Detection System and Method Based on Holographic Template for Electron Beam Complex Amplitude Modulation

Abstract

This invention provides a detection system and method for complex amplitude modulation of an electron beam based on a holographic template. The system includes: a magnetic lens system module for shaping the electron beam generated by an electron gun to obtain an incident electron beam; an electron holographic template module for performing complex amplitude modulation on the incident electron beam; the electron holographic template module includes an electron phase template, which is a phase plate that performs overall phase encoding based on the target distribution of the expected electron wave function; and an electron camera module for imaging and detecting the modulated electron beam. This invention can perform overall encoding based on the target distribution of the expected electron wave function to achieve complex amplitude modulation of the electron wave function, enabling the system to not only control the vibration phase of the electron wave at various points in space, but also to precisely control its amplitude distribution.

Description

Technical Field

[0001] This invention relates to the field of electron optics technology, and in particular to a detection system and method based on electron beam complex amplitude modulation using a holographic template. Background Technology

[0002] As a direct manifestation of the matter wave concept in quantum mechanics, the spatial propagation and evolution of electron waves can be completely described by complex-valued wave functions. These wave functions simultaneously contain amplitude and phase information, corresponding to the probability distribution of electrons in space and their coherence and interference properties, respectively. Therefore, achieving precise control of the complex amplitude of the electron wave function—that is, independently and programmably modulating the amplitude and phase on the same platform—has always been one of the core problems in electron optics and free electron quantum state engineering. With electron microscopy transforming from an imaging tool to a quantum state manipulation platform, single phase modulation can no longer meet the needs of structured control of electron wave functions. This is especially true in the study of novel electron wave packets such as electron vortex beams, Bessel beams, and Airy beams, where high-fidelity preparation of target states is difficult to achieve solely through phase modulation. Against this backdrop, electron complex amplitude modulation has gradually become a key technological direction driving the development of this field.

[0003] Currently, methods for modulating electron wave functions mainly include Volta templates, Zernike templates, Zach templates, Boersch templates, and optical templates. Volta templates utilize the surface potential spontaneously generated on the thin film surface after electron beam irradiation to apply a phase delay to unscattered electrons passing through the center of the film, thus enhancing phase contrast. Zernike templates consist of a carbon thin film with a central micropore; scattered and unscattered electrons experience different phase differences when passing through the template, thereby enhancing the contrast of weakly phased objects. Zach templates use a controllable electrostatic potential generated by microfabricated electrodes to introduce a defined phase delay into the electron wave. Boersch templates are electrostatic ring-structured phase plates that apply a uniform phase delay to unscattered electrons by placing a ring with electrodes on the back focal plane. Optical templates are a fully tunable and controllable template design method that utilizes the interaction between electrons and photons to achieve modulation.

[0004] However, none of the current template design methods have the ability to simultaneously achieve precise amplitude and phase control, and the design principles of these templates require modifications to the original structure in the transmission electron microscope optical path, making it difficult to freely achieve patterned modulation of the electron beam as needed. Summary of the Invention

[0005] This invention provides a detection system and method for electron beam complex amplitude modulation based on a holographic template, which solves the defect in the prior art that the template cannot simultaneously achieve precise control of amplitude and phase. Based on the target distribution of the expected electron wave function, the system performs overall encoding to achieve complex amplitude modulation of the electron wave function, so that the system can not only control the vibration phase of the electron wave at various points in space, but also precisely control its amplitude distribution.

[0006] This invention provides a detection system based on holographic template for complex amplitude modulation of an electron beam, comprising: a magnetic lens system module for shaping the electron beam generated by an electron gun to obtain an incident electron beam; an electron holographic template module for performing complex amplitude modulation on the incident electron beam; the electron holographic template module includes an electron phase template, which is a phase plate that performs overall phase encoding according to the target distribution of the expected electron wave function; and an electron camera module for imaging and detecting the modulated electron beam.

[0007] According to the present invention, an electron beam complex amplitude modulation detection system based on a holographic template is provided. The electron phase template includes: a silicon substrate, the first surface of which is provided with a thin region or suspended structure formed by thinning process; a functional thin film layer, which is disposed on the second surface of the silicon substrate opposite to the first surface, and the surface of the functional thin film layer is provided with a micro / nano structure with discrete thickness variation for phase modulation of the incident electron beam.

