Electronic exposure machine

Abstract

The application relates to an electron exposure machine for exposing a sample, the electron exposure machine comprising a light source for emitting laser, an electron source and an electron optical assembly, the electron source comprising an optical fiber coupled to the light source and an electron emission layer, the electron emission layer at least comprising an electron excitation layer, the electron excitation layer is arranged on a light emitting path of laser emitted by the optical fiber, so that the electron excitation layer can emit electron beams under excitation of the laser; the electron excitation layer comprises at least one of a zero-dimensional material, a one-dimensional material and a two-dimensional material, the electron source further comprises a light modulator, the light modulator is connected between the light source and the optical fiber and used for controlling whether laser is propagated to the optical fiber, and the electron optical assembly is arranged on the electron beam emergent side of the electron source and used for adjusting the deflection direction of electron beams. Enabling the electron beam to be incident on the sample, and forming a preset exposure pattern on the sample.

Description

Technical Field

[0001] This application relates to the technical field of electron exposure machines, and particularly to an electron exposure machine. Background Art

[0002] An electron exposure machine is a patterning means applied in semiconductor processes. The electron beam excited by the electron exposure machine can denature the photoresist on the sample surface, cause cross-linking or decomposition of the organic chain structure of the photoresist, or transfer the designed pattern to the photoresist based on other mechanisms, so that the photoresist becomes a temporary mask for subsequent patterning operations.

[0003] The pattern quality of the electron exposure machine in the related technology is poor. Summary of the Invention

[0004] Based on this, it is necessary to provide an electron exposure machine to solve the problem of poor pattern quality of the electron exposure machine in the related technology.

[0005] An electron exposure machine for exposing a sample, the electron exposure machine comprising:

[0006] A light source for emitting laser light;

[0007] An electron source including an optical fiber coupled to the light source and an electron emission layer, the electron emission layer at least including an electron excitation layer, the electron excitation layer being disposed on the light-emitting path of the laser emitted by the optical fiber so that the electron excitation layer can emit an electron beam under the excitation of the laser; the electron excitation layer includes at least one of zero-dimensional materials, one-dimensional materials, and two-dimensional materials; and

[0008] An electron optical component disposed on the electron beam emission side of the electron source, the electron optical component being used to adjust the focusing and deflection directions of the electron beam so that the electron beam is incident on the sample to form a preset exposure pattern on the sample.

[0009] In one embodiment, the electron exposure machine further includes a housing;

[0010] The housing has a vacuum chamber, and the light-emitting end of the optical fiber of the electron source and the electron optical component are spaced apart from each other and disposed in the vacuum chamber;

[0011] The electron excitation layer is disposed on the light-emitting end of the optical fiber to be located on the light-emitting path of the laser emitted by the optical fiber.

[0012] In one embodiment, the housing is provided with an opening communicating with the vacuum chamber, and the light-incident end of the optical fiber of the electron source is exposed through the opening and coupled to the light source;

[0013] The outer peripheral wall of the optical fiber is hermetically connected to the inner side wall of the opening.

[0014] In one embodiment, the light incident end of the optical fiber of the electron source extends through the opening to the outside of the vacuum chamber to be coupled to the light source; or

[0015] The end face of the light incident end of the optical fiber of the electron source is flush with the plane where the opening is located.

[0016] In one embodiment, the electron source further includes a light modulator, which is connected between the light source and the optical fiber for controlling whether the laser propagates to the optical fiber.

[0017] In one embodiment, the electron optical assembly includes a focusing magnetic lens and a deflection coil, and the focusing magnetic lens and the deflection coil are arranged at intervals along the emission direction of the electron beam on the electron beam emission side of the electron source.

[0018] In one embodiment, the light modulator includes an electro-optic modulator or an optical switch.

[0019] In one embodiment, the optical fiber includes a core for transmitting laser and a cladding layer wrapping the core, and the end face of the light output end of the optical fiber is arranged at an angle to the extending direction of the core;

[0020] The electron emission layer is arranged on the end face of the light output end of the optical fiber, and the electron excitation layer covers the core of the optical fiber. The laser emitted from the core can directly irradiate on the electron emission layer, so that the electron excitation layer is excited by the laser emitted from the core and emits electrons.

[0021] In one embodiment, the optical fiber includes a core for transmitting laser and a cladding layer wrapping the core;

[0022] A light leakage notch is formed in the light output end of the optical fiber along the radial direction of the optical fiber;

[0023] The electron excitation layer is arranged on the bottom wall surface of the light leakage notch, the bottom wall surface of the light leakage notch is configured as a plane, and the projection of the electron excitation layer on the bottom wall surface covers the projection of the core on the bottom wall surface;

[0024] The electron excitation layer further extends to the light output end of the optical fiber.

[0025] In one embodiment, the optical fiber is configured as a perforated optical fiber, and the perforated optical fiber has a light guiding hole;

[0026] The electron excitation layer is at least arranged on the side wall of the light guiding hole and extends to the light output end of the optical fiber along the longitudinal extension direction of the light guiding hole.

[0027] In one embodiment, the optical fiber is configured as a porous optical fiber;

[0028] The electron excitation layer is disposed on an end surface of the light-emitting end of the porous optical fiber and covers one end of the light-guiding hole located on the end surface of the light-emitting end;

[0029] The laser emitted by the porous optical fiber can directly irradiate the electron emission layer, so that the electron excitation layer is excited by the laser emitted by the porous optical fiber and emits electrons.

[0030] In one embodiment, a pointed end portion is provided at the light-emitting end of the optical fiber, and the electron excitation layer covers the surface of the pointed end portion of the optical fiber;

[0031] The optical fiber includes a core for transmitting laser light, and the laser light emitted by the optical fiber can directly irradiate the electron emission layer, so that the electron excitation layer is excited by the laser light emitted by the core and emits electrons.

[0032] In one embodiment, the electron source further includes a conductive connection layer, which is disposed on the optical fiber and electrically connected to the electron excitation layer.

[0033] In one embodiment, the electron source further includes an anode, the anode has a first electron channel, and the electron optical component has a second electron channel communicating with the first electron channel;

[0034] A preset electric field is provided between the anode and the electron excitation layer, and the electron beam can pass through the first electron channel and the second electron channel under the drive of the preset electric field and be incident on the sample.

[0035] In one embodiment, the thickness of the electron excitation layer is less than or equal to 50 nm.

[0036] In one embodiment, the included angle between the axial direction of the one-dimensional material in the electron excitation layer and the laser emission direction is 0 to 90°.

[0037] In one embodiment, the electron excitation layer includes at least two two-dimensional materials stacked in sequence along the laser emission direction; or

[0038] The electron excitation layer includes at least two two-dimensional materials with different materials connected to each other on the same plane.

[0039] In one embodiment, the electron excitation layer includes zero-dimensional materials and zero-dimensional materials disposed at the end and / or side of the one-dimensional material.

[0040] In one embodiment, the electron excitation layer includes a zero-dimensional material and a two-dimensional material, and the zero-dimensional material is disposed on the surface of the two-dimensional material.

[0041] In one embodiment, the electron excitation layer includes a one-dimensional material and a two-dimensional material, and the one-dimensional material is disposed on the surface of the two-dimensional material.

[0042] The above-mentioned electron exposure machine forms an electron beam by laser-exciting a low-dimensional material. The electron beam moves to the sample under the adjustment of the electron optical component to achieve the exposure of the sample, and the laser is modulated by the light modulation component, so that the electron beam can be modulated. It can be understood that the electron source of the present application uses at least one of a zero-dimensional material, a one-dimensional material, and a two-dimensional material as the material for emitting electrons. Since the electron excitation layer has a strong light-material interaction and a rich electron bandgap, the laser can better interact with the electron excitation layer to excite the electrons in the electron excitation layer, and the electrons tunneling and emitting from the electron excitation layer have the characteristics of concentrated energy, small energy dispersion, high brightness, and high stability. Moreover, the setting of the low-dimensional material does not need to consider the transfer and scattering process of electrons in the low-dimensional material between the front and rear cross-sections of the low-dimensional material. That is, the process in which electrons in the low-dimensional material are excited by laser and emitted into the vacuum is an ultrafast process on the femtosecond scale, and the exposure pattern formed on the sample is also finer, reducing blurring. And the excitation of electrons in the low-dimensional material is affected by the laser. By adjusting the laser through the light modulation component, the emission of the electron beam can be sensitively modulated, so that the exposure dose during the scanning process of the electron beam exposure pattern can be accurately controlled, and the emission of the electron beam at the scanning position gap can be accurately and quickly controlled, thereby improving the quality of the pattern exposed by the optoelectronic exposure machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Shows a schematic structural diagram of an electron exposure machine of the present application.

[0044] Figure 2 Shows Figure 1 An enlarged schematic diagram of part A of

[0045] Figure 3 Shows a schematic structural diagram of an embodiment in which the end face of the light-emitting end of the optical fiber in the present application is arranged at an angle with the extending direction of the fiber core.

[0046] Figure 4 Shows a schematic structural diagram of an embodiment in which the light-emitting end of the optical fiber in the present application is provided with a light leakage notch.

[0047] Figure 5 Shows Figure 4 A side view of

[0048] Figure 6The structural schematic diagram of the embodiment in the present application where the electron excitation layer is disposed on the sidewall of the light guiding hole of the fiber with holes is shown.

[0049] Figure 7 is shown Figure 6 The enlarged schematic diagram at C of

[0050] Figure 8 The structural schematic diagram of the embodiment in the present application where the electron excitation layer is disposed on the end face of the light output end of the fiber with holes is shown.

[0051] Figure 9 is shown Figure 8 The enlarged schematic diagram at D of

[0052] Figure 10 The structural schematic diagram of the embodiment in the present application where the light output end of the optical fiber is provided with a pointed end portion is shown.

[0053] Figure 11 is shown Figure 10 The enlarged schematic diagram at E of

[0054] Figure 12 The structural schematic diagram where the auxiliary layer is disposed on one side of the end face of the electron excitation layer close to the light output end is shown.

[0055] Figure 13 The process schematic diagram of the preparation method of the electron source in an embodiment of the present application is shown.

[0056] Description of reference numerals:

[0057] 10, electron exposure machine;

[0058] 100, electron source; 110, optical fiber; 111, core; 112, cladding layer; 1101, light input end; 1102, light output end; 11021, end face; h, light leakage notch; h1, bottom wall surface; h2, side wall surface; k, side wall of light guiding hole; j, pointed end portion; j1, surface; 120, electron emission layer; 121, electron excitation layer; 1211, first part; 1212, second part; 122, auxiliary layer; 130, conductive connection layer; 131, first conductive part; 132, second conductive part;

[0059] 200, light source;

[0060] 300, housing; 310, vacuum chamber;

[0061] 400, sample stage; 410, sample;

[0062] 500, light modulation component;

[0063] 600, electron optical component; 610, focusing magnetic lens; 620, deflection coil;

[0064] 20. Temporary substrate;

[0065] 30. Perforated glass slide;

[0066] 40. Annular heating sheet. Detailed implementation manners

[0067] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0068] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0069] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0070] In the present application, unless otherwise clearly specified and limited, the terms "mount", "connect", "couple", "fix", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0071] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is lower than that of the second feature.

