pattern to the detector 214; and the detector 214 is used for super-resolution imaging or defect detection of the nano-pattern on the sample 208 to be measured. The phase pattern on the phase modulation device 212 and the rotationally symmetric center of the nano-pattern on the sample 208 to be measured coincide with each other, and the symmetry axis of the phase pattern and the azimuth angle of the symmetry axis of the nano-pattern on the sample 208 to be measured coincide with each other; the polarizer 204, the first lens 205, the first objective 207, the second objective 215, the second lens 209, and the third lens 210 satisfy the conjugate arrangement between adjacent devices; and the phase modulation device 212, the fourth lens 213, and the detector 214 satisfy the conjugate arrangement between adjacent devices.

[0046] Working principle: the light source 200 generates a coherent illumination beam; the illumination beam is converged on the rotating scattering sheet 202 through the lens 201; the scattering beam generated by the rotating scattering sheet 202 is collected and collimated by the lens 203; the high-speed rotating rotating scattering sheet 202 can generate a dynamically changing speckle light field to suppress the coherent illumination speckle; the collimated illumination beam is incident on the first lens 205 to control the polarization state of the illumination light field through the polarizer 204; the illumination beam is converged on the back focal plane of the first objective 207, that is, the first Fourier plane, after passing through the first lens 205; the converged illumination beam generates a wide-field collimated illumination beam on the surface of the sample to be measured 208 after passing through the first objective 207; the wide-field collimated illumination beam generated on the surface of the sample to be measured 208 forms a first frequency domain scattered light field; the wide-field collimated illumination beam generated on the surface of the sample to be measured 208 passes through the sample to be measured 208 and is transmitted to the second objective 215, and the light beam passing through the second objective 215 propagates to the second lens 209 and the third lens 210 in turn; the second ratio beam splitter 211 reflects the imaging light beam from the third lens 210 to the plane where the phase modulator 212 is located, that is, the second Fourier plane, and forms a second frequency domain scattered light field; and the second frequency domain scattered light field and the first frequency domain scattered light field are mutually conjugate and satisfy the object-image relationship; the phase modulator 212 modulates the phase distribution of the light field incident thereon to form a phase pattern, the phase pattern is reflected by the phase modulator 212 and passes through the second ratio beam splitter 211, the fourth lens 213 in turn, and forms a spatial image on the detector 214; the detector captures the spatial image of the sample, thereby realizing super-resolution imaging or defect detection of the nano-pattern of the sample to be measured.

[0047] Embodiment 4 A nano-pattern super-resolution imaging or defect detection device, when the sample to be measured 208 and the phase modulation device 212 are both transparent devices, as shown in Figure 13 , comprising a light source 200, a polarizer 204, a first lens 205, a first objective 207, a second lens 209, a third lens 210, a phase modulation device 212, a fourth lens 213, a second objective 215 and a detector 214; The polarizer 204, the first lens 205, the first objective 207, the second objective 215, the second lens 209, the third lens 210, the phase modulation device 212, the fourth lens 213 and the detector 214 are coaxially and parallelly arranged in turn; the light source 200 and the polarizer 204 further comprise a speckle elimination assembly, and the speckle elimination assembly comprises a fifth lens 201, a rotating scattering sheet 202 and a sixth lens 203 arranged in turn.

[0048] The polarizer 204 is used to polarize the collimated light emitted from the light source 200 and then emit the polarized light to the first lens 205; the first lens 205 is used to focus the light emitted from the polarizer 204 to the first objective 207; the first objective 207 is used to transmit the light incident thereon to the sample 208 to be measured; the second objective 215 is used to receive the light transmitted from the sample 208 to be measured and then transmit the light to the second lens 209; the second lens 209 is used to focus the light incident thereon to the third lens 210; the third lens 210 is used to focus the reflected light incident thereon to the phase modulation device 212; the phase modulation device 212 is used to modulate the phase distribution of the light field incident thereon and form a phase pattern; the fourth lens 213 is used to receive the phase pattern incident from the phase modulation device 212 and then transmit the phase pattern to the detector 214; the detector 214 is used for super-resolution imaging or defect detection of the nano-pattern on the sample 208 to be measured. The phase pattern on the phase modulation device 212 coincides with the center of the rotationally symmetric nano-pattern on the sample 208 to be measured, and the symmetry axis of the phase pattern coincides with the azimuth angle of the symmetry axis of the nano-pattern on the sample 208 to be measured; the polarizer 204, the first lens 205, the first objective 207, the second objective 215, the second lens 209, the third lens 210, the phase modulation device 212, the fourth lens 213 and the detector 214 satisfy the conjugate setting between adjacent devices.