[0008] According to the present invention, a detection system based on holographic template electron beam complex amplitude modulation is provided. The spatial distribution of the micro / nano structure is a discrete thickness distribution constructed based on the optimal processing size and the binarized spatial phase distribution. The spatial distribution of the micro / nano structure is determined based on a preset iterative process, which includes: using a reference optical carrier to transform the target complex amplitude distribution to obtain a binarized spatial phase distribution; using the binarized spatial phase distribution, the reference optical carrier, and the processing size to determine the diffraction theory results, and combining them with the two-dimensional time-dependent Schrödinger equation to obtain the spatial distribution of the first-order diffraction peak positions; determining the similarity between the spatial distribution of the first-order diffraction peak positions and the target complex amplitude distribution, and adjusting the processing size according to the similarity and re-executing the above process until the optimal processing size is determined.

[0009] According to the present invention, an electron beam complex amplitude modulation detection system based on a holographic template is provided. The spatial distribution of the first-order diffraction peak position is obtained by obtaining the wave function at a preset propagation distance based on the diffraction theory results and the two-dimensional time-dependent Schrödinger equation, and by extracting the spatial intensity distribution corresponding to the wave function under far-field conditions.

[0010] According to the detection system based on holographic template electron beam complex amplitude modulation provided by the present invention, the optimal processing size is determined by increasing or decreasing the corresponding processing size based on similarity during each iteration to improve the similarity between the spatial distribution of the first-order diffraction peak position and the target complex amplitude distribution, until the similarity reaches the maximum value as the processing size is adjusted, or when the processing size is reduced to the limit resolution capability of the processing equipment, the iteration is terminated and the current size is determined as the optimal processing size.

[0011] According to the present invention, an electron beam complex amplitude modulation detection system based on a holographic template is provided, wherein the material of the functional thin film layer includes at least one of silicon nitride, silicon dioxide and carbon film.

[0012] According to the present invention, an electron beam complex amplitude modulation detection system based on a holographic template is provided. The electron holographic template module further includes a support structure. The electron phase template is fixed on the support structure. The material of the support structure includes at least one of silicon, silicon nitride, silicon dioxide and carbon film.

[0013] According to the present invention, an electron beam complex amplitude modulation detection system based on a holographic template is provided. The system further includes an objective lens, an intermediate lens, and a projection lens. The objective lens is used to spatially separate the emitted electron waves with different propagation directions obtained by the electron holographic template module according to the scattering angle at the back focal plane of the objective lens, forming a reciprocal space intensity distribution. In the diffraction imaging mode, by adjusting the intermediate lens and the projection lens, the back focal plane of the objective lens is magnified and imaged on the electron detection plane of the electron camera module, so that the electron camera module can detect and obtain the equivalent far-field diffraction pattern of the electron.

[0014] The present invention also provides a detection method based on holographic template electron beam complex amplitude modulation, which is applied to the detection system based on holographic template electron beam complex amplitude modulation as described above. The method includes: shaping the electron beam generated by the electron gun to obtain the incident electron beam; using an electron holographic template to perform complex amplitude modulation on the incident electron beam; and imaging and detecting the modulated electron beam.

[0015] According to the present invention, a detection method for electron beam complex amplitude modulation based on a holographic template includes the following steps before performing complex amplitude modulation on the incident electron beam using an electron holographic template: providing a silicon substrate; growing a thin film on a second surface of the silicon substrate to form a functional thin film layer; thinning a first surface of the silicon substrate to form a thin region or suspended structure; and etching the functional thin film layer to form a micro / nano structure with discrete thickness variations.

