A 3D micro-nanostructure direct writing system based on spatial potential confinement

Abstract

The present invention relates to the field of micro-nanotechnology, and in particular to a 3D micro-nanostructure direct writing system based on spatial potential confinement, comprising: a model construction module, which constructs a 3D structure model based on the morphology and characteristics of the micro-nanostructure to be constructed, and generates a digital control signal and the dwell time and scanning rate of the electron beam during the direct writing process; a digital-to-analog conversion module, which performs digital-to-analog conversion and amplifies the digital control signal to obtain an analog control signal; a workbench module, which is used to carry the material to be written and adjust the angle of the material to be written; an electron beam module, which is used to emit an electron beam and focus it on the top of the material to be written, and control the focus of the electron beam to scan along a set path, directly writing the material to be written to obtain the micro-nanostructure to be constructed; and a beam gate module, which is opened and closed to control whether the electron beam is focused on the top of the material to be written. The present invention can flexibly, conveniently and at low cost realize the direct writing construction of micro-nanostructures and nanodevices, and has wide material universality.

Description

Technical Field

[0001] The present invention relates to the fields of 3D micro-nano processing and additive manufacturing, and in particular to a 3D micro-nano structure direct writing system based on spatial potential confinement. Background Art

[0002] Metal and semiconductor 3D micro-nanostructures hold broad application prospects in fields such as integrated circuits, optical metamaterials, and micro-electromechanical systems. However, current 3D micro-nanofabrication equipment and 3D printing systems, due to limitations in their structural processing principles, suffer from unavoidable technical drawbacks such as low processing resolution, low fabrication efficiency, poor material compatibility, and a narrow range of applications. For example, scanning tunneling microscope atom manipulation equipment, while capable of transporting single atoms and constructing structures with atomic-level precision, suffers from low throughput and efficiency, and relies on an ultra-high vacuum environment.

[0003] Electron beam induced deposition is currently the only technology that can directly write 3D metal and semiconductor micro-nanostructures without a template. It mainly uses an additional precursor injection device to the electron microscope system, using the chemical activity of the electron beam to decompose the gaseous precursor, causing the deposition of non-volatile substances, thereby achieving the direct writing of 3D metal and semiconductor micro-nanostructures. The types of materials that can be deposited by this technology mainly rely on metal organic precursors, and the effective utilization rate of the precursors is low, most of which are dissipated during the construction process; the prepared structure is prone to contain organic impurity fragments such as carbon and chlorine. Although some impurity removal methods, such as electron beam irradiation, annealing, laser-assisted deposition, and plasma post-treatment, have made great progress in structural purification, the introduction of impurity removal methods has also complicated the structure construction process, invisibly increased the cost of structure construction, and reduced efficiency.

[0004] Currently, the market still lacks direct-writing equipment for metal and semiconductor 3D micro-nano structures that combines wide material applicability, high operational flexibility, and strong real-time performance. The main reason for this is the lack of innovative structural forming principles and the micro-processing equipment based on them. Summary of the Invention

[0005] In view of this, the present invention provides a 3D micro-nanostructure direct writing system based on spatial potential confinement, which can realize the direct writing construction of metal and semiconductor micro-nanostructures and nanodevices flexibly, conveniently and at low cost; the processing accuracy spans the micron and nanometer scales; the material universality is wide, and it is suitable for the direct writing construction of structures of most metal and semiconductor materials.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A 3D micro-nanostructure direct writing system based on spatial potential confinement, comprising:

[0008] A model building module, which builds a 3D structure model based on the morphology and characteristics of the micro-nanostructure to be constructed, and generates a digital control signal and the dwell time and scanning rate of the electron beam during the direct writing process of the micro-nanostructure to be constructed based on the characteristics of the 3D structure model;

[0009] A digital-to-analog conversion module performs digital-to-analog conversion and amplifies the digital control signal to obtain an analog control signal;

[0010] a workbench module, configured to carry a substrate and a material to be written, and to adjust the spatial position of the substrate according to the analog control signal, and to adjust the angle of the material to be written according to the analog control signal;

[0011] an electron beam module, configured to emit an electron beam according to the analog control signal and focus the electron beam on the material to be written, and control the focus of the electron beam to scan along a set path based on the dwell time and the scan rate, so as to directly write the material to be written, thereby obtaining the micro-nanostructure to be constructed;

[0012] The beam gate module is opened and closed based on the analog control signal to control whether the electron beam is focused on the material to be written.