[0049] Working principle: the light source 200 generates a coherent illumination beam; the illumination beam is converged on the rotating scattering plate 202 by the lens 201; the scattering beam generated by the rotating scattering plate 202 is collected and collimated by the lens 203; the high-speed rotating rotating scattering plate 202 can generate a dynamically changing speckle light field to suppress the coherent illumination speckle; the collimated illumination beam is incident on the first lens 205 by controlling the polarization state of the illumination light field by the polarizer 204; the illumination beam is converged on the back focal plane of the first objective 207, that is, the first Fourier plane, after passing through the first lens 205; the converged illumination beam generates a wide-field collimated illumination beam on the surface of the sample to be measured 208 after passing through the first objective 207; the wide-field collimated illumination beam generated on the surface of the sample to be measured 208 forms a first frequency domain scattered light field; the wide-field collimated illumination beam generated on the surface of the sample to be measured 208 passes through the sample to be measured 208 and is transmitted to the second objective 215, and the light beam passing through the second objective 215 is sequentially transmitted to the second lens 209 and the third lens 210; the third lens 210 focuses the light to the plane where the phase modulator 212 is located, that is, the second Fourier plane, and forms a second frequency domain scattered light field; and the second frequency domain scattered light field and the first frequency domain scattered light field are mutually conjugate and satisfy the object-image relationship; the phase modulator 212 modulates the phase distribution of the light field incident thereon to form a phase pattern, and the phase pattern passes through the phase modulator 212 and is sequentially transmitted to the fourth lens 213, the detector 214, and forms a spatial image on the detector 214; the detector captures the spatial image of the sample, thereby realizing super-resolution imaging or defect detection of the nano pattern of the sample to be measured.

[0050] Embodiment 5 The method for defect detection of a nano structure by using the nano pattern super-resolution imaging or defect detection device in Embodiment 1 comprises the following steps: (1) Select a target nano pattern. The symmetry of the target nano pattern should be determined according to the actual imaging and detection requirements, and when the nano pattern does not have symmetry, the symmetry should be broken by the structural defect part, that is, the abnormal loss or increase of the structure destroys the symmetry of the original host structure, as shown in FIG. 1. Figure 7 The symmetry of the original host structure is broken, but the symmetry should still be determined according to the spatial distribution of the original host structure and the entire symmetry axis should be found. The target nano pattern is placed at the center of the system imaging field to achieve the best high-resolution and high-contrast imaging effect.

[0051] (2) Determine the symmetry characteristics of the target nano pattern. The symmetry of the original host structure is broken, but the symmetry should still be determined according to the spatial distribution of the original host structure and the entire symmetry axis should be found, and the symmetry axis should not coincide with the structural region of the target nano pattern, as shown in FIG. 2. Figure 7

[0052] ​(3) Design a phase pattern that matches the symmetry of the target nanopattern. Based on the axis of symmetry of the host structure corresponding to the target nanopattern obtained in step (2), design a phase pattern such that the center of rotational symmetry of the target nanopattern coincides with the center of rotational symmetry of the designed phase pattern, and the axis of symmetry of the designed phase pattern coincides with the azimuth angle of the axis of symmetry of the target nanopattern, such as... Figure 4 As shown.

[0053] The optimal phase difference between the phase modulation amounts on both sides of the phase discontinuity line in the design pattern is π, so as to produce the best super-resolution imaging effect; a phase difference in the range of 0.8π to 1.2π can produce a good imaging effect.

[0054] (4) The designed phase pattern is loaded onto the phase modulation device to modulate the second Fourier scattering field of the sample.