[0016] The detection system and method for electron beam complex amplitude modulation based on holographic templates provided by this invention utilizes a magnetic lens system as a pre-processing module. Through precise electromagnetic field control, the electron beam is focused, collimated, or shaped, effectively filtering electrons with non-ideal spatial frequencies. This significantly improves the spatial and temporal coherence of the incident electron beam, while simultaneously imparting a uniform intensity distribution to the beam spot. This provides ideal high-purity plane wave incident conditions for subsequent high-fidelity modulation of the electron phase template. Furthermore, based on the target distribution of the expected electron wavefunction, overall encoding is performed to achieve complex amplitude modulation of the electron wavefunction. This allows the system to encode the required complex wavefront information into the physical phase plate with extremely high degrees of freedom, enabling a single static physical device to batch and stably etch the desired wavefront information. The system requires a complex electron wave function, and thus uses an electron phase template to modulate the incident electron beam. This allows the system to control not only the phase of the electron wave at various points in space, but also its amplitude distribution. This enables the generation of arbitrary target electron wave fields containing complex intensity envelopes and phase gradients, greatly expanding the dimensions and precision of electron beam manipulation. Furthermore, an electron camera module can be used to capture the intensity distribution of the electron beam modulated by the electron phase template with high sensitivity and low noise, enabling the detection of the electron wave amplitude distribution and the inversion of the true phase distribution through interference fringes. This allows the abstract expected electron wave function to be visualized and quantitatively verified, providing reliable data feedback for the accuracy assessment of electron phase template preparation and subsequent applications such as electron microscopy and electron beam processing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the detection system based on holographic template and electron beam complex amplitude modulation provided by the present invention; Figure 2 This is a schematic diagram of the detection method based on holographic template electron beam complex amplitude modulation provided by the present invention; Figure 3 This is a schematic diagram of the manufacturing process of the electronic phase plate provided by the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] Figure 1 This is a schematic diagram of the detection system based on holographic templates and electron beam complex amplitude modulation provided by the present invention, as shown below. Figure 1 As shown, the system includes the following: The magnetic lens system module 11 is used to shape the electron beam generated by the electron gun 12 to obtain the incident electron beam; The electron holographic template module 13 is used to perform complex amplitude modulation on the incident electron beam; the electron holographic template module includes an electron phase template, which is a phase plate that performs overall phase encoding according to the target distribution of the expected electron wave function; Electronic camera module 14 is used to image and detect modulated electron beams.

[0021] In this embodiment, the magnetic lens system module includes, but is not limited to, a focusing lens, a collimating lens, an objective lens, or a projection lens, used to focus, collimate, and control the transmission of the electron beam; by adjusting the magnetic lens current parameters, the beam spot size and convergence angle of the electron beam at the electron phase template can be changed.

[0022] In addition, the electron gun is used to generate a high-energy, highly coherent electron beam, providing a stable electron source for electron complex amplitude modulation. The electron gun and magnetic lens system module are located upstream of the transmission electron microscope, and their specific dimensions can be adjusted according to the transmission electron microscope model and system integration requirements.

[0023] Furthermore, the electron beam accelerating voltage is preferably 200 kV, but in other embodiments it can be any value within the range of 80 kV–300 kV. The electron gun type can be a thermionic electron gun, a field emission electron gun, or a Schottky electron gun to meet different spatial coherence and energy broadening requirements.

[0024] It should be noted that the main function of the electron gun and magnetic lens system module is to generate an electron beam with good coherence and stable energy distribution, and to control its spatial propagation characteristics so that the overall optical path satisfies the paraxial approximation, and the generated initial electron beam approximates a planar electron beam. The electron gun and magnetic lens system module can be implemented using a far-field diffraction transmission electron microscope or a spherical aberration transmission electron microscope, etc., depending on the specific requirements.

[0025] In this embodiment, the electronic phase template includes: a silicon substrate, the first surface of which is provided with a thin region or suspended structure formed by thinning process

[11] ; a functional thin film layer, which is disposed on the second surface of the silicon substrate opposite to the first surface, and the surface of the functional thin film layer is provided with a micro-nano structure with discrete thickness variation for phase modulation of the incident electron beam.

[0026] It should be noted that by thinning the first side of the silicon substrate to form an extremely thin region or suspended structure, most of the incident electron beam can penetrate through in a near-straight path, minimizing the inelastic interaction between electrons and the substrate material and reducing background scattering noise. This ensures that the phase modulation information carried by the electron beam can be transmitted downstream with extremely high fidelity, creating conditions for subsequent high-precision holographic interference. Furthermore, the phase modulation structure is designed as a discrete micro-nano structure array to decompose the complex continuous phase distribution into multiple independent and precisely controllable units. This discretization design transforms the fabrication challenge into precise control of the size and height of each unit, significantly improving the accuracy and manufacturability of phase modulation. Thus, the functional thin film layer on the second side can be used to achieve precise phase modulation tasks, while the first side provides mechanical support.