[0013] Preferably, the workbench module, the electron beam module and the beam gate module are located in a vacuum environment.

[0014] Preferably, the digital-to-analog conversion module includes:

[0015] a digital-to-analog conversion unit, performing digital-to-analog conversion on the digital control signal to obtain an initial analog control signal;

[0016] The amplifier circuit amplifies the initial analog control signal to obtain the analog control signal.

[0017] Preferably, the workbench module has two-dimensional translational freedom, vertical freedom, rotational freedom and tilting freedom.

[0018] Preferably, the electron beam module comprises:

[0019] An electron beam unit provides the electron beam, the electron beam unit includes an electron gun for emitting the electron beam and a high-voltage device; the high-voltage device accelerates the electron beam;

[0020] an X deflection coil, configured to adjust an x-axis coordinate of a focus of the electron beam based on the analog control signal, the dwell time, and the scan rate;

[0021] a Y deflection coil, configured to adjust the y-axis coordinate of the focus of the electron beam based on the analog control signal, the dwell time, and the scan rate;

[0022] A Z focusing coil adjusts the z-axis coordinate of the focus of the electron beam based on the analog control signal, the dwell time and the scan rate.

[0023] Preferably, the system further comprises:

[0024] A secondary electron imaging module is used to perform morphological imaging of the micro-nano structure to be constructed before and after writing.

[0025] Preferably, the electron beam is focused above the material to be written, generating a low potential area on the surface of the material to be written at the point closest to the focus of the electron beam, and the charged atoms and atomic groups desorbed from the material to be written migrate and diffuse toward the low potential point under spatial potential confinement, and accumulate to form micro-protrusions;

[0026] A spatial potential confinement domain is formed between the focus of the electron beam and the material to be written. The spatial potential confinement domain is a funnel-shaped potential distribution between the low potential point on the surface of the material to be written and the focus of the electron beam; the funnel-shaped potential distribution constrains the migration and diffusion of charged atoms and atomic clusters.

[0027] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0028] The present invention relates to the field of 3D micro-nano processing and additive manufacturing, and in particular to a 3D micro-nano structure direct writing system based on spatial potential confinement, comprising: a model construction module, which constructs a 3D structure model based on the morphology and characteristics of the micro-nano structure to be constructed, and generates a digital control signal and the residence time and scanning rate of the electron beam during the direct writing process of the micro-nano structure to be constructed; a digital-to-analog conversion module, which performs digital-to-analog conversion and amplifies the digital control signal to obtain an analog control signal; a workbench module, which is used to carry a substrate and a material to be written, and adjust the angle of the material to be written; an electron beam module, which is used to emit an electron beam and focus it on the top of the material to be written, and control the focus of the electron beam to scan according to a set path according to the above-mentioned analog control signal, directly write the material to be written, and obtain the micro-nano structure to be constructed; a beam gate module, which is opened and closed to control whether the electron beam is focused on the top of the material to be written. The present invention can flexibly, conveniently and at low cost realize the direct writing construction of micro-nano structures and nano devices, and has wide material universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a structural diagram of the 3D micro-nanostructure direct writing system based on spatial potential confinement of the present invention;

[0031] Figure 2 It is a two-dimensional schematic diagram of the spatial potential confinement principle of the present invention;

[0032] Figure 3 This is a structural diagram of the electron beam module of the present invention.

