CN207425790U

CN207425790U - A kind of low energy scanning electron microscope system

Info

Publication number: CN207425790U
Application number: CN201721565080.0U
Authority: CN
Inventors: 李帅; 何伟
Original assignee: Spotlight Technology (beijing) Co Ltd
Current assignee: Spotlight Technology (beijing) Co Ltd
Priority date: 2017-11-21
Filing date: 2017-11-21
Publication date: 2018-05-29
Anticipated expiration: 2027-11-21

Abstract

The utility model discloses a kind of low energy scanning electron microscope system, including：Electron source, for generating electron beam；Electronics accelerating structure, for increasing the movement velocity of the electron beam；Complex objective lens, for being converged to the electron beam accelerated through the electronics accelerating structure；Arrangement for deflecting, between the inner wall of the magnetic lenses and the optical axis of the electron beam, for changing the direction of motion of the electron beam；Detection device acts on the first sub- detection device of the secondary electron generated on sample and backscattered electron including being used to receiving electron beam, for receiving the second of the backscattered electron the sub- detection device and for changing the secondary electron and the control device of the direction of motion of the backscattered electron；Electric lens including the second sub- detection device, sample stage and coordination electrode, for reducing the movement velocity of the electron beam, and change the direction of motion of the secondary electron and the backscattered electron.

Description

A kind of low energy scanning electron microscope system

Technical field

The utility model is related to Scanning electron microscopy more particularly to a kind of low energy scanning electron microscope systems

Background technology

Scanning electron microscope is widely used in observing sample in micron or the feature of nano-scale range；In observation biology When nonmetal samples, low energy (energy is less than 3keV) scanning electron microscope is due to can for sample or semiconductor samples It reduces to damage and the charge effect of sample and extensive use.

On the one hand, under low energy condition, the sample of detection is mostly non-conducting material, in order to prevent electric charging effect or damage Hinder sample, the incident usual very little of scanning beam line, only hundreds of pA or even several pA, thus it is electric from the signal of sample excitation It is sub seldom；In order to ensure image quality, detector needs collection signal electron as much as possible, and signal electron collection efficiency Image taking speed is influenced, i.e. signal electron collection efficiency influences scanning electron microscope flux；Therefore, the collection of signal electron is improved Efficiency is vital.

On the other hand, incident beam is excited on sample in the signal electron of generation, and energy is secondary less than 50eV Electronics (Secondary Electrons, SE), energy close to incident electron be backscattered electron (Back-scatter Electrons, BSE).Secondary electron can characterize the shape characteristic of sample, and backscattered electron is due to the original with observed material Material information of the sub- ordinal number in relation to more characterization samples, sample is received compared with the backscattered electron of sample surface emitted at small angles The influence of product surface undulation can also reflect the information of sample surface morphology.Therefore, different classes of signal electron, different angles The backscattered electron of degree outgoing reflects different sample messages.Particularly with biological sample, due to being dyed by heavy metal so that pure Backscattered electron image be more conducive to characterization sample structure.Therefore, by separately detecting secondary electron and backscattered electron, The image of more preferable contrast can be formed, helps to distinguish sample structure.

At present, under low energy condition, there is no simultaneously meet high resolution, signal electron collection efficiency reaches 100% or close to 100%, can flexibly detect the backscattered electron of different launch angles and can flexibly control and receive The scanning electron microscope of the requirements such as the classification of signal electron.

Utility model content

In view of this, the utility model embodiment provides a kind of low energy scanning electron microscope system, is swept keeping low energy While retouching electron microscopy system high-resolution, the collection efficiency of signal electron is improved, the signal electricity flexibly controlled and received The classification of son.

The utility model provides a kind of low energy scanning electron microscope system, including：

For generating the electron source of electron beam；

For increasing the electronics accelerating structure of the movement velocity of the electron beam；

It is made of electric lens and magnetic lenses, is answered for what is converged to the electron beam accelerated through the electronics accelerating structure Close object lens；

Between the inner wall of the magnetic lenses and the optical axis of the electron beam, for changing through the electronics accelerating structure The arrangement for deflecting of the direction of motion of the electron beam of acceleration；

The first son detection of the secondary electron generated on sample and backscattered electron is acted on including being used to receiving electron beam Device and the detection device for receiving the second of the backscattered electron the sub- detection device；

For changing the secondary electron and the control device of the direction of motion of the backscattered electron；

It is made of the second sub- detection device, sample stage and coordination electrode, for reducing the movement velocity of the electron beam, and Change the electric lens of the direction of motion of the secondary electron and the backscattered electron.

In said program, the electronics accelerating structure is an anode.

In said program, the electronics accelerating structure include anode and high-voltage tube, the high-voltage tube, respectively with the sun Pole, the second sub- detection device connection.

In said program, further include：

For changing the electron beam regulating device of the feature of the electron beam after the accelerating structure.

In said program, the electron beam regulating device includes：Converging device and/or diaphragm；Wherein

The converging device, for being converged to the electron beam after electronics accelerating structure acceleration.

The diaphragm, for being filtered to electron beam, the center of the diaphragm is located at the optical axis.

In said program, the first sub- detection device, between the anode and the magnetic lenses, close to the magnetic Lens direction；

The second sub- detection device, positioned at the lower section of the magnetic lenses, close to the pole shoe of the magnetic lenses.

The second sub- detection device, positioned at the lower section of the magnetic lenses, is connected with the lower face of the high-voltage tube.

In said program, the control device includes：Multipole electric deflection device and multipole magnetic deflector.

In said program, the magnetic lenses is the immersion magnetic lenses of current coil excitation, and the pole shoe of the magnetic lenses is opened Mouthful direction is towards the sample.

In said program, the center-hole diameter of the first sub- detection device is not more than 1 millimeter.

In said program, the center-hole diameter of the second sub- detection device is straight less than the centre bore of the coordination electrode Footpath.

In said program, the voltage value V1 ＜ -5kV of the electron source, the voltage value of the anode is zero.

In said program, the second sub- detection device is in ground potential, and the voltage value of the sample stage is V2, V1 ＜ V2 ＜ -5kV, the voltage value V3 of the coordination electrode support to adjust, V3≤0kV.

In said program, the voltage value V1 ＜ 0kV of the electron source, the electricity of the voltage value of the anode and the high-voltage tube Pressure value is V4, V4 ＞+5kV.

In said program, the second sub- detection device voltage value is V4, and the voltage value of the sample stage is V2, V1 ＜ V2 ≤ 0kV, the voltage value V3 of the coordination electrode support to adjust, V3≤V4.

In said program, in the voltage value V3 of the coordination electrode, filled more than the second son detection for forming the electric lens The voltage value put and during the voltage value V2 less than the sample stage for forming the electric lens,

The first sub- detection device, specifically for receiving the angle of secondary electron and exit direction compared with sample surfaces Degree is more than the backscattered electron of first threshold；

The second sub- detection device is less than the first threshold specifically for receiving exit direction compared with the angle of sample surfaces The backscattered electron of value.