[0072] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0073] An electron exposure machine is a patterning means applied in semiconductor processes. Similar to ultraviolet exposure, an electron beam can denature the photoresist on the processing surface, causing cross-linking or decomposition of the organic chain structure thereof, or based on other mechanisms, transferring the designed pattern onto the photoresist. At this time, the photoresist becomes a temporary mask for subsequent patterning operations, and this step is a core step in the integrated circuit process.

[0074] The electron sources in the related art are thermionic electron sources, field emission electron sources and photoemission electron sources according to the excitation method. The electron beam emitted by the thermionic electron source has a low brightness and poor coherence. The electron beam of the field emission electron source has a high brightness and good coherence, but has high requirements for the vacuum degree and is very sensitive to vibrations. The regulation of the electron emission properties by simple thermal excitation or electric field excitation is limited. Moreover, in the related art, inside the vacuum chamber of the electron exposure machine, the electron beam emitted by the electron source is mainly controlled by an electron beam shutter to deflect from the main optical axis to avoid reaching other areas on the sample. That is to say, the electron beam shutter is applied to the situation where some areas need to be exposed while some areas cannot be exposed. Using the electron beam shutter can avoid the formation of exposure connections due to scanning between discrete exposure areas. However, the process of blocking electrons by the electron beam shutter is slow, resulting in difficulty in more precise control of the exposure dose, limiting the speed of patterning scanning at the same time, and the setting of the electron beam shutter relatively increases the volume of the electron exposure machine and affects its miniaturized design.

[0075] In traditional technologies, for thermionic electron sources, materials with metallic properties such as tungsten filaments and lanthanum hexaboride are mainly selected. When heated to thousands of degrees Celsius, electrons are thermally excited to escape from the material surface to form vacuum electrons. For field emission electron sources, metallic tips such as tungsten are mainly selected. Under the action of a strong external electric field, a tip discharge effect is generated. Among them, the electron beam emitted by the thermionic electron source can work in a relatively poor vacuum environment, has good environmental adaptability and stability, but has a low brightness and poor coherence. The electron beam of the field emission electron source has a high brightness and good coherence, but has high requirements for vacuum degree and is very sensitive to vibrations. Whether it is a thermionic electron source or a field emission electron source, the regulation of electron emission properties is limited, and it is impossible to balance the emission efficiency and stability.

[0076] In traditional technologies, for photoemission electron sources, metallic materials such as Au are used as the materials for the electron emission layer, with a thickness of more than 50 nm, and even reaching hundreds of nanometers. However, the inventors of the present application have found through research that the electron emission layer of metallic materials has a relatively large thickness, and the distance between the bottom layer directly interacting with the laser and the surface layer for electron emission is relatively far (50 nm to hundreds of nanometers). During the process of electrons excited from the bottom layer passing through the electron emission layer, they are easily affected by metal lattice scattering, thereby affecting the emission efficiency. Moreover, metallic materials are prone to damage under high-power laser irradiation, affecting the service life of the electron emission layer, and thus affecting the electron emission efficiency and stability.

[0077] In traditional technologies, there is also a type of photoemission electron source that excites electrons by an external laser incident on the surface of a metallic tip. Since the size of the metallic tip is in the nanometer range, it is difficult to align the laser spot to the metallic tip. If a high-magnification microscope is set up to align the external laser to the metallic tip, the system will have poor tolerance to environmental vibrations.

[0078] In addition, in traditional technologies, graphene is used as a saturable absorber. Graphene has broadband saturable absorption characteristics and a fast recovery time, and is used in the Q-switching and mode-locking of lasers, or the laser spectrum is adjusted by graphene to achieve sensing detection.

[0079] Based on this, it is necessary to provide an electron source that can balance the electron emission efficiency and stability.

[0080] The present application uses low-dimensional materials such as zero-dimensional materials, one-dimensional materials, or two-dimensional materials as the materials for the electron emission layer. The low-dimensional materials emit electrons under the action of photoelectric effect, multiphoton emission, and optical field emission under laser irradiation. The low-dimensional materials have atomic-level thickness, no dangling bonds, and stable properties, thus having characteristics such as good stability and high service life. Moreover, the low-dimensional materials can be directly integrated with optical fibers, and the optical fibers can provide a stable excitation source with adjustable wavelength, polarization, and optical mode, and can be applicable to different application scenarios, such as the following electron exposure machine.

[0081] The electron source 100 of the present application has a large beam current, strong electron coherence, and stable operation, and can operate in a relatively poor vacuum. In addition, the electron source of the present application can modulate properties such as electron energy, momentum, deflection state, time-space distribution, etc. by modulating the incident light, thereby improving the control accuracy and facilitating the miniaturization design of the electron exposure machine 10 of the present application.

[0082] Refer to Figure 1 and Figure 2 As shown, the present application provides an electron exposure machine 10 for exposing a sample 410, and can achieve effects such as good stability, precise regulation, high exposure quality, and easy miniaturization design.

[0083] The electron exposure machine 10 includes a light source 200, an electron source 100, an optical modulator 500, and an electron optical component 600. The light source 200 can emit laser light for excitation. The laser light propagates to the electron source 100 to excite the electron source 100 to form an electron beam. The electron beam is modulated by the electron optical component 600 and projected onto the sample 410 to expose the sample 410.

[0084] The electron source 100 includes an optical fiber 110 and an electron emission layer 120. The optical fiber 110 has a light input end 1101 coupled to the light source 200 and a light output end 1102 relative to the light input end 1101. The laser light emitted by the light source 200 enters the optical fiber 110 from the light input end 1101 and exits from the light output end 1102 after propagating through the optical fiber 110. The electron emission layer at least includes an electron excitation layer 121. The electron excitation layer 121 is disposed on the light output path of the laser light emitted by the optical fiber 110 so that the electron excitation layer 121 can emit an electron beam under the excitation of the laser light. In other words, the optical fiber 110 includes a core 111 for transmitting laser light, and the electron excitation layer 121 is disposed on the light output path of the laser light emitted by the core 111 and is configured to be able to emit an electron beam outward from the light output end 1102 under the excitation of the laser light transmitted in the core 111. The laser light propagates in the core 111 and exits from the light output end 1102 onto the electron excitation layer 121, and the electron excitation layer 121 emits an electron beam under excitation.

[0085] It should be noted that the wavelength of the laser light can be a wavelength that enables electrons in the electron excitation layer 121 to absorb a photon and transition, for example, a wavelength in the visible light - near infrared - ultraviolet range, or it can be a wavelength that enables electrons in the electron excitation layer 121 to absorb multiple photons and transition, for example, a wavelength outside the visible light - near infrared - ultraviolet range, and no specific limitation is made here.

[0086] The electron excitation layer 121 includes at least one of low-dimensional materials such as zero-dimensional materials, one-dimensional materials, and two-dimensional materials. These low-dimensional materials have atomic-level thickness, no dangling bonds, and stable properties, thus having characteristics such as good stability and long service life. Moreover, the low-dimensional materials can be directly integrated with the optical fiber, and the optical fiber can provide a stable excitation source with adjustable wavelength, polarization, and optical mode, and can be applied to different application scenarios. In addition, the stability of the electron beam emitted by the interaction between the laser and the low-dimensional material is higher. Compared with the ordinary electron excitation layer 121, the moving distance of electrons in the low-dimensional material is shorter and is not easily affected by the thickness of the electron excitation layer 121, thereby improving the controllability of the formed electron beam, further making the electron beam more stable and the detection quality higher. Setting the low-dimensional material as the electron excitation layer 121 on the optical fiber 110 to achieve electron excitation abandons the complex spatial light coupling structure set due to the introduction of external laser and also abandons the high-magnification microscope set to solve the alignment problem of the metal tip, which can reduce the process cost of the electron exposure machine 10 and improve the stability.

[0087] Compared with setting a metal layer on the optical fiber tip and directly interacting the laser transmitted in the optical fiber with the metal layer to excite electrons (during the process of electrons passing through the metal layer, they are easily affected by lattice scattering, resulting in low electron emission efficiency, wide energy dispersion, and serious heat accumulation), this application uses low-dimensional materials such as zero-dimensional materials, one-dimensional materials, or two-dimensional materials as the material of the electron excitation layer 121. The low-dimensional materials have atomic-level thickness, and the back-incident electrons can be emitted without passing through in-body transmission, with high electron emission efficiency. Moreover, the low-dimensional materials have no dangling bonds, stable properties, and high melting points, are not easily damaged, and can be applied to high-power excitation scenarios, having characteristics such as good stability and long service life. In addition, the low-dimensional materials also have strong light-material interaction and rich electron band gaps, enabling the laser to better interact with the electron excitation layer 121 to excite the electrons in the electron excitation layer 121. These electrons are excited and detached into the vacuum to form an electron beam, and the electron beam tunneling and emitting from the electron excitation layer 121 have the characteristics of small energy dispersion, high brightness, and high stability.

[0088] In addition, the low-dimensional materials and the optical fiber 110 can be directly integrated. The optical fiber 110 transmits the laser and serves as the carrier of the low-dimensional materials, can provide a stable excitation source with adjustable wavelength, polarization, and optical mode, can be applied to different application scenarios, and does not require a complex optical path, having characteristics such as small volume and high integration.

[0089] Zero-dimensional materials refer to materials whose dimensions in the three spatial dimensions are in the nanoscale, such as nanoparticles, atomic clusters, and quantum dots, etc., which are generally composed of a small number of atoms and molecules. There are many zero-dimensional carbon nanomaterials, such as carbon black, nanodiamond, diamond color center, nanometer fullerene C 60or carbon-coated nano-metal particles, etc. Zero-dimensional materials have typical discrete energy levels. Under the action of laser excitation, electrons are mainly excited by tunneling from discrete energy levels, so that the electron beam tunneling and emitting from the electron excitation layer 121 has the characteristics of small energy dispersion, high brightness and high stability.

[0090] Electrons in one-dimensional materials can be transmitted along the linear chain of one-dimensional materials. Combining with the electron excitation layer 121 being arranged on the end face 11021 of the light-emitting end 1102 of the optical fiber 110 is conducive to the efficient emission of electrons emitted by the electron source 100 along the longitudinal extension direction of the optical fiber 110. One-dimensional materials have the characteristics of a small (nanoscale) radius of curvature, which can enhance the interaction between light and matter and provide a large field enhancement factor, ensuring multi-photon emission, optical field emission, etc., and are applied to scenarios that require a high-brightness electron source 100.

[0091] One-dimensional materials can be nanotubes, nanorods or nanowires, nanoribbons or coaxial nanocables, etc.