[0033] Explanation of symbols: 1. Model building module; 2. Digital-to-analog conversion module; 3. Workbench module; 4. Electron beam module; 5. Beam gate module; 6. Secondary electron imaging module; 7. Material to be written; 41. Electron beam unit; 42. X deflection coil; 43. Y deflection coil; 44. Z focusing coil; 100. Micro-bump; 200. Focus; 300. Minimum point of positive potential; 400. Minimum point of negative potential; 500. Positive distribution curve; 600. Negative distribution curve. DETAILED DESCRIPTION

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

[0035] The purpose of the present invention is to provide a 3D micro-nanostructure direct writing system based on spatial potential confinement, which can realize the direct writing construction of metal and semiconductor micro-nanostructures and nanodevices flexibly, conveniently and at low cost; the processing accuracy spans the micron and nanometer scales; the material universality is wide, and it is suitable for the direct writing construction of structures of most metal and semiconductor materials.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Figure 1 This is a structural diagram of the 3D micro-nano structure direct writing system based on spatial potential confinement of the present invention. Figure 1 As shown, the present invention provides a 3D micro-nanostructure direct writing system based on spatial potential confinement, including: a model construction module 1, a digital-to-analog conversion module 2, a workbench module 3, an electron beam module 4, a beam gate module 5 and a secondary electron imaging module 6.

[0038] The workbench module 3 , the electron beam module 4 and the beam gate module 5 are located in a vacuum environment.

[0039] The model building module 1 constructs a 3D structural model based on the morphology and characteristics of the micro-nanostructure to be constructed, and based on the characteristics of the 3D structural model, generates digital control signals and the electron beam dwell time and scan rate during the direct writing process of the micro-nanostructure to be constructed. In this embodiment, the model building module 1 uses the FEBiD 3D Direct-Write CAD graphical operation application running on Matlab to construct the 3D structural model, generate the dwell time, the scan rate, and the digital control signals, which include a digital path coordinate sequence, a digital beam gate control signal, and a digital workbench control signal.

[0040] The digital-to-analog conversion module 2 performs digital-to-analog conversion and amplification on the digital control signal to obtain an analog control signal. The analog control signal includes an analog path coordinate sequence, an analog beam gate control signal, and an analog workbench control signal.

[0041] Preferably, the digital-to-analog conversion module 2 includes a digital-to-analog conversion unit and an amplifying circuit. The digital-to-analog conversion unit is connected to the model building module 1 via a 16-bit high-speed digital-to-analog converter AD768 chip.

[0042] The digital-to-analog conversion unit performs digital-to-analog conversion on the digital control signal to obtain an initial analog control signal.

[0043] The amplifying circuit is composed of a low-drift high-precision operational amplifier AD707, a broadband high-speed operational amplifier AD844, a power amplifier and a current-type power amplifier. The amplifying circuit amplifies the initial analog control signal to obtain the analog control signal.

[0044] The workbench module 3 has two-dimensional translational freedom, vertical freedom, rotational freedom and tilting freedom.

[0045] The workbench module 3 is used to support the substrate and the material to be written 7 and adjust the spatial position of the substrate according to the analog workbench control signal. The workbench module 3 adjusts the angle of the material to be written according to the analog control signal, and then adjusts the incident angle and azimuth angle of the electron beam relative to the surface of the material to be written 7. In this embodiment, the workbench module 3 uses the 5-axis motorized sample stage provided by the NovaNanoSEM 450 scanning electron microscope system to meet the requirements of growth point position selection and adjustment of the azimuth angle and incident angle of the electron beam.

[0046] The electron beam module 4 is used to emit an electron beam according to the analog control signal and focus it above the material to be written 7, and control the focus 200 of the electron beam to scan along a set path to directly write the material to be written 7 to obtain the micro-nano structure to be constructed.