In said program, it is described control electric lens in coordination electrode voltage value V3 than the sample stage voltage value V2 extremely When young when 50V,

The first sub- detection device is more than first specifically for only receiving exit direction compared with the angle of sample surfaces The backscattered electron of threshold value；

The second sub- detection device is less than first specifically for only receiving exit direction compared with the angle of sample surfaces The backscattered electron of threshold value.

In said program, further include：

It is connected with the described first sub- detection device and/or the second sub- detection device, for the described first sub- detection device The first signal that secondary electron and/or backscattered electron based on reception generate is handled and/or for the described second son The signal processing apparatus that the secondary signal that backscattered electron of the detection device based on reception generates is handled.

In said program, the signal processing apparatus includes：

Signal for being amplified to first signal and/or the secondary signal amplifies sub-device；

For the signal processing sub-device handled the first amplified signal and/or secondary signal.

In said program, the signal processing apparatus further includes：

For to being handled through the signal processing sub-device treated the first signal and through the signal processing sub-device Secondary signal afterwards carries out synthesis processing, forms the signal synthesis sub-device of combination picture.

In the utility model embodiment, by controlling electron source, electronics accelerating structure, the second sub- detection device, control electricity Pole and the voltage of sample stage so that the drop point energy that electron beam reaches sample is less than 5keV；It is made of electric lens and magnetic lenses Complex objective lens improve the resolution ratio of scanning electron microscope system；Pass through electric lens and the synergistic effect of control device so that 100% is close to or up to the collection efficiency of signal electron；Also, it by the voltage value of adjusting control electrode, can flexibly control The backscattered electron of classification and the special angle outgoing of received signal electronics processed.

Description of the drawings

Fig. 1 is the composition structure diagram of one low energy scanning electron microscope system of the utility model embodiment；

Fig. 2 is the schematic diagram that one detector of the utility model embodiment receives signal electron；

Fig. 3 a are one electric lens field schematic diagram one of the utility model embodiment；

Fig. 3 b are one electric lens field schematic diagram two of the utility model embodiment；

Fig. 4 is the composition structure diagram of two low energy scanning electron microscope system of the utility model embodiment；

Fig. 5 a are the composition structure diagram one of three low energy scanning electron microscope system of the utility model embodiment；

Fig. 5 b are the composition structure diagram two of three low energy scanning electron microscope system of the utility model embodiment；

Fig. 6 is the composition structure diagram of four low energy scanning electron microscope system of the utility model embodiment；

Fig. 7 is the schematic diagram that four detector of the utility model embodiment receives signal electron；

Fig. 8 a are four electric lens field schematic diagram one of the utility model embodiment；

Fig. 8 b are four electric lens field schematic diagram two of the utility model embodiment；

Fig. 9 is the composition structure diagram of five low energy scanning electron microscope system of the utility model embodiment；

Figure 10 a are the composition structure diagram one of six low energy scanning electron microscope system of the utility model embodiment；

Figure 10 b are the composition structure diagram two of six low energy scanning electron microscope system of the utility model embodiment；

Figure 11 is the composition structure diagram of seven low energy scanning electron microscope system of the utility model embodiment；

Figure 12 is the process flow schematic diagram of the utility model embodiment Aug. 1st kind sample detection method；

Figure 13 is a kind of process flow schematic diagram of nine sample detection method of the utility model embodiment.

Specific implementation pattern

With reference to the accompanying drawings and embodiments, the utility model is further elaborated.It should be appreciated that this place is retouched The specific embodiment stated is only used to explain the utility model, is not used to limit the utility model.

Before the utility model is further elaborated, to the noun and art involved in the utility model embodiment Language illustrates, and the noun and term involved in the utility model embodiment are suitable for following explanation.

1) in electron-optical system, electron beam is caused due to having coulomb active force between electronics for space charge effect " expansion ", the phenomenon that increasing the aberration of electron beam imaging systems；Especially when electron beam forms and intersects beam spot, electronics is intersecting Very dense at beam spot, the mutual distance very little between electronics, due to square being inversely proportional for Coulomb force and interelectric distance, Therefore, larger Coulomb force can cause the focusing beam spot of electron beam to expand.

2) initial electron beam, electron beam being generated by electron source, reaching between sample is initial electron beam.

3) signal electron, electron beam are applied to the electronics generated on sample, including：Secondary electron and backscattered electron.

4) optical axis, the optical centre axis of electron beam.

5) launch angle refers to the angle between the exit direction of signal electron and sample surfaces.

It should be noted that in the attached drawing of the utility model, signal electron under the influence of a magnetic field, along optical axis rotation Movement locus is not labeled out, and only beacon signal electronics is in the track where optical axis on meridian plane.

In correlation technique, under low energy condition, the aberration of single magnetic lenses or single electric lens substantially increases, by The aberration of magnetic lenses can be partly compensated in electric lens, therefore it provides a kind of scanning electron microscope, saturating using electric lens and magnetic Microscope group into complex objective lens, to reduce aberration, so improve scanning electron microscope resolution ratio.In an alternative embodiment, Scanning electron microscope has high-voltage tube structure, an electrode of the high-voltage tube in object lens as electric lens, what electron source was emitted Initial electron beam is able to maintain that higher speed in high-voltage tube, and when close to sample, is subject to high-voltage tube and sample composition The influence of electric lens and reduce speed.Another intergrade of optional electrode as electric lens between high-voltage tube and sample, The electric field that electric lens generate is overlapped or is connected with the magnetic field that magnetic lenses generates so that under low energy, electric lens and magnetic lenses The complex objective lens of composition can improve the resolution ratio of scanning electron microscope, improve the performance of scanning electron microscope.

In correlation technique, to improve the resolution ratio of scanning electron microscope, a kind of scanning electron microscope is provided, utilizes magnetic An electrode of the lens pole shoe as electric lens, applies negative voltage on sample, is slowed down with being formed between sample and magnetic lenses Electric field so that the initial electron beam of electron source outgoing is decelerated between magnetic lenses and sample.Between magnetic lenses and sample Another intergrade of optional electrode as electric lens.In the scanning electron microscope, place above object lens and visited in a mirror Device is surveyed, detector is also referred to as in-column detectors in the mirror.Compared to traditional mirror external detector, due to detector in mirror The space between object lens and sample is prevented take up, therefore the operating distance of object lens can be small as far as possible, so that scanning electron is shown Micro mirror can keep higher resolution ratio.

Also, attracted from the secondary electron of sample excitation by the electrostatic field in complex objective lens, form an intersection spot, pass through Object lens are collected by detector in mirror.It is therefore, almost all of secondary less than 50eV even 5eV since secondary electron energy is very low Electronics can be collected by detector in mirror, and only minority electrons are not collected by the centre bore of detector in mirror, are improved The collection efficiency of secondary electron.But since backscattered electron energy is higher, it is not easy to be attracted by electric lens, exit direction phase For the small backscattered electron of the angle of departure of sample surface, it is impossible to be collected by detector in mirror, incide into object lens inner surface or object lens Outside, therefore, detector is very low for the detection efficient of backscattered electron in mirror.