[0055] Under normal incident plane wave illumination generated by the illumination path, the scattered field of the target nanopattern will partially retain the symmetry of the host nanopattern and the asymmetric properties induced by defects, such as... Figure 8 As shown. The first Fourier plane is conjugate-imaged onto the second Fourier plane by a 4f system consisting of the second lens 209 and the third lens 210. The designed phase pattern is loaded onto the phase modulation device 212, i.e., the second Fourier plane, to form the applied phase pattern; the modulation displacement stage makes the center of the applied phase pattern coincide with the center of the sample scattering field pattern, and the symmetry axis of the designed phase pattern coincides with the azimuth axis of the symmetry axis of the nanopattern on the sample 208; the sample scattering field is then modulated by the applied phase pattern to obtain the modulated scattering field; the amplitude of the modulated scattering field does not change, but the phase of some regions is reversed, losing the original quasi-symmetry, such as... Figure 9 As shown.

[0056] (5) The modulated light field is imaged onto the image plane. The modulated scattered field is directly imaged onto the detector 214 after passing through lens 213. The detector can capture the spatial image of the target nanopattern, such as... Figure 9 As shown.

[0057] Figure 10 The image on the left is a conventional microscope image obtained without using a designed phase pattern, and is therefore indistinguishable. Figure 7 The four nanoparticles contained in the target nanopattern can only sense whether a defect exists; Figure 10 The image on the right is the imaging result of the method proposed in this invention, obtained using the designed phase pattern. It allows direct observation of the perturbation signals generated by four-nanometer particles below the diffraction limit and defects in the target nanopattern. The background intensity of the unstructured region is significantly reduced, demonstrating improved resolution and imaging contrast.

[0058] Those skilled in the art can easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A nanopattern super-resolution imaging or defect detection device, characterized in that, It includes a light source (200), a polarizer (204), a first lens (205), a first proportional beam splitter (206), a first objective lens (207), a second lens (209), a third lens (210), a second proportional beam splitter (211), a phase modulation device (212), a fourth lens (213), and a detector (214); The polarizer (204), the first lens (205), and the first objective lens (207) are arranged coaxially and parallel in sequence, and the first proportional beam splitter (206) is disposed between the first lens (205) and the first objective lens (207); the second lens (209) and the third lens (210) are arranged coaxially and parallel in sequence; the phase modulator (212), the fourth lens (213), and the detector (214) are arranged coaxially and parallel in sequence; the second proportional beam splitter (211) is disposed between the phase modulator (212) and the fourth lens (213); The polarizer (204) is used to polarize the collimated light emitted from the light source (200) and direct it to the first lens (205); the first lens (205) is used to focus the light emitted from the polarizer (204) onto the first objective lens (207); the first objective lens (207) is used to transmit the light incident on it to the sample to be tested (208); the first proportional beam splitter (206) is used to reflect the light reflected from the sample to be tested (208) onto the second lens (209); the second lens (209) is used to focus the reflected light incident on it onto the third lens (210); the first... The third lens (210) is used to focus the reflected light incident on it onto the second proportional beam splitter (211); the second proportional beam splitter (211) is used to reflect the light incident on it onto the phase modulation device (212); the phase modulation device (212) is used to modulate the phase distribution of the light field incident on it according to the designed phase pattern; the fourth lens (213) is used to receive the phase pattern incident from the phase modulation device (212) and transmit it to the detector (214); the detector (214) is used for super-resolution imaging or defect detection of the nanopattern on the sample under test (208); The designed phase pattern on the phase modulation device (212) coincides with the rotational symmetry center of the nanopattern on the sample under test (208), and the symmetry axis of the designed phase pattern coincides with the azimuth angle of the symmetry axis of the nanopattern on the sample under test (208); the polarizer (204), the first lens (205), and the first objective lens (207) are configured as conjugates between adjacent devices; the first objective lens (207) and the second lens (209) are configured as conjugates, and the second lens (209) and the third lens (210) are configured as conjugates; the third lens (210) and the phase modulation device (212) are configured as conjugates; the phase modulation device (212), the fourth lens (213), and the detector (214) are configured as conjugates between adjacent devices.