[0027] It should be added that the electron holographic template module is set after the electron gun and magnetic lens system and before the electron camera module. It is used to perform complex amplitude modulation on the transmitted electron wave function. By arranging the electron phase template module at the position where the electron beam has completed acceleration and preliminary shaping but has not yet entered the final imaging or detection stage, effective control of the electron wavefront can be achieved without affecting the stability of the electron source and the basic structure of the imaging system.

[0028] In addition, the electronic holographic template module can adopt models such as silicon nitride window structure, focused ion beam etched sample thin film, and carbon film structure.

[0029] Furthermore, the electronic phase template can be a thin film or a hollow support structure. The electronic phase template can perform overall phase encoding according to the target distribution of the expected electronic wave function. The main function of the electronic holographic template module is to controllably modulate the complex amplitude of the transmitted electronic wave function according to the pre-designed holographic phase distribution, so that an electron beam with the target spatial intensity distribution and phase structure is formed after the holographic template.

[0030] In addition, for electron phase templates made of non-conductive or weakly conductive materials, an ultra-thin conductive functional thin film layer can be deposited on its surface to avoid charge accumulation during electron beam irradiation, which would affect the stability and modulation accuracy of the electron beam.

[0031] In an optional embodiment, the electron holographic template module further includes a support structure on which the electron phase template is fixed. The material of the support structure includes at least one of silicon, silicon nitride, silicon dioxide, and carbon film to ensure good mechanical strength under high vacuum and electron beam irradiation conditions without increasing electron loss.

[0032] In one alternative embodiment, the material of the functional thin film layer includes at least one of silicon nitride, silicon dioxide, and carbon film.

[0033] Specifically, the spatial distribution of the micro / nano structure is a discrete thickness distribution constructed based on the optimal processing size and the binarized spatial phase distribution. The spatial distribution of the micro / nano structure is determined based on a preset iterative process, which includes: using a reference optical carrier to transform the target complex amplitude distribution to obtain a binarized spatial phase distribution; using the binarized spatial phase distribution, the reference optical carrier, and the processing size to determine the diffraction theory results, and combining them with the two-dimensional time-dependent Schrödinger equation to obtain the spatial distribution of the first-order diffraction peak positions; determining the similarity between the spatial distribution of the first-order diffraction peak positions and the target complex amplitude distribution, and adjusting the processing size based on the similarity and re-executing the above process until the optimal processing size is determined.

[0034] It should be noted that by introducing a reference optical carrier for interferometric conversion, the continuous complex amplitude distribution, which is difficult to physically process, is cleverly encoded into a binary spatial phase distribution containing only 0 and π (or two fixed phase differences). This binary design transforms the complex three-dimensional morphology processing into a standard photolithography and etching process, greatly reducing the difficulty of physical template preparation and improving process compatibility and mass production feasibility. Furthermore, by combining macroscopic optical diffraction theory with microscopic two-dimensional time-dependent Schrödinger equation, the quantum evolution process of electron wave packets after passing through a binary phase structure with a specific processing size is accurately simulated using the Schrödinger equation. This allows for the accurate calculation of the precise distribution of the first-order diffraction peak carrying the target phase information in real space. Using similarity as an evaluation criterion, the processing size of the micro / nano structure is iteratively adjusted in reverse to form a closed-loop optimization cycle. This process can automatically absorb and compensate for edge effects not considered in the previous steps, coupling scattering between adjacent structures, and deviations in the actual processing technology, ensuring that the final determined optimal processing size can accurately reproduce the target complex amplitude distribution on the physical entity.

[0035] It should be added that the target complex amplitude distribution can be represented using the target electronic wave function, specifically: in, Indicates the complex amplitude distribution of the target; Indicates the spatial distribution of amplitude. Represents the spatial distribution of phase; It represents the imaginary unit and is an exponential function. A key component of this is that makes the wave function a complex number; Represents the natural constant.

[0036] Furthermore, the binary spatial phase distribution is represented as: in, It represents the phase distribution in binary space, i.e., the transmitted phase at a specific location; This indicates the spatial frequency of the reference optical carrier.

