CN113555267A

CN113555267A - Electron microscope system

Info

Publication number: CN113555267A
Application number: CN202110693214.1A
Authority: CN
Inventors: 曹峰; 卢志钢; 姚一帆; 刘纪凯; 孙思嘉; 张齐容; 栗宽; 徐强
Original assignee: Najing Dingxin Particle Technology Guangzhou Co ltd
Current assignee: Najing Dingxin Particle Technology Guangzhou Co ltd
Priority date: 2021-06-22
Filing date: 2021-06-22
Publication date: 2021-10-26

Abstract

An electron microscope system for generating a plurality of electron beams (50) for scanning a sample (40) comprises: a multi-electron beam forming subsystem (10) and a multi-electron beam scanning subsystem (20), wherein the multi-electron beam forming subsystem (10) is configured to form a plurality of electron beams (50), the multi-electron beam scanning subsystem (20) is configured to project the plurality of electron beams (50) onto a sample (40), and wherein the multi-electron beam scanning subsystem (20) comprises a deflector module (240), and the deflector module (240) is configured to change a trajectory of the electron beams (50) by an applied electric field and/or magnetic field to scan the sample (40).

Description

Electron microscope system

Technical Field

The present application relates to the field of electron microscope technology, and more particularly, to an electron microscope system.

Background

An electron microscope is an important scientific instrument, and plays a great role in the fields of material science, life science, semiconductor industry and the like. Electron microscopes can be generally classified into transmission electron microscopes and scanning electron microscopes. Generally, a tem can also have a scanning transmission function, in which a focused narrow high-energy electron beam is used to scan a sample, and during the scanning process, the electron beam information of a thin sample is collected to achieve the purpose of characterizing the microscopic morphology of a substance. Although microscopic details of the sample are shown to meet human demand, the efficiency (i.e., the area of the image that can be scanned per unit time) is too low. And existing electron microscopes generally only support scanning of a single sample and are not capable of simultaneously collecting transmission information efficiently for the scanned sample.

In view of the above technical problems that the conventional electron microscope in the prior art only supports scanning of a single sample, and has low scanning efficiency and cannot simultaneously collect transmission information of the scanned sample, no effective solution has been proposed at present.

Disclosure of Invention

The present disclosure provides an electron microscope system to at least solve the technical problems existing in the prior art that an electron microscope only supports scanning of a single sample, and the scanning efficiency is low and transmission information of the scanned sample cannot be collected at the same time.

According to an aspect of the present application, there is provided an electron microscope system for generating a plurality of electron beams for scanning a sample, comprising: a multiple electron beam forming subsystem and a multiple electron beam scanning subsystem. Wherein the deflector multi-beam forming subsystem is configured to form a plurality of beams and the deflector multi-beam scanning subsystem is configured to project the deflector plurality of beams onto the sample. And wherein the deflector multi-beam scanning subsystem comprises a deflector module that scans the sample by changing the trajectory of the deflector beam by an applied electric and/or magnetic field.

According to another aspect of the present application, there is provided an electron microscope system for generating a plurality of electron beams for scanning a sample, comprising: a multi-electron beam forming subsystem for forming a plurality of electron beams and a multi-electron beam scanning subsystem for projecting the plurality of electron beams to a sample, and wherein the multi-electron beam scanning subsystem comprises: a focusing lens module array, an electron beam shutter array and a diaphragm. The focusing lens module array is arranged at the lower side of the multi-electron beam forming subsystem and is used for focusing a plurality of electron beams on the electron beam gate array; and the electron beam gate array is arranged at the lower side of the focusing lens module array and is used for controlling the inclination of each electron beam in the plurality of electron beams so as to control each electron beam to pass through or deviate from the diaphragm hole of the diaphragm.

According to another aspect of the present application, there is provided an electron microscope system for generating a plurality of electron beams for scanning a sample, comprising: a multi-electron beam collection subsystem disposed on an underside of a sample carrier for carrying a sample, wherein the multi-electron beam collection subsystem comprises: the projection lens module and the scanning transmission detector array are arranged on the lower side of the projection lens module. The projection lens module is used for projecting the electron beam penetrating through the sample onto the scanning transmission detector array; and the scanning transmission detector array comprises a plurality of independent detectors for respectively collecting different electron beams transmitted through the sample.

Therefore, according to the electron microscope system provided by the embodiment of the application, a plurality of electron beams for scanning a sample are formed by the multi-electron beam forming subsystem, and then the plurality of electron beams are projected onto the sample by the multi-electron beam scanning subsystem to scan the sample. The multi-electron beam scanning subsystem is provided with a deflector module, and the technical effect of vertical projection scanning on a sample is achieved by applying an electric field or a magnetic field on the deflector module to change the motion tracks of a plurality of electron beams. Thereby the electron microscope system of this application not only can form a plurality of electron beams that scan the sample to realize a plurality of electron beam vertical projection samples through the deflector module, and then can more fully obtain the vertical projection information of sample, the structural information of the detection sample of undistorted reaches and carries out high-efficient scanning and the transmission electron signal's of being convenient for to collect the sample technical effect to the sample. And the electron beams scanned by the sample are collected by the multi-electron beam collection subsystem, so that the technical effect of displaying the projection information of the sample is achieved. And then solved the scanning that the present electron microscope that exists only supports single sample among the prior art to scanning efficiency is low and can't collect the transmission information of scanning the sample simultaneously technical problem.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present application will be described in detail hereinafter by way of illustration and not limitation with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

FIG. 1 is a schematic diagram of an electron microscope system according to an embodiment of the present application;

FIG. 2 is a schematic diagram of the electron microscopy system of FIG. 1 controlling the tilt of each electron beam by an array of electron brake beams; and

FIG. 3 is a schematic diagram of a prior art scanning electron collection system.

Detailed Description

It should be noted that, in the present disclosure, the embodiments and features of the embodiments may be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

In order to make the technical solutions of the present disclosure better understood by those skilled in the art, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only some embodiments of the present disclosure, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

It should be noted that the terms "first," "second," and the like in the description and claims of the present disclosure and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances for describing the embodiments of the disclosure herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Fig. 1 is a schematic diagram of an electron microscope system for generating a plurality of electron beams 50 for scanning a sample 40 according to a first aspect of an embodiment of the present application. Referring to fig. 1, the electron microscope system includes: a multiple electron beam forming subsystem 10 for forming a plurality of electron beams 50, and a multiple electron beam scanning subsystem 20 for projecting the plurality of electron beams 50 onto a sample 40. And wherein the multi-beam scanning subsystem 20 includes a deflector module 240, the deflector module 240 altering the trajectory of the electron beam 50 by an applied electric and/or magnetic field to scan the sample 40.

As described in the background, electron microscopes can be generally classified into transmission electron microscopes and scanning electron microscopes. Generally, a tem can also have a scanning transmission function, in which a focused narrow high-energy electron beam is used to scan a sample, and during the scanning process, the electron beam information of a thin sample is collected to achieve the purpose of characterizing the microscopic morphology of a substance. Although microscopic details of the sample are shown to meet human demand, the efficiency (i.e., the area of the image that can be scanned per unit time) is too low. And existing electron microscopes generally only support scanning of a single sample and are not capable of simultaneously collecting transmission information efficiently for the scanned sample.

In view of this, the embodiment of the present application provides an electron microscope system, which forms a plurality of electron beams 50 for scanning a sample 40 by a multi-electron beam forming subsystem 10, and then projects the plurality of electron beams 50 onto the sample 40 by a multi-electron beam scanning subsystem 20 to scan the sample 40. The multi-electron beam scanning subsystem 20 is provided with a deflector module 240, and the motion trajectory of the plurality of electron beams 50 is changed by applying an electric field or a magnetic field to the deflector module 240, so as to achieve the technical effect of performing vertical projection scanning on the sample 40. Thereby the electron microscope system of this application not only can form a plurality of electron beams 50 that scan sample 40 to realize a plurality of electron beams 50 vertical projection sample 40 through deflector module 240, and then can more fully obtain the vertical projection information of sample, the structural information of the detection sample of undistorted reaches and carries out high-efficient scanning and be convenient for collect the transmission electron signal's of sample 40 technical effect to sample 40. And further the technical problems that the existing electron microscope in the prior art only supports the scanning of a single sample and the scanning efficiency is low are solved.

Optionally, the multi-electron beam scanning subsystem 20 further comprises: a first magnetic lens 230 disposed on an upper side of the deflector module 240; and a diaphragm 250 disposed at a lower side of the deflector module 240, wherein the first magnetic lens 230 is used for changing a motion trajectory of the plurality of electron beams 50 such that the plurality of electron beams 50 pass through a first diaphragm hole 251 of the diaphragm 250.

Specifically, referring to fig. 1, the trajectories of the plurality of electron beams 50 are changed by the first magnetic lens 230 so that the plurality of electron beams 50 can pass through the first diaphragm hole 251 previously provided on the diaphragm 250. And the aperture 250 is used to control the electron beam irradiated on the sample. And the deflector module 240 is disposed above the diaphragm 250, and the proportional force of the scanning of the deflector module 240 is adjusted in advance, ensuring that a plurality of electron beams 50 can pass through the first diaphragm hole 251 at the same time. In addition, the scan field of the plurality of electron beams 50 over the scanned transmissive sample 40 is controlled by the deflector module 240. Therefore, the technical effect of realizing multi-electron beam vertical projection scanning on the sample 40 is achieved through the arrangement of the multi-electron scanning subsystem 20. Thereby making it possible to sufficiently obtain the vertical projection information of the sample 40.

Optionally, the deflector module 240 includes an upper coil 241 and a lower coil 242 arranged in a stack, wherein the upper coil 241 and the lower coil 242 are dimensioned proportionally to enable the electron beam 50 passing through the deflector module 240 to pass through the first diaphragm aperture 251 of the diaphragm 250.

Specifically, referring to fig. 1, and the deflector module 240 is disposed above the diaphragm 250, the deflector module 240 is composed of a plurality of deflectors, wherein each deflector is provided with an upper coil 241 and a lower coil 242. In the case of applying a deflection field to the deflector, more electron beams 50 may pass through the first diaphragm hole 251 by configuring a size ratio (e.g., a coil ratio) of the upper coil 241 and the lower coil 242 in advance. That is, the proportional forces scanned by the upper and

lower coils

241 and 242 can be configured in advance to ensure that a plurality of parallel electron beams can pass through the first aperture 251 at the same time. Thereby achieving the technical effect of performing a full scan of the sample 40.

Alternatively, the multiple electron beam forming subsystem 10 includes an electron source 110 and a beam splitting module 120 disposed below the electron source 110, and the beam splitting module 120 includes: a beam splitting aperture array 121 disposed on a lower side of the electron source 110, and a second magnetic lens 122 disposed on a lower side of the beam splitting aperture array 121, wherein the beam splitting aperture array 121 includes a plurality of second aperture apertures 1211 arranged in an array form for dividing electrons emitted from the electron source 110 into a plurality of electron beams 50; and a second magnetic lens 122 for shaping the plurality of electron beams 50 into a plurality of parallel electron beams.

Specifically, referring to FIG. 1, the electron source position 110 was located at the uppermost position of the electron microscope system, and electrons were emitted from the electron source after heating it to 1700k and simultaneously increasing the field strength of 10e6v/cm at the surface of the electron source 110. Thereby achieving the emission of electrons.

Further, the beam splitting module 120 includes a beam splitting aperture array 121 and a second magnetic lens 122. Wherein a plurality of second diaphragm apertures 1211 are provided in an array form on the beam splitting diaphragm 121 in advance so that the electrons can be split into a plurality of electron beams 50. Wherein the positions and sizes of the plurality of diaphragm apertures 1211 are preset. And referring to fig. 1, the second magnetic lens 122 may be a parallel electron beam magnetic lens, and after the plurality of electron beams 50 are projected onto the second magnetic lens 122, the second magnetic lens 122 may converge the plurality of electron beams 50 into a plurality of parallel or approximately parallel electron beams 50. Thereby achieving the technical effect of forming a plurality of parallel electron beams 50.

Optionally, the multi-electron beam scanning subsystem 20 further comprises: a focusing lens module array 210 and an electron beam shutter array 220, wherein the focusing lens module array 210 is disposed at a lower side of the multi-electron beam forming subsystem 10 for focusing the plurality of electron beams 50 on the electron beam shutter array 220; and an electron beam shutter array 220 disposed between the focusing lens module array 210 and the deflector module 240 for controlling the tilt of each of the plurality of electron beams 50 and further controlling each electron beam to pass through or deviate from the first aperture 251 of the aperture 250.

Specifically, referring to fig. 1, a plurality of electron beams 50 enter a preset focusing lens module array 210 and then are converged in a preset electron beam shutter array 220. The focusing lens module array 210 can adjust the height of the spot focused on the electron beam shutter array 220 by adjusting the electric potential value. Because some of the electron beams 50 are imaged off-axis in the case of scanning the sample by the electron microscope, the phase difference caused by off-axis imaging can be compensated by appropriately adjusting the height and size of the focused spots in the electron beam shutter array 220. And the voltage of the middle electrode of the focusing lens module array 210 is independently adjusted, so that the upper and lower positions of the focusing spot of the electron beam gate array 220 can be adjusted, thereby achieving the technical effect of improving the imaging quality of the sample.

Optionally, the electron beam gate array 220 includes electron beam gates 221 respectively corresponding to the electron beams 50, and the electron beam gates 221 are configured to apply an electric field and/or a magnetic field to the corresponding electron beams to control the tilt of the corresponding electron beams.

Specifically, referring to fig. 2, the focusing spot of the electron beam 50 is focused at the middle position of the electron beam gate in the electron beam gate array 220, and the plurality of electron beams 50 passing through it are focused on the back focal plane thereof by applying a suitable magnetic field excitation value to the first magnetic lens 230. The diaphragm 250 is located on the back focal plane of the first magnetic lens 230. Referring to fig. 2, when a deflection electric field or a magnetic field is applied to the electron beam shutter array 220, the passing electron beam may be tilted, and the tilted electron beam may not pass through the first diaphragm hole 251 of the lower diaphragm 250 and thus may not be irradiated onto the sample. This allows independent control of which beams can impinge on the sample, never avoiding some beams scanning vulnerable parts of the sample.

Alternatively, the focusing lens module array 210 includes focusing lens systems 211 respectively corresponding to the respective electron beams 50, wherein the focusing lens systems 211 include an upper electrode 211a, a middle electrode 211b, and a lower electrode 211c that are sequentially stacked, and wherein the upper electrode 211a and the lower electrode 211c are grounded, and the middle electrode 211b receives a voltage for focusing the corresponding electron beam 50.

Specifically, referring to fig. 1, the focusing lens module array 210 includes focusing lens systems 211 respectively corresponding to the electron beams 50, and an upper electrode 211a, a middle electrode 211b, and a lower electrode 211c, which are sequentially stacked on the focusing lens systems 211. The upper and

lower electrodes

211a and 211c are grounded, and the middle electrode 211b receives a voltage for controlling the tilt of the corresponding electron beam, which is set to achieve focusing of the electron beam current. The middle electrode 211b of the focusing lens module array 210 can independently adjust the electric potential value, so as to properly adjust the height of the focusing spot inside the electron beam shutter array 220. Because some of the electron beams 50 are imaged off-axis, the phase difference caused by the off-axis imaging can be compensated by appropriately adjusting the height and size of the focused spots in the electron beam shutter array 220.

Optionally, the multi-electron beam scanning subsystem 20 further comprises: and an objective lens 260 disposed at a lower side of the stop 250, a front focal plane of the objective lens 260 having the same height as the stop 250 for vertically projecting the plurality of electron beams 50 onto the sample 40.

Specifically, referring to fig. 1, the front focal plane of the objective lens 260 is disposed at the same height as the stop 250, so that the electron beam 50 passing through the stop 250 can be vertically incident on the sample 40 after entering the objective lens 260. The specimen 40 is located at the back focal plane of the objective lens 260, and when incident parallel electron beams 50 are converged on the specimen 40 at a position set in advance. When the deflector module 240 applies scanning deflection to the plurality of parallel electron beams 50, the plurality of electron beams 50 can pass through the first diaphragm aperture 251 and enter the objective lens 260, so that the scanning process can be realized on the sample 40, and the multiple electron beams can be vertically focused on the sample 40. Therefore, the electron beam 50 is scanned and incident to the sample at a vertical or approximately vertical angle, and the vertical projection information of the sample can be fully obtained, and the structural information of the sample can be detected without distortion. And the single electron beam with vertical incidence is also beneficial to the detection of the scanning transmission signal, the efficiency of the detector 331 for scanning the transmission beam is improved, the signal to noise ratio is improved, and the imaging quality is improved.

Optionally, the method further comprises: a multi-electron beam collection subsystem 30 disposed on an underside of a sample carrier for carrying a sample 40, wherein the multi-electron beam collection subsystem 30 comprises: the projection lens module 320 and the scanning transmission detector array 330 disposed at the lower side of the projection lens module 320, and the projection lens module 320 is used for projecting the electron beam transmitted through the sample 40 onto the scanning transmission detector array 330; and the scanning transmission detector array 330 includes a plurality of individual detectors 331 for respectively collecting the different electron beams 50 transmitted through the sample 40.

Specifically, referring to FIG. 1, the multi-electron beam collection subsystem 30 includes a projection mirror module 320 and a scanning transmission detector array 330. The projection mirror module 320 projects the multiple electron beams 50 transmitted through the sample 40 to the location of the scanning transmission detector array 330. Fig. 3 shows a conventional sample-transmitting electron collecting system, which has a technical problem that the detector is inconvenient to install, but the detector 331 is provided with a physical space for installation by the multi-electron beam collecting subsystem 30 proposed in the present application. The position and area of the detector 331 are pre-designed so that the projection lens module 320 can collect the scanning transmission electrons containing sample information onto the detector 331 when the multi-electron beam 50 is scanned over the sample 40. The electron beam spot projected onto the scanning transmission detector array 330 may be a focused spot, or may not be a focused spot, but a small-area electron beam spot, and it is necessary to ensure that the electron beam spot can enter the corresponding independent detector 331, so that the electron beam spot projected onto the detector 331 is not limited to a focused spot, as long as it is projected onto the detector 331.

So that the collection of the transmitted electron beam can be achieved by the above arrangement. Further, the technical problem that due to the fact that the distance between each beam of the multi-electron beam 50 on the sample is small, approximately dozens of micrometers to hundreds of micrometers, if the scanning transmission detector array is directly placed below the sample, corresponding detector channels can interfere with each other, and information of corresponding areas cannot be independently collected is solved.

Optionally, the multi electron beam collection subsystem 30 further comprises: and an imaging diaphragm array 310 disposed on the upper side of the projection lens module 320, wherein the imaging diaphragm array 310 includes a plurality of third diaphragm holes 311 arranged in an array.

Specifically, referring to fig. 1, the multi-electron beam collecting subsystem 30 further includes an imaging diaphragm array 310 disposed on an upper side of the projector module 320, and the imaging diaphragm array 310 includes a plurality of third diaphragm holes 311 arranged in an array form. Thereby limiting stray electrons and high angle scanning transmission electron imaging through the third imaging aperture 311 of imaging aperture array 310. Thereby achieving the technical effect of increasing the image quality.

In addition, a second aspect of the embodiments of the present application proposes an electron microscope system for generating a plurality of electron beams to scan a sample 40, including: a multi-electron beam forming subsystem 10 and a multi-electron beam scanning subsystem 20, wherein the multi-electron beam forming subsystem 10 is for forming a plurality of electron beams 50, the multi-electron beam scanning subsystem 20 is for projecting the plurality of electron beams 50 to a sample 40, and wherein the multi-electron beam scanning subsystem 20 comprises: a focusing lens module array 210, an electron beam shutter array 220 and a diaphragm 250, wherein the focusing lens module array 210 is disposed at the lower side of the multi-electron beam forming subsystem 10 for focusing a plurality of electron beams on the electron beam shutter array 220; and an electron beam shutter array 220 disposed under the focusing lens module array 210 for controlling the tilt of each of the plurality of electron beams 50 and further controlling each electron beam to pass through or deviate from the aperture opening 251 of the aperture 250.

Specifically, reference is made to the description of the electron microscope according to the first aspect of the present embodiment, and details are not repeated here.

Further, a third aspect of the embodiments of the present application proposes an electron microscope system for generating a plurality of electron beams to scan a sample 40, including: a multi-electron beam collection subsystem 30 disposed on an underside of a sample carrier for carrying a sample 40, wherein the multi-electron beam collection subsystem 30 comprises: the projection lens module 320 and the scanning transmission detector array 330 disposed at the lower side of the projection lens module 320, and the projection lens module 320 is used for projecting the electron beam transmitted through the sample 40 onto the scanning transmission detector array 330; and the scanning transmission detector array 330 includes a plurality of individual detectors 331 for respectively collecting the different electron beams 50 transmitted through the sample 40.

Thus, according to the electron microscope system provided in the embodiment of the present application, the multiple electron beam forming subsystem 10 forms the multiple electron beams 50 for scanning the sample 40, and then the multiple electron beam scanning subsystem 20 projects the multiple electron beams 50 onto the sample 40 to scan the sample 40. The multi-electron beam scanning subsystem 20 is provided with a deflector module 240, and the motion trajectory of the plurality of electron beams 50 is changed by applying an electric field or a magnetic field to the deflector module 240, so as to achieve the technical effect of performing vertical projection scanning on the sample 40. Thereby the electron microscope system of this application not only can form a plurality of electron beams 50 that scan sample 40 to realize a plurality of electron beams 50 vertical projection sample 40 through deflector module 240, and then can more fully obtain the vertical projection information of sample, the structural information of the detection sample of undistorted reaches and carries out high-efficient scanning and be convenient for collect the transmission electron signal's of sample 40 technical effect to sample 40. And the electron beams scanned over the sample 40 are collected by the multi-electron beam collection subsystem 30, so that the technical effect of displaying the projection information of the sample 40 is achieved. And then solved the scanning that the present electron microscope that exists only supports single sample among the prior art to scanning efficiency is low and can't collect the transmission information of scanning the sample simultaneously technical problem.

In addition, in a typical scanning transmission electron microscope system, a single electron beam is often focused and scanned on a sample, and transmission electron information of different areas is collected in the process to form a local microscopic image of the sample. The system realizes the simultaneous scanning imaging of multiple electron beams on different areas on a sample. The specific experimental mode is as follows:

when the electron source 110 is positioned at the top, when the electron source is heated to 1700k, and meanwhile, after the field intensity of 10e6v/cm is increased on the surface of the electron source 110, electrons are emitted from the electron source 110 and enter the beam splitting diaphragm array 121, and the beam splitting diaphragm array 121 is provided with designed diaphragm holes, so that the light beams are split into multiple beams. In the application, the position and size of the multiple holes on the diaphragm are designed in advance, and after the second magnetic lens 122 converges, a plurality of approximately parallel electron beams can be obtained.

The focusing lens module array 210 is a plurality of electric lens systems 211, and each electric lens system 211 is composed of an upper, a middle and a lower three

poles

211a, 211b and 211 c. The upper and lower poles are grounded, and the middle pole is connected with a higher or lower potential, so that the voltage setting can realize the focusing of electron beams. The intermediate electrodes in the focusing lens module array 210 can independently adjust the potential value, so that the height of the focusing spot inside the electron beam gate can be properly adjusted. Since some of the beams in a multiple electron beam system are imaged off-axis, the focus spot in the electron beam shutter can be adjusted appropriately in order to compensate for the phase difference caused by the off-axis imaging.

The plurality of electron beams enter the second magnetic lens 122, and the electron beams entering the second magnetic lens 122 are corrected to be parallel beams or approximately parallel beams. The parallel or approximately parallel beams enter the focusing lens array module 210 and then converge, and a converging spot is formed below. Thus, the formation of multiple electron beams from a single electron beam is completed. In the design, the beam spot is focused at the middle position of the electron beam shutter 220, and when a proper magnetic field excitation value is applied to the first magnetic lens 230, the multiple electron beams passing through it are focused on the back focal plane thereof. The diaphragm 250 is located on the back focal plane of the first magnetic lens 230. When a deflection electric field or a magnetic field is applied to the electron beam shutter array 220, the passing electron beam can be tilted, and the tilted electron beam cannot pass through the lower diaphragm 250 and thus cannot be irradiated onto the sample. This allows independent control of which beams can impinge on the sample.

In a scanning transmission scene, the multi-electron beam can be focused and can be vertically incident on a sample:

the single electron beam scanning is preferably incident on the sample at a vertical or near-vertical angle, so that the vertical projection information of the sample can be obtained more sufficiently, and the structural information of the sample can be detected without distortion. Under the single-beam scanning transmission mode, the single electron beam which is vertically incident is also beneficial to the detection of the scanning transmission signal, the detector efficiency of the single-scanning transmission beam is improved, the signal to noise ratio is improved, and the imaging quality is improved.

Similarly, multi-beam scanning transmission is also expected to result in multiple beams all incident vertically and focused on the sample, and although difficult to achieve, this approach is well designed to achieve the above requirements. The specific implementation method comprises the following steps: the deflector module 240 is disposed above the diaphragm 250, and the proportional force of the deflector is adjusted during design to ensure that multiple electron beams can pass through the diaphragm 250 at the same time. The front focal plane of the objective lens 260 is at the same height as the aperture 250, so that the electron beam passing through the aperture 250 can be vertically incident on the sample after entering the objective lens 260. The specimen is located at the back focal plane of the objective lens 260 and the parallel incident electron beams are collected on the specimen at the position set in advance. When the deflector module 220 applies scanning deflection to a plurality of electron beams, the plurality of electron beams can pass through the first diaphragm hole 251 and enter the objective lens 260, so that the scanning process can be realized on the sample, and the plurality of electron beams can be vertically focused on the sample. The scanning field of the multiple electron beams on the scanned transmissive sample is controlled by the deflector module 240.

Method of collecting multi-beam scanning transmission electron signals:

some conventional transmission electron microscopes or scanning electron microscopes include a scanning transmission function, and after an electron beam incident on a sample is scattered by the sample, information about different structures or materials of the sample is obtained. The basic principle is that the incident electron beam strikes the sample at a normal or near normal angle, and electrons are transmitted under the sample, and the transmitted electrons contain the structural or elemental information of the sample. The intensity of the information signal corresponds to the gray scale value displayed on the screen. At this time, the scanning drive is applied to the electron beam, the focused electron beam can scan on the sample point by point, the scanning transmission signals are continuously collected, the gray scale information corresponding to each point can be displayed on the fluorescence, and the two-dimensional scale characteristics on the sample can be displayed.

Because the distance between each of the multiple electron beams on the sample 40 is small, on the order of tens of microns to hundreds of microns, if the scanning transmission detector array 330 is placed directly under the sample, the corresponding detector 331 channels will interfere with each other and cannot independently collect information in the corresponding area. The invention provides a mode, and a system for collecting multi-beam scanning transmission electronic signals consists of an imaging diaphragm array 310, a projection lens module 320 and a scanning transmission detector array 330. The projection mirror module 320 projects the multiple electron beams transmitted through the sample to the location of the scanning transmission detector array 330. In this way, physical space is provided for the installation of the detector 331. The position and area of the detector 331 also need to be carefully designed so that when multiple electron beams are scanned over the sample, the projection lens module 320 can still collect the scanned transmitted electrons containing sample information onto the detector 331. The projection onto the scanning transmission detector array 330 may or may not be a focused spot, but rather a small area electron beam spot, as necessary to ensure that the electron beam spot is able to enter the corresponding individual detector 331. The detector 331 may be a semiconductor direct detector or a scintillator photomultiplier detector.

Further, the multi-electron beam scanning transmission electron microscope system: includes a multi-electron beam forming subsystem 10, a multi-electron beam scanning subsystem 20, and a multi-electron beam collecting subsystem 30.

1. The multi electron beam forming subsystem 10: 1) the electron beam of the system comes out from the electron source 110, is split by the multi-aperture beam splitting diaphragm 121, and then is converged into parallel light by the second magnetic lens 122. 2) The voltage of the middle electrode of the focusing lens module array 210 can be adjusted independently, so that the upper and lower positions of the focusing spot of the electron beam gate array 220 can be adjusted, and the imaging quality of the sample can be improved to a certain extent.

2. Multi-electron beam scanning subsystem 20: the aperture 250 is located at the front focal plane of the objective lens 260, and the ratio of the upper and lower scanning coils of the deflector module 240 is selected so that the scanned electron beam just passes through the first aperture 251 and so that the electron beam 50 can vertically irradiate onto the sample 40.

3. The multi electron beam collection subsystem 30: 1) the system consists of an imaging diaphragm array 310, a projection lens module 320 and a scanning transmission detector array 330. 2) An imaging aperture array 310 is added to limit stray electrons and high angle scanning transmission electron imaging. 3) The multi-electron beam scanning transmission electronic signal is projected onto the corresponding detector 331 of the detector array 330, providing a physical space for the arrangement of the detector array 330. 4) The projection mirror module 320 projects the scanning transmission signal onto the scanning transmission detector array 330, and may or may not form a focused spot on the scanning transmission detector 331, and the multi-electron scanning transmission electron beam may be projected onto the detector 331.

The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In the description of the present disclosure, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are presented only for the convenience of describing and simplifying the disclosure, and in the absence of a contrary indication, these directional terms are not intended to indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the disclosure; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An electron microscope system for generating a plurality of electron beams (50) for scanning a sample (40), comprising: a multi-electron beam forming subsystem (10) for forming the plurality of electron beams (50), and a multi-electron beam scanning subsystem (20) for projecting the plurality of electron beams (50) to the sample (40), and wherein

The multi-electron beam scanning subsystem (20) comprises a deflector module (240), the deflector module (240) changing the trajectory of the electron beam (50) by means of an applied electric and/or magnetic field, scanning the sample (40).

2. The electron microscope system of claim 1, wherein the multiple electron beam scanning subsystem (20) further comprises: a first magnetic lens (230) disposed on an upper side of the deflector module (240); and a diaphragm (250) disposed at a lower side of the deflector module (240), wherein

The first magnetic lens (230) is used for changing the motion tracks of the plurality of electron beams (50) so that the plurality of electron beams (50) pass through a first diaphragm hole (251) of the diaphragm (250).

3. The electron microscope system according to claim 2, characterized in that the deflector module (240) comprises an upper coil (241) and a lower coil (242) arranged one above the other, wherein the upper coil (241) and the lower coil (242) are dimensioned in such a ratio that the electron beam (50) passing through the deflector module (240) can pass through the first diaphragm aperture (251) of the diaphragm (250).

4. The electron microscope system according to claim 1, wherein the multiple electron beam forming subsystem (10) comprises an electron source (110) and a beam splitting module (120) disposed below the electron source (110), and the beam splitting module (120) comprises: a beam splitting diaphragm array (121) arranged on the lower side of the electron source (110) and a second magnetic lens (122) arranged on the lower side of the beam splitting diaphragm array (121), wherein

The beam splitting aperture array (121) includes a plurality of second aperture apertures (1211) arranged in an array form for splitting electrons emitted from the electron source (110) into a plurality of electron beams (50); and

the second magnetic lens (122) is for shaping the plurality of electron beams (50) into the plurality of parallel electron beams.

5. The electron microscope system of claim 2, wherein the multi-electron beam scanning subsystem (20) further comprises: an array of focusing lens modules (210) and an array of electron beam shutters (220), wherein

The focusing lens module array (210) is arranged at the lower side of the multi-electron beam forming subsystem (10) and is used for focusing the plurality of electron beams (50) on the electron beam brake array (220); and

the electron beam shutter array (220) is disposed between the focusing lens module array (210) and the deflector module (240) and is used for controlling the inclination of each electron beam (50) in the plurality of electron beams (50) so as to control each electron beam to pass through or deviate from the first diaphragm aperture (251) of the diaphragm (250).

6. The electron microscope system according to claim 5,

the electron beam gate array (220) comprises electron beam gates (221) corresponding to the respective electron beams (50), respectively, the electron beam gates (221) being configured to apply an electric field and/or a magnetic field to the respective electron beams, controlling a tilt of the respective electron beams; and/or

The focusing lens module array (210) includes focusing lens systems (211) respectively corresponding to the electron beams (50), wherein the focusing lens systems (211) include an upper electrode (211a), a middle electrode (211b), and a lower electrode (211c) which are sequentially stacked, and wherein the upper electrode (211a) and the lower electrode (211c) are grounded, and the middle electrode (211b) receives a voltage for focusing the corresponding electron beam (50).

7. The electron microscope system of claim 2, wherein the multi-electron beam scanning subsystem (20) further comprises: an objective lens (260) disposed below the diaphragm (250), a front focal plane of the objective lens (260) having the same height as the diaphragm (250) for perpendicularly projecting the plurality of electron beams (50) on the sample (40).

8. The electron microscope system of claim 1, further comprising: a multi electron beam collection subsystem (30) disposed on an underside of a sample carrier for carrying a sample (40), wherein the multi electron beam collection subsystem (30) comprises: a projection lens module (320) and a scanning transmission detector array (330) arranged on the lower side of the projection lens module (320), and

the projection lens module (320) is used for projecting the electron beam (50) which is transmitted through the sample (40) onto the scanning transmission detector array (330);

the scanning transmission detector array (330) comprises a plurality of individual detectors (331) for separately collecting different electron beams (50) transmitted through the sample (40); and/or

The multi electron beam collection subsystem (30) further comprises: the imaging diaphragm array (310) is arranged on the upper side of the projection lens module (320), and the imaging diaphragm array (310) comprises a plurality of third diaphragm holes (311) which are arranged in an array form.

9. An electron microscope system for generating a plurality of electron beams (50) for scanning a sample (40), comprising: a multi-electron beam forming subsystem (10) for forming a plurality of electron beams (50), and a multi-electron beam scanning subsystem (20) for projecting the plurality of electron beams (50) onto a sample (40), and wherein the multi-electron beam scanning subsystem (20) comprises: an array of focusing lens modules (210), an array of electron beam shutters (220), and an aperture stop (250), wherein

the electron beam shutter array (220) is disposed under the focusing lens module array (210) and is used for controlling the inclination of each electron beam of the plurality of electron beams (50) and further controlling each electron beam to pass through or deviate from the diaphragm aperture (251) of the diaphragm (250).

10. An electron microscope system for generating a plurality of electron beams (50) for scanning a sample (40), comprising: a multi electron beam collection subsystem (30) disposed on an underside of a sample carrier for carrying a sample (40), wherein the multi electron beam collection subsystem (30) comprises: a projection lens module (320) and a scanning transmission detector array (330) arranged on the lower side of the projection lens module (320), and

the projection lens module (320) is used for projecting the electron beam transmitted through the sample (40) onto the scanning transmission detector array (330); and

the scanning transmission detector array (330) comprises a plurality of individual detectors (331) for separately collecting the different electron beams (50) transmitted through the sample (40).