2. A nanopattern super-resolution imaging or defect detection device, characterized in that, It includes a light source (200), a polarizer (204), a first lens (205), a first proportional beam splitter (206), a first objective lens (207), a second lens (209), a third lens (210), a phase modulation device (212), a fourth lens (213), and a detector (214); The polarizer (204), the first lens (205), and the first objective lens (207) are arranged coaxially and parallel in sequence, and the first proportional beam splitter (206) is disposed between the first lens (205) and the first objective lens (207); the second lens (209), the third lens (210), the phase modulation device (212), the fourth lens (213), and the detector (214) are arranged coaxially and parallel in sequence. The polarizer (204) is used to polarize the collimated light emitted from the light source (200) and direct it to the first lens (205); the first lens (205) is used to focus the light emitted from the polarizer (204) to the first objective lens (207); the first objective lens (207) is used to transmit the light incident on it to the sample to be tested (208); the first proportional beam splitter (206) is used to reflect the light reflected from the sample to be tested (208) to the second lens (209); the second lens (209) is used to focus the reflected light incident on it to the third lens (210); the third lens (210) is used to focus the reflected light incident on it to the phase modulation device (212); the phase modulation device (212) is used to modulate the phase distribution of the light field incident on it according to the designed phase pattern and transmit it to the fourth lens (213); the detector (214) is used to receive the light emitted from the fourth lens (213) for nanopattern super-resolution imaging or defect detection. The phase pattern designed on the phase modulation device (212) coincides with the rotational symmetry center of the nanopattern on the sample to be tested (208), and the symmetry axis of the designed phase pattern coincides with the azimuth angle of the symmetry axis of the nanopattern on the sample to be tested; the polarizer (204), the first lens (205), and the first objective lens (207) satisfy the conjugate setting between adjacent devices; the first objective lens (207) and the second lens (209) are mutually conjugate; the second lens (209), the third lens (210), the phase modulation device (212), the fourth lens (213), and the detector (214) satisfy the conjugate setting between adjacent devices.

3. A nanopattern super-resolution imaging or defect detection device, characterized in that, It includes a light source (200), a polarizer (204), a first lens (205), a first objective lens (207), a second lens (209), a third lens (210), a second proportional beam splitter (211), a phase modulation device (212), a fourth lens (213), a second objective lens (215), and a detector (214); The polarizer (204), first lens (205), first objective lens (207), second objective lens (215), second lens (209), and third lens (210) are arranged coaxially and parallel in sequence; the phase modulation device (212), fourth lens (213), and detector (214) are arranged coaxially and parallel in sequence; the second proportional beam splitter (211) is disposed between the phase modulation device (212) and the fourth lens (213); The polarizer (204) is used to polarize the collimated light emitted from the light source (200) and direct it to the first lens (205); the first lens (205) is used to focus the light emitted from the polarizer (204) onto the first objective lens (207); the first objective lens (207) is used to transmit the light incident on it to the sample to be tested (208); the second objective lens (215) is used to receive the light transmitted from the sample to be tested (208) and transmit it to the second lens (209); the second lens (209) is used to focus the light incident on it onto the third lens (210); the third objective lens (210) is used to focus the light incident on it onto the third lens (210); the third objective lens (210) is used to focus the light incident on it onto the third lens (210); the second objective lens (215) is used to focus the light transmitted from the sample to be tested (208) onto the third lens (209); the second objective lens (209) is used to focus the light incident on it onto the third lens (210); the second objective lens (215) is used to focus the light transmitted from the sample to be tested (208) onto the third lens (209); the second objective lens (215) is used to focus the light transmitted from the sample to be tested (208) onto the third lens (210 ... A mirror (210) is used to focus the reflected light incident upon it onto the second proportional beam splitter (211); the second proportional beam splitter (211) is used to reflect the light incident upon it onto the phase modulation device (212); the phase modulation device (212) is used to modulate the phase distribution of the light field incident upon it according to a designed phase pattern; the fourth lens (213) is used to receive the phase pattern incident from the phase modulation device (212) and transmit it to the detector (214); the detector (214) is used for super-resolution imaging or defect detection of the nanopattern on the sample under test (208); The phase pattern designed on the phase modulation device (212) coincides with the rotational symmetry center of the nanopattern on the sample to be tested (208), and the symmetry axis of the designed phase pattern coincides with the azimuth angle of the symmetry axis of the nanopattern on the sample to be tested (208); the polarizer (204), the first lens (205), the first objective lens (207), the second objective lens (215), the second lens (209), and the third lens (210) satisfy the conjugate setting between adjacent devices; the phase modulation device (212), the fourth lens (213), and the detector (214) satisfy the conjugate setting between adjacent devices.