[0092] The nanotube can be a carbon nanotube, which can be regarded as a seamless tubular structure formed by winding single-layer or multi-layer graphite according to certain rules. The nanotube can also be a silicon (Si) nanotube, a selenium (Se) nanotube, a tellurium (Te) nanotube, a bismuth (Bi) nanotube, a boron nitride (BN) nanotube, a boron and nitrogen co-doped carbon nanotube (BCN nanotube), a tungsten disulfide (WS2) nanotube, a molybdenum disulfide (MoS2) nanotube or a titanium dioxide (TiO2) nanotube, etc.

[0093] The material of the nanowire can be silicon (Si) or germanium (Ge); the nanowire can also be an oxide nanowire, such as tin oxide (SnO) or zinc oxide (ZnO), etc.; of course, the nanowire can also be a nitride nanowire, such as gallium nitride (GaN) or silicon nitride (Si3N4), etc.; the nanowire can also be a sulfide nanowire, such as cadmium sulfide (CdS) and zinc sulfide (ZnS), etc.; the nanowire can also be a ternary compound nanowire, such as barium titanate (BaTiO3) and lead titanate (PbTiO3), etc.

[0094] The nanoribbon is quite different from the above two nanoscale structures (nanotubes and nanowires). Its cross-section is not close to a circle like that of a nanotube or a nanowire, but is quadrilateral, and the aspect ratio distribution range is generally from several to more than a dozen. The material of the nanoribbon can be an oxide, such as tin oxide (SnO) or zinc oxide (ZnO), etc.

[0095] The coaxial nanocable can be a graphite / boron nitride (C / BN) coaxial nanocable or a silicon carbide / sulfur dioxide (CSi / SiO2) coaxial nanocable, etc.

[0096] In some embodiments, the angle between the axial direction of the one-dimensional material in the electron excitation layer 121 and the emission direction of the emitted laser is 0 to 90°, for example, it can be 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80° or 90°.

[0097] In some embodiments, the axial direction of the one-dimensional material is the same as the emission direction of the laser, so that point emission of the electron source 100 can be achieved, and the resolution is high. If a low-density arrangement of one-dimensional materials is adopted, the energy dispersion of the emitted electrons is low and the brightness is high. If a high-density arrangement of one-dimensional materials is adopted, a large electron beam of the electron source 100 can be achieved. Among them, low density refers to the number of one-dimensional materials per unit area. For example, a density less than 1 / nm 2 is low density, and greater than 1 / nm 2 is high density.

[0098] In some embodiments, there is an angle between the axial direction of the one-dimensional material and the emission direction of the laser, and the angle can be a right angle or an acute angle. Laser excitation of the one-dimensional material can generate a linear electron source.

[0099] Optionally, the electron excitation layer 121 may also include a two-dimensional material. The electrons in the two-dimensional material can be transmitted along the two-dimensional plane. Combined with the fact that the electron excitation layer 121 is provided on the end face 11021 of the light-emitting end 1102 of the optical fiber 110, in this way, it is beneficial for the electrons emitted by the electron source 100 to be efficiently emitted along the longitudinal extension direction of the optical fiber 110; and compared with setting a thin metal layer on the optical fiber 110, it will cause the melting point of the metal layer to decrease, and then lead to the problem that the metal layer is easily damaged. The two-dimensional material selected in this application has no dangling bonds, is relatively stable, has a high melting point, is not easily damaged, and is suitable for high-power excitation and large electron beams of the electron source 100. In addition, the energy levels of the two-dimensional material are more discrete, and the energy of the electron beam emitted by tunneling is more concentrated and the energy dispersion is smaller.

[0100] The two-dimensional material has the characteristic of including different atomic layer thicknesses. The thickness of the two-dimensional material can be the thickness of a single atomic layer or the thickness of multiple atomic layers. During the process of the laser acting on the two-dimensional material, it hardly affects the light transmission mode and has high stability; moreover, the excited electrons can be directly emitted without internal scattering in the material, ensuring the purity of the properties of the emitted electrons and an extremely narrow pulse width.

[0101] The two-dimensional material can be graphene, transition metal sulfide, two-dimensional perovskite, two-dimensional diamond or boron nitride, etc.

[0102] Taking two-dimensional material graphene as an example for illustration, the carbon atoms of graphene are bonded in the plane in the form of covalent bonds, forming a hexagonal honeycomb planar structure. The electron excitation layer 121 can have an atomic thickness of about 0.34 nanometers, or the electron excitation layer 121 can also have several or dozens of atomic thicknesses.

[0103] Of course, this application is not limited thereto. The electron excitation layer 121 also includes two or more of zero-dimensional materials, one-dimensional materials, and two-dimensional materials.

[0104] In some embodiments, the electron excitation layer 121 includes at least two stacked two-dimensional materials arranged in sequence along the laser emission direction, or the electron excitation layer 121 includes at least two two-dimensional materials with different materials connected to each other on the same plane.

[0105] In some embodiments, at least two two-dimensional materials are stacked, or at least two two-dimensional materials are spliced to form the same plane. Further, the materials of two adjacent two-dimensional materials are different, thereby forming a vertical heterojunction or a planar heterojunction. The heterojunction structure can enhance the interaction between light and two-dimensional materials, realize efficient electron emission under low laser power, and the heterojunction has the function of interfacial energy band regulation. Through material design and twist angle regulation, special interfacial states can be obtained to realize high-brightness and low-energy-dispersion electron emission.

[0106] In some embodiments, the materials in the electron excitation layer 121 include one-dimensional materials and zero-dimensional materials disposed at the ends and / or sides of the one-dimensional materials.

[0107] In this application, by combining zero-dimensional materials with one-dimensional materials and disposing the zero-dimensional materials at the ends or sides of the one-dimensional materials, that is, using zero-dimensional materials to modify the surface structure of one-dimensional materials. Both zero-dimensional materials and one-dimensional materials have typical discrete energy levels. Under the action of laser, electrons are mainly excited by tunneling from discrete energy levels, and the emitted electrons have characteristics such as concentrated energy, small energy dispersion, and high emission efficiency.

[0108] In some embodiments, the electron excitation layer 121 includes zero-dimensional materials and two-dimensional materials, and the zero-dimensional materials are disposed on the surface of the two-dimensional materials.

[0109] In this application, the zero-dimensional materials are disposed on the surface of the two-dimensional materials. The two-dimensional materials can not only serve as a support layer for carrying the zero-dimensional materials, but also avoid the addition of a conductive layer by using conductive two-dimensional materials. That is, the two-dimensional materials can serve as the auxiliary layer 122 of the zero-dimensional materials to achieve the functions of support and conduction.

[0110] In some embodiments, the electron excitation layer 121 includes one-dimensional materials and two-dimensional materials, and the one-dimensional materials are disposed on the surface of the two-dimensional materials. Optionally, the angle between the axial direction of the one-dimensional materials and the surface of the two-dimensional materials is 0 to 90°.

[0111] In this application, the one-dimensional material is disposed on the surface of the two-dimensional material. The two-dimensional material can not only serve as a support layer for carrying the one-dimensional material, but also avoid the addition of a conductive layer by using a conductive two-dimensional material. That is, the two-dimensional material can serve as an auxiliary layer for the one-dimensional material to achieve the functions of support and conduction.

[0112] In some embodiments, the thickness of the electron excitation layer 121 is less than or equal to 50 nm.

[0113] It can be understood that the thickness of the electron excitation layer 121 is in the nanometer range and the thickness of the electron excitation layer 121 is small. Thus, it is more conducive to reducing the process of in-body transmission of the excited electrons in the electron excitation layer 121, more conducive to improving the emission efficiency and emission density of electrons, and further, the electron source 100 can be used to realize an electron beam with ultra-short pulses.

[0114] In some embodiments, the zero-dimensional material, one-dimensional material or two-dimensional material independently includes a doping element.

[0115] In this application, by doping elements into the low-dimensional material, the conductivity of the low-dimensional material is improved, the work function is changed, and the electron emission performance is adjusted. For example, alkali metals and alkaline earth metal elements can improve the conductivity of the low-dimensional material and at the same time reduce the work function of the low-dimensional material to enhance the emission beam current. Elements such as B, C, N, O, F and rare earths can create discrete energy levels to obtain an electron beam with a narrow energy range.

[0116] Optionally, the doping element includes at least one of alkali metals, alkaline earth metals, transition metals, rare earth elements, halogen elements and light elements (B, C, N, O, F).

[0117] Continue to refer to Figure 1 As shown, the electron source 100 further includes an optical modulator 500. The optical modulator 500 is connected between the light source 200 and the optical fiber 110 and is used to control whether the laser propagates to the optical fiber 110. In some embodiments, the optical modulator 500 includes an electro-optic modulator or an optical switch. The optical switch can control whether the laser emitted by the light source 200 propagates to the optical fiber 110. The electro-optic modulator can adjust the phase of the laser emitted by the light source 200 while controlling whether the laser emitted by the light source 200 propagates to the optical fiber 110. Since the electron beam is controlled by controlling the laser through the optical modulator 500, there is no need to provide an electron beam shutter to modulate the electron beam. And the existing electron microscope can be modified to form the electron exposure machine 10 of this application. During the modification, since the electron beam can be controlled by the optical modulator 500, there is no need to consider the influence of adding an electron beam shutter structure and the corresponding electric and magnetic field distributions and the wiring problem. After using the electron source 100 of this application, the optical modulator 500 can be directly added to the external optical path, such as the optical fiber 110, to complete the hardware modification of the electron exposure function.

[0118] The electron exposure machine 10 further includes an electron optical component 600, which is disposed on the electron beam exit side of the electron source 100, and is used to adjust the deflection direction of the electron beam so that the electron beam is incident on the sample 410. In some embodiments, the electron optical component 600 includes a focusing magnetic lens 610 and a deflection coil 620, which are arranged at intervals on the electron beam exit side of the electron source 100 along the exit direction of the electron beam, and are mainly used to modulate the deflection direction of the electron beam so that it can be projected onto the sample 410, and a preset exposure pattern is formed on the sample.

[0119] In some embodiments, the electron source 100 also includes an anode, and there is a preset electric field between the anode and the electron excitation layer 121. The electron beam can be incident on the sample 410 under the drive of the preset electric field. That is to say, the electron excitation layer 121 emits an electron beam under the excitation of the laser to form a cathode opposite to the anode. The electrons can move toward the sample 410 under the action of the electric field between the anode and the electron excitation layer 121. The electron optical component 600 is arranged on the side of the electron source 100 that emits the electron beam, and is used to adjust the deflection direction of the electron beam, so that the electron beam emitted from the electron excitation layer 121 can be incident on the sample 410 for exposure.