[0037] It should be noted that, through The encoding method packages the amplitude and phase information of the target wave function into a single, physically realizable phase distribution through a series of mathematical operations, so that when the electron beam passes through it and propagates to the far field, its diffraction wave function can accurately reproduce the target wave function Ψ(x,y).

[0038] Furthermore, the spatial distribution of the first-order diffraction peak position is obtained by extracting the spatial intensity distribution of the wave function at a predetermined propagation distance based on the diffraction theory results and the two-dimensional time-dependent Schrödinger equation, and then extracting the corresponding spatial intensity distribution of the wave function under far-field conditions.

[0039] It should be noted that, under the paraxial condition, the two-dimensional time-dependent Schrödinger equation is expressed as: in, Indicates the transverse Laplace operator; Indicates the direction of propagation. Indicates any propagation distance The wave function at that point.

[0040] In addition, the optimal processing size is determined by increasing or decreasing the corresponding processing size based on similarity during each iteration to improve the similarity between the spatial distribution of the first-order diffraction peak position and the target complex amplitude distribution. The iteration is terminated and the current size is determined as the optimal processing size when the similarity reaches its maximum value as the processing size is adjusted, or when the processing size is reduced to the limit resolution capability of the processing equipment.

[0041] The electron phase plate is preferably made of materials with high electron transmittance and low inelastic scattering cross-section, such as silicon nitride thin film or carbon film, and an ultrathin conductive metal layer is introduced on its surface to suppress charge accumulation effects. This material combination, while ensuring mechanical strength and environmental stability, effectively reduces electron absorption loss and energy broadening during modulation, allowing the modulation process to primarily focus on phase control, thereby achieving high electron transmittance and complex amplitude modulation efficiency. Compared to modulation schemes achieved through metal shielding or microelectrode deflection, this approach maintains high electron flux while effectively utilizing the electron wavefunction, making it particularly suitable for engineering applications requiring high signal strength, such as imaging, diffraction measurement, and electron beam manipulation.

[0042] The electron phase template obtained by the above method is directly compatible with existing transmission electron microscope platforms, enabling electron wavefunction manipulation without altering the original electron optics system structure, significantly reducing system integration and debugging difficulty. Since there are no dynamic adjustment components, this scheme exhibits higher stability and reliability during long-term operation, making it suitable for electron beam shaping, electron interferometry experiments, and the engineering applications of electron optics devices.

[0043] In an optional embodiment, the system further includes an objective lens, an intermediate lens, and a projection lens, wherein: the objective lens is used to spatially separate the emitted electron waves with different propagation directions modulated by the electronic holographic template module according to the scattering angle at the rear focal plane of the objective lens, forming a reciprocal space intensity distribution; in diffraction imaging mode, by adjusting the intermediate lens and the projection lens, the rear focal plane of the objective lens is magnified and imaged on the electron detection plane of the electronic camera module, so that the electronic camera module can detect and obtain the equivalent far-field diffraction pattern of the electrons.

[0044] It should be added that the positions of different diffraction spots or diffraction rings in the equivalent far-field diffraction pattern correspond to different electron scattering angles. In addition, by introducing a selected area aperture or using a converging beam illumination method in the electron optical path, the spatial range of the electron beam participating in diffraction can be limited to obtain the far-field diffraction characteristics of a local region.

[0045] In an optional embodiment, the electronic camera module is used to image and detect the electron beam modulated by the electronic phase template. The electronic camera module is positioned behind the electronic phase template, and its effective imaging size can be adjusted according to the magnetic lens system of the transmission electron microscope to ensure that the modulated electron beam can be completely received and effectively recorded.

[0046] In addition, the electronic camera module can be an electronic detector camera, which can be a fluorescent screen, a direct electron detector, a fluorescent screen and charge-coupled device camera, a fluorescent screen and complementary metal oxide camera, or other electronic imaging devices suitable for transmission electron microscopy, used to record the spatial intensity distribution of the modulated electron beam on the image plane or diffraction plane.

[0047] Furthermore, in order to achieve quantitative measurement of the spatial distribution of the electron beam, parameters such as camera length and magnification can be calibrated.