In correlation technique, to improve the detection efficient of backscattered electron, an alternative embodiment is also provided, including：In height Pressure pipe places to collect the back scattering electronic detector of the backscattered electron of emitted at small angles, and conduct close to one end of sample One electrode of electric lens；Back scattering electronic detector collects the small pure backscattered electron signal of launch angle；All two Secondary electronics and the backscattered electron of wide-angle transmitting pass through the centre bore of back scattering electronic detector, are placed on above object lens Detector detects in mirror.In correlation technique, another alternative embodiment is also provided, including：Back scattering electronic detector is placed In high-voltage tube, for collecting the backscattered electron of emitted at small angles, secondary electron is drawn through back scattering electronic detector Centre bore, be placed on above object lens secondary electron detector detection or back scattering electronic detector is placed on magnetic In lens, and positioned at the lower section of secondary electron detector.Angle involved by above-described embodiment refers to the outgoing of backscattered electron Direction compared with sample surfaces angle.

But at least there is technical issues that in the above embodiment it is as follows, under low energy condition, It is required that scanning electron microscope has higher flux and higher secondary electron and backscattered electron detection efficient；It is and above-mentioned In embodiment, backscattered electron beam by initial electron beam after sample surfaces excitation, the back scattering that is directly transmitted to outside object lens On electron detector；Since under low energy, the energy of backscattered electron is down to less than 3keV so that incide into back scattering electricity The signal of backscattered electron excitation on sub- detector is weaker, and the gain of back scattering electronic detector is smaller.Alternatively, back scattering is electric When son is incident to after electric field acceleration on back scattering electronic detector, since part secondary electron and backscattered electron are from the top The centre bore of detector is fled from, and reduces the detectivity of secondary electron and backscattered electron.Further, since different launch angles Backscattered electron can characterize the information of sample different dimensions, the small backscattered electron of the angle on shooting angle relative sample surface The topographical information of sample can be characterized, the backscattered electron that the angle on shooting angle relative sample surface is big can characterize sample Material information.For given drop point energy, due to the intensity of electric field, the intensity in magnetic field and back scattering electronic detector Position is fixed, therefore, it is impossible to the fortune work(path by changing backscattered electron, to realize back scattering electronic detector to spy Determine the detection of the backscattered electron of launch angle.

In another optional embodiment, back scattering electronic detector has the detection channels of several annulars, for distinguishing The backscattered electron of different launch angles.But the receipts for having the back scattering electronic detector of the structure relative complex, selective Collect different drop point energy, different launch angle backscattered electron very flexible.

Embodiment one

In view of the above-mentioned problems, the utility model embodiment one provides a kind of low energy scanning electron microscope system, scanning electricity The composition structure of sub- microscopic system, as shown in figure 3, including：Electron source 101, electronics accelerating structure, by magnetic lenses 107 and electricity Complex objective lens 11, arrangement for deflecting 106 and the detection device 105 that lens 10 are formed；Wherein,

The electron source 101, for generating electron beam；In an optional embodiment, the electron source is field emission Electron source, such as the electron source of thermal field emission or the electron source of cold field emission, the heat made with tungsten filament and lanthanum hexaboride material is sent out The source of penetrating is compared, and is had better current density and brightness, and with smaller virtual source, can be reduced Electron Beam Focusing in sample The upper size for generating beam spot improves the resolution ratio of scanning electron microscope system detection sample.

The electronics accelerating structure is anode 102, along the electron beam direction of the launch, positioned at the lower section of the electron source 101, For forming an electric field, increase the movement velocity of the electron beam.In correlation technique, the anode and electronics of scanning electron microscope Between source, at least one absorption pole is generally included；In the utility model embodiment, the electron beam that the electron source 101 generates is straight It connects through anode field emission, and controls the distance of the anode 102 and the transmitting point of the electron source 101 as small as possible, help It is dissipated in the energy for reducing electron beam, and then reduces the influence for the electron beam that space charge effect emits electron source 101.This practicality is new In type embodiment, after electron beam is accelerated by anode, into complex objective lens 11 formed focousing field near, can keep compared with High energy also reduces the influence for the electron beam that space charge effect emits electron source 101.

In the utility model embodiment, the representative value of voltage value V1 the ＜ -5kV, V1 of the electron source 101 are -10kV；Institute It states anode 102 to be grounded, voltage value zero, the electron beam that the electron source 101 generates passes through after anode 102, movement velocity meeting Increase.

The arrangement for deflecting 106, between 107 inner wall of magnetic lenses and the optical axis 110 of the electron beam, for changing Become the direction of motion of the electron beam before inciding into the sample.The arrangement for deflecting 106 includes at least：First deflector 106a and Second deflector 106b, it is possibility to have more deflector participations carry out the scanning of initiating electron.First deflector 106a, Second deflector 106b may each be magnetic deflector or electric deflection device；First deflector 106a and the second deflector 106b are located at magnetic In lens objectives, the first deflector 106a and the second deflector 106b mating reactions, and close to magnetic lenses field, help to reduce An aberration at scanning field edge when exposing thoroughly.First deflector 106a and the second deflector 106b is usually the magnetic deflector of multipole Or electric deflection device, such as 4 poles, 8 poles, 12 poles, 16 poles etc., the arbitrary scanning field for deflecting direction can be generated.The utility model is real It applies in example, it is preferably quiet since the element on the electron beam path of anode 102 to back scattering electronic detector 105b is grounded Electric deflection device, static deflecter compared to magnetic deflector speed faster, are more advantageous to realizing the electronics beam scanning of high speed, contribute to Improve the image taking speed of electron beam microscopes.

The detection device 105 acts on the secondary electron and the back of the body that are generated on sample including being used to receiving initial electron beam First sub- detection device 105a of scattered electron, for receive the second of the backscattered electron the sub- detection device 105b and For changing the secondary electron and the control device 105c of the direction of motion of the backscattered electron.

In an alternative embodiment, detector centered on the first sub- detection device 105a, positioned at the magnetic lenses 107 Top.The second sub- detection device 105b is back scattering electronic detector, positioned at the lower section of the magnetic lenses 107, and it is tight Paste the pole shoe of the magnetic lenses 107.

The central detector 105a and back scattering electronic detector 105b is the circular detector with centre bore, To be detector that semiconductor detector, avalanche type detector or scintillator and photoconductive tube form.Back scattering electronic detector The thinner thickness of 105b is controlled in 2mm even below 1mm, to avoid the excessive occupancy magnetic lenses 107 and sample stage Space between 109 ensures that the operating distance between object lens and sample is smaller so as to ensureing higher resolution ratio；It visits at the center Device 105a center-hole diameter 2≤1mm of Φ are surveyed, to improve the receiving efficiency of signal electron.

In an alternative embodiment, the control device 105c, positioned at the lower section of the first sub- detection device 105a, the second son The top of detection device 105b.The control device 105c is made of electric deflection device and magnetic deflector, electric deflection device and magnetic deflection Device generates compound electromagnetic field；Wherein, the size and Orientation of electric field strength, magnetic field intensity size and Orientation and initiating electron The speed of beam is related.In a preferred embodiment, the function of the control device 105c can be realized by Wei grace analyzer.

Electric deflection device in control device 105c generates an electric field, and the electric field force that initiating electron is subject to is：

Fe=qE (1)；

Wherein, q is the carried charge of charged particle, and E is electric field strength.