[0120] In some embodiments, the anode has a first electron channel, and the electron optical component 600 has a second electron channel connected to the first electron channel, so that the electron beam can pass through the first electron channel and the second electron channel under the drive of a preset electric field and be incident on the sample 410. That is, the electron beam is driven by the electric field to pass through the first electron channel, and is regulated by the electron optical component 600 when passing through the second electron channel, and the deflection direction of the electron beam changes, and finally incident on the sample 410. It can be understood that the anode can be set to a hollow ring, and the middle of the ring-shaped anode is the first electron channel for the electron beam to pass through. Thereby, the anode can cooperate with the electron excitation layer 121 to form an electric field that drives the electron beam, and will not affect the passage of the electron beam.

[0121] like Figure 1 As shown, in some embodiments, the electronic exposure machine 10 further includes a sample stage 400, which is disposed on a side of the electron optical component 600 away from the electron source 100 along the propagation direction of the electron beam, and is used to carry a sample 410. In some embodiments, a Faraday cup is further disposed on the sample stage 400 to measure the beam current of the electron beam, that is, to measure the intensity of the electron beam incident on the sample 410, so as to adjust the electron beam and thus control the exposure effect.

[0122] In some embodiments, the electron exposure machine 10 further includes a housing 300 which has a vacuum chamber 310. The light-emitting end 1102 of the optical fiber 110 of the electron source 100, the electron optical component 600, and the sample stage 400 are sequentially arranged in the vacuum chamber 310 at intervals. The electron excitation layer 121 is disposed on the light-emitting end 1102 of the optical fiber 110 so as to be located on the light-emitting path of the laser emitted by the optical fiber 110, so that the electron source 100 emits an electron beam into the vacuum chamber 310. In other words, the electron source 100 penetrates through one end of the housing 300 along its longitudinal direction. An opening communicating with the vacuum chamber 310 is provided on the housing 300. The light-incident end 1101 of the optical fiber 110 of the electron source 100 is exposed through the opening and is coupled to the light source 200. And the outer peripheral wall of the optical fiber is hermetically connected to the inner side wall of the opening, thereby ensuring the airtightness of the cavity and improving the overall quality of the cavity.

[0123] Furthermore, the present application can modify an existing electron microscope. When modifying, only the electron source 100 needs to be replaced to realize the output of the electron beam, and there is no need to open an optical window on the housing 300 near the electron source 100, and there is no need to damage the cavity of the existing electron exposure machine. That is, the modification is simple, the modification cost is low, and the detection effect after modification is good.

[0124] In some embodiments, according to different exposure patterns, a plurality of electron sources 100 can be combined and set for scanning exposure, which can improve the exposure efficiency. For the high-precision area of the preset pattern to be exposed, the optical fiber 110 in the present application can be set as a single-mode optical fiber, and the electron beam emitted by the electron source 100 is a small-beam current electron beam. For a large-area scanning area, the optical fiber 110 can be set as a multi-mode or other types of optical fibers, and the electron beam emitted by the electron source 100 is a large-beam current electron beam. In actual operation, the spot size or exposure time of the electron beam formed by the electron source using different optical fibers can also be calculated and adjusted according to the beam current size, so as to achieve fast and high-precision scanning exposure.

[0125] It can be, as Figure 1-2 shown, the light-incident end 1101 of the optical fiber 110 extends outside the vacuum chamber 310 through the opening so that the optical fiber is coupled to the light source 200. Of course, it can also be that the end face of the light-incident end 1101 of the optical fiber 110 is flush with the plane where the opening is located. In this way, the optical fiber 110 can be generally encapsulated in the housing 300, and the end face of the light-incident end 1101 of the optical fiber 110 is exposed through the opening, so that the light source 200 can be coupled to the light-incident end 1101 of the optical fiber 110. While better protecting the optical fiber 110, it is also convenient for the laser emitted by the light source 200 to be transmitted through the optical fiber 110.

[0126] When the electron source 100 of the present application is in use, the laser can be transmitted along the core 111 of the optical fiber 110, so that the laser transmitted in the core 111 can propagate to the end face 11021 of the light output end 1102 and be emitted, and interact with the electron excitation layer 121, so that the electrons in the electron excitation layer 121 absorb the photons of the laser and undergo an energy transition to escape outside the electron excitation layer 121, realizing the excitation of electrons. The electron source 100 realizes the excitation of electrons by arranging the electron excitation layer 121 on the optical fiber, and abandons the complex spatial light coupling structure set due to the introduction of external lasers, which can reduce the process cost of the electron source 100; in addition, the electron source 100 of the present application uses low-dimensional materials as the materials for emitting electrons. Since the electron excitation layer 121 has strong light-material interaction and rich electron band gaps, the laser can better interact with the electron excitation layer 121 to excite the electrons in the electron excitation layer 121, and the electrons tunneling and emitting from the electron excitation layer 121 have the characteristics of small energy dispersion, high brightness and high stability.

[0127] The present application has various embodiments for the setting manners of the optical fiber 110 and the electron excitation layer 121.

[0128] In some embodiments, please refer to Figure 3 , the optical fiber 110 includes a core 111 for transmitting the laser and a cladding layer 112 wrapped around the core. The end face 11021 of the light output end 1102 of the optical fiber 110 is arranged at an angle α with the extending direction of the core 111, and the angle α is selected between 0 and 90 degrees. The electron emission layer 120 is arranged on the end face 11021 of the light output end 1102 of the optical fiber 110, and the electron excitation layer 121 covers the core 111 of the optical fiber 110. The laser emitted from the core 111 can directly irradiate on the electron emission layer 120, so that the electron excitation layer 121 is excited by the laser emitted from the core 111 and emits electrons.

[0129] It can be understood that the electron excitation layer 121 is located on the light output path of the laser emitted from the core 111.

[0130] In this way, the oblique incidence on the electron excitation layer 121 can be realized, and the photoelectric field perpendicular to the end face 11021 of the light output end 1102 can be realized. The emission angle of electrons can be changed by changing the angle α, or the emission angle of electrons can be adjusted by adjusting the polarization state of the laser in the optical fiber 110, which is beneficial to broadening the application range of the electron source 100.

[0131] In some embodiments, please refer to Figure 4 and Figure 5, a light leakage notch h is formed along the radial direction of the optical fiber 110 at the light output end 1102 of the optical fiber 110. The electron excitation layer 121 is disposed on the bottom wall surface h1 of the light leakage notch h, and the bottom wall surface h1 of the light leakage notch h is configured as a plane. The projection of the electron excitation layer 121 on the bottom wall surface h1 covers the projection of the fiber core 111 on the bottom wall surface h1. The electron excitation layer 121 also extends to the light output end 1102 of the optical fiber 110.

[0132] Optionally, the light leakage notch h further has a side wall surface h2 extending along the radial direction of the optical fiber 110, and the bottom wall surface h1 and the side wall surface h2 jointly define the light leakage notch h.

[0133] Optionally, the bottom wall surface h1 of the light leakage notch h is configured as a plane, and the bottom wall surface h1 of the light leakage notch h extends along the extending direction of the optical fiber 110.

[0134] It can be that the bottom wall surface h1 of the light leakage notch h is spaced apart from the fiber core 111, and the bottom wall surface h1 of the light leakage notch h is parallel to the tangent plane of the outer surface of the fiber core 111; it can also be that the bottom wall surface h1 of the light leakage notch h is tangent to the outer surface of the fiber core 111 (as Figure 5 shown); of course, it can also be that the bottom wall surface h1 of the light leakage notch h is configured as a plane partially formed on the fiber core 111. For example, by cutting the fiber core 111 and the cladding 112 simultaneously to form the light leakage notch h, and making a part of the bottom wall surface h1 of the light leakage notch h formed on the fiber core 111 and another part of the bottom wall surface h1 of the light leakage notch h formed on the cladding 112.

[0135] In this way, it can enable the laser transmitted in the fiber core 111 of the optical fiber 110 to generate an evanescent wave at the bottom wall surface h1 of the light leakage notch h. And since the electron excitation layer 121 is disposed on the bottom wall surface h1 of the light leakage notch h, and the projection of the electron excitation layer 121 in the plane parallel to the bottom wall surface h1 covers the projection of the fiber core 111 in the bottom wall surface h1, therefore, the laser transmitted in the fiber core 111 of the optical fiber 110 can interact with the electron excitation layer 121 through the evanescent wave, so that the electrons in the electron excitation layer 121 absorb the energy of the evanescent wave and transition. These electrons can escape outside the electron excitation layer 121, and thus the excitation of electrons can be realized.

[0136] In some embodiments, please refer to Figure 6 and Figure 7 , the optical fiber 110 includes a porous optical fiber. The porous optical fiber has a light guiding hole. The porous optical fiber can include a hollow porous optical fiber, and the hollow porous optical fiber can be a single-hole or multi-hole hollow optical fiber; of course, the porous optical fiber can also include a solid-core porous optical fiber, and the solid-core porous optical fiber can be a single-hole or multi-hole solid-core optical fiber, which is not specifically limited herein.

[0137] The light guide hole is provided with a core 111 composed of air. The fiber with holes further includes a cladding layer 112 surrounding the core 111. In some embodiments, the cladding layer 112 is an annular light guide tube body, and the side wall k of the light guide hole is formed on the inner side wall of the annular light guide tube body. Specifically, the material of the annular light guide tube body can be borosilicate, glass, quartz, etc. More specifically, the fiber with holes is a capillary fiber.

[0138] The electron excitation layer 121 is at least provided on the side wall k of the light guide hole, and the electron excitation layer 121 extends along the extension direction of the light guide hole to the light emitting end 1102 of the optical fiber 110.

[0139] When the electron source 100 is in use, during the process of the laser transmitting in the core 111 of the fiber with holes by means of the light guiding medium, an evanescent wave can be generated at the side wall k of the light guide hole. Since the electron excitation layer 121 is provided on the side wall k of the light guide hole, the laser can interact with the electron excitation layer 121 through the evanescent wave, so that the electrons in the electron excitation layer 121 absorb the energy of the evanescent wave and transition. These electrons can escape outside the electron excitation layer 121, and thus the excitation of electrons can be realized.

[0140] In some embodiments, please refer to Figure 8 and Figure 9 , the optical fiber 110 includes a fiber with holes. The fiber with holes has a light guide hole. The fiber with holes can include a hollow fiber with holes. The hollow fiber with holes can be a single-hole or multi-hole hollow fiber; of course, the fiber with holes can also include a solid-core fiber with holes. The solid-core fiber with holes can be a single-hole or multi-hole solid-core fiber, which is not specifically limited herein.

[0141] The light guide hole is provided with a core 111 composed of air. The fiber with holes further includes a cladding layer 112 surrounding the core 111. In some embodiments, the cladding layer 112 is an annular light guide tube body, and the side wall k of the light guide hole is formed on the inner side wall of the annular light guide tube body. Specifically, the material of the annular light guide tube body can be borosilicate, glass, quartz, etc. More specifically, the fiber with holes is a capillary fiber.

[0142] The electron emission layer 120 is provided on the end face 11021 of the light emitting end 1102 of the fiber with holes, and the electron excitation layer 121 covers one end of the light guide hole located at the end face 11021 of the light emitting end 1102. The laser emitted from the fiber with holes can directly irradiate on the electron emission layer 120, so that the electron excitation layer 121 is excited by the laser emitted from the fiber with holes and emits electrons.