[0048] In an optional embodiment, after the electronic imaging signal acquired by the electronic camera module, the method further includes: transmitting the electronic imaging signal obtained from imaging and detection to a data processing module; the data processing module is used to analyze the spatial distribution, diffraction order characteristics, and complex amplitude modulation effect of the modulated electron beam, thereby realizing the verification and characterization of the modulation performance of the electronic phase template. By comparing and analyzing the data obtained under different imaging modes, the accuracy and stability of the electronic phase template in controlling the electronic wave function can be intuitively evaluated.

[0049] In summary, this invention uses a magnetic lens system as a pre-processing module to focus, collimate, or shape the electron beam through precise electromagnetic field control. This effectively filters out electrons with non-ideal spatial frequencies, significantly improving the spatial and temporal coherence of the incident electron beam. Simultaneously, it imparts a uniform intensity distribution to the beam spot, providing ideal high-purity plane wave incident conditions for subsequent high-fidelity modulation of the electron phase template. Furthermore, based on the target distribution of the expected electron wavefunction, overall encoding is performed to achieve complex amplitude modulation of the electron wavefunction. This allows the system to encode the required complex wavefront information into the physical phase plate with extremely high degrees of freedom, enabling a single static physical device to batch and stably sculpt the required complex electron wavefunctions. This allows the system to modulate the incident electron beam using an electronic phase template, enabling it to control not only the phase of the electron wave at various points in space but also its amplitude distribution. This generates arbitrary target electron wave fields containing complex intensity envelopes and phase gradients, greatly expanding the dimensions and precision of electron beam manipulation. Furthermore, an electron camera module can capture the intensity distribution of the electron beam modulated by the electronic phase template with high sensitivity and low noise, enabling the detection of the electron wave amplitude distribution and the inversion of the true phase distribution through interference fringes. This allows the abstract expected electron wave function to be visualized and quantitatively verified, providing reliable data feedback for evaluating the accuracy of electronic phase template preparation and for subsequent applications such as electron microscopy and electron beam processing.

[0050] The detection method based on holographic template electron beam complex amplitude modulation provided by the present invention will be described below. The detection method based on holographic template electron beam complex amplitude modulation described below can be referred to in correspondence with the detection system based on holographic template electron beam complex amplitude modulation described above.

[0051] Figure 2 A detection method based on holographic template electron beam complex amplitude modulation is shown, which is applied to the detection system based on holographic template electron beam complex amplitude modulation as described above. The method includes: S21, the electron beam generated by the electron gun is shaped to obtain the incident electron beam; S22 utilizes an electronic holographic template to perform complex amplitude modulation on the incident electron beam; S23 is used for imaging and detection of modulated electron beams.

[0052] Specifically, refer to Figure 3 Before using an electron holographic template to perform complex amplitude modulation on an incident electron beam, the process includes: providing a silicon substrate; growing a thin film on a second surface of the silicon substrate to form a functional thin film layer; thinning a first surface of the silicon substrate to form a thin region or suspended structure; and etching the functional thin film layer to form a micro / nano structure with discrete thickness variations.

[0053] It should be added that the target functional thin film can be grown using methods such as chemical vapor deposition (CVD), low-pressure chemical vapor deposition (LPCVD), or atomic layer deposition (ALD), generally using electron-transparent materials such as silicon nitride. By precisely controlling the growth thickness to ensure that the film thickness is <100nm, a thin film layer with uniform thickness, good mechanical stability, and meeting the requirements for electron transmission or structural support can be obtained.

[0054] In addition, thinning methods include wet etching and dry etching. By selectively removing the substrate material, a thin area or suspended structure is formed in the target space, thereby significantly reducing the material thickness in the electron transmission path. This ensures that the window maintains mechanical strength while having good electron transmission performance. The target space can be determined based on actual design and prior experience, such as a 3mm*3mm space, without further limitation here.

[0055] Furthermore, the electronic phase template contains phase delay information required for different spatial locations. Micro- and nano-structures can be directly fabricated on functional thin film layers using focused ion beam etching technology. By precisely controlling the scanning and dwell time of the ion beam, micro- and nano-structures with discrete thickness variations can be formed on the thin film, thereby introducing predetermined phase modulation during electron transmission.

[0056] Because focused ion beams possess sub-100-nanometer spatial resolution, this method enables the fabrication of high-precision, programmable holographic templates without the need for complex masks and multi-step photolithography processes, significantly reducing the complexity of the fabrication process and the requirements for equipment alignment accuracy. This fabrication process can produce holographic phase templates with high structural precision, stable phase modulation, and suitability for electron optics systems, providing a reliable device foundation for subsequent electron wavefunction manipulation and related experimental applications.