[0047] Furthermore, if Figure 3 As shown, the electron beam module 4 includes an electron beam control unit, an electron beam unit 41, an X deflection coil 42, a Y deflection coil 43, and a Z focusing coil 44. The electron beam control unit controls the electron beam unit 41 to emit the electron beam. In this embodiment, the electron beam unit includes an electron gun for emitting the electron beam and a high-voltage device; the high-voltage device accelerates the electron beam, and the voltage range of the electron beam is 0.1 kV-30 kV. The electron beam module 4 uses the FEI NovaNanoSEM 450.

[0048] The simulation path coordinate sequence includes an x-axis coordinate sequence, a y-axis coordinate sequence, and a z-axis coordinate sequence. The set path is the simulation path coordinate sequence.

[0049] The electron beam control unit controls the X deflection coil 42 to adjust the x-axis coordinate of the focus 200 of the electron beam based on the x-axis coordinate sequence, the dwell time, and the scan rate; the electron beam control unit controls the Y deflection coil 43 to adjust the y-axis coordinate of the focus 200 of the electron beam based on the y-axis coordinate sequence, the dwell time, and the scan rate; and the electron beam control unit controls the Z focusing coil 44 to adjust the z-axis coordinate of the focus 200 of the electron beam based on the z-axis coordinate sequence, the dwell time, and the scan rate.

[0050] Specifically, the electron beam control unit changes the x-axis coordinate of the electron beam focus 200 by changing the current value input to the X deflection coil 42; the electron beam control unit changes the y-axis coordinate of the electron beam focus 200 by changing the current value input to the Y deflection coil 43; and the electron beam control unit changes the z-axis coordinate of the electron beam focus 200 by changing the current value input to the Z deflection coil.

[0051] The beam gate module 5 is opened and closed based on the analog beam gate control signal to control whether the electron beam is focused on the material to be written 7 .

[0052] The beam gate module 5 includes a beam gate control unit, a first metal electrode plate and a second metal electrode plate;

[0053] The first metal electrode plate and the second metal electrode plate are located on the same horizontal plane. The beam gate control unit controls the generation of a set voltage difference between the first metal electrode plate and the second metal electrode plate based on the analog beam gate control signal, thereby preventing the electron beam from passing through, and no writing will be performed on the material to be written 7 when the focus 200 position is changed.

[0054] The secondary electron imaging module 6 is used to perform site selection observation and morphology imaging on the micro-nano structure to be constructed before writing, and to perform observation and morphology imaging on the micro-nano structure to be constructed after writing.

[0055] First, based on the morphology and characteristics of the micro-nanostructure to be constructed, a 3D structural model is constructed, and the digital control signal and the residence time and scanning rate of the electron beam during the direct writing process of the micro-nanostructure to be constructed are obtained. The digital control signal is converted into analog and amplified to obtain the analog control signal. The electron beam unit 41 emits the electron beam, the beam gate module 5 is opened, and the electron beam is focused above the material to be written 7. A low potential area is generated on the surface of the material to be written 7 at the closest point to the focus 200 of the electron beam. The charged atoms and atomic groups desorbed from the material to be written 7 migrate and diffuse to the low potential point, and accumulate to form micro-protrusions 100, as shown in FIG. Figure 2 As shown, positively charged atoms and atomic groups migrate and diffuse toward the positive potential minimum point 300, and negatively charged atoms and atomic groups migrate and diffuse toward the negative potential minimum point 400. The negative potential minimum point 400 is the lowest point in electric potential for the negatively charged atoms and atomic groups in the space above the material to be written 7, and the positive potential minimum point 300 is the lowest point in electric potential for the positively charged atoms and atomic groups on the surface of the material to be written 7. The positive distribution curve 500 is a schematic curve for the electric potential distribution of the positively charged atoms and atomic groups on the surface of the material to be written 7, and the negative distribution curve 600 is a schematic curve for the electric potential distribution of the negatively charged atoms and atomic groups in the space above the material to be written 7.