[0143] Exemplarily, the fiber with holes is a capillary fiber, and the electron excitation layer 121 covers the core 111 of the fiber with holes. It can be that the electron excitation layer 121 directly covers the core 111 of the fiber with holes, or it can be that the electron excitation layer 121 indirectly covers the core 111 of the fiber with holes, which is not specifically limited herein.

[0144] In this way, during the process that the laser transmitted in the core 111 propagates to the end face 11021 of the light-emitting end 1102 and exits, this part of the laser can interact with the electron excitation layer 121, so that the electrons in the electron excitation layer 121 absorb the photons of the laser, and undergo an energy transition to escape outside the electron excitation layer 121, realizing the excitation of electrons.

[0145] In some embodiments, please refer to Figure 10 and Figure 11 , the light-emitting end 1102 of the optical fiber 110 is provided with a pointed end j, the electron excitation layer 121 covers the surface j1 of the pointed end j of the optical fiber 110, and the laser emitted from the core 111 can directly irradiate the electron emission layer 120, so that the electron excitation layer 121 is excited by the laser emitted from the core 111 and emits electrons.

[0146] During the process that the laser transmitted in the core 111 of the optical fiber 110 propagates to the pointed end j and exits, this part of the laser can interact with the electron excitation layer 121, so that the electrons in the electron excitation layer 121 absorb the photons of the laser, and undergo an energy transition to escape outside the electron excitation layer 121, and thus the excitation of electrons can be realized.

[0147] Optionally, along the extending direction of the core 111, the radial dimension of the pointed end j gradually decreases.

[0148] The electron excitation layer 121 of the present application is arranged on the pointed end j of the optical fiber 110 and covers the surface j1 of the pointed end j of the optical fiber 110. Since the pointed end j of the optical fiber 110 has a geometric structure similar to a needle tip, the field emission enhancement factor is improved, and a higher-brightness electron source 100 can be obtained.

[0149] Optionally, in this embodiment, along the extending direction of the core 111, the dimension of the pointed end j is L1, and the dimension of the electron excitation layer 121 is L2, where L1 is greater than L2. Specifically, the dimensions of the pointed end j and the electron excitation layer 121 satisfy the following relationship: L2 > 1 / 2 * L1.

[0150] The electron excitation layer 121 covers the surface j1 of the pointed end j, and the electron excitation layer 121 is arranged around the pointed end j. Since L2 > 1 / 2 * L1, in this way, the contact area between the electron excitation layer 121 and the surface j1 of the pointed end j can be increased, the bonding strength between the electron excitation layer 121 and the optical fiber 110 can be improved, and it is also beneficial to use the laser transmitted by the core 111 to excite the electron excitation layer 121 to emit electrons outward.

[0151] In some embodiments, the electron source 100 further includes a conductive connection layer 130, which is at least disposed on the light-emitting end 1102 of the optical fiber 110 and is electrically connected to the electron excitation layer 121.

[0152] The conductive connection layer 130 may be a conductive thin film. Specifically, the conductive connection layer 130 may be a metal thin film, a graphite thin film, or a low-dimensional material thin film, etc.

[0153] It should be added that the conductive connection layer 130 is not disposed on the light-emitting path of the laser emitted from the core 111.

[0154] In this way, the electron excitation layer 121 can be electrically connected to the negative electrode of the power supply through the conductive connection layer 130. On the one hand, the power supply can be used to supply electrons to the electron excitation layer 121, which is beneficial for the electron excitation layer 121 to continuously emit electrons under the excitation of the laser. On the other hand, the direction and convergence of the electrons emitted from the electron excitation layer 121 can be regulated by the voltage applied to the conductive connection layer 130 by the power supply. For example, the direction of the electrons emitted from the electron excitation layer 121 can be regulated by the voltage applied to the anode target 200 and the conductive connection layer 130 by the power supply.

[0155] Optionally, the electron excitation layer 121 includes a first portion 1211 located on the light-emitting path of the laser emitted from the core 111, and a second portion 1212 connected to the periphery of the first portion 1211. The second portion 1212 is electrically connected to the conductive connection layer 130. Among them, the second portion 1212 can be directly in electrical contact with the conductive connection layer 130 to be electrically connected to the conductive connection layer 130; the second portion 1212 can also be electrically connected to the conductive connection layer 130 through other conductive structures.

[0156] Specifically, in the embodiment as Figure 3 shown, the first portion 1211 and the second portion 1212 are disposed on the end face 11021 of the light-emitting end 1102. The first portion 1211 covers the core 111 of the optical fiber 110, and the second portion 1212 is disposed around the first portion 1211 and is electrically connected to the conductive connection layer 130.

[0157] The first portion 1211 can directly cover the core 111 of the optical fiber 110, or the first portion 1211 can also indirectly cover the core 111 of the optical fiber 110, and no specific limitation is made here.

[0158] Specifically, in the embodiment as Figure 4 and Figure 5In the illustrated embodiment, the first part 1211 and the second part 1212 are disposed on the bottom wall surface h1 of the light leakage notch h. The projection of the first part 1211 on the bottom wall surface h1 covers the projection of the fiber core 111 on the bottom wall surface h1. The second part 1212 is located on the periphery of the first part 1211 and is electrically connected to the conductive connection layer 130.

[0159] Specifically, in the embodiment as shown in Figure 6 and Figure 7 In the illustrated embodiment, the electron excitation layer 121 includes a first part 1211 that completely covers the side wall k of the light guiding hole, and a second part 1212 disposed on the end face 11021 of the light output end 1102 of the fiber with holes. The first part 1211 is connected to the second part 1212, and the second part 1212 is electrically connected to the conductive connection layer 130.

[0160] Specifically, in the embodiment as shown in Figure 8 and Figure 9 In the illustrated embodiment, the electron excitation layer 121 includes a first part 1211 and a second part 1212 that are disposed on the end face 11021 of the light output end 1102 and are connected to each other. The first part 1211 covers one end of the light guiding hole located on the end face 11021 of the light output end 1102. The second part 1212 is disposed around the first part 1211 and is electrically connected to the conductive connection layer 130.

[0161] Specifically, in the embodiment as shown in Figure 10 and Figure 11 In the illustrated embodiment, the electron excitation layer 121 includes a first part 1211 and a second part 1212 that are connected. The projection of the first part 1211 in a target plane perpendicular to the extending direction of the fiber core 111 covers the projection of the fiber core 111 in the target plane. The projection of the second part 1212 in the target plane is located on the periphery of the projection of the first part 1211 in the target plane, and the second part 1212 overlaps with the conductive connection layer 130.

[0162] In this way, by electrically connecting the conductive connection layer 130 to the second part 1212 of the electron excitation layer 121, and combining the fact that the second part 1212 is located on the periphery of the first part 1211, the conductive connection layer 130 can supply electrons to the electron excitation layer 121 without affecting the interaction between the fiber core 111 and the electron excitation layer 121, which is beneficial for the electron excitation layer 121 to continuously emit electrons outward under the excitation of laser light.

[0163] Optionally, the conductive connection layer 130 includes a first conductive part 131 disposed on the light output end 1102 and a second conductive part 132 disposed on the outer peripheral surface of the optical fiber 110. The first conductive part 131 is connected to the second conductive part 132, and the first conductive part 131 overlaps with the second part 1212 of the electron excitation layer 121.

[0164] Specifically, in Figure 3 , Figure 6 - Figure 9 the embodiment shown, the first conductive portion 131 is disposed on the end face 11021 of the light-emitting end 1102 and overlaps with the second portion 1212 of the electron excitation layer 121. Specifically, in Figure 4 and Figure 5 the embodiment shown, the first conductive portion 131 is disposed on the bottom wall surface h1 of the light leakage notch h and overlaps with the second portion 1212 of the electron excitation layer 121. The first conductive portion 131 also extends to the light-emitting end 1102. Specifically, in Figure 10 and Figure 11 the embodiment shown, the first conductive portion 131 is disposed on the tip portion j on the light-emitting end 1102 and overlaps with the second portion 1212 of the electron excitation layer 121.

[0165] In this way, the conductive connection layer 130 can cover more of the optical fiber 110, improving the bonding strength between the conductive connection layer 130 and the optical fiber, and also facilitating better utilization of the conductive connection layer 130 to supply electrons to the electron excitation layer 121.

[0166] Optionally, the conductive connection layer 130 includes a first metal layer and a second metal layer stacked thereon. The adhesion of the first metal layer is greater than that of the second metal layer, and the corrosion resistance of the first metal layer is less than that of the second metal layer.

[0167] Exemplarily, the material of the first metal layer is titanium, and the material of the second metal layer is gold.

[0168] In this way, the first metal layer with higher adhesion can make the conductive connection layer 130 better adhere to the optical fiber 110, and the second metal layer with better corrosion resistance is used to protect the first metal layer, improving the bonding strength between the conductive connection layer 130 and the optical fiber 110, and also facilitating the improvement of the service life of the conductive connection layer 130.

[0169] In some embodiments, the electron emission layer 120 further includes an auxiliary layer 122. The auxiliary layer 122 is stacked on one side of the electron excitation layer 121 close to the optical fiber 110, or the auxiliary layer 122 is stacked on one side of the electron excitation layer 121 away from the optical fiber 110.

[0170] It can be that the auxiliary layer 122 is stacked on one side of the electron excitation layer 121 close to the end face 11021 of the light-emitting end 1102 of the optical fiber 110, or it can be that the auxiliary layer 122 is stacked on one side of the electron excitation layer 121 away from the end face 11021 of the light-emitting end 1102 of the optical fiber 110.

[0171] Of course, it can also be that the auxiliary layer 122 is stacked on one side of the electron excitation layer 121 close to or away from the bottom wall surface h1 of the light leakage notch h.

[0172] Of course, it is also possible that the auxiliary layer 122 is stacked on one side of the surface j1 of the electronic excitation layer 121 close to or away from the tip j of the optical fiber 110.

[0173] Figure 8 、 Figure 9 and Figure 12 An example is given where the auxiliary layer 122 is stacked on one side of the end face 11021 of the electronic excitation layer 121 close to the light output end 1102.

[0174] In this application, the auxiliary layer 122 is added. When the electronic excitation layer 121 requires structural support, the auxiliary layer 122 is used to provide structural support for the electronic excitation layer 121, that is, the electronic excitation layer 121 is disposed on the auxiliary layer 122; or, when the electronic excitation layer 121 cannot be directly connected and conducted to the conductive connection layer 130, the conductive auxiliary layer 122 is used to connect to the conductive connection layer 130, and the auxiliary layer 122 is used to achieve electrical conduction between the electronic excitation layer 121 and the conductive connection layer 130.

[0175] Optionally, the auxiliary layer 122 includes at least one of a conductive support layer and a heat dissipation support layer.