[0057] In one optional embodiment, before forming the micro / nano structure with discrete thickness variations, the process includes: determining the spatial distribution of the micro / nano structure based on a preset iterative process. The preset iterative process includes: converting the target complex amplitude distribution using a reference optical carrier to obtain a binarized spatial phase distribution; determining the diffraction theory results using the binarized spatial phase distribution, the reference optical carrier, and the processing size, and combining this with the two-dimensional time-dependent Schrödinger equation to obtain the spatial distribution of the first-order diffraction peak positions; determining the similarity between the spatial distribution of the first-order diffraction peak positions and the target complex amplitude distribution, adjusting the processing size based on the similarity, and re-executing the above process until the optimal processing size is determined.

[0058] Furthermore, based on the diffraction theory results and combined with the two-dimensional time-dependent Schrödinger equation, the spatial distribution of the first-order diffraction peak positions is obtained, including: obtaining the wave function at the preset propagation distance based on the diffraction theory results and the two-dimensional time-dependent Schrödinger equation; extracting the spatial intensity distribution of the wave function under far-field conditions to obtain the spatial distribution of the first-order diffraction peak positions.

[0059] In addition, the processing size is adjusted according to the similarity and the above process is repeated until the optimal processing size is determined. This includes: reducing the processing size in each iteration to improve the similarity between the spatial distribution of the first-order diffraction peak position and the target complex amplitude distribution; when the similarity no longer increases with the decrease of the processing size and reaches its maximum value, or when the processing size is reduced to the limit resolution capability of the processing equipment, the iteration is terminated and the current size is determined as the optimal processing size.

[0060] In an optional embodiment, the system further includes an objective lens, an intermediate lens, and a projection lens. Before imaging and detecting the modulated electron beam, the system further includes: using the objective lens to spatially separate the emitted electron waves with different propagation directions modulated by the electron holographic template module according to the scattering angle at the rear focal plane of the objective lens, forming a reciprocal space intensity distribution; in diffraction imaging mode, by adjusting the intermediate lens and the projection lens, the rear focal plane of the objective lens is magnified and imaged on the electron detection plane of the electron camera module for detection by the electron camera module to obtain the equivalent far-field diffraction pattern of the electron.

[0061] In an optional embodiment, after imaging and detecting the modulated electron beam, the method further includes: analyzing the spatial distribution, diffraction order characteristics, and complex amplitude modulation effect of the modulated electron beam based on the electron imaging signal obtained from imaging and detection, thereby realizing the verification and characterization of the electronic phase template modulation performance.

[0062] In summary, the embodiments of the present invention effectively filter out electrons with non-ideal spatial frequencies by focusing, collimating, or shaping the electron beam, significantly improving the spatial and temporal coherence of the incident electron beam. Simultaneously, they impart a uniform intensity distribution to the beam spot, providing ideal high-purity plane wave or spherical wave incident conditions for subsequent high-fidelity modulation of the electron phase template. Furthermore, based on the target distribution of the expected electron wavefunction, overall encoding is performed to achieve complex amplitude modulation of the electron wavefunction. This allows the system to encode the required complex wavefront information into the physical phase plate with extremely high degrees of freedom, enabling a single static physical device to batch and stably sculpt the required complex electron wavefunctions. Thus, the electron phase template is used to modulate the incident electron wavefront. By modulating the electron beam, the system can not only control the vibration phase of the electron wave at various points in space, but also precisely control its amplitude distribution. This allows the generation of arbitrary target electron wave fields containing complex intensity envelopes and phase gradients, greatly expanding the dimensions and precision of electron beam manipulation. Furthermore, an electron camera module can be used to capture the intensity distribution of the electron beam modulated by the electron phase template with high sensitivity and low noise, enabling the detection of the electron wave amplitude distribution and the inversion of the true phase distribution through interference fringes. This allows the abstract expected electron wave function to be visualized and quantitatively verified, providing reliable data feedback for the accuracy assessment of electron phase template preparation and subsequent applications such as electron microscopy imaging and electron beam processing.