Meanwhile magnetic deflector in control device 105c generates one perpendicular to the magnetic field of electric field strength, initiating electron by To Lorentz force be：

Fm=qv × B (2)；

Wherein, B is magnetic induction intensity, and v is the speed of charged particle.

For initial electron beam, electron beam is also subject to the Fm of an opposite direction while electric field force Fe is subject to act on The force balance of the effect of magnetic field force, electric field force and magnetic field force does not cause to deflect to initiating electron.

The signal electron generated on sample is applied to for initial electron beam, during by Wei grace analyzer, due to Lorentz Power is related with the moving direction of electronics, and electric field force is unrelated with the moving direction of electronics, and therefore, the incident direction of signal electron becomes On the contrary, Lorentz force Fm and electric field force Fe becomes identical direction at this time, signal electron is subject to the effect that the two is made a concerted effort to electric field The direction deflection of power.

In an optional embodiment, the electric deflection device in Wei grace analyzer is the multi-electrode type knot for including multiple stationary electrodes Structure, the magnetic deflector in Wei grace analyzer is the multi-electrode type structure for including multiple magnetic poles；Such as 4 pole, 8 poles, 12 poles, 16 poles Deng so, it is possible to generate electric field and the magnetic field of the balances for any direction being distributed along the rotation of 360 degree of optical axis, and then control signal Electronics is along any directions of 360 degree of optical axis rotation into horizontal deflection.

In the utility model embodiment, the complex objective lens 11 include：Magnetic lenses 107, electric lens 10；Wherein, the magnetic Lens 107 are preferably the immersion magnetic lenses of current coil excitation, and being coiled into magnetic material outside excitation coil by conducting wire is made Housing, the opening of the magnetic lenses 107 is the pole shoe of magnetic lenses, and the opening direction of pole shoe is towards sample, sample surface position Near the most strength in the Z-direction magnetic field of the magnetic lenses 107.In correlation technique.The boots opening of non-immersion magnetic lenses pole, court To 110 direction of optical axis of electron beam, and the focousing field of magnetic lenses apart from sample surface farther out.Therefore, the utility model embodiment The imaging aberration of middle immersion magnetic lenses 107, the imaging aberration smaller of the non-immersion magnetic lenses in the correlation technique that compares, carries The resolution ratio of high scanning electron microscope system.

In the utility model embodiment, the electric lens 10 are by the second sub- detection device 105b, sample stage 109 and control electricity Pole 108 is formed.

In an optional embodiment, the second sub- detection device 105b is back scattering electronic detector, positioned at described The lower section of magnetic lenses 107, and it is close to the pole shoe of the magnetic lenses 107.The coordination electrode 108 carries centre bore, the control Electrode 108 is between the described second sub- detection device 105b and the sample stage 109.

In an optional embodiment, the electric lens 10 are the cathode lens of a deceleration, are added for reducing through anode The movement velocity of electron beam after speed and the motion path of control signal electronics；The second sub- detection device 105b is in Ground potential, i.e., the voltage value of the second sub- detection device 105b is zero, and electron beam is from the sub- detection device 105b institutes of anode 102 to the second The voltage value in the path of process is ground potential；The voltage value V2 of sample stage 109 is V1 ＜ V2 ＜ -5kV, and sample is placed on sample After on platform 109, there is the voltage value same or similar with sample stage 109.The voltage value V3 of the coordination electrode 108 is adjusted, Voltage value V3≤0kV of coordination electrode 108.Pass through the voltage value of adjusting control electrode 108, point of adjustment deceleration electric lens field Cloth acts on the rail of the signal electron generated on sample so as to influence the focus condition of initial electron beam and initial electron beam Mark.Therefore, the electron beam that charged component 101 generates focuses to sample after the acceleration of anode 102, by the electric lens 10 deceleration, The sample is positioned over sample stage.Can be semiconductor samples, conductor sample, non-conductive sample etc..Meanwhile electric lens 10 can be with The part aberration of magnetic lenses 107 is compensated, improves the resolution ratio of scanning electron microscope.

In the utility model embodiment, initial electron beam excited on sample generation signal electron include secondary electron and Backscattered electron, under the electric field action of the magnetic field of magnetic lenses 107 and electric lens 10, the track of secondary electron and backscattered electron It will be affected.Under the collective effect of the magnetic field of magnetic lenses 107 and electric field, the backscattered electron that script straight line is sent is subject to Along the active force for being directed toward optical axis 110 direction (r to), moved closer to being issued to from sample surface by the movement locus of backscattered electron Optical axis 110.

Under specific drop point energy condition, i.e., current potential V on sample₂Under certain situation, voltage V in coordination electrode₃It is arranged to special During definite value, between sample surface is issued to detected device reception, the motion path of backscattered electron is not present backscattered electron Crosspoint；Unless in the drop point energy of very low (being less than 50eV), backscattered electron energy and secondary electron energy are special Close, due to being acted on be subject to electromagnetic field, the track of backscattered electron can form crosspoint and pass through back scattering electronic detector Centre bore.Under the strong effect of electromagnetic field, since secondary electron energy is too small (be less than 50eV) so that secondary electron just from Sample surfaces are sent, and movement locus is just between sample and back scattering electronic detector or back scattering electronic detector hole is attached It is near to form crosspoint.When the value of back scattering electronic detector center-hole diameter Φ 1 is in particular range, secondary electron can be complete Portion from back scattering electronic detector centre bore pass through without it is detected in addition close to the parallel secondary electron sent of sample surfaces all It can be detected by electromagnetic field effect through backscattered electron centre bore.At this point, the backscattered electron that launch angle is small, due to Be subject to towards optical axis 110 power and to 110 center convergence of optical axis；Under suitable object lens field condition, even if launch angle approaches Backscattered electron in zero can also be detected by back scattering electronic detector 105b.In addition, the backscattered electron that launch angle is big, i.e., The backscattered electron sent close to optical axis 110 can pass through the centre bore of back scattering electronic detector 105b, by central detector 105a is detected.The centre bore Φ 1 of back scattering electronic detector 105b is arranged on the magnitude of several mm.Initial electron beam acts on In the signal electron that sample surfaces generate, accelerated by electric lens 10 and after the deflection of Wei grace analyzer 105c by detector 105 detections；Wherein, a part for signal electron is directly detected by 105b, and another part is detected by 105a, and secondary electron can be complete The full centre bore for passing through back scattering electronic detector 105b.

By taking control device 105c is Wei grace analyzer as an example, in the case where Wei grace analyzer 105c is closed, such as Fig. 2 institutes Show, signal electron after being accelerated by electric lens 10, wherein, the small backscattered electron of launch angle is detected completely by backscattered electron Device 105b is detected；In the case of the centre bore very little of central detector 105a, almost all of secondary electron and launch angle Big backscattered electron can be detected by central detector 105a, and only a small number of secondary electrons passes through central detector 105a Centre bore be unable to be received by detector 105.