[0056] A spatial potential confinement domain is formed between the focus 200 of the electron beam and the material to be written 7. The spatial potential confinement domain is a funnel-shaped potential distribution between the low potential point on the surface of the material to be written 7 and the focus 200 of the electron beam; the funnel-shaped potential distribution constrains the migration and diffusion of charged atoms and atomic clusters.

[0057] After completing the writing of a point, the beam gate module 5 is closed, the electron beam is blocked by the beam gate module 5, and cannot be focused above the material to be written 7, and will not be written to the material to be written 7. Scanning and direct writing are performed according to the set path to obtain the micro-nano structure to be constructed.

[0058] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0059] This document uses specific examples to illustrate the principles and implementations of the present invention. The above examples are only intended to help understand the system and core concepts of the present invention. At the same time, those skilled in the art will appreciate that variations in the specific implementations and scope of application are possible based on the concepts of the present invention. In summary, this specification should not be construed as limiting the present invention.

Claims

1. A 3D micro-nanostructure direct writing system based on spatial potential confinement, characterized in that: include: A model building module, which builds a 3D structure model based on the morphology and characteristics of the micro-nano structure to be constructed, and generates a digital control signal and the dwell time and scanning rate of the electron beam during the direct writing process of the micro-nano structure to be constructed based on the characteristics of the 3D structure model; A digital-to-analog conversion module performs digital-to-analog conversion and amplifies the digital control signal to obtain an analog control signal; a workbench module, for carrying a substrate and a material to be written, and adjusting the spatial position of the substrate according to the analog control signal, and adjusting the angle of the material to be written according to the analog control signal; an electron beam module, configured to emit an electron beam according to the analog control signal and focus the electron beam on the material to be written, and control the focus of the electron beam to scan along a set path based on the dwell time and the scan rate, so as to directly write the material to be written, thereby obtaining the micro-nanostructure to be constructed; The electron beam is focused above the material to be written, generating a low potential area on the surface of the material to be written at the point closest to the focus of the electron beam. Charged atoms and atomic clusters desorbed from the material to be written migrate and diffuse toward the low potential point under spatial potential confinement, and accumulate to form micro-protrusions. A spatial potential confinement region is formed between the focus of the electron beam and the material to be written, and the spatial potential confinement region is a funnel-shaped potential distribution between a low potential point on the surface of the material to be written and the focus of the electron beam; The funnel-shaped potential distribution constrains the migration and diffusion of charged atoms and atomic clusters; The beam gate module is opened and closed based on the analog control signal to control whether the electron beam is focused on the material to be written.

2. The 3D micro-nanostructure direct writing system according to claim 1, characterized in that: The workbench module, the electron beam module and the beam gate module are located in a vacuum environment.

3. The 3D micro-nanostructure direct writing system according to claim 1, characterized in that: The digital-to-analog conversion module includes: a digital-to-analog conversion unit, performing digital-to-analog conversion on the digital control signal to obtain an initial analog control signal; The amplifier circuit amplifies the initial analog control signal to obtain the analog control signal.

4. The 3D micro-nanostructure direct writing system according to claim 1, characterized in that: The workbench module has two-dimensional translational freedom, vertical freedom, rotational freedom and tilting freedom.

5. The 3D micro-nanostructure direct writing system according to claim 1, characterized in that: The electron beam module comprises: An electron beam unit, providing the electron beam, wherein the electron beam unit comprises an electron gun for emitting the electron beam and a high voltage system; an X deflection coil, configured to adjust an x-axis coordinate of a focus of the electron beam based on the analog control signal, the dwell time, and the scan rate; a Y deflection coil, configured to adjust the y-axis coordinate of the focus of the electron beam based on the analog control signal, the dwell time, and the scan rate; A Z focusing coil adjusts the z-axis coordinate of the focus of the electron beam based on the analog control signal, the dwell time and the scan rate.

6. The 3D micro-nanostructure direct writing system according to claim 1, characterized in that: The system further comprises: A secondary electron imaging module is used to perform morphological imaging of the micro-nano structure to be constructed before and after writing.

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