4. A nanopattern super-resolution imaging or defect detection device, characterized in that, It includes a light source (200), a polarizer (204), a first lens (205), a first objective lens (207), a second lens (209), a third lens (210), a phase modulation device (212), a fourth lens (213), a second objective lens (215), and a detector (214); The polarizer (204), first lens (205), first objective lens (207), second objective lens (215), second lens (209), third lens (210), phase modulation device (212), fourth lens (213) and detector (214) are arranged coaxially and parallel in sequence; The polarizer (204) is used to polarize the collimated light emitted from the light source (200) and direct it to the first lens (205); the first lens (205) is used to focus the light emitted from the polarizer (204) onto the first objective lens (207); the first objective lens (207) is used to transmit the light incident on it to the sample to be tested (208); the second objective lens (215) is used to receive the light transmitted from the sample to be tested (208) and transmit it to the second lens (209); the second lens (209) is used to direct the light incident on it... Light is focused onto the third lens (210); the third lens (210) is used to focus the reflected light incident on it onto the phase modulation device (212); the phase modulation device (212) is used to modulate the phase distribution of the light field incident on it according to the designed phase pattern; the fourth lens (213) is used to receive the phase pattern incident from the phase modulation device (212) and transmit it to the detector (214); the detector (214) is used for super-resolution imaging or defect detection of the nanopattern on the sample to be tested (208); The phase pattern designed on the phase modulation device (212) coincides with the rotational symmetry center of the nanopattern on the sample to be tested (208), and the symmetry axis of the designed phase pattern coincides with the azimuth angle of the symmetry axis of the nanopattern on the sample to be tested (208); the polarizer (204), the first lens (205), the first objective lens (207), the second objective lens (215), the second lens (209), the third lens (210), the phase modulation device (212), the fourth lens (213), and the detector (214) satisfy the conjugate arrangement between adjacent devices.

5. A nanopattern super-resolution imaging or defect detection device as described in any one of claims 1 to 4, characterized in that, The light source (200) and the polarizer (204) are also provided with a speckle-reducing component.

6. The nanopattern super-resolution imaging or defect detection device as described in claim 5, characterized in that, The speckle-reducing assembly includes a fifth lens (201), a rotating scattering sheet (202), and a sixth lens (203) arranged in sequence.

7. A nanopattern super-resolution imaging or defect detection device as described in any one of claims 1 to 4, characterized in that, The phase modulation device (212) is disposed on the displacement stage and is used to adjust the spatial position and azimuth angle of the phase modulation device (212).

8. A method for performing nanopattern super-resolution imaging or defect detection using a nanopattern super-resolution imaging or defect detection device as described in any one of claims 1 to 7, specifically comprising the following steps: (1) Select the sample to be tested and determine the rotational symmetry center and symmetry axis of the nanopattern on the sample to be tested; (2) A designed phase pattern is inserted into the phase modulation device such that the center of rotational symmetry of the designed phase pattern coincides with the center of rotational symmetry of the nanopattern on the sample to be tested, and the azimuth angle of the axis of symmetry of the designed phase pattern coincides with the azimuth angle of the axis of symmetry of the nanopattern on the sample to be tested. (3) Turn on the light source so that the nanopattern on the sample to be tested is modulated and imaged onto the detector. The detector captures the spatial image of the nanopattern and completes the super-resolution imaging or defect detection of the nanopattern.

Images