In the utility model embodiment, in the case where Wei grace analyzer 105c is opened, as shown in Figure 1, being analyzed in Wei grace Device 105c generate electric field and magnetic field it is suitable in the case of, signal electron after being accelerated by electric lens 10, wherein, launch angle is small Backscattered electron detected completely by back scattering electronic detector 105b, all secondary electrons and the big back scattering of launch angle Electronics is detected by central detector 105a.At this point, under the auxiliary of Wei grace analyzer 105c, the detection effect of detection device 105 Rate is improved to about 100%.On the one hand, due in low energy scan electron microscopy system, the collection efficiency of signal electron Directly determine the speed of scanning electron microscope system.On the other hand, usually low energy scan electron beam microscopes are seen The sample examined is the non-conductors such as semiconductor or organic material, and the yield of signal electron has a long way to go compared to good conductor, because This image taking speed as much as possible collected signal electron and be conducive to improve electron microscope.In another aspect, secondary electron and the back of the body Scattered electron is all subject to acting on for the additional acceleration fields of the generation of electric lens 10 so that secondary electron and backscattered electron energy improve About V₂Electron volts can generate higher signal gain, help to improve the electron beam under low energy condition on the detector Image taking speed.

Due to the voltage value V of the coordination electrode 108₃It is to support to adjust, i.e., the voltage value V3's of coordination electrode 108 is big I flexible modulation as needed；Therefore by can flexibly adjust electric lens 10 to the adjusting of 108 voltage of coordination electrode , so as to control the movement locus of backscattered electron and secondary electron.As shown in Figure 3a, 108 voltage value V of coordination electrode₃It is carrying on the back 109 voltage value V of scattered electron detector voltage value and sample stage₂Between when adjusting, can be in sample stage 109 and backscattered electron Form an electrostatic lenses field between detector 105b, 13 institutes in the equipotential lines such as Fig. 3 a of electric lens field in the utility model embodiment Show, the magnetic field of electrostatic lenses field and object lens jointly acts on signal electron；It is worn completely at this point, secondary electron forms intersection spot The centre bore of back scattering electronic detector 105b is crossed, the big backscattered electron of shooting angle is also passed through in back scattering electronic detector Heart hole 105b, and under the action of Wei grace analyzer 105c, detected by central detector 105a.The small back scattering electricity of shooting angle Son is detected under the action of electric lens 10 by back scattering electronic detector 105b.Also, since the voltage of coordination electrode 108 can With consecutive variations, therefore, the backscattered electron that can be accurately controlled in the outgoing of special angle scope is detected by detector 105b, And shooting angle is made to be more than the centre bore that the backscattered electron of particular value passes through detector 105b to detect, it is caught by 105a detectors It obtains.

The material information entrained by backscattered electron sent due to different angle is otherwise varied, and the small back of the body of launch angle dissipates Radio receives the influence of sample surfaces fluctuating, can characterize the information of sample surface morphology；Launch angle is big (to be approached 90 °) backscattered electron, i.e. the backscattered electron close to optical axis 110 can characterize the information of specimen material.Therefore by control The adjustment of 108 voltage value of electrode can control backscattered electron of the launch angle in particular value to be detected by detector 105b, into And determine that the backscattered electron image of back scattering electronic detector 105b acquisitions can more characterize the material information of sample, still more The information of sample surface morphology can be characterized.Further, since the difference of sample itself, initial electron beam generates after acting on sample Backscattered electron launch angle it is also different, can by flexibly select detection backscattered electron dissipated to obtain the optimal back of the body The sub- contrast image of radio.Therefore, the electric field of electric lens in complex objective lens 11 can be flexibly controlled by coordination electrode 108, The type and distribution angle for the signal electron to be detected can flexibly be selected；It is using a back scattering electronic detector 105b The backscattered electron sent in the range of capture special angle may be selected, with back scattering electronic detector is divided into band in correlation technique The annulus for having several detection channels is compared, and more can adapt to the requirement of the backscattered electron in the range of selection capture different angle, Reduce the complexity of detector.

In the utility model embodiment, as 108 voltage value V of coordination electrode₃Compared to 109 voltage value V of sample stage₂It is small at least During 50V, electrostatic field distribution change as shown in Figure 3b, formed one between coordination electrode 108 and sample stage 109 to electricity The electric field of sub- downward force, 14 be electric field equipotential lines under the embodiment；Secondary electron cannot be upward by the compacting of downward electric field, returns to On sample；Backscattered electron is by the outside power in r directions；Therefore, the small backscattered electron of launch angle can also be by back scattering electricity Sub- detector 105b detections, the backscattered electron of bigger launch angle are detected by central detector 105a, central detector 105a With back scattering electronic detector 105b obtain be different shooting angles pure backscattered electron, there is no secondary electrons.

Therefore, the electric field of electric lens 10 is flexibly controlled by coordination electrode 108, can also flexibly select central detector Device 105a detects the type of electronics, so select to detect individual backscattered electron or detection comprising backscattered electron and The signal electron of secondary electron.It is dissipated with increasing in correlation technique before central detector with adjustable strainer for obtaining the pure back of the body Radio sub-information is compared, and the utility model embodiment reduces the complexity of detection device.

To sum up, by adjusting control electrode 108, it can select to detect the backscattered electron of different shooting angles, individually Backscattered electron or backscattered electron and secondary electron mixed information or individual secondary electron, so as to improve low point energy The flexibility of detectable signal electronics under the conditions of amount.

As can be seen that in the utility model embodiment, one is formed on Electron Beam Focusing that electron source 101 generates to sample Focus point intersects beam spot, on the path between electron source 101 and sample 109, does not generate other focus points or intersection Beam spot；For electron beam before by anode 102 to the lens field close to complex objective lens, electron beam keeps a higher energy； If the value of the voltage V1 of electron source 101 is -10kV, initiating electron is kept on the optical path approached before meeting object lens field The energy of 10keV, and do not form other focus points or intersect spot, in this way, efficiently reducing space charge effect to light The influence of system.

Embodiment two

The low energy scanning electron microscope system that the utility model embodiment two is provided and the utility model embodiment one The scanning electron microscope system provided is similar, the difference is that, the scanning electron that the utility model embodiment two provides The composition structure of microscopic system, further includes electron beam regulating device, and the lower section of anode 102 is arranged at along 110 direction of optical axis, uses In the feature for changing the electron beam after anode 102；The feature of the electron beam includes at least：The beam current density and electricity of electron beam The diameter of beamlet.

In an optional embodiment, as shown in figure 4, the electron beam regulating device is converging device 103, along initial The exit direction of electron beam is arranged at the lower section of anode 102, for being converged to the electron beam accelerated by anode, that is, changes electricity The transmitting subtended angle of beamlet, so control electron beam reach sample beam current density, and electron beam after converging device 103 not It is formed and intersects spot.

In a preferred embodiment, converging device 103 be electric excitation magnetic lenses, the focusing magnetic field of converging device 103 It can continuously adjust.

Embodiment three

Low energy scanning electron microscope system that the utility model embodiment three is provided and the utility model embodiment one, The low energy scanning electron microscope system that embodiment two is provided is similar.The difference is that the utility model embodiment three carries The composition structure of the low energy scanning electron microscope system of confession as shown in Figure 5 a, provides low with the utility model embodiment one Energy scanning electron microscope system is compared, and electron beam regulating device is diaphragm 104, and the diaphragm 104 is located at institute along optical axis direction The lower section of anode is stated, for being filtered by the electron beam of anode 102.

Or the composition structure of the low energy scanning electron microscope system of the offer of the utility model embodiment three, such as Fig. 5 b institutes Show, compared with the low energy scanning electron microscope system that the utility model embodiment two provides, electron beam regulating device further includes Diaphragm 104, along optical axis direction, positioned at the lower section of the converging device 103, for the electron beam by converging device 103 into Row filtering, the electron beam that electron source 101 generates are downward along optical axis 110 after anode 102, converging device 103 and diaphragm 104 Movement.

Example IV

The low energy scanning electron microscope system that the utility model embodiment four provides, carries with the utility model embodiment one The low energy scanning electron microscope system of confession is similar, as shown in fig. 6, the difference is that, shown in the utility model embodiment four The electronics accelerating structure of low energy scanning electron microscope system include：Anode 102 and high-voltage tube 401；

In the utility model embodiment, due in this path of anode 102 to back scattering electronic detector 105b, electronics Beam keeps at a high speed, voltage value being applied on high-voltage tube as V in high-voltage tube₄High pressure, so it is preferable to use magnetic for arrangement for deflecting 106 Deflector.

In the utility model embodiment, electronics accelerating structure is made of anode 102 and high-voltage tube 401, and high-voltage tube 401 is distinguished It is connected with 102 and second sub- detection device 105b of anode, the voltage value V1 of electron source 101<0kV, voltage value and the height of anode 102 The voltage value of pressure pipe 401 is V4, V4>+5kV；Electric lens 10 are the cathode lens of a deceleration, are accelerated for reducing through anode The movement velocity of electron beam afterwards and the motion path of control signal electronics；The voltage of the second sub- detection device 105b It is worth for V4, the voltage value of electron beam from the sub- detection device 105b paths traversed of anode 102 to the second is V4；Sample stage 109 voltage value V2 is V₁<V₂≤ 0kV after sample is placed on sample stage 109, has same or similar with sample stage 109 Voltage value.The voltage value V3 of the coordination electrode 108 is adjusted, voltage value V3≤V4 of coordination electrode 108.Pass through adjusting control The voltage value of electrode 108, the distribution of adjustment deceleration electric lens field, so as to influence the focus condition of initial electron beam and initial Electron beam acts on the track of the signal electron generated on sample.

By taking control device 105c is Wei grace analyzer as an example, in the case where Wei grace analyzer 105c is closed, such as Fig. 7 institutes Show, signal electron after being accelerated by electric lens 10, wherein, the small backscattered electron of shooting angle is detected completely by backscattered electron Device 105b is detected；In the case of the centre bore very little of central detector 105a, almost all of secondary electron and shooting angle Big backscattered electron is detected by central detector 105a, and only a small number of secondary electrons passes through the center of central detector 105a Hole is without detected.In the case where Wei grace analyzer 105c is opened, as shown in fig. 6, the electricity generated in Wei grace analyzer 105c And magnetic field it is suitable in the case of, signal electron after being accelerated by electric lens 10, wherein, the small backscattered electron of shooting angle is complete It is detected entirely by back scattering electronic detector 105b；The big backscattered electron of all secondary electrons and shooting angle is by central detector Device 105a is detected.Therefore, analyzer 105c improves detection efficient to about 100%.In low energy scanning electron beam microscope, signal The collection efficiency of electronics directly determines the speed of scanning electron microscope, and usually low energy scanning electron beam microscope observation Sample be semiconductor or organic material non-conductor, signal electron yield has a long way to go compared to good conductor, therefore to the greatest extent may be used The image taking speed that signal electron is conducive to improve electron microscope can be collected.In addition, secondary electron and backscattered electron are all subject to The effect of the additional acceleration fields of one cathode electric lens, this acceleration fields can cause secondary electron and backscattered electron to improve about V₂ Electron volts can generate higher signal gain on the detector, help to improve the electron beam imaging speed under low-energy condition.

Due to the voltage value V of the coordination electrode 108₃To support to adjust, i.e. the voltage value V of coordination electrode 108₃It is big It is small to adjust, therefore the field by can flexibly adjust electric lens 10 to the adjusting of 108 voltage of coordination electrode, so as to control The movement locus of backscattered electron and secondary electron.As shown in Figure 8 a, 108 voltage value V of coordination electrode₃It is detected in backscattered electron Device voltage value V₄With 109 voltage value V of sample stage₂Between when adjusting, can be in sample stage 109 and back scattering electronic detector 105b Between form an electrostatic lenses field, for the equipotential lines of electric lens field as shown in 21 in Fig. 8 a, electrostatic is saturating in the utility model embodiment The magnetic field of Jing Chang and object lens jointly acts on signal electron；At this point, secondary electron, which forms intersection spot, passes completely through back scattering The centre bore of electron detector 105b, the big backscattered electron of shooting angle also pass through back scattering electronic detector centre bore 105b, and under the action of Wei grace analyzer 105c, detected by central detector 105a.The small backscattered electron of shooting angle exists Under the action of electric lens 10, detected by back scattering electronic detector 105b.Also, since the voltage of coordination electrode 108 can connect Continuous variation, therefore, the backscattered electron that can be accurately controlled in the outgoing of special angle scope are detected by detector 105b, and are made Shooting angle is more than the backscattered electron of particular value through the centre bore of detector 105b, is captured by 105a detectors.

The material information entrained by backscattered electron sent due to different angle is otherwise varied, and the small back of the body of launch angle dissipates Radio receives the influence of sample surfaces fluctuating, can characterize the information of sample surface morphology；Launch angle is big (to be approached 90 °) backscattered electron, i.e. the backscattered electron close to optical axis can characterize the information of specimen material.Therefore by control electricity The adjustment of 108 voltage value of pole can control backscattered electron of the launch angle in particular value to be detected by detector 105b, and then The material information of sample can more be characterized by determining the backscattered electron image of back scattering electronic detector 105b acquisitions, still more can Enough characterize the information of sample surface morphology.Further, since the difference of sample itself, initial electron beam acts on after sample what is generated The launch angle of backscattered electron is also different, can be by the way that detection backscattered electron is flexibly selected to obtain optimal back scattering Electronics contrast image.Therefore, the electric field of electric lens in complex objective lens 11 can be flexibly controlled by coordination electrode 108, also may be used Flexibly to select the type for the signal electron to be detected and distribution angle；Use a back scattering electronic detector 105b The backscattered electron sent in the range of selection capture selected angle, carries with being divided into back scattering electronic detector in correlation technique The annulus of several detection channels is compared, and more can adapt to the requirement of the backscattered electron in the range of selection capture different angle, drop The low complexity of detector.

In the utility model embodiment, as 108 voltage value V of coordination electrode₃Compared to 109 voltage value V of sample stage₂It is small at least During 50V, electrostatic field distribution change as shown in Figure 8 b, formed one between coordination electrode 108 and sample stage 109 to electricity The electric field of sub- downward force, 22 be electric field equipotential lines under the embodiment；Secondary electron cannot be upward by the compacting of downward electric field, returns to On sample；Backscattered electron is by the outside power in r directions；Therefore, the small backscattered electron of launch angle can also be by back scattering electricity Sub- detector 105b detections, the backscattered electron of bigger launch angle are detected by central detector 105a, central detector 105a With back scattering electronic detector 105b obtain be different shooting angles pure backscattered electron, there is no secondary electrons.

Embodiment five

The low energy scanning electron microscope system that the utility model embodiment five is provided and the utility model embodiment four The low energy scanning electron microscope system provided is similar, the difference is that, the low energy that the utility model embodiment five provides The composition structure of scanning electron microscope system, further includes electron beam regulating device, is arranged at along optical axis direction under anode 102 Side, for changing the feature of the electron beam after anode 102；The feature of the electron beam includes at least：The line of electron beam is close The diameter of degree and electron beam.

In an optional embodiment, as shown in figure 9, the electron beam regulating device is converging device 103, along initial The exit direction of electron beam is arranged at the lower section of anode 102, for being converged to the electron beam accelerated by anode, that is, changes electricity The transmitting subtended angle of beamlet, and then the effect of the beam current density of electron beam arrival sample is controlled, and electron beam passes through converging device Intersection spot is not formed after 103.

Embodiment six

Low energy scanning electron microscope system that the utility model embodiment six is provided and the utility model embodiment four, The low energy scanning electron microscope system that embodiment five is provided is similar.The difference is that the utility model embodiment six carries The composition structure of the low energy scanning electron microscope system of confession as shown in Figure 10 a, provides low with the utility model embodiment four Energy scanning electron microscope system is compared, and electron beam regulating device is diaphragm 104, and the diaphragm 104 is located at institute along optical axis direction The lower section of anode is stated, for being filtered by the electron beam of anode 102.

Or the composition structure of the low energy scanning electron microscope system of the offer of the utility model embodiment six, such as Figure 10 b institutes Show, compared with the low energy scanning electron microscope system that the utility model embodiment five provides, electron beam regulating device further includes Diaphragm 104, along optical axis direction, positioned at the lower section of the plus lens 103, for the electron beam by plus lens 103 into Row filtering, the electron beam that electron source 101 generates are downward along optical axis 110 after anode 102, plus lens 103 and diaphragm 104 Movement.

Embodiment seven

The low energy scanning electron microscope provided based on above-described embodiment one to embodiment six, the utility model embodiment seven System as shown in figure 11, further includes signal processing apparatus 30, with the described first sub- detection device and/or the second sub- detection device Connection, for the first signal to secondary electron of the described first sub- detection device based on reception and/or backscattered electron generation It is handled；And/or the secondary signal for being generated to backscattered electron of the described second sub- detection device based on reception carries out Processing.

In an optional embodiment, the signal processing apparatus includes：Signal amplifies sub-device and signal processing dress It puts；Wherein,

Signal amplifies sub-device, including：First signal amplifies sub-device 300a, for being put to first signal Greatly；And/or secondary signal amplification sub-device 300b, for being amplified to the secondary signal；

Signal processing sub-device, including：First signal processing sub-device 301a, for the first amplified signal into It is exported after row processing, forms the first image；And/or secondary signal processing sub-device 301b, for the second amplified letter It is exported after number being handled, forms the second image.

In an optional embodiment, the signal processing apparatus further includes：Signal synthesizes sub-device, for described in warp Signal processing sub-device treated the first signal and treated that secondary signal is synthesized through the signal processing sub-device Processing forms combination picture.

It, can be respectively to the signal and the second sub- detection device of the first sub- detection device output in the utility model embodiment The signal of output is amplified, processing operation, generates the secondary electron image targetedly detected or backscattered electron figure respectively Picture.After signal synthesis sub-device 302 can also be utilized to the first signal of treated the first sub- detection device output and processing The secondary signal of the second sub- detection device output synthesized, obtain a width collection rate for 100% or close to 100% synthesis Image.

Embodiment eight

Based on the low energy scanning electron microscope system described in above-described embodiment one to embodiment seven, the utility model is implemented Example eight also provides a kind of sample detection method, the process flow of the sample detection method, as shown in figure 12, including following step Suddenly：

Step S101, the electron beam that electron source generates increase movement velocity after electronics accelerating structure.

In an optional embodiment, the electronics accelerating structure be an anode, the voltage value V1 of the electron source<- 5kV, plus earth.

In another optional embodiment, the electronics accelerating structure includes：Anode and high-voltage tube, electron source voltage value V1 <0kV, anode voltage value V4 are V4>+ 5kV, high-voltage tube voltage value are V4.

Energy is remained above 5keV, representative value after the electron beam that the electron source generates is accelerated by the electronics accelerating structure For 10keV, moved downward along optical axis；The high-power electron beam moved downward is accumulated by plus lens, but does not form intersection spot, And passing through diaphragm, the two adjusts the line size and beam spot diameter, of electron beam.

Step S102, through the electronics accelerating structure accelerate electron beam, converged through complex objective lens, electric lens slow down and Arrangement for deflecting is acted on after changing the direction of motion on sample, generates secondary electron and backscattered electron.

In a preferred embodiment, the increased electron beam of movement velocity converged through complex objective lens, electric lens slow down and It after arrangement for deflecting deflects, is scanned in sample surfaces, generates secondary electron and backscattered electron.Wherein, complex objective lens include：Magnetic Lens and electric lens；The magnetic lenses is preferably the immersion magnetic lenses of current coil excitation, is coiled by conducting wire outside excitation coil Housing made of portion's magnetic material, the opening of the magnetic lenses are the pole shoe of magnetic lenses, the opening direction direction of pole shoe Sample, sample surface are located near the most strength in the Z-direction magnetic field of the magnetic lenses.In correlation technique.Non-immersion magnetic lenses pole Boots opening, towards the optical axis direction of electron beam, and the focousing field of magnetic lenses apart from sample surface farther out.Therefore, this practicality is new The imaging aberration of immersion magnetic lenses in type embodiment, the imaging aberration of the non-immersion magnetic lenses in the correlation technique that compares is more It is small, improve the resolution ratio of scanning electron microscope system.

In an optional embodiment, back scattering electronic detector is in ground potential, the sample stage in the electric lens Voltage value be V2, V1<V2<- 5kV, the voltage value V3 of the coordination electrode is adjustable, and size is V3≤0kV；It is dissipated from anode to the back of the body It is ground potential that electron detector electron beam institute, which is penetrated, through path.

In another optional embodiment, back scattering electronic detector is in V4 current potentials in the electric lens；Sample stage Voltage value is V1<V2≤0kV；The voltage value V3 of coordination electrode is adjustable, is V3≤V4.

The focusing magnetic field and electric lens that magnetic lenses generates in the complex objective lens generate retarding field and form a complex focusing , the high-power electron beam moved downward along optical axis is accumulated by complex focusing field, while converges electron beam by the electricity that slows down Field is decelerated to energy less than or equal to 5keV focusing illuminations to sample to be tested；Low energy focuses on the deflection field that electron beam is generated in deflector It under effect, is scanned on sample, signal electron is generated, including secondary electron and backscattered electron.

Step S103, the secondary electron and the backscattered electron under the action of the electric lens and control device, Change the direction of motion, received with detected device.