[0176] Optionally, the thickness of the auxiliary layer 122 is 0.1 nm to 100 nm.

[0177] Optionally, the light transmittance of the auxiliary layer 122 is 10% or more, such as 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100%.

[0178] Optionally, the auxiliary layer 122 includes a conductive support layer, and the conductive support layer is electrically connected to the conductive connection layer 130.

[0179] In some embodiments, the auxiliary layer 122 includes a conductive support layer, the material of the conductive support layer includes a conductive metal, the laser wavelength in the optical fiber 110 is 200 nm to 10 μm, the pulse power is 1 nw to 1 w, and the repetition frequency is 0 Hz to 10 GHz.

[0180] In this application, the auxiliary layer 122 uses a conductive metal and controls the laser parameters, thereby avoiding the problem of melting caused by laser irradiation of the conductive metal and ensuring that the auxiliary layer has the functions of support and conduction.

[0181] The auxiliary layer 122 may also include a conductive support layer, such as Figure 8 and Figure 9As shown, the electron excitation layer 121 is disposed on the end face 11021 of the light output end 1102 through the auxiliary layer 122, and the auxiliary layer 122 has a bearing plane for bearing the electron excitation layer 121. The auxiliary layer 122 can be made of a light-transmitting material; the auxiliary layer 122 can also be made of a non-light-transmitting material, and the auxiliary layer 122 has an annular structure, and the orthographic projection of the auxiliary layer 122 on the end face 11021 of the light output end 1102 is located outside the core 111 of the optical fiber 110.

[0182] In this way, on the one hand, the bearing plane of the auxiliary layer 122 can be utilized to make the electron excitation layer 121 more flatly disposed on the end face 11021 of the light output end 1102, and on the other hand, the interaction between the electron excitation layer 121 and the core 111 of the optical fiber 110 will not be affected, which is beneficial to the formation of an electron beam with concentrated energy and small energy dispersion from the electrons tunneling and emitting within the electron excitation layer 121.

[0183] The auxiliary layer 122 may also include a heat dissipation support layer. Exemplarily, the material of the auxiliary layer 122 may be hexagonal boron nitride. Of course, the material of the auxiliary layer 122 may also be selected from other materials that can dissipate heat from the electron excitation layer 121 and enable the electron excitation layer 121 to be flatly disposed on the end face 11021 of the light output end 1102. In this way, the heat dissipation efficiency of the electron excitation layer 121 can be increased by using the auxiliary layer 122, so that the electron excitation layer 121 can emit a larger electron beam current.

[0184] The electron source 100 of the present application can be prepared through the following steps:

[0185] S210. Provide the optical fiber 110. Among them, the optical fiber 110 includes a core 111 for transmitting laser light and a cladding layer 112 wrapped around the core 111.

[0186] Optionally, an appropriate length of the optical fiber 110 can be intercepted, the end coating layer of the optical fiber 110 can be removed, and one end of the cut optical fiber 110 can be processed to form the light output end 1102. Specifically, a cutting mechanism can be used to cut one end of the cut optical fiber 110 to form the light output end 1102. By using the cutting method to form the light output end 1102, the cross section where the end face 11021 of the light output end 1102 is located can be relatively flat, which is beneficial to forming a flat electron excitation layer 121 on the end face 11021 of the light output end 1102.

[0187] S220. Form an electron excitation layer 121 on the end face 11021 of the light output end 1102 of the optical fiber 110, and the electron excitation layer 121 covers the core 111 of the optical fiber 110 so that the electron excitation layer 121 is located on the light output path of the laser light emitted from the core 111.

[0188] The electron excitation layer 121 can be formed by at least one of dry transfer, wet transfer, and direct growth.

[0189] In some embodiments, the electron excitation layer 121 is prepared by a dry transfer method. The preparation method includes: transferring zero-dimensional materials, one-dimensional materials, and / or two-dimensional materials onto a tape by mechanical exfoliation, and transferring the zero-dimensional materials, one-dimensional materials, and / or two-dimensional materials onto the end face 11021 of the light-emitting end 1102 of the optical fiber 110.

[0190] Taking two-dimensional materials as an example for illustration, the preparation process of forming the electron excitation layer 121 by the dry transfer method is as follows:

[0191] (1) The two-dimensional material can be thinned by mechanical exfoliation until the electron excitation layer 121 with a preset thickness is formed. Specifically, the two-dimensional material is adhered to a highly sticky tape A, and a highly sticky tape B can be used to mechanically exfoliate along the crystal cleavage plane of the two-dimensional material repeatedly until the electron excitation layer 121 with a preset thickness is formed.

[0192] (2) Transfer the electron excitation layer 121 with a preset thickness onto the temporary substrate 20 and remove the tape B on the electron excitation layer 121. Specifically, the tape B can be made easier to peel by heating and then peeled off from the electron excitation layer 121. Or without heating, the tape B can be directly peeled off from the electron excitation layer 121.

[0193] (3) Transfer the electron excitation layer 121 on the temporary substrate 20 onto the end face 11021 of the light-emitting end 1102 of the optical fiber 110.

[0194] Optionally, the electron excitation layer 121 is selected as a two-dimensional material, and the material of the temporary substrate 20 can be selected as a polycarbonate propylene film.

[0195] Of course, the present application is not limited to this. The dry transfer method can also be combined with a direct growth method (such as chemical vapor deposition). For example, an electron excitation layer 121 with a preset thickness is grown on a substrate to be peeled off, and then the electron excitation layer 121 is transferred from the substrate to be peeled off to the temporary substrate 20 by acid etching to remove the substrate to be peeled off or by hand tearing, and then the electron excitation layer 121 on the temporary substrate 20 is transferred onto the end face 11021 of the light-emitting end 1102 of the optical fiber 110. Among them, the substrate to be peeled off can be a metal or other materials that can be acid-etched or torn by hand.

[0196] In some other embodiments, the electron excitation layer 121 is prepared by a wet transfer method. The preparation method includes: directly preparing zero-dimensional materials, one-dimensional materials, or two-dimensional materials in a solution and floating them on the liquid surface, making the end face 11021 of the light-emitting end 1102 of the optical fiber 110 contact the zero-dimensional materials, one-dimensional materials, or two-dimensional materials on the liquid surface, and drying the zero-dimensional materials, one-dimensional materials, and / or two-dimensional materials on the end face 11021 of the light-emitting end 1102 of the optical fiber 110.

[0197] In some other embodiments, the electron excitation layer 121 is prepared by direct growth, and the preparation method includes: preparing the electron excitation layer 121 on the end face 11021 of the light output end 1102 of the optical fiber 110 by at least one of chemical vapor deposition, physical vapor deposition, molecular beam epitaxy, and liquid filling directly.

[0198] Optionally, before or after forming the electron excitation layer 121 on the end face 11021 of the light output end 1102 of the optical fiber 110, the preparation method of the electron source 100 further includes:

[0199] S230. Forming a conductive connection layer 130 on the end face 11021 of the light output end 1102 of the optical fiber 110, so that the conductive connection layer 130 overlaps with the electron excitation layer 121.

[0200] That is to say, the conductive connection layer 130 can be formed first, and then the electron excitation layer 121 is formed; or the electron excitation layer 121 can be formed first, and then the conductive connection layer 130 is formed; as long as the electron excitation layer 121 and the conductive connection layer 130 are electrically connected to each other, in this way, electrons can be supplied to the electron excitation layer 121 by means of the conductive connection layer 130, which is beneficial to the continuous emission of electrons from the electron excitation layer 121 under the excitation of laser.

[0201] Optionally, forming a conductive connection layer 130 on the end face 11021 of the light output end 1102 of the optical fiber 110, so that the conductive connection layer 130 overlaps with the electron excitation layer 121 specifically includes:

[0202] S231. Forming a core protection layer on the end face 11021 of the light output end 1102 of the optical fiber 110, and the core protection layer covers the core 111 of the optical fiber 110.

[0203] It can be that the core protection layer directly covers the core 111 of the optical fiber 110, or it can be that the core protection layer indirectly covers the core 111 of the optical fiber 110, and no specific limitation is made here.

[0204] Optionally, the polymer microsphere solution can be coated on the end face 11021 of the light output end 1102 of the optical fiber 110 to form a core protection layer covering the core 111. Exemplarily, the polymer microsphere solution is a polymethyl methacrylate suspension.

[0205] S232. Forming a conductive material layer covering the core protection layer on the optical fiber 110.

[0206] The conductive material layer can be formed by evaporation. Specifically, a metal evaporation device can be used to form the conductive material layer on the optical fiber 110.

[0207] S233. Remove the core protection layer and the part of the conductive material layer disposed on the core protection layer to form the conductive connection layer 130.

[0208] Optionally, a solvent capable of dissolving the core protection layer and having no interaction with the conductive material layer can be used to remove the core protection layer. Specifically, the light-emitting end 1102 of the optical fiber 110 can be immersed in acetone, so that the core protection layer (polymer beads) is dissolved, and the part of the conductive material layer disposed on the core protection layer (part of the metal coating) is peeled off to obtain the conductive connection layer 130.

[0209] It can be understood that the core protection layer can be used to make the orthographic projection of the conductive connection layer 130 on the end face 11021 of the light-emitting end 1102 not coincide with the orthographic projection of the core 111 of the optical fiber 110 on the end face 11021 of the light-emitting end 1102, so that the laser transmitted in the core 111 of the optical fiber 110 can better interact with the electron excitation layer 121 covering the core 111 of the optical fiber 110.

[0210] In some embodiments, please refer to Figure 13 , the step S220 of forming the electron excitation layer 121 on the end face 11021 of the light-emitting end 1102 of the optical fiber 110 specifically includes the following steps. Specifically, the specific steps of transferring the electron excitation layer 121 on the temporary substrate 20 to the end face 11021 of the light-emitting end 1102 of the optical fiber 110 are as follows:

[0211] S221. Dispose the electron excitation layer 121 and the end face 11021 of the light-emitting end 1102 of the optical fiber 110 opposite to each other in the first direction and parallel to each other.

[0212] Specifically, observe the end face 11021 of the light-emitting end 1102 of the optical fiber 110 and the electron excitation layer 121 under a microscope, and dispose the electron excitation layer 121 and the end face 11021 of the light-emitting end 1102 of the optical fiber 110 opposite to each other in the first direction and parallel to each other, and make the center connection line of the two extend in the first direction.

[0213] S222. Drive the optical fiber 110 to move in the first direction to contact the electron excitation layer 121.

[0214] S223. Make the electron excitation layer 121 adhere to the end face 11021 of the light-emitting end 1102 of the optical fiber 110 at a preset temperature.

[0215] In this way, a microscope can be used to align the center of the electron excitation layer 121 with the center of the end face 11021 of the light output end 1102 of the optical fiber 110, and the two are placed in contact with each other at a certain temperature, so that the electron excitation layer 121 and the end face 11021 of the light output end 1102 of the optical fiber 110 can be closely attached under the action of van der Waals force, improving the bonding strength of the electron excitation layer 121 on the optical fiber 110, and also facilitating the electron excitation layer 121 to completely cover the fiber core 111 of the optical fiber 110, enabling the laser transmitted by the fiber core 111 to better interact with the electron excitation layer 121.

