Electron beam mechanical force measurement system, electron beam mechanical force measurement method, and electron beam mechanical force simulation method

Abstract

The application provides an electron beam mechanical force measuring system, an electron beam mechanical force measuring method and an electron beam mechanical force simulation method. The electron beam mechanical force measuring system comprises a weak force measuring device, a fixing device and a cooling device. The weak force measuring device is used for receiving an electron beam to be measured and acquiring the mechanical force of the electron beam to be measured. One end of the fixing device is fixedly connected with the weak force measuring device, and the other end is fixedly connected with a cold table, and is used for fixing the weak force measuring device. One side of the cooling device is in contact with the fixing device, and is used for cooling the weak force measuring device. The weak force measuring device is used for capturing the mechanical force of the electron beam, and the cooling device is used for avoiding the melting of the weak force measuring device, so that the long-time stable and effective measurement of the mechanical force of the electron beam is realized.

Description

Technical Field

[0001] This application belongs to the field of micro-nano optoelectronics and relates to an electron beam mechanical force measurement technology, particularly to an electron beam mechanical force measurement system, an electron beam mechanical force measurement method, and an electron beam mechanical force simulation method. Background Technology

[0002] Electron beams, as high-energy particle beams, are used in electron beam etching, electron beam-induced deposition, SEM (Scanning Electron Microscopy) or ESEM (Environmental Scanning Electron Microscopy) to perform high-precision micro / nano structure fabrication or microstructure analysis of targets. Furthermore, analyzing the interaction process of the electron beam with the target after it is incident on it is beneficial for achieving even more precise micro / nano structure fabrication or microstructure analysis.

[0003] The mechanical impact generated by the electron beam incident on the target material can cause drift, wrinkling, and even affect the target's microstructure. Therefore, obtaining the mechanical force and its changes after the electron beam incident on the target material can help correct deviations in the spatial position and morphology caused by the mechanical force of the electron beam, which is beneficial for further improving the accuracy of micro / nano structure fabrication and microstructure analysis. However, due to the extremely small mass of electrons, the mechanical force generated by the electron beam incident on the target material is weak. Furthermore, the complex trajectory of electrons during the electron beam's movement makes the quantification of mechanical force extremely difficult. It is challenging to accurately obtain the mechanical force generated by the electron beam and capture its changes, thus making accurate analysis of the mechanical force of the electron beam impossible. Summary of the Invention

[0004] The purpose of this application is to provide an electron beam mechanical force measurement system, an electron beam mechanical force measurement method, and an electron beam mechanical force simulation method to solve the problem that the electron beam mechanical force cannot be obtained in the prior art, resulting in errors in the processing and application of electron beams.

[0005] In a first aspect, this application provides an electron beam mechanical force measurement system, which is set in a sealed chamber and is used to measure the mechanical force of the electron beam to be tested output by an electron beam emitting device. A weak force measuring device, a fixing device and a cooling device are arranged sequentially in the output direction of the electron beam to be tested.

[0006] The weak force measuring device is used to receive the electron beam under test and obtain the mechanical force of the electron beam under test; the weak force measuring device includes a three-dimensional micro-helical spring structure, an optical fiber, a laser source and a signal analysis unit; one side of the three-dimensional micro-helical spring structure is fixedly connected to the optical fiber, and the other side is provided with a receiving end plate facing the electron beam under test; the end of the optical fiber away from the three-dimensional micro-helical spring structure is connected to the laser source and the signal analysis unit respectively;

[0007] One end of the fixing device is fixedly connected to the weak force measuring device, and the other end is fixedly connected to the cold table, for fixing the weak force measuring device;

[0008] One side of the cooling device is in contact with the fixing device, and is used to cool down the weak force measuring device.

[0009] In one embodiment of this application, a thermally conductive film is provided on the side of the receiving end plate that receives the electron beam to be tested.

[0010] In one embodiment of this application, the thermally conductive film is a silver film.

[0011] In one embodiment of this application, the fixing device includes a metal bracket; one end of the metal bracket is in fixed contact with the three-dimensional micro-helical spring structure, and the other end is in contact with the cooling device.

[0012] In one embodiment of this application, the cooling device includes a water-cooling unit.

[0013] In one embodiment of this application, the cooling device includes a Peltier unit.

[0014] In one embodiment of this application, a gas input pipe is also included.

[0015] Secondly, this application provides a method for measuring the mechanical force of an electron beam, comprising:

[0016] The sealed chamber is pre-treated to bring the preset measurement conditions into place; and after pre-calibrating the electron beam emitting device and the weak force measuring device, the electron beam emitting device is turned off.

[0017] After a preset stabilization time, the electron beam emitting device is turned on again to emit corresponding electron beams based on preset electron beam energies, and the mechanical force corresponding to each electron beam is obtained and recorded by the weak force measuring device.

[0018] Based on the electron beam energy and the corresponding mechanical force, the electron beam mechanical force relationship is obtained.

[0019] In one embodiment of this application, the pretreatment of the sealing chamber to bring the sealing chamber to a preset measurement condition includes:

[0020] The sealed chamber is cooled to reach the preset measurement temperature range;

[0021] The sealed chamber is evacuated, and then low-pressure gas is introduced to achieve the preset working pressure range.

[0022] Thirdly, this application provides an electron beam mechanical force simulation method, including:

[0023] An electron beam with a preset electron beam energy and a surface to be struck are constructed, and the trajectory of each electron after the electron beam bombards the surface is obtained by the Monte Carlo method.

[0024] Based on the trajectories of each electron in the electron beam, the backscattering transmission characteristics of the electron beam are obtained; the backscattering transmission characteristics include the backscattering ratio and backscattering angle of the electron beam, as well as the transmission ratio and transmission angle ratio.

[0025] Based on the backscattering transmission conditions, a mechanical force scaling factor is obtained; and based on the electron beam energy, the emission mechanical force of the electron beam is obtained; based on the emission mechanical force and the mechanical force scaling factor, the mechanical force of the electron beam is obtained.

[0026] As described above, this application provides an electron beam mechanical force measurement system, an electron beam mechanical force measurement method, and an electron beam mechanical force simulation method. The system achieves accurate acquisition of electron beam mechanical force through a weak force measurement device. At the same time, in order to prevent the heat generated by the electron beam bombardment from melting the weak force measurement device, a cooling device is used to cool the weak force measurement device, thereby extending the service life of the electron beam mechanical force measurement system and achieving long-term stable electron beam mechanical force measurement. Attached Figure Description

[0027] Figure 1 The diagram shown is a structural schematic of an electron beam mechanical force measurement system according to an embodiment of this application.

[0028] Figure 2 The diagram shown is a structural schematic of another electron beam mechanical force measurement system described in an embodiment of this application.

[0029] Figure 3 The diagram shown illustrates the melting of a three-dimensional micro-helical spring structure as described in an embodiment of this application.

[0030] Figure 4 The diagram shown is a flowchart illustrating an electron beam mechanical force measurement method according to an embodiment of this application.

[0031] Figure 5 The diagram shown is a schematic representation of a preprocessing and precalibration process as described in an embodiment of this application.

[0032] Figure 6 The diagram shown illustrates the relationship between the mechanical force of an electron beam and the accelerating voltage of the electron beam, as described in an embodiment of this application.

[0033] Figure 7 The diagram shown is a flowchart illustrating an electron beam mechanical force simulation method according to an embodiment of this application.

[0034] Figure 8 The diagram shown is a simulation of an electron beam bombardment as described in an embodiment of this application.

[0035] Figure 9 This diagram illustrates the actual etching depth and the mechanical etching depth during an ice etching process as described in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures

[0037] 10: Sealed chamber; 20: Electron beam emitting device; 30: Weak force measuring device; 31: Three-dimensional micro-helical spring structure; 32: Optical fiber; 33: Laser source; 34: Signal analysis unit; 40: Fixing device; 50: Water cooling device; 51: Water cooling unit; 52: Peltier unit. Detailed Implementation

[0038] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0039] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0040] The mechanical force exerted by an electron beam on a target material has a significant impact on the accuracy of micro / nano structure fabrication or microstructure analysis. However, the mechanical force of an electron beam is difficult to accurately obtain, and there is currently no effective method for capturing this force.

[0041] To address the technical problems existing in the prior art, the following embodiments of this application provide an electron beam mechanical force measurement system, an electron beam mechanical force measurement method, and an electron beam mechanical force simulation method. By using a weak force measurement device, the electron beam mechanical force is accurately captured, and a cooling device is used to cool the weak force measurement device to prevent it from generating excessive heat and melting due to the electron beam striking it. This allows for stable recording of the electron beam's mechanical force over a long period, achieving stable, effective, and accurate acquisition of the electron beam mechanical force.

[0042] The following embodiments of this application provide an electron beam mechanical force measurement system and method, including but not limited to acquiring the electron beam mechanical force in scenarios such as electron beam etching, electron beam induced deposition, SEM, and ESEM, to assist in achieving higher precision micro / nano structure fabrication or microstructure analysis. The following description will use the acquisition of electron beam mechanical force in ESEM as an example.

[0043] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0044] like Figures 1 to 2 As shown, this embodiment provides an electron beam mechanical force measurement system, disposed within a sealed chamber 10, for measuring the mechanical force of the electron beam under test output by an electron beam emitting device 20. The electron beam emitting device 20 outputs an electron beam for applications such as electron beam etching, electron beam-induced deposition, SEM, or ESEM. For example, when measuring the mechanical force of an electron beam in an ESEM, the electron beam emitting device 20 is an ESEM microscope, and the sealed chamber 10 is the cavity of the ESEM microscope.

[0045] Optionally, the electron beam mechanical force measurement system includes a weak force measuring device 30, a fixing device 40, and a cooling device 50 arranged sequentially along the output direction of the electron beam under test. The weak force measuring device 30 is used to receive the electron beam under test and acquire its mechanical force.

[0046] Specifically, such as Figures 1 to 2As shown, the weak force measurement device 30 includes a three-dimensional micro-helical spring structure 31, an optical fiber 32, a laser source 33, and a signal analysis unit 34. One end of the optical fiber 32 is fixedly connected to the three-dimensional micro-helical spring structure 31, and the other end is connected to both the laser source 33 and the signal analysis unit 34. The three-dimensional micro-helical spring structure 31 includes three coaxial parallel helical springs and a receiving end plate disposed at the end away from the optical fiber 32, forming a Fabry-Perot resonant cavity on the end face of the optical fiber 32 near the end of the three-dimensional micro-helical spring structure 31. During mechanical force measurement, the laser emitted by the laser source 33 is transmitted to the other end through the optical fiber 32 and reflected at the end face of the optical fiber 32 and the receiving end plate of the three-dimensional micro-helical spring structure 31 near the optical fiber 32, respectively. The two reflected beams interfere, forming a signal that is transmitted by the optical fiber 32 to the signal analysis unit 34, based on which the magnitude of the weak force is obtained. Exemplarily, the signal analysis unit 34 includes an optical power meter or a spectrometer.

[0047] For example, the three-dimensional micro-helical spring structure 31 is formed by coating one end of the optical fiber 32 with photoresist and integrally molding it using a two-photon polymerization photolithography process, thereby fixing the three-dimensional micro-helical spring structure 31 to one end of the optical fiber 32. The other side is a receiving end plate, which is positioned directly facing the electron beam to be tested, so as to directly receive the electron beam bombardment; that is, the electron beam emitted by the electron beam emitting device 20 is perpendicularly incident on the center of the receiving end plate. When the electron beam incident on the receiving end plate, the three coaxial parallel helical springs are compressed, the cavity length of the Fabry-Perot resonant cavity changes, and thus the resonant wavelength of the resulting resonant signal changes. Based on the degree of change in the resonant wavelength, the magnitude of the weak force can be accurately obtained.

[0048] Furthermore, to more sensitively and accurately measure the mechanical force of the electron beam, the three-dimensional micro-helical spring structure 31 has a small elastic coefficient. Preferably, during the fabrication of the three-dimensional micro-helical spring structure 31, a support structure is also obtained through a two-photon polymerization lithography process to support the three-dimensional micro-helical spring structure 31, preventing it from collapsing during fabrication, thereby obtaining a three-dimensional micro-helical spring structure 31 with an extremely low elastic coefficient. For example, the elastic coefficient of the three-dimensional micro-helical spring structure 31 is 0.00078 N / m.

[0049] Based on this, the three-dimensional micro-helical spring structure 31 is fixed by the fixing device 40 so that the receiving end plate is facing the electron beam emitted by the electron beam emitting device 20, thereby realizing the measurement of the mechanical force of the electron beam.

[0050] However, it should be noted that when the electron beam strikes the receiving end plate, the kinetic energy of the electrons is converted into a large amount of heat during the interaction between the incident electrons and the material of the receiving end plate. This causes a sharp increase in the temperature of the three-dimensional micro-helical spring structure 31, especially at the receiving end plate, which in turn melts and destroys the three-dimensional micro-helical spring structure 31. Please refer to [link / reference]. Figure 3 The image shows a three-dimensional micro-helical spring structure 31 that melted due to excessive heat.

[0051] Based on this, in some optional embodiments, a thermally conductive film is provided on the side of the receiving end plate that receives the electron beam under test, i.e., the side away from the optical fiber 32. Specifically, the thermally conductive film is used to achieve rapid heat conduction on the receiving end plate to avoid heat accumulation on the receiving end plate, thereby reducing the risk of melting of the three-dimensional micro-helical spring structure 31.

[0052] For example, the thermally conductive film is a metal film, which improves the thermal conductivity of the three-dimensional micro-helical spring structure 31 based on the high thermal conductivity of metal. For example, the thermally conductive film is a silver film, which is used to quickly conduct heat on the receiving end plate to the surrounding environment, thereby avoiding heat accumulation. At the same time, the silver film can also reflect the electron beam, thereby reducing the heat generated by the electron beam on the three-dimensional micro-helical spring structure 31, further reducing the heat accumulated on the three-dimensional micro-helical spring structure 31, and preventing the three-dimensional micro-helical spring structure 31 from melting. This allows the weak force measuring device 30 to effectively and stably measure the mechanical force of the electron beam for a long time.

[0053] Specifically, a silver film of a predetermined thickness is deposited on the side of the receiving end plate that receives the electron beam under test by a conformal metallization process using magnetron sputtering. The thickness of the silver film can be set by those skilled in the art according to actual needs. For example, a 23.3 nm silver film is deposited on the side of the receiving end plate that receives the electron beam under test by a conformal metallization process using magnetron sputtering.

[0054] It should be noted that the working environment of the electron beam is usually close to a vacuum, that is, the sealed chamber 10 is in a near-vacuum state. This makes thermal convection within the sealed chamber 10 essentially ineffective, and the three-dimensional micro-helical spring structure 31 difficult to dissipate heat. Therefore, preferably, in this embodiment, the electron beam mechanical force measurement system further includes a gas input pipe, exemplarily connected from the outside to the inside of the sealed chamber 10, for supplying low-pressure gas into the sealed chamber 10. Exemplarily, the supplied low-pressure gas is any one or more of nitrogen, water vapor, helium, and argon to increase the gas pressure within the sealed chamber 10 to reach a preset working gas pressure, but not exceeding a preset maximum working gas pressure. This improves thermal convection within the sealed chamber 10, thereby improving the thermal conductivity of the three-dimensional micro-helical spring structure 31 and preventing heat accumulation on the three-dimensional micro-helical spring structure 31 from causing melting. Specifically, those skilled in the art can supply low-pressure gas into the sealed chamber 10 according to the actual application scenario of the electron beam to achieve a specific working gas pressure. For example, for ESEM, the maximum working pressure is 2600 Pa, and nitrogen is introduced into the chamber to bring the chamber pressure to a range of 10 Pa to 2600 Pa.

[0055] In some alternative implementations, this embodiment also includes a cooling platform fixed below the fixing device 40 for cooling the three-dimensional micro-helical spring structure 31.

[0056] Specifically, one side of the cooling device 50 is in contact with the fixing device 40, thereby realizing a heat conduction channel from the three-dimensional micro helical spring structure 31 to the fixing device 40 to the cooling device 50, so that the heat on the three-dimensional micro helical spring structure 31 can be transferred to the cooling device 50 for cooling along the heat conduction channel. At the same time, the ambient temperature is reduced by the cooling device 50, thereby reducing the temperature of the three-dimensional micro helical spring structure 31.

[0057] Optionally, the cooling device 50 may include a water-cooling unit 51 and / or a Peltier unit 52.

[0058] Preferably, such as Figure 2 As shown, the cooling device 50 includes a water-cooling unit 51 and a Peltier unit 52. The Peltier unit 52 is located below the fixing device 40, and the water-cooling unit 51 is located below the Peltier unit 52. Specifically, the heat-absorbing side of the Peltier unit 52 is in close contact with the fixing device 40, and the heat-releasing side is in close contact with the water-cooling unit 51. The water-cooling unit 51 includes a heat-conducting element and a water-cooling pipe passing through the heat-conducting element. Based on this, the heat-absorbing side of the Peltier unit 52 absorbs the temperature from the three-dimensional micro-helical spring structure 31 through the fixing device 40, and cools the three-dimensional micro-helical spring structure 31 by lowering the ambient temperature. Simultaneously, the heat generated by the heat-releasing side of the Peltier unit 52 is absorbed by the water-cooling unit 51, thereby continuously cooling the three-dimensional micro-helical spring structure 31.

[0059] Furthermore, the fixing device 40 includes a metal bracket, such as a copper bracket. One end of the metal bracket is in fixed contact with the three-dimensional micro-helical spring structure 31, and the other end is in contact with the cooling device 50. This allows heat to be quickly and effectively conducted from the three-dimensional micro-helical spring structure 31 through the metal bracket to the cooling device 50, thereby improving the heat dissipation efficiency of the three-dimensional micro-helical spring structure 31 and preventing the three-dimensional micro-helical spring structure 31 from melting due to heat accumulation, so as to achieve long-term effective and stable mechanical force measurement.

[0060] Based on this, in this embodiment, the electron beam mechanical force is measured by the weak force measuring device 30. At the same time, the three-dimensional micro helical spring structure 31 is cooled by the cooling device 50, and the heat dissipation efficiency of the three-dimensional micro helical spring structure 31 is improved by the low-pressure gas input through the heat-conducting film and gas delivery pipe, so as to avoid the three-dimensional micro helical spring structure 31 from melting due to heat accumulation, so as to achieve long-term stable and effective electron beam mechanical force measurement.

[0061] On the other hand, this application also provides an electron beam mechanical force measurement method for measuring the mechanical force of an electron beam using the electron beam mechanical force measurement system as described above.

[0062] Specifically, such as Figure 4 As shown, the electron beam mechanical force measurement method includes:

[0063] S10, pre-process the sealed chamber 10 to achieve the preset measurement conditions; and after pre-calibrating the electron beam emitting device 20 and the weak force measuring device 30, turn off the electron beam emitting device 20.

[0064] The preset measurement conditions include a preset measurement temperature range and a preset working air pressure range. Based on this, such as... Figure 5 As shown, the pretreatment steps for the sealing chamber 10 include cooling and regulating the air pressure of the sealing chamber 10.

[0065] Specifically, to prevent the three-dimensional micro-helical spring structure 31 from melting during electron beam mechanical force measurement, the temperature inside the sealed chamber 10 is reduced to within a preset measurement temperature range, thereby preventing the three-dimensional micro-helical spring structure 31 from heating up too quickly and melting. For example, the measurement temperature range is -50°C to 50°C.

[0066] For example, the sealed chamber 10 is cooled by the cooling device 50.

[0067] Furthermore, during subsequent electron beam measurements, the temperature inside the sealed chamber 10 and the three-dimensional micro-helical spring structure 31 is maintained within the measurement temperature range by the cooling device 50, so as to avoid the three-dimensional micro-helical spring structure 31 from being in the measurement range, thereby achieving long-term effective and stable mechanical force measurement.

[0068] Furthermore, to improve the thermal conductivity of the three-dimensional micro-helical spring structure 31 and further prevent heat accumulation leading to melting, in this embodiment, a low-pressure gas is used to bring the gas pressure inside the sealed chamber 10 to the working gas pressure range. This enhances the thermal convection between the three-dimensional micro-helical spring structure 31 and its surroundings, improves the heat dissipation efficiency of the three-dimensional micro-helical spring structure 31, and prevents the three-dimensional micro-helical spring structure 31 from melting. For example, the low-pressure gas supplied is any one or more of nitrogen, water vapor, helium, and argon, and the working gas pressure range is 10 Pa to 2600 Pa.

[0069] Furthermore, the preset measurement conditions also include the working conditions of the electron beam. For example, when measuring the mechanical force of electron beam deposition, the measurement conditions are the working conditions of electron beam deposition; when measuring the mechanical force of electron beam etching, the measurement conditions are the working conditions of electron beam etching; and when measuring the mechanical force of ESEM, the measurement conditions are the working conditions of ESEM, so as to facilitate the measurement and acquisition of the mechanical force of the electron beam in actual applications.

[0070] The pre-calibration of the electron beam emitting device 20 and the weak force measuring device 30 includes calibrating the electron beam emitted by the electron beam emitting device 20 so that the electron beam is incident perpendicularly at the center of the receiving end plate at a preset size.

[0071] For example, such as Figure 5 As shown, taking the electron beam emitting device 20 as an ESEM microscope as an example, before measurement, the electron beam current and accelerating voltage are set, and the electron tube of the ESEM microscope is cross-aligned, the aperture is aligned, astigmatism is corrected and the focus is optimized in sequence, so that the receiving end plate receives a circular light spot and the center of the light spot coincides with the center of the receiving end plate.

[0072] Furthermore, after completing the pre-calibration, the electron beam emitting device 20 is turned off to stabilize the shaking caused by the electron beam hitting the receiving end plate during the pre-calibration process, thereby improving the accuracy of subsequent mechanical force measurements.

[0073] S20, after a preset stabilization time, the electron beam emitting device 20 is turned on again to emit corresponding electron beams based on preset electron beam energies, and the mechanical force of each electron beam is obtained and recorded by the weak force measuring device 30.

[0074] In this process, a settling time is used to allow the weak force measuring device to return to a stable state, thereby improving the accuracy of subsequent mechanical force measurements. For example, a preset settling time is used.

[0075] After a preset stabilization time, the weak force measuring device 30 returns to stability and the electron beam emitting device 20 is turned on again. At this time, due to the electron beam hitting the receiving end plate, the cavity length of the Fabry-Perot resonant cavity formed between the three-dimensional micro-helical spring structure 31 and the end face of the optical fiber 32 changes, thereby changing the resonant wavelength. The magnitude of the mechanical force has been obtained by the signal analysis unit 34 and recorded.

[0076] S30: Based on the energy of each electron beam and the corresponding mechanical force, the mechanical force relationship of the electron beam is obtained.

[0077] Specifically, the signal analysis unit 34 acquires the resonant wavelength variation of each electron beam, thereby obtaining the magnitude of the mechanical force of each electron beam. Based on the energy of each electron beam and its corresponding mechanical force, a fitting is performed to obtain the relationship between the mechanical force and the electron beam energy, which is then used as the electron beam mechanical force relationship.

[0078] For example, such as Figure 6 As shown, the relationship between the fitted electron beam mechanical force and the electron beam accelerating voltage is illustrated. The mechanical force exhibits a non-monotonic dependence on the accelerating voltage, first increasing and then decreasing, reaching its maximum value near approximately 10 kV. It should be noted that the electron beam energy is the product of the electron beam accelerating voltage and the electron charge. Based on this, the relationship between the mechanical force and the electron beam energy can be reflected, serving as the electron beam mechanical force relationship.

[0079] On the other hand, this application also provides an electron beam mechanical force simulation method for simulating an electron beam with a preset electron beam energy to obtain the magnitude of the mechanical force of the electron beam.

[0080] Specifically, such as Figure 7 As shown, the electron beam mechanical force simulation method includes:

[0081] S100 constructs an electron beam with a preset electron beam energy and a surface to be struck, and obtains the trajectory of each electron after the electron beam bombards the surface using the Monte Carlo method.

[0082] The struck surface is used to characterize the surface bombarded by the electron beam. It should be noted that those skilled in the art can set the struck surface according to actual needs, such as the surface shape, thickness and material of the struck surface, etc., and this embodiment does not impose specific limitations.

[0083] The Monte Carlo method simulates the process of an electron beam bombarding a surface. This involves independently sampling, simulating, and tracking the complete random journey of each electron in the beam. The number of electrons in the beam is determined by a preset beam energy, specifically the product of the accelerating voltage and the electron charge. Based on this preset energy, the number of electrons contained in the cross-section of the beam is obtained, and these electrons are sampled and simulated one by one to obtain the mechanical force generated on the surface during a single electron beam impact.

[0084] It should be noted that the trajectories of each electron simulated by the Monte Carlo method all conform to the quantum electrodynamic laws governing elastic scattering of electrons in a Coulomb field. Specifically, the Mott Cross Section Model in the CASINO software can be used for Monte Carlo simulations.

[0085] Based on this, the trajectories of individual electrons can be obtained when an electron beam bombards a surface. For example, such as... Figure 8 As shown, the simulation results of electron beams with energies of 1 keV and 10 keV were obtained using the Mott scattering cross section model in CASINO software and the Monte Carlo method. Subplots a to d reflect the simulation results for an electron beam with an energy of 1 keV. Subplot a shows the trajectory of each electron; the red trajectory represents the electrons that are backscattered after hitting the surface, and the blue trajectory represents the electrons that are transmitted after hitting the surface. Subplots b and c reflect the backscattering of the electron beam, and subplot d reflects the transmission of the electron beam. Subplots e to h reflect the simulation results for an electron beam with an energy of 10 keV. Subplot e shows the trajectory of each electron; the red trajectory represents the electrons that are backscattered after hitting the surface, and the blue trajectory represents the electrons that are transmitted after hitting the surface. Subplots f and g reflect the backscattering of the electron beam, and subplot h reflects the transmission of the electron beam.

[0086] S200 obtains the backscattering transmission of the electron beam based on the trajectory of each electron in the electron beam.

[0087] The backscattering transmission situation includes the backscattering ratio and backscattering angle of the electron beam, as well as the transmission ratio and transmission angle ratio.

[0088] Specifically, based on such Figure 8The simulation results shown indicate that the number of backscattered electrons is obtained, and the ratio of this number to the total number of electrons in the electron beam cross-section is used as the backscattering ratio. Furthermore, based on the trajectories of each backscattered electron, the beam center direction is calculated, and this beam center direction is taken as the direction of electron beam backscattering. The angle between this beam center direction and the normal to the impacted surface is defined as the backscattering angle. It should be noted that those skilled in the art should know how to obtain the beam center direction based on the trajectories of each backscattered electron; this embodiment will not elaborate on this method.

[0089] Similarly, the number of transmitted electrons is obtained, and the ratio of this number to the total number of electrons in the electron beam cross-section is used as the transmission ratio. Furthermore, based on the trajectories of each transmitted electron, the beam center direction is calculated, and this beam center direction is taken as the direction of electron beam backscattering. The angle between this beam center direction and the normal to the struck surface is defined as the backscattering angle. For details, please refer to the aforementioned content on obtaining the backscattering ratio and backscattering angle; this embodiment will not repeat them here.

[0090] S300 obtains the mechanical force scaling factor based on backscatter transmission conditions; and obtains the output mechanical force of the electron beam based on the electron beam energy; and obtains the mechanical force of the electron beam based on the output mechanical force and the mechanical force scaling factor.

[0091] Among them, the outgoing mechanical force refers to the mechanical force corresponding to the kinetic energy of the electron beam as it leaves the electron beam emitting device. Specifically, the kinetic energy of the electron beam leaving the electron beam emitting device is calculated based on the electron beam energy, i.e., the outgoing kinetic energy, and the outgoing mechanical force of the electron beam is calculated based on the outgoing kinetic energy.

[0092] The mechanical force of an electron beam refers to the mechanical force generated on a surface when an electron beam bombards it.

[0093] During the incident process of an electron beam on a surface, backscattered electrons leave the surface in the opposite direction, generating momentum in the opposite direction; while transmitted electrons pass through the surface, carrying away the remaining momentum after the electron bombardment. Based on this, and considering the backscattering and transmission characteristics of the electron beam, combined with the exit momentum of the electron beam, the mechanical force generated on the surface when the electron beam bombards the surface can be obtained. To facilitate understanding of the above calculation process for the electron beam mechanical force by those skilled in the art, the calculation process will be explained in detail below.