[0063] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0064] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0066]

[11] One side of the silicon substrate is a thin area or a completely hollow structure obtained by thinning. The thin film is a functional thin film layer.

Claims

1. A detection system based on electron beam complex amplitude modulation using a holographic template, characterized in that, include: The magnetic lens system module is used to shape the electron beam generated by the electron gun to obtain the incident electron beam; An electron holographic template module is used to perform complex amplitude modulation on the incident electron beam; the electron holographic template module includes an electron phase template, which is a phase plate that performs overall phase encoding according to the target distribution of the expected electron wave function; An electronic camera module is used to image and detect modulated electron beams.

2. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 1, characterized in that, The electronic phase template includes: A silicon substrate, wherein a thin region or suspended structure is formed by a thinning process on the first surface of the silicon substrate; A functional thin film layer is disposed on a second surface of the silicon substrate opposite to the first surface, and the surface of the functional thin film layer is provided with micro / nano structures with discrete thickness variations for phase modulation of the incident electron beam.

3. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 2, characterized in that, The spatial distribution of the micro / nano structure is a discrete thickness distribution constructed based on the optimal processing size and the binarized spatial phase distribution. The spatial distribution of the micro / nano structures is determined based on a preset iterative process, which includes: The target complex amplitude distribution is transformed using a reference optical carrier to obtain a binarized spatial phase distribution; Using the binarized spatial phase distribution, the reference optical carrier, and the processing dimensions, the diffraction theory results are determined, and combined with the two-dimensional time-dependent Schrödinger equation, the spatial distribution of the first-order diffraction peak positions is obtained; Based on the spatial distribution of the first-order diffraction peak positions and the target complex amplitude distribution, the similarity is determined, and the processing size is adjusted according to the similarity. The above process is then repeated until the optimal processing size is determined.

4. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 3, characterized in that, The spatial distribution of the first-order diffraction peak position is obtained by obtaining the wave function at a preset propagation distance based on the diffraction theory results and the two-dimensional time-dependent Schrödinger equation, and by extracting the spatial intensity distribution of the wave function under far-field conditions.

5. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 3, characterized in that, The optimal processing size is determined by increasing or decreasing the corresponding processing size based on similarity during each iteration to improve the similarity between the spatial distribution of the first-order diffraction peak position and the target complex amplitude distribution, until the similarity reaches its maximum value as the processing size is adjusted, or when the processing size is reduced to the limit resolution capability of the processing equipment, at which point the iteration is terminated and the current size is determined as the optimal processing size.

6. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 2, characterized in that, The material of the functional thin film layer includes at least one of silicon nitride, silicon dioxide, and carbon film.

7. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 1, characterized in that, The electronic holographic template module also includes a support structure, on which the electronic phase template is fixed. The material of the support structure includes at least one of silicon, silicon nitride, silicon dioxide, and carbon film.

8. The detection system based on holographic template and electron beam complex amplitude modulation according to claim 1, characterized in that, The system also includes an objective lens, an intermediate lens, and a projection lens, wherein: The objective lens is used to cause the emitted electron waves with different propagation directions, which are modulated by the electronic holographic template module, to be spatially separated at the rear focal plane of the objective lens according to the scattering angle, forming an inverted spatial intensity distribution. In diffraction imaging mode, by adjusting the intermediate lens and the projection lens, the back focal plane of the objective lens is magnified and imaged onto the electron detection plane of the electronic camera module, so that the electronic camera module can detect and obtain the equivalent far-field diffraction pattern of electrons.

9. A detection method based on holographic template electron beam complex amplitude modulation, applied to the detection system based on holographic template electron beam complex amplitude modulation as described in any one of claims 1-8, characterized in that, The methods include: The electron beam generated by the electron gun is shaped to obtain the incident electron beam. The incident electron beam is subjected to complex amplitude modulation using an electronic holographic template; Imaging and detection of modulated electron beams.

10. The detection method based on holographic template and electron beam complex amplitude modulation according to claim 9, characterized in that, Before using an electronic holographic template to perform complex amplitude modulation on the incident electron beam, the process includes: Provide silicon substrate; A functional thin film layer is formed by growing a thin film on the second surface of the silicon substrate. The first surface of the silicon substrate is thinned to form a thin region or a suspended structure. Etching is performed on the functional thin film layer to form micro / nano structures with discrete thickness variations.

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