Angle scanning photoemitted electron micro imaging system and methodTechnical field
The present invention relates to a kind of photoemitted electron microscope, relate in particular to a kind of angle scanning light transmittingElectron microscope imaging system and method.
Background technology
Photoemitted electron microscope (PEEM, PhotoemissionElectronMicroscope) is onePlant and utilize photoelectric effect to carry out the electronic optical instrument of sample surfaces imaging, at chemistry, physics, material etc.Research field has important application. Its operation principle is (to comprise the optics light such as ultraviolet light with excitation sourceSource or X ray etc.) excite the electronics in surface of solids atom, utilize photoelectric effect to carry out sample surfacesImaging, in the time that exciting light incides sample surfaces, as meets photoelectric effect occurrence condition, body surface electricitySon is subject to photon excitation that disengaging object is become to photoelectron, and photoelectron, can after electromagnetic lens is collected also imagingReflect the information such as body surface composition, pattern, for the research of Surface Science provides abundant information.
In existing PEEM, excitation source scioptics system incides sample surfaces, and incidence angle is commonBe a fixed value, can bring difficulty to some research, for example, the fluctuating of sample surfaces may block intoPenetrate light, form " shade " at sample surfaces, this " shade " is difficult to simple products different from surface compositionRaw grey scale change makes a distinction, thereby can mislead to researcher. As Chinese patent literatureCN102479652A discloses a kind of high spatial resolution transmitting electricity that adopts ultraviolet or deep ultraviolet laser sourceSub-microscope, this microscope utilizes ultraviolet light or deep ultraviolet laser as light source, and the laser optical path of transmitting is logicalCross photoemitted electron microscope (PEEM) and impinge perpendicularly on sample stage, inspire be positioned on sample stage testedBody surface photoelectron, thus by electron-optical system, the imaging of surface light electron emission is obtained to exterior viewPicture information. The light source incidence angle of this electron microscope is fixed as 90 degree vertical irradiation samples, Bu NengmanThe needs that foot is studied sample variation surface texture, if regulate light source incidence angle, necessaryTurn off electron microscope, manual adjustments incident angle, accuracy is very poor, and bothers very much.
In addition, in some special researchs, also need in imaging process, regulate incident angle, such asWhile utilizing PEEM to carry out surface plasma wave (SPW, SurfacePlasmonWave) imaging, lightIncidence angle must meet certain relation, at this moment just need to regulate laser incident angle, especially sampleWhen surface texture more complicated, for meet the imaging demand of different structure simultaneously, laser incident angle needsRegulate fast. For another example,, in perpendicular magnetic recording research, also need to carry out the reality of incident angle of lightTime high accuracy change scanning, truly to reflect the distribution of surperficial magnetic domain.
For this reason, in prior art, occurred driving turntable motion by stepper motor, and then changed incidence angleDegree is realized the method for angle scanning, but this mode turntable is driven by stepper motor, and translational speed is very slow,Moving to angle position two from angle position one often needs hundreds of millisecond consuming time, is difficult to meet multi-angleThe requirement of real-time of picture, and because Measuring Time is elongated, drift, position that sample heating or refrigeration causeThe drift that moves mechanical drift, the electron-optical imaging system of platform all can be more obvious; And, by stepping electricityMachine drives turntable to move and then the mode of change incident angle is vibrated greatly, repetitive positioning accuracy is low, greatlyAffect observation effect.
Summary of the invention
For this reason, technical problem to be solved by this invention is photoemitted electron microscope light in prior artSource incident angle changes inconvenience and pace of change is slow, vibration greatly, repetitive positioning accuracy is low, observation effectPoor, meet different observation requirementses thereby propose one, realize angle scanning fast, accurately, it is fixed to repeatPosition precision is high, angle scanning photoemitted electron microscopy imaging system and method that observation effect is good.
For solving the problems of the technologies described above, of the present invention adopted technical scheme:
A kind of angle scanning photoemitted electron micro imaging system, comprises
Optical beam scanning system, comprises excitation source, shaping mirror, focus lamp, galvanometer and imaging lens;
Described excitation source, is positioned at the first vacuum cavity outside, for launching exciting light;
Described shaping mirror, is positioned at described the first vacuum cavity inside, for described excitation source is sent outThe exciting light of penetrating carries out shaping, and exciting light focus a place in described shaping mirror after shaping is converged formsFocal beam spot;
Described focus lamp and described galvanometer, be positioned at described the first vacuum cavity inside, for focusing onHot spot imaging is also projected to the speculum pivot place of described galvanometer;
Described imaging lens, is positioned at described the first vacuum cavity inside, for by through described galvanometerReverberation is imaged onto the surface of sample;
Electron microscopic system, is positioned at the second vacuum cavity inside, for to described sample surface lightElectronics carries out imaging;
Control system, is positioned at the outside of described the first vacuum cavity and described the second vacuum cavity, forControl the operation of described optical beam scanning system and described electron microscopic system.
In above-mentioned angle scanning photoemitted electron micro imaging system, described electron microscopic system comprises
Sample stage, is connected with negative high voltage, for placing described sample;
Electromagnetism object lens, with electromotive force be connected, between described sample and described electromagnetism object lens, formElectronics accelerating field;
Electronics planar array detector, the reverberation through described galvanometer is imaged onto detected sample by described imaging lensBehind the surface of product, described sample surface electronic is subject to photon excitation, is meeting photoelectric effect generation barWhen part, sample surface projects described electronics face through described electromagnetism object lens successively described in electron detachmentImaging on array detector.
In above-mentioned angle scanning photoemitted electron micro imaging system, at described electromagnetism object lens and described electronicsBetween planar array detector, be also provided with electronics beam splitter, sample surface is passed through successively described in electron detachmentDescribed electromagnetism object lens, described electronics beam splitter project imaging on described electronics planar array detector.
In above-mentioned angle scanning photoemitted electron micro imaging system, at described electronics beam splitter and described electricityBetween sub-planar array detector, be also provided with field lens and projection lens, sample surface successively described in electron detachmentProject described electronics face through described electromagnetism object lens, described electronics beam splitter, described field lens and projection lensImaging on array detector.
In above-mentioned angle scanning photoemitted electron micro imaging system, at described electromagnetism object lens and described electronicsBetween planar array detector, be also provided with field lens and projection lens, sample surface warp successively described in electron detachmentCross described electromagnetism object lens, described field lens and projection lens and project imaging on described electronics planar array detector.
In above-mentioned angle scanning photoemitted electron micro imaging system, described control system comprises
Data collecting system, is electrically connected with described electronics planar array detector, for gathering described electronics faceThe image information forming on array detector;
Microcomputer, is electrically connected with described data collecting system, for receiving described data acquisition isImage information and the user's operation information of system transmission;
Communication system, is electrically connected with described microcomputer, sends for accepting described microcomputerCommand information;
Galvanometer controller, is electrically connected with described communication system, described galvanometer, and described galvanometer controller is logicalCross described communication system and receive the command information that described microcomputer sends, and then control described galvanometer and turnMoving, to adjust scanning angle.
In above-mentioned angle scanning photoemitted electron micro imaging system, described data collecting system comprises successivelySignal condition and conversion circuit, timing generator circuit and the first communication and the control circuit of electrical connection;
Described signal condition and conversion circuit are electrically connