An electron beam deflection pulse generating device for transmission electron microscope

Abstract

The present application discloses an electron beam deflection pulse generating device for a transmission electron microscope, which is applied to the objective lens system of the transmission electron microscope, and includes a square wave pulse module and a negative pulse generating module; the square wave pulse module is used to send a square wave trigger pulse signal of a preset frequency to the negative pulse generating module according to the characteristics of the sample to be tested; the negative pulse generating module is used to perform waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage; wherein the negative pulse output signal is used to change the incident angle of the electron beam and the number of incident electrons. The present invention can generate a fast pulse signal with a DC bias voltage and a narrow pulse width, so that the electron beam is deflected under the action of the DC bias voltage without being irradiated on the sample; when the fast pulse arrives, the electron beam is irradiated on the sample in a very short time when the pulse occurs, which can protect the sample and extend the service life of the sample.

Description

Technical Field

[0001] The invention relates to the technical field of transmission electron microscopes, and in particular to an electron beam deflection pulse generating device for a transmission electron microscope. Background Art

[0002] Transmission Electron Microscope (TEM) can show fine structures smaller than 0.2um that cannot be seen clearly under an optical microscope. It has the characteristics of high resolution, sensitivity to chemical composition, and intuitive and easy-to-interpret images. It is widely used in the fields of material science and biology and has become one of the most widely used characterization equipment. Its working principle is as follows: the electron beam emitted by the electron gun passes through the condenser along the optical axis of the microscope in the vacuum channel, and is converged into a sharp, bright and uniform light spot through the condenser, which irradiates the sample in the sample chamber; the electron beam after passing through the sample carries the internal structural information of the sample; after the convergence and focusing of the objective lens and the primary magnification, the electron beam enters the lower intermediate lens and projection lens for comprehensive magnification and imaging; finally, the magnified electron image is projected on the fluorescent screen in the observation room; the fluorescent screen converts the electron image into a visible light image for the user to observe.

[0003] Although transmission electron microscopy achieves in-situ characterization with ultra-high spatial and energy resolution through highly accelerated electrons in a vacuum, it is impossible to accurately measure electrochemical signals in a vacuum environment, and the irradiation damage of high-energy electron beams can lead to structural changes and observational artifacts. If the sample is irradiated by the electron beam for too long, it will cause irreversible structural damage and changes.

[0004] Therefore, it is necessary to propose an electron beam deflection pulse generating device for a transmission electron microscope, which can solve the problem that the irradiation of high-energy electron beams in existing transmission electron microscopes damages the sample or causes its structure to change, resulting in observation illusions. Summary of the invention

[0005] In view of this, it is necessary to provide an electron beam deflection pulse generating device for a transmission electron microscope to solve the technical problems in the prior art that the transmission electron microscope uses high-energy electron beam irradiation to continuously irradiate the sample, causing sample damage or causing its structural changes, shortening the service life of the sample, and causing observation illusions.

[0006] In order to solve the above problems, the present invention provides an electron beam deflection pulse generating device for a transmission electron microscope, which is applied to an objective lens system of a transmission electron microscope. The device includes a square wave pulse module and a negative pulse generating module;

[0007] The square wave pulse module is used to send a square wave trigger pulse signal of a preset frequency to the negative pulse generation module according to the characteristics of the sample to be tested;

[0008] The negative pulse generating module is used to perform waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage; wherein the negative pulse output signal is used to change the incident angle of the electron beam and the number of incident electrons.

[0009] Furthermore, the square wave pulse module includes a host computer and an embedded control module;

[0010] The host computer is used to determine the frequency of the square wave trigger pulse signal according to the characteristics of the sample to be tested, and send a control instruction containing the frequency information to the embedded control module;

[0011] The embedded control module is used to generate a square wave trigger pulse signal according to the control information sent by the host computer, and input the square wave trigger pulse signal into the negative pulse generating module.

[0012] Furthermore, the negative pulse generating module includes a pulse generating circuit, a pulse shaping circuit and a pulse bias circuit;

[0013] The pulse generating circuit is used to convert the square wave trigger pulse signal to obtain a first negative pulse signal;

[0014] The pulse shaping circuit is used to adjust the pulse width of the first negative pulse signal to obtain a second negative pulse signal;

[0015] The pulse bias circuit is used to provide a DC bias voltage for the second negative pulse signal to obtain a negative pulse output signal with a bias voltage.

[0016] Furthermore, the pulse generating circuit includes an N-channel MOS tube, a MOS tube driver and a charging capacitor;

[0017] The drain of the N-channel MOS tube is connected to one end of the charging capacitor and is connected to the charging power supply through a pull-up resistor; the gate of the N-channel MOS tube is connected to the level output pin of the MOS tube driver; the signal input end of the MOS tube driver is connected to the embedded control module; the other end of the charging capacitor is grounded through a pull-down resistor;

[0018] When the square wave trigger pulse is at a low level, the MOS tube driver outputs a low level, the N-channel MOS tube is not turned on, and the charging power supply charges the charging capacitor;

[0019] When the square wave trigger pulse is at a low level, the MOS tube driver outputs a high level, the N-channel MOS tube is turned on, and the charging capacitor is discharged through the N-channel MOS tube.

[0020] Furthermore, the pulse shaping circuit includes a first shaping diode and a second shaping diode; the anode of the first shaping diode is connected to the cathode of the second shaping diode, and the cathode is connected to the output end of the pulse generating circuit and the anode of the second shaping diode; the anode of the second shaping diode is also connected to the input end of the pulse bias circuit, and the cathode is grounded.

[0021] Furthermore, the first shaping diode is a step recovery diode; and the second shaping diode is a Schottky diode.

[0022] Furthermore, the output end of the negative pulse generating module includes an IPEX interface, and the IPEX interface is connected to the objective aperture of the lens electron microscope through a coaxial line.

[0023] Furthermore, the output IPEX interface of the negative pulse generating module is a fifth-generation IPEX interface, and the IPEX interface is welded to the output port of the negative pulse generating module.

[0024] Furthermore, the coaxial line is an RF0.6 radio frequency wire.

[0025] Furthermore, the frequency of the square wave trigger pulse signal output by the square wave pulse module can be adjusted in the range of 1 MHz to 10 MHz.

[0026] Compared with the prior art, the beneficial effects of the present invention include: sending a square wave trigger pulse signal of a preset frequency to a negative pulse generating module according to the characteristics of the sample to be tested through a square wave pulse module, performing waveform processing on the square wave trigger pulse signal through the negative pulse generating module, obtaining a negative pulse output signal with a bias voltage, controlling the incident angle of the electron beam and the number of incident electrons, thereby controlling the irradiation energy of the electron beam on the sample. The present invention can adjust the frequency range of the square wave trigger pulse signal according to the characteristics of the sample through the square wave pulse module to meet the detection requirements of different samples; generating a fast pulse with a DC bias voltage and a narrow pulse width through the negative pulse generating module, which can deflect the electron beam under the action of the DC bias voltage when the fast pulse does not arrive, so that the electron beam is not irradiated on the sample; when the fast pulse arrives, the electron beam is irradiated on the sample in a very short time when the pulse occurs, giving the sample a structural relaxation environment and relaxation time, so that the sample is restored to the original intrinsic structure, thereby achieving the purpose of protecting the sample and extending the service life of the sample, and also avoiding the occurrence of observation illusions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of an embodiment of a transmission electron microscope;

[0028] Figure 2 A schematic structural diagram of an embodiment of an electron beam deflection pulse generating device for a transmission electron microscope provided by the present invention;

[0029] Figure 3 A schematic diagram of the structure of an embodiment of a square wave pulse module provided by the present invention;

[0030] Figure 4 A schematic diagram of an operation interface of an upper computer according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of an embodiment of a negative pulse generating module provided by the present invention;

[0032] Figure 6 A schematic diagram of the circuit structure of an embodiment of a pulse generating circuit provided by the present invention;

[0033] Figure 7 A schematic diagram of the circuit structure of an embodiment of a pulse shaping circuit provided by the present invention;

[0034] Figure 8 This is a test result diagram of an embodiment of the oscilloscope provided by the present invention testing a negative pulse output signal. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0036] Before describing the embodiments, the relevant terms of the present application are first explained.

[0037] Transmission Electron Microscope, Transmission Electron Microscope, abbreviated as TEM.

[0038] like Figure 1 As shown, the overall working principle of TEM is as follows:

[0039] The electron beam emitted by the electron gun passes through the condenser (focusing lens) along the optical axis of the mirror in the vacuum channel, and is converged by the condenser into a sharp, bright and uniform light spot, which is irradiated on the sample in the sample chamber. After interacting with the atomic nuclei and extranuclear electrons of the sample material, the direction or energy of the incident electron beam changes (or both change at the same time). This phenomenon is called electron scattering. Depending on whether the energy changes during scattering, it is divided into elastic scattering (only the direction changes) and inelastic scattering (both the direction and energy change). Elastic scattering is the basis of electron diffraction spectrum, diffraction contrast image and phase contrast imaging, while the inelastic electrons that lose energy and other signals converted into them (such as heat, light, X-rays, secondary electrons, cathode fluorescence, Auger electrons and transmitted electrons, etc.) are mainly used for chemical element analysis of samples (such as EDXS or EELS analysis) or surface observation.

[0040] Transmission electron microscopes generally provide two imaging modes: TEM and STEM. In TEM mode, after the parallel incident electron beam passes through the sample, the intensity (brightness and darkness) changes on the electron image due to differences in sample mass thickness or different diffraction abilities of various parts of the crystal material to the incident electrons, which is an amplitude contrast image. In STEM mode, the incident electron beam converges to form a very fine electron beam (<0.2nm) and scans on the thin sample; secondary electron images and backscattered electron images can be formed respectively by installing secondary electron and backscattered electron detectors above the sample (similar to the working principle of a scanning electron microscope), and placing detectors below the thin sample can form bright field or dark field STEM images.

[0041] Aperture: Aperture refers to an entity that limits the light beam in an optical system. It can be the edge of a lens, a frame, or a specially set screen with holes. Its function can be divided into two aspects: limiting the light beam or limiting the size of the field of view (imaging range).

[0042] Objective aperture: It is used to block part of the diffraction spots in a transmission electron microscope. In a transmission electron microscope, the high-frequency electron beam contains the detailed information of the sample, while the low-frequency electron beam contains the contour information of the sample. The diffracted electron beam will be collected by the objective lens and then converged at the back focal plane (BFP), which is the position of the objective aperture; part of the diffraction spots are blocked by the objective aperture. The aperture size of the objective aperture is generally smaller than the size of the diffraction image on the back focal plane, so that part of the high-frequency diffraction spots can be blocked.

[0043] The inventive concept of the present application is described below.

[0044] In the prior art, since the high-energy electron beam continuously irradiates the sample, it may cause irreversible structural damage and changes to the sample, and the electrochemical signal cannot be accurately measured in a vacuum environment, which easily leads to observation illusions.

[0045] The invention provides an electron beam deflection pulse generating device for a transmission electron microscope, which is applied to an objective lens system of the transmission electron microscope, and realizes deflection control of the electron beam and control of the number of electrons irradiated on a sample by controlling the electric field environment of the objective lens aperture, thereby avoiding structural damage to the sample caused by electron beam radiation, and realizing accurate measurement of electrochemical signals of the sample by the transmission electron microscope.

[0046] The present invention provides an electron beam deflection pulse generating device for a transmission electron microscope, such as Figure 2 As shown, Figure 2 The schematic diagram of the structure of the electron beam deflection pulse generating device 200 for a transmission electron microscope provided in this embodiment is applied to the objective lens system of the transmission electron microscope, and the device includes a square wave pulse module 201 and a negative pulse generating module 202;

[0047] The square wave pulse module 201 is used to send a square wave trigger pulse signal of a preset frequency to the negative pulse generation module 202 according to the characteristics of the sample to be tested;

[0048] The negative pulse generating module 202 is used to perform waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage; wherein the negative pulse output signal is used to change the incident angle of the electron beam and the number of incident electrons.

[0049] The electron beam deflection pulse generating device for a transmission electron microscope provided in this embodiment sends a square wave trigger pulse signal of a preset frequency to a negative pulse generating module through a square wave pulse module according to the characteristics of a sample to be tested, and the negative pulse generating module performs waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage, thereby controlling the incident angle and the number of incident electrons of the electron beam, thereby controlling the irradiation energy of the electron beam on the sample. The device provided in this embodiment can adjust the frequency range of the square wave trigger pulse signal according to the characteristics of the sample through the square wave pulse module to meet the detection requirements of different samples; generate a fast pulse with a DC bias voltage and a narrow pulse width through the negative pulse generation module, which can deflect the electron beam under the action of the DC bias voltage when the fast pulse does not arrive, so that the electron beam does not irradiate the sample; when the fast pulse arrives, the electron beam irradiates the sample in a very short time when the pulse occurs, giving the sample an environment and relaxation time for structural relaxation, so that the sample recovers to its original intrinsic structure, thereby protecting the sample and extending the service life of the sample, while also avoiding observation illusions and realizing accurate measurement of the electrochemical signals of the sample by a transmission electron microscope.

[0050] As a preferred embodiment, Figure 3 As shown, the square wave pulse module 201 includes a host computer 301 and an embedded control module 302;

[0051] The host computer 301 is used to determine the frequency of the square wave trigger pulse signal according to the characteristics of the sample to be tested, and send a control instruction containing the frequency information to the embedded control module 302;

[0052] The embedded control module 302 is used to generate a square wave trigger pulse signal according to the control information sent by the host computer, and input the square wave trigger pulse signal to the negative pulse generation module 202.

[0053] As a specific example, Figure 4 As shown, Figure 4 The operation interface diagram of the host computer 301 is shown in Figure 3. The NILabVIEW platform is used to control the switch of the host computer serial port by turning on the serial port button. When in use, enter the required frequency (range is 1MHz to 10MHz) in the input frequency input box, click the send button, and the frequency data can be sent to the embedded control module 302. In addition, the square wave pulse data collected by the embedded control module 302 can also be received and displayed in the waveform chart.

[0054] As a specific embodiment, the embedded control module 302 uses a main control STC32G12K128, which generates a PWM wave with a duty cycle of 50% by controlling its built-in hardware-level PWM timer to form the square wave trigger pulse signal. It should be noted that when the module is initialized, it will generate a square wave pulse with a frequency of 5MHz. After receiving the data sent by the host computer, the frequency of the square wave pulse is changed by changing the value of the counter, so as to achieve adjustable working frequency, and can input square wave trigger pulse signals of different frequencies to the negative pulse generation module 202 according to the detection requirements of different samples.

[0055] In order to reduce hardware costs while ensuring communication quality, as a specific embodiment, the host computer 301 and the embedded control module 302 use serial port communication, the communication chip is CH340, the embedded control module sends square wave pulse data to the host computer through the serial port, and the host computer sends frequency data to the embedded control module.

[0056] As a preferred embodiment, Figure 5 As shown, the negative pulse generating module 202 includes a pulse generating circuit 501, a pulse shaping circuit 502 and a pulse bias circuit 503;

[0057] The pulse generating circuit 501 is used to convert the square wave trigger pulse signal to obtain a first negative pulse signal;

[0058] The pulse shaping circuit 502 is used to adjust the pulse width of the first negative pulse signal to obtain a second negative pulse signal;

[0059] The pulse bias circuit 503 is used to provide a DC bias voltage for the second negative pulse signal to obtain a negative pulse output signal with a bias voltage.

[0060] As a preferred embodiment, the pulse generating circuit 501 includes an N-channel MOS transistor, a MOS transistor driver and a charging capacitor;

[0061] The drain of the N-channel MOS tube is connected to one end of the charging capacitor and is connected to the charging power supply through a pull-up resistor; the gate of the N-channel MOS tube is connected to the level output pin of the MOS tube driver; the signal input end of the MOS tube driver is connected to the embedded control module; the other end of the charging capacitor is grounded through a pull-down resistor;

[0062] When the square wave trigger pulse is at a low level, the MOS tube driver outputs a low level, the N-channel MOS tube is not turned on, and the charging power supply charges the charging capacitor;

[0063] When the square wave trigger pulse is at a low level, the MOS tube driver outputs a high level, the N-channel MOS tube is turned on, and the charging capacitor is discharged through the N-channel MOS tube.

[0064] As a specific example, Figure 6 As shown, Figure 6 : is a specific structural diagram of the pulse generating circuit. When the trigger pulse level is low, the MOS tube driver outputs a low level, the MOS tube is not turned on, and the power supply V1 charges the charging capacitor C1; when the trigger pulse level is high, the MOS tube driver outputs a high level, the MOS tube is turned on, and the capacitor C1 is discharged through the MOS tube.

[0065] It should be noted that in order to further reduce the irradiation time of the electron beam on the sample, when selecting here, the conduction time of the MOS tube needs to be at the 10 nanosecond level, and the capacitance of the charging capacitor is about 10pF, so that the first negative pulse signal is a negative pulse with a falling edge of 661ps and a rising edge of 65ps.

[0066] As a preferred embodiment, the pulse shaping circuit 502 includes a first shaping diode and a second shaping diode;

[0067] The anode of the first shaping diode is connected to the cathode of the second shaping diode, and the cathode is connected to the output end of the pulse generating circuit and the anode of the second shaping diode; the anode of the second shaping diode is also connected to the input end of the pulse bias circuit, and the cathode is grounded.

[0068] As a preferred embodiment, the first shaping diode is a step recovery diode, and the fall time of the step recovery diode when it is turned off is almost zero, so it has the characteristic of rapid cutoff; the second shaping diode is a Schottky diode. Since the Schottky diode has the advantages of low power consumption and high speed, it is widely used as a high-frequency, low-voltage, and high-current rectifier diode.

[0069] As a specific example, Figure 7 As shown, Figure 7 4 is a specific circuit structure diagram of the pulse shaping circuit 502. Figure 7 In the figure, diode D1 is a step recovery diode with a reverse rapid cutoff characteristic; D2 is a Schottky diode with a fast turn-on performance. When the first negative pulse signal generated by the pulse generating circuit reaches the pulse shaping circuit, the waveform is superimposed at the branch (circuit output end) to form a negative pulse with a 168ps falling edge and a 51ps rising edge, thereby shaping the first negative pulse signal generated by the pulse generating circuit into a fast pulse with a narrow pulse width, and obtaining a second negative pulse signal.

[0070] As a specific embodiment, the pulse bias circuit 503 is used to provide a DC bias voltage to the fast pulse (second negative pulse signal) shaped by the pulse shaping circuit. In this embodiment, the DC bias voltage applied is 10V.

[0071] As a preferred embodiment, the output end of the negative pulse generation module includes an IPEX interface, and the IPEX interface is connected to the objective aperture of the lens electron microscope through a coaxial line.

[0072] In order to reduce the thickness of the PCB board, as a preferred embodiment, the output IPEX interface of the negative pulse generating module is a fifth-generation IPEX interface, and the IPEX interface is welded to the output port of the negative pulse generating module.

[0073] Since the thickness of the objective lens aperture is usually around 2mm, the fifth-generation IPEX interface is selected, which has a height of less than 1.3mm. It can effectively transmit the signal without changing the size of the objective lens system.

[0074] As a preferred embodiment, the coaxial line is RF0.6 radio frequency wire. By using RF0.64 high-performance coaxial line for transmission, impedance matching and connection between the pulse generator and the transmission electron microscope objective aperture are ensured.

[0075] As a specific embodiment, in this example, the width of the pulse transmission line is designed using POLAR Si9000 calculation software, and the pad width or height of the corresponding component is changed to keep the width of the entire transmission path unchanged, thereby achieving 50 ohm impedance matching and reducing reflections in the transmission path.

[0076] In order to verify the effect of the present invention, Figure 8 As shown, Figure 8 The measurement results of the negative pulse output signal using an oscilloscope are shown. The oscilloscope used is WaveMaster830Zi-B, with a bandwidth of 30GHz and a sampling rate of 80GHz / s. When the input impedance is 50 ohms, the amplitude of the input pulse should be within the range of ±2V. In order to protect the test equipment, a 30dB attenuator is connected to the output port. The test results show that the pulse amplitude is 348mV and the pulse width is 112.7ps, that is, the actual amplitude of the pulse is 10.78V, so the incident angle and the number of electrons of the electronic pulse signal can be adjusted at the level of 100ps.

[0077] The present invention discloses an electron beam deflection pulse generating device for a transmission electron microscope. A square wave pulse module sends a square wave trigger pulse signal of a preset frequency to a negative pulse generating module according to the characteristics of a sample to be tested. The negative pulse generating module performs waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage, and controls the incident angle and the number of incident electrons of the electron beam, thereby controlling the irradiation energy of the electron beam on the sample.