[0094] Specifically, the ejection momentum is calculated as follows:

[0095] When the electron beam energy does not exceed 30 keV, the electron velocity is relatively low, and the ejection momentum is calculated based on classical mechanics:

[0096]

[0097] When the electron beam energy exceeds 30 keV, the electrons move at higher speeds, and the ejection momentum is calculated based on special relativity:

[0098]

[0099] in, Used to characterize the outgoing momentum, that is, the total momentum of the electron beam when it is emitted. Used to characterize the speed of light, exemplarily , Used to characterize electron beam energy Used to characterize the rest mass of a single electron.

[0100] Furthermore, based on the emission momentum of a single electron corresponding to the energy of each electron beam, the emission mechanical force corresponding to each electron beam is calculated as follows:

[0101]

[0102] in, Used to characterize the ejection mechanical force corresponding to each electron beam, that is, the mechanical force corresponding to the total momentum when the electron beam is emitted. The electron beam current value is calculated based on the parameters obtained during the simulation of the Mott scattering cross section model. Those skilled in the art should know the specific calculation process, and this embodiment does not impose any specific limitations.

[0103] Because backscattering and transmission occur after the electron beam strikes the target surface, resulting in energy loss, the magnitude of the mechanical force generated on the struck surface is not necessarily equal to the emitted mechanical force. Specifically, the electron beam mechanical force, that is, the mechanical force generated by the electron beam on the struck surface, is:

[0104]

[0105] in, Let be the total momentum of all backscattered electrons, specifically, , Let be the total energy of all backscattered electrons. , This represents the backscattering ratio; This is the backscattering angle; For the total momentum of all transmitted electrons, specifically, , Let be the total energy of all electrons that undergo transmission. , This represents the transmission ratio; The angle is the transmission angle.

[0106] For example, a mechanical force scaling factor is calculated as the ratio between the emitted mechanical force and the mechanical force generated by the electron beam bombarding the surface being struck, thereby facilitating the calculation of the mechanical force generated by the electron beam bombarding the surface being struck based on the emitted mechanical force, i.e.:

[0107]

[0108] in, Used to characterize the mechanical force generated when an electron beam bombards a surface being struck. Used to reflect the degree of energy loss caused by electron beam backscattering transmission. The larger the size, the smaller the loss.

[0109] It should be noted that, regarding the mechanical force proportionality factor... It is determined by the backscattering transmission of the electron beam. Specifically, the mechanical force scaling factor is characterized as:

[0110]

[0111] in, Used to reflect the backscattering transmission of the electron beam. Used to characterize the backscattering ratio of an electron beam. Used to characterize the backscattering angle of an electron beam. Used to characterize the transmission ratio of an electron beam. Used to characterize the transmission angle of an electron beam.

[0112] Based on this, and considering the backscattering and transmission characteristics of the electron beam, the mechanical force scaling factor is calculated. Combined with the launching mechanical force This allows us to calculate the magnitude of the mechanical force required to acquire the electron beam.

[0113] Specifically, in the actual simulation process, the backscattering ratio is obtained based on the trajectory of each simulated electron. Backscattering angle Transmission ratio and transmission angle To calculate the mechanical force scaling factor And the exit momentum of the electron beam is calculated based on the electron beam energy. Then, the ejection mechanical force of the electron beam is calculated. Therefore, based on the mechanical force proportionality factor and ejection mechanical force The product of these factors is used to calculate the mechanical force of the electron beam.

[0114] It should be noted that by obtaining the mechanical force of the electron beam based on simulation and comparing it with the results of measuring the same electron beam energy using the aforementioned electron beam mechanical force measurement system, it can be found that the mechanical force measured by the two methods is almost equal, thus reflecting that the electron beam mechanical force measurement system in this application has high measurement accuracy.

[0115] Furthermore, in order to facilitate those skilled in the art to understand the specific methods and application scenarios of obtaining electron beam mechanical force in this application, the following will provide a detailed explanation through a specific analysis of the electron beam etching process of ice.

[0116] In one specific application embodiment, the above-described electron beam mechanical force measurement system is used to study the interaction between an electron beam and ice.

[0117] In this method, when using an electron beam to etch ice, the electron beam etches the ice not only through the mechanical force generated during impact, but also through heat, ionization, and radiation. In this embodiment, by calculating the magnitude of the mechanical force generated by the electron beam, the depth to which the electron beam can etch the ice is calculated based on this mechanical force. This calculation, combined with the actual etching depth of the ice, reflects the degree of influence of the electron beam's mechanical force on the ice etching process.

[0118] First, an electron beam is used to pattern and etch amorphous ice, and the etching depth after the ice is etched is recorded as the actual etching depth.

[0119] Secondly, based on the electron beam mechanical force measurement system in this application, the magnitude of the mechanical force of the electron beam is measured, and based on the magnitude of the electron beam mechanical force, the etching depth that the mechanical force can cause is calculated as the mechanical force etching depth. The mechanical force etching depth value is actually the product of the total number of electrons per unit area, the effective cross-section of a single electron sputtering, and the effective monolayer thickness of a single water molecule.

[0120]

[0121] in, For etching depth, The total charge injected per unit area of ​​the electron beam. The fundamental charge, Used to characterize the atomic number of the target atom. Vacuum permittivity, The kinetic energy of electrons during a single palace examination. To break free from the threshold binding energy, The mass of the water molecule center, The molar mass of water, Let Avogadro's constant be 1. This refers to the macroscopic mass density of ice.

[0122] The influence of electron beam mechanical force on the etching process of ice was analyzed by comparing the actual etching depth and the mechanical etching depth. Figure 9 The figure shows the actual etching depth and the mechanical etching depth of ice. Clearly, the experimentally measured total etching depth far exceeds the upper limit of the purely mechanically induced depth, with a difference of more than four orders of magnitude. Furthermore, the scaling trend of the mechanical contribution with accelerating voltage is inconsistent with the energy dependence of the actual etching depth. This proves that the mechanical force of the electron beam is not the dominant factor in electron beam etching of ice. In fact, during ice etching, the electron beam has a greater influence on the etching process through heat, ionization, and radiation.

[0123] In summary, this application can achieve accurate and long-term stable measurement of electron beam mechanical force, which can help correct deviations in the spatial position and morphological characteristics of the target material caused by the influence of electron beam mechanical force, and is conducive to further improving the accuracy of micro-nano structure processing and micro-morphological analysis.

[0124] The descriptions of the processes or structures corresponding to the above figures each have their own emphasis. For parts of a process or structure that are not described in detail, please refer to the relevant descriptions of other processes or structures.

[0125] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An electron beam mechanical force measurement system, wherein the electron beam mechanical force measurement system is disposed in a sealed chamber and is used to measure the mechanical force of an electron beam to be tested output by an electron beam emitting device, characterized in that, A weak force measuring device, a fixing device, and a cooling device are sequentially arranged in the output direction of the electron beam to be tested; The weak force measuring device is used to receive the electron beam under test and obtain the mechanical force of the electron beam under test; the weak force measuring device includes a three-dimensional micro-helical spring structure, an optical fiber, a laser source and a signal analysis unit; one side of the three-dimensional micro-helical spring structure is fixedly connected to the optical fiber, and the other side is provided with a receiving end plate facing the electron beam under test; the end of the optical fiber away from the three-dimensional micro-helical spring structure is connected to the laser source and the signal analysis unit respectively; One end of the fixing device is fixedly connected to the weak force measuring device, and the other end is fixedly connected to the cold table, for fixing the weak force measuring device; One side of the cooling device is in contact with the fixing device, and is used to cool down the weak force measuring device.

2. The electron beam mechanical force measurement system according to claim 1, characterized in that, A thermally conductive film is provided on the side of the receiving end plate that receives the electron beam to be tested.

3. The electron beam mechanical force measurement system according to claim 2, characterized in that, The thermally conductive film is a silver film.

4. The electron beam mechanical force measurement system according to claim 1, characterized in that, The fixing device includes a metal bracket; one end of the metal bracket is in fixed contact with the three-dimensional micro-helical spring structure, and the other end is in contact with the cooling device.

5. The electron beam mechanical force measurement system according to claim 1, characterized in that, The cooling device includes a water-cooling unit.

6. The electron beam mechanical force measurement system according to claim 1, characterized in that, The cooling device includes a Peltier unit.

7. The electron beam mechanical force measurement system according to claim 1, characterized in that, It also includes gas input pipes.

8. A method for measuring the mechanical force of an electron beam, characterized in that, include: The sealed chamber is pre-treated to bring the preset measurement conditions into place. After pre-calibrating the electron beam emitting device and the weak force measuring device, the electron beam emitting device is turned off. After a preset stabilization time, the electron beam emitting device is turned on again to emit corresponding electron beams based on preset electron beam energies, and the mechanical force corresponding to each electron beam is obtained and recorded by the weak force measuring device. Based on the electron beam energy and the corresponding mechanical force, the electron beam mechanical force relationship is obtained.

9. The electron beam mechanical force measurement method according to claim 8, characterized in that, The pretreatment of the sealing chamber to bring the sealing chamber to the preset measurement conditions includes: The sealed chamber is cooled to reach the preset measurement temperature range; The sealed chamber is evacuated, and then low-pressure gas is introduced to achieve the preset working pressure range.

10. A method for simulating the mechanical force of an electron beam, characterized in that, include: An electron beam with a preset electron beam energy and a surface to be struck are constructed, and the trajectory of each electron after the electron beam bombards the surface is obtained by the Monte Carlo method. Based on the trajectories of each electron in the electron beam, the backscattering transmission characteristics of the electron beam are obtained; the backscattering transmission characteristics include the backscattering ratio and backscattering angle of the electron beam, as well as the transmission ratio and transmission angle ratio. Based on the backscattering transmission situation, the mechanical force scaling factor is obtained; and based on the electron beam energy, the emission mechanical force of the electron beam is obtained. The mechanical force of the electron beam is obtained based on the emitted mechanical force and the mechanical force scaling factor.

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