In an optional embodiment, detection device includes back scattering electronic detector and central detector, is returned from sample The signal electron returned by the electric field acceleration of electric lens, the voltage value V3 of the control device can consecutive variations, when control fills When the voltage value V3 put is adjusted between back scattering electronic detector voltage value and sample stage voltage value V2, secondary electron and outgoing The backscattered electron that angle is more than first threshold is detected by central detector, and shooting angle is less than the backscattered electron of first threshold It is detected by back scattering electronic detector；It is secondary as the voltage value V3 of coordination electrode at least 50Vs small compared to sample stage voltage value V2 Electronics is pressed counter sample product, and the backscattered electron that shooting angle is more than first threshold is detected by central detector, and shooting angle is small It is detected in the backscattered electron of first threshold by back scattering electronic detector.Here, first threshold and back scattering electronic detector The attributes such as position it is related.

In an optional embodiment, when the control device is Wei grace analyzer, produced by adjusting Wei grace analyzer Raw electric field and the intensity in magnetic field improve collection efficiency of the central detector to secondary electron and/or backscattered electron.

To sum up, by the voltage value of control set for adjusting, can select to detect the backscattered electron letter of different shooting angles Breath, pure backscattered electron information, backscattered electron and secondary electron mixed information and pure secondary electron information.

Embodiment nine

The sample detection method that the utility model embodiment nine provides, as shown in figure 13, the sample provided with embodiment eight Detection method is similar, the difference is that, after step S103 is performed, further include：

Step S104, to the signal that central detector and/or back scattering electronic detector received signal electronics generate into Row processing.

In the utility model embodiment, the signal and the back of the body that can be generated respectively to central detector received signal electronics The signal that scattered electron detector received signal electronics generates is amplified, processing operation, generates two targetedly two Secondary electronic image or backscattered electron image.It can also be to the letter in the signal and central detector in back scattering electronic detector After number being handled, synthesized, obtain a width collection rate for 100% or close to 100% image.

The above is only the specific implementation pattern of the utility model, but the scope of protection of the utility model is not limited to In this, in the technical scope that any one skilled in the art discloses in the utility model, variation can be readily occurred in Or replace, it should be covered within the scope of the utility model.Therefore, the scope of protection of the utility model should be with the power Subject to the protection domain of profit requirement.

Claims

1. a kind of low energy scanning electron microscope system, which is characterized in that including：

For generating the electron source of electron beam；

It is made of electric lens and magnetic lenses, for the compound converged to the electron beam accelerated through the electronics accelerating structure Mirror；

Between the inner wall of the magnetic lenses and the optical axis of the electron beam, accelerate for changing through the electronics accelerating structure Electron beam the direction of motion arrangement for deflecting；

Acted on including being used to receiving electron beam the secondary electron generated on sample and backscattered electron the first sub- detection device, And the detection device for receiving the second of the backscattered electron the sub- detection device；

It is made of the second sub- detection device, sample stage and coordination electrode, for reducing the movement velocity of the electron beam, and changes The electric lens of the direction of motion of the secondary electron and the backscattered electron.

2. low energy scanning electron microscope system as described in claim 1, which is characterized in that the electronics accelerating structure is one Anode.

3. low energy scanning electron microscope system as described in claim 1, which is characterized in that the electronics accelerating structure includes Anode and high-voltage tube, the high-voltage tube are connected respectively with the anode, the second sub- detection device.

4. low energy scanning electron microscope system as described in claim 1, which is characterized in that further include：

5. low energy scanning electron microscope system as claimed in claim 4, which is characterized in that the electron beam regulating device bag It includes：Converging device and/or diaphragm；Wherein

The converging device, for being converged to the electron beam after electronics accelerating structure acceleration；

6. low energy scanning electron microscope system as claimed in claim 2, which is characterized in that the first sub- detection device, Between the anode and the magnetic lenses, close to the magnetic lenses direction；

7. low energy scanning electron microscope system according to claim 3, which is characterized in that the first son detection dress It puts, between the anode and the magnetic lenses, close to the magnetic lenses direction；

8. low energy scanning electron microscope system as described in claim 1, which is characterized in that the control device includes：It is more Pole electric deflection device and multipole magnetic deflector.

9. low energy scanning electron microscope system as described in claim 1, which is characterized in that the magnetic lenses is current coil The immersion magnetic lenses of excitation, the pole shoe opening direction of the magnetic lenses is towards the sample.

10. low energy scanning electron microscope system as described in claim 1, which is characterized in that the first sub- detection device Center-hole diameter be not more than 1 millimeter.

11. low energy scanning electron microscope system as described in claim 1, which is characterized in that the second sub- detection device Center-hole diameter be less than the coordination electrode center-hole diameter.

12. low energy scanning electron microscope system as claimed in claim 2, which is characterized in that the voltage value of the electron source V1 ＜ -5kV, the voltage value of the anode is zero.

13. low energy scanning electron microscope system as claimed in claim 12, which is characterized in that the second sub- detection device In ground potential, the voltage value of the sample stage is V2, and V1 ＜ V2 ＜ -5kV, the voltage value V3 of the coordination electrode support to adjust Section, V3≤0kV.

14. low energy scanning electron microscope system as claimed in claim 3, which is characterized in that the voltage value of the electron source V1 ＜ 0kV, the voltage value of the anode and the voltage value of the high-voltage tube are V4, V4 ＞+5kV.

15. low energy scanning electron microscope system as claimed in claim 14, which is characterized in that the second sub- detection device Voltage value is V4, and the voltage value of the sample stage is V2, and V1 ＜ V2≤0kV, the voltage value V3 of the coordination electrode support to adjust, V3≤V4。

16. the low energy scanning electron microscope system as described in claim 13 or 15, which is characterized in that in the coordination electrode Voltage value V3, more than the second sub- detection device for forming the electric lens voltage value and less than forming the electric lens Sample stage voltage value V2 when,

The first sub- detection device is big compared with the angle of sample surfaces specifically for receiving secondary electron and exit direction In the backscattered electron of first threshold；

The second sub- detection device is less than first threshold specifically for receiving exit direction compared with the angle of sample surfaces Backscattered electron.

17. low energy scanning electron microscope system as claimed in claim 16, which is characterized in that controlled in the control electric lens The voltage value V3 of electrode processed than the sample stage voltage value V2 at least below 50V when,

The first sub- detection device is more than first threshold specifically for only receiving exit direction compared with the angle of sample surfaces Backscattered electron；

The second sub- detection device is less than first threshold specifically for only receiving exit direction compared with the angle of sample surfaces Backscattered electron.

18. low energy scanning electron microscope system as described in claim 1, which is characterized in that further include：

It is connected with the described first sub- detection device and/or the second sub- detection device, for being based on to the described first sub- detection device The first signal that the secondary electron and/or backscattered electron of reception generate is handled and/or for being detected to the described second son The signal processing apparatus that the secondary signal that backscattered electron of the device based on reception generates is handled.

19. low energy scanning electron microscope system as claimed in claim 18, which is characterized in that the signal processing apparatus bag It includes：

20. low energy scanning electron microscope system as claimed in claim 19, which is characterized in that the signal processing apparatus is also Including：

For to through the signal processing sub-device treated the first signal and treated through the signal processing sub-device Secondary signal carries out synthesis processing, forms the signal synthesis sub-device of combination picture.