[0078] The present invention can adjust the frequency range of a square wave trigger pulse signal according to sample characteristics through a square wave pulse module to meet the detection requirements of different samples; a fast pulse with a DC bias voltage and a narrow pulse width is generated through a negative pulse generation module, so that when the fast pulse does not arrive, the electron beam can be deflected under the action of the DC bias voltage, so that the electron beam is not irradiated on the sample; when the fast pulse arrives, the electron beam is irradiated on the sample in a very short time when the pulse occurs, giving the sample a structural relaxation environment and relaxation time, so that the sample is restored to its original intrinsic structure, thereby achieving the technical effect of protecting the sample and extending the service life of the sample, and also avoiding the occurrence of observation illusions, so as to realize the accurate measurement of the electrochemical signal of the sample by the transmission electron microscope.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An electron beam deflection pulse generating device for a transmission electron microscope, applied to an objective lens system of a transmission electron microscope, characterized in that: The device comprises a square wave pulse module and a negative pulse generation module; The square wave pulse module is used to send a square wave trigger pulse signal of a preset frequency to the negative pulse generation module according to the characteristics of the sample to be tested; The negative pulse generating module is used to perform waveform processing on the square wave trigger pulse signal to obtain a negative pulse output signal with a bias voltage; wherein the negative pulse output signal is used to change the incident angle of the electron beam and the number of incident electrons; The negative pulse generating module comprises a pulse generating circuit, a pulse shaping circuit and a pulse bias circuit; The pulse generating circuit is used to convert the square wave trigger pulse signal to obtain a first negative pulse signal; The pulse shaping circuit is used to adjust the pulse width of the first negative pulse signal to obtain a second negative pulse signal; The pulse bias circuit is used to provide a DC bias voltage for the second negative pulse signal to obtain a negative pulse output signal with a bias voltage; The pulse generating circuit comprises an N-channel MOS tube, a MOS tube driver and a charging capacitor; The drain of the N-channel MOS tube is connected to one end of the charging capacitor and is connected to the charging power supply through a pull-up resistor; the gate of the N-channel MOS tube is connected to the level output pin of the MOS tube driver; the signal input end of the MOS tube driver is connected to the embedded control module; the other end of the charging capacitor is grounded through a pull-down resistor; When the square wave trigger pulse is at a low level, the MOS tube driver outputs a low level, the N-channel MOS tube is not turned on, and the charging power supply charges the charging capacitor; When the square wave trigger pulse is at a low level, the MOS tube driver outputs a high level, the N-channel MOS tube is turned on, and the charging capacitor is discharged through the N-channel MOS tube.

2. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 1, characterized in that: The square wave pulse module includes a host computer and an embedded control module; The host computer is used to determine the frequency of the square wave trigger pulse signal according to the characteristics of the sample to be tested, and send a control instruction containing the frequency information to the embedded control module; The embedded control module is used to generate a square wave trigger pulse signal according to the control information sent by the host computer, and input the square wave trigger pulse signal into the negative pulse generating module.

3. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 1, characterized in that: The pulse shaping circuit includes a first shaping diode and a second shaping diode; The anode of the first shaping diode is connected to the cathode of the second shaping diode, and the cathode is connected to the output end of the pulse generating circuit and the anode of the second shaping diode; The anode of the second shaping diode is also connected to the input end of the pulse bias circuit, and the cathode is grounded.

4. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 3, characterized in that: The first shaping diode is a step recovery diode; the second shaping diode is a Schottky diode.

5. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 1, characterized in that: The output end of the negative pulse generation module comprises an IPEX interface, and the IPEX interface is connected to the objective aperture of the lens electron microscope through a coaxial line.

6. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 5, characterized in that: The output IPEX interface of the negative pulse generating module is a fifth-generation IPEX interface, and the IPEX interface is welded to the output port of the negative pulse generating module.

7. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 5, characterized in that: The coaxial line is RF0.6 radio frequency wire.

8. The electron beam deflection pulse generating device for a transmission electron microscope according to claim 1, characterized in that: The frequency of the square wave trigger pulse signal output by the square wave pulse module can be adjusted in the range of 1Mhz to 10MHz.

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