[0216] In some specific embodiments, the step S220 of forming the electron excitation layer 121 on the end face 11021 of the light output end 1102 of the optical fiber 110 specifically includes the following steps. Specifically, the specific steps of transferring the electron excitation layer 121 on the temporary substrate 20 to the end face 11021 of the light output end 1102 of the optical fiber 110 are as follows:

[0217] S2201. Stick an annular heating sheet 40 on the back of the perforated glass slide 30 of the microscope, fix the temporary substrate 20 with the electron excitation layer 121 on the bottom side of the annular heating sheet 40 (the temporary substrate 20 can be fixed on the bottom side of the annular heating sheet 40 by an adhesive fixing method), and make the electron excitation layer 121 on the temporary substrate 20 face downward, and fix the optical fiber 110 below the electron excitation layer 121, so that the central axes of the objective lens of the microscope, the perforated glass slide 30, the annular heating sheet 40, the center of the electron excitation layer 121 and the center of the fiber core 111 coincide, and the objective lens of the microscope, the perforated glass slide 30, the annular heating sheet 40, the electron excitation layer 121 and the optical fiber 110 are arranged in sequence from top to bottom.

[0218] Optionally, a fixture can be used to fix the optical fiber 110 on the moving platform, and make the end face 11021 of the light output end 1102 of the optical fiber 110 face upward. The moving platform is used to adjust the position of the optical fiber 110 in the first direction and to adjust the angle of the end face 11021 of the light output end 1102 of the optical fiber 110 relative to the horizontal plane to make it horizontal.

[0219] Optionally, the fixture can be a pneumatic gripper or an electric gripper.

[0220] Optionally, the moving platform can be a six-degree-of-freedom platform. The moving platform can also include a linear drive mechanism and a rotary drive mechanism connected to the linear drive mechanism. The output end of the rotary drive mechanism is connected to the fixture to drive the fixture and the optical fiber 110 clamped by the fixture to rotate around an axis parallel to the horizontal plane, so that the end face 11021 of the light output end 1102 is horizontal. The linear drive mechanism is used to drive the rotary drive mechanism, the fixture and the optical fiber 110 to move in the first direction.

[0221] Among them, the linear drive mechanism can be a motor or a cylinder, and the rotary drive mechanism can be a motor or a rotary cylinder.

[0222] S2202. Observe the end face 11021 of the light-emitting end 1102 of the optical fiber 110 and the electron excitation layer 121 under a microscope, and arrange the electron excitation layer 121 and the end face 11021 of the light-emitting end 1102 of the optical fiber 110 to be opposite to each other and parallel to each other in the first direction, and make the center connection line of the two extend in the first direction.

[0223] The center alignment of the end face 11021 of the light-emitting end 1102 and the electron excitation layer 121 can be completed with the aid of a microscope.

[0224] S2203. Connect the annular heating sheet 40 to an external power supply to apply a first preset voltage to the annular heating sheet 40, and preheat the electron excitation layer 121 on the temporary substrate 20 (heat it to the preheating temperature), which is beneficial to making the electron excitation layer 121 more flat.

[0225] Optionally, the first preset voltage is 1V - 1.5V, and the preheating temperature is 50 - 60°C.

[0226] S2204. Drive the optical fiber 110 to move in the first direction to contact the electron excitation layer 121. Newton's rings may appear when the end face 11021 of the light-emitting end 1102 contacts the electron excitation layer 121.

[0227] S2205. Make the electron excitation layer 121 closely adhere to the end face 11021 of the light-emitting end 1102 of the optical fiber 110 at a preset temperature, specifically including: applying a second preset voltage to the annular heating sheet 40 and heating the electron excitation layer 121 on the temporary substrate 20 to the preset temperature, which is beneficial to making the electron excitation layer 121 more closely arranged on the end face 11021 of the light-emitting end 1102.

[0228] Optionally, the second preset voltage is 2.5V - 4V, and the preset temperature is 90 - 100°C.

[0229] S2206. Remove the temporary substrate 20. The temporary substrate 20 can be removed by a method combining melting heating and solvent immersion. Specifically, apply a third preset voltage to the annular heating sheet 40 and heat the temporary substrate 20 to the melting temperature to melt it. It should be noted that the melting point of the electron excitation layer 121 is much higher than that of the temporary substrate 20.

[0230] Optionally, the third preset voltage is 5.5V - 6V, and the melting temperature is 130 - 150°C.

[0231] After the electron excitation layer 121 is closely disposed on the end face 11021 of the light output end 1102, the portion of the temporary substrate 20 in contact with the annular heating sheet 40 can be melted by means of melting and heating, and the electron excitation layer 121 can be detached from the annular heating sheet 40 and closely adhered to the end face 11021 of the light output end 1102 of the optical fiber 110, which is convenient for subsequent removal of the temporary substrate 20 remaining on the electron excitation layer 121. The portion of the temporary substrate 20 not in contact with the annular heating sheet 40 remains on the electron excitation layer 121. The optical fiber 110 can be removed from the fixture and the light output end 1102 of the optical fiber 110 can be immersed in acetone to dissolve the temporary substrate 20 remaining on the electron excitation layer 121 and completely remove the temporary substrate 20.

[0232] After the electron source 100 is prepared, the electron exposure machine 10 can be prepared by setting up structures such as the outer shell and the control system. The vacuum chamber 310 inside the outer shell 300 is connected to an external vacuum system to keep the vacuum chamber 310 inside the outer shell 300 in a vacuum state. Along the axis of the vacuum chamber 310 of the outer shell 300 from top to bottom, the electron source 100, the focusing magnetic lens 610 and the deflection coil 620 are sequentially arranged in the vacuum chamber 310, and then the sample stage 400 is correspondingly arranged so that the electron beam emitted by the electron source 100 can be projected onto the position of the sample stage 400, facilitating the exposure of the sample 410 on the sample stage 400. The sample stage 400 can be arranged on an electronically controlled displacement stage to facilitate driving the sample stage 400 to move through the electronically controlled displacement stage, thereby facilitating the picking and placing of the sample 410. After the hardware assembly is completed, the electron source 100, the focusing magnetic lens 610, the deflection coil 620 and the Faraday cup can be respectively connected to the control system to facilitate the control system to control them.

[0233] The control system can realize the connection between the above components through software such as Labview, input the patterned data to be exposed into the control system, and the control system converts the received patterned data into an exposure unit, and automatically calculates the scanning path of the electron beam and the switching light time of the electron source 100 according to the beam current intensity of the electron beam during exposure, the vacuum state of the vacuum chamber 310 inside the outer shell 300, and the focusing effect of the electron beam, forming two sets of commands for focusing deflection and electro-optical modulation, that is, controlling the focusing magnetic lens 610 and the deflection coil 620 to adjust the focusing and deflection states of the electron beam, and controlling the light modulation component 500 to control the passing situation of the laser in the optical fiber 110, so as to obtain a better exposure effect. The above two sets of commands for focusing deflection and electro-optical modulation can also be calibrated to make them highly consistent in time to avoid mismatch of the control system during the exposure operation.

[0234] The embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. For the experimental methods without specific conditions in the following examples, the guidance given in the present invention is preferably referred to, and it can also be carried out according to the experimental manuals or conventional conditions in the art, or according to the conditions recommended by the manufacturer, or by referring to the experimental methods known in the art.

[0235] Example 1

[0236] The optical fiber 110 is a single-mode optical fiber. The diameter of the core 111 of the optical fiber 110 is 8.2 μm, the diameter of the optical fiber 110 is 125 μm, the angle ɑ is selected as 30 degrees, that is, the bevel angle of the optical fiber 110 forms a 30-degree angle with the axis of the optical fiber 110, and the wavelength of the laser transmitted in the optical fiber 110 is 1550 nm. The conductive connection layer 130 includes 5 nm of titanium and 60 nm of gold laminated on the optical fiber 110. Among them, the core 111 at the end face 11021 of the light-emitting end 1102 is exposed (without being covered by the conductive connection layer 130). The electron excitation layer 121 is made of graphene two-dimensional material (the thickness of the graphene two-dimensional material is 1 nm). The shape of the graphene two-dimensional material is not limited and can be polygonal, circular, elliptical, etc. The electron excitation layer 121 is disposed on the end face 11021 of the light-emitting end 1102 of the optical fiber 110 and completely covers the core 111 of the optical fiber 110. For example, in the radial direction of the optical fiber 110, the size of the electron excitation layer 121 is 30-60 μm (much larger than the diameter of the core 111. In this embodiment, in the radial direction of the optical fiber 110, the size of the electron excitation layer 121 is 50 μm).

[0237] Example 2

[0238] The optical fiber 110 is a single-mode optical fiber. The diameter of the core 111 of the optical fiber 110 is 8.2 μm, the diameter of the optical fiber 110 is 125 μm, and the wavelength of the laser transmitted in the optical fiber 110 is 1550 nm. The conductive connection layer 130 includes 5 nm of titanium and 60 nm of gold laminated on the optical fiber 110. Among them, the core 111 at the light-emitting end 1102 is exposed (without being covered by the conductive connection layer 130). The electron excitation layer 121 is made of graphene two-dimensional material (the graphene two-dimensional material is set to be a single layer or a few layers, and its thickness is 0.34 nm to 10 nm). The shape of the graphene two-dimensional material is not limited and can be polygonal, circular, elliptical, etc. The electron excitation layer 121 is disposed on the end face 11021 of the light-emitting end 1102 of the optical fiber 110 and completely covers the core 111 of the optical fiber 110. For example, in the radial direction of the optical fiber 110, the size of the electron excitation layer 121 is 30-60 μm (much larger than the diameter of the core 111. In this embodiment, in the radial direction of the optical fiber 110, the size of the electron excitation layer 121 is 40 μm).

[0239] Example 3

[0240] The optical fiber 110 is a single-mode optical fiber. The diameter of the core 111 of the optical fiber 110 is 8.2 μm, the diameter of the optical fiber 110 is 125 μm, and the wavelength of the laser transmitted in the optical fiber 110 is 1550 nm. The above-mentioned conductive connection layer 130 is formed on the outer surface of the optical fiber 110. The conductive connection layer 130 includes 5 nm of titanium and 50 nm of gold laminated on the light-emitting end 1102 of the optical fiber 110. Among them, the core 111 at the light-emitting end 1102 is exposed (without being covered by the conductive connection layer 130). An auxiliary layer 122 with a thickness of 1 nm and made of graphene is deposited on the end face 11021 of the light-emitting end 1102 of the optical fiber 110; then a plurality of nanotubes are deposited on the auxiliary layer 122, and the axial direction of the nanotubes is parallel to the extension direction of the core 111 to obtain an electron excitation layer 121, and then an electron source 100 is obtained. Among them, the first conductive part 131 of the conductive connection layer 130 is arranged on the end face 11021 of the light-emitting end 1102 of the optical fiber 110 and overlaps with the auxiliary layer 122, and the second conductive part 132 of the conductive connection layer 130 is arranged on the outer peripheral surface of the optical fiber 110.

[0241] Comparative Example 1

[0242] The electron source 100 is prepared according to the structure of Example 1, and the difference is only that the electron excitation layer 121 in Example 1 is replaced by a gold layer with a thickness of 100 nm, and the gold layer is prepared by deposition.

[0243] Comparative Example 2

[0244] The electron source 100 is prepared according to the structure of Comparative Example 1, and the difference is only that the electron excitation layer 121 in Comparative Example 1 is replaced by a gold layer with a thickness of 1 nm.

[0245] The electron source 100 is prepared by using the above-mentioned examples and comparative examples, and the performance of the prepared electron source 100 is tested. The test results are as follows in the table:

[0246] Table 1

[0247] Number Stability Lifespan Working vacuum degree Example 1 1％ 2000h 10 Pa Example 2 1％ 2000h 10 Pa Example 3 2％ 500 h <![CDATA[10 -3 Pa]]> Comparative Example 1 10％ 100 h <![CDATA[10 -5 Pa]]> Comparative Example 2 20％ 20 h <![CDATA[10 -5 Pa]]>

[0248] Among them, the stability refers to that when the excitation power of the electron source 100 is 50% or more of the damage power, the vacuum degree is 2×10 -5 Pa, and the continuous emission current is 1 hour. After removing the bad points, the ratio of the difference between the maximum current and the minimum current to the average current is the stability, and the stability can reflect the working stability of the electron source 100. The lifetime refers to that when the excitation power of the electron source 100 is 50% or more of the damage power, the vacuum degree is 2×10 -5Pa, Continuously emit current until the current decays to less than 10% of the initial value, which is defined as the lifetime. The operating vacuum degree refers to the continuous emission current when the excitation power of the electron source 100 is 50% or more of the damage power. The vacuum degree is gradually increased until a rapid decay of the current occurs (the rapid decay is defined as the current decaying by more than 50% within 1 minute). The vacuum degree at this time is defined as the operating vacuum degree. It can be seen from the above table that: the electron source 100 of the present application has good stability, a long lifetime, and a good operating vacuum degree.

[0249] In the present application, low-dimensional materials such as zero-dimensional materials, one-dimensional materials, and two-dimensional materials have atomic-scale sizes. Electrons incident from the back can be emitted into the vacuum without passing through in-body transmission, which is very suitable for an ultrafast electron source with a narrow pulse width; moreover, low-dimensional materials and different types of optical fibers can be directly integrated, bringing ultra-high stability and integratability; in addition, low-dimensional materials have no dangling bonds, are stable, have a high melting point, and are not easily damaged, making them suitable for a large-beam electron source with high-power excitation; when low-dimensional materials and a tip are integrated, a very sharp optical fiber tip can be obtained, which has a large optical field and electric field enhancement factor and provides a large emission beam current; there are many combinations of low-dimensional materials, which are suitable for optoelectronic sources with various properties. Finally, the optical fiber integrated with a low-dimensional material electron source and the low-dimensional material integration have significant advantages. The optical fiber can not only transmit laser light, but also, as a carrier of the low-dimensional material, provide a stable excitation source with adjustable wavelength, polarization, and optical mode, can be applied to different application scenarios, and does not require a complex optical path, having the characteristics of small size and high integration. When integrated with other devices, stable integration can be achieved without cracking and transforming the vacuum electron device.

[0250] The laser-excited electron-excitation layer 121 of the present application forms an electron-beam setting, eliminating the complex spatial light-coupling structure set due to the introduction of an external laser, making the electron exposure machine 10 less affected by the environment, having a stable-excited electron beam, and thus being able to improve the scanning stability of the sample 410 to be measured. In addition, the electron source 100 of the present application uses a low-dimensional material as the material for emitting electrons. Since the electron-excitation layer 121 has a strong light-material interaction and a rich electron bandgap, the laser can better interact with the electron-excitation layer 121 to excite the electrons in the electron-excitation layer 121, and the electrons tunneling and emitting from the electron-excitation layer 121 have the characteristics of small energy dispersion, high brightness, and high stability. Moreover, in the present application, an electron beam with a pulsed property can be formed by laser-exciting the electron-excitation layer 121, without the need to open an additional window on the electron microscope to provide a pulsed electron beam, without damaging the electron microscope cavity, and without setting an electron-beam shutter to modulate the electron beam, further saving space and facilitating the realization of a miniaturized design. And by modulating the laser through the electron-optical component 600, the electron beam excited by it can be modulated, thereby reducing the influence on the scanning quality when modulating the electron beam, and thus being able to stably expose the sample 410 to be measured.

[0251] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0252] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An electronic exposure machine for exposing a sample, characterized in that, The electron exposure machine includes: A light source for emitting laser light; An electron source including an optical fiber coupled to the light source and an electron emission layer. The electron emission layer at least includes an electron excitation layer, and the electron excitation layer is disposed on the light-emitting path of the laser emitted from the optical fiber, so that the electron excitation layer can emit an electron beam under the excitation of the laser. The electron excitation layer includes at least one of a zero-dimensional material, a one-dimensional material, and a two-dimensional material; and An electron optical component disposed on the electron beam emission side of the electron source. The electron optical component is used to adjust the focusing and deflection direction of the electron beam, so that the electron beam is incident on the sample to form a preset exposure pattern on the sample.

2. The electronic exposure machine according to claim 1, wherein The electron exposure machine further includes a housing; The housing has a vacuum chamber, and the light-emitting end of the optical fiber of the electron source and the electron optical component are spaced apart from each other and disposed in the vacuum chamber; The electron excitation layer is disposed on the light-emitting end of the optical fiber to be located on the light-emitting path of the laser emitted from the optical fiber.

3. The electronic exposure machine according to claim 2, wherein, An opening communicating with the vacuum chamber is provided on the housing, and the light-incident end of the optical fiber of the electron source is exposed through the opening and coupled to the light source; The outer peripheral wall of the optical fiber is hermetically connected to the inner side wall of the opening.

4. The electronic exposure machine according to claim 3, wherein The light-incident end of the optical fiber of the electron source extends outside the vacuum chamber through the opening to be coupled to the light source; or The end face of the light-incident end of the optical fiber of the electron source is flush with the plane where the opening is located.

5. The electronic exposure machine according to claim 1, characterized in that, The electron source further includes an optical modulation member connected between the light source and the optical fiber for controlling whether the laser propagates to the optical fiber.

6. The electronic exposure machine according to claim 5, characterized in that, The electron optical component includes a focusing magnetic lens and a deflection coil, and the focusing magnetic lens and the deflection coil are disposed at intervals along the emission direction of the electron beam on the electron beam emission side of the electron source.

7. The electronic exposure machine according to claim 5, characterized in that The optical modulation member includes an electro-optic modulator or an optical switch.

8. The electronic exposure machine according to any one of claims 1-6, characterized in that, The optical fiber includes a core for transmitting laser light and a cladding layer wrapped around the core. The end face of the light-emitting end of the optical fiber is disposed at an angle to the extending direction of the core; The electron emission layer is disposed on the end face of the light-emitting end of the optical fiber, and the electron excitation layer covers the core of the optical fiber. The laser emitted from the core can directly irradiate the electron emission layer, so that the electron excitation layer is excited by the laser emitted from the core and emits electrons.

9. The electronic exposure machine according to any one of claims 1-6, characterized in that, The optical fiber includes a core for transmitting laser light and a cladding layer wrapped around the core; A light leakage notch is formed in the light-emitting end of the optical fiber along the radial direction of the optical fiber; The electron excitation layer is disposed on the bottom wall surface of the light leakage notch. The bottom wall surface of the light leakage notch is configured as a plane, and the projection of the electron excitation layer on the bottom wall surface covers the projection of the core on the bottom wall surface; The electron excitation layer further extends to the light-emitting end of the optical fiber.

10. The electronic exposure machine according to any one of claims 1-6, characterized in that, The optical fiber is configured as a perforated optical fiber, and the perforated optical fiber has a light guiding hole; The electron excitation layer is at least disposed on the side wall of the light guiding hole and extends to the light-emitting end of the optical fiber along the longitudinal extension direction of the light guiding hole.

11. The electronic exposure machine according to any one of claims 1-6, characterized in that, The optical fiber is configured as a perforated optical fiber, and the perforated optical fiber has a light guiding hole; The electron emission layer is disposed on the end face of the light output end of the holey optical fiber, and the electron excitation layer covers one end of the light guiding hole located on the end face of the light output end; The laser emitted from the holey optical fiber can directly irradiate on the electron emission layer, so that the electron excitation layer is excited by the laser emitted from the holey optical fiber and emits electrons.

12. The electronic exposure machine according to any one of claims 1-6, characterized in that, The light output end of the optical fiber is provided with a pointed end portion; The electron excitation layer covers the surface of the pointed end portion of the optical fiber; The optical fiber includes a core for transmitting laser, and the laser emitted from the optical fiber can directly irradiate on the electron emission layer, so that the electron excitation layer is excited by the laser emitted from the core and emits electrons.

13. The electronic exposure machine according to any one of claims 8-12, characterized in that, The electron source further includes a conductive connection layer, which is disposed on the optical fiber and electrically connected to the electron excitation layer.

14. The electronic exposure machine according to any one of claims 8-12, characterized in that, The electron source further includes an anode, the anode has a first electron channel, and the electron optical component has a second electron channel communicating with the first electron channel; A preset electric field exists between the anode and the electron excitation layer, and the electron beam can pass through the first electron channel and the second electron channel under the drive of the preset electric field and be incident on the sample.

15. The electronic exposure machine according to claim 1, characterized in that, The thickness of the electron excitation layer is less than or equal to 50 nm.

16. The electronic exposure machine according to claim 1, wherein, The included angle between the axial direction of the one-dimensional material in the electron excitation layer and the laser emission direction is 0 to 90°; 17. The electronic exposure machine according to claim 1, characterized in that, The electron excitation layer includes at least two two-dimensional materials stacked in sequence along the laser emission direction; or The electron excitation layer includes at least two two-dimensional materials with different materials connected to each other on the same plane.

18. The electronic exposure machine according to claim 1, wherein, The electron excitation layer includes zero-dimensional materials and zero-dimensional materials arranged at the end and / or side of the one-dimensional material.

19. The electronic exposure machine according to claim 1, characterized in that, The electron excitation layer includes zero-dimensional materials and two-dimensional materials, and the zero-dimensional materials are arranged on the surface of the two-dimensional materials.

20. The electronic exposure machine according to claim 1, characterized in that The electron excitation layer includes one-dimensional materials and two-dimensional materials, and the one-dimensional materials are arranged on the surface of the two-dimensional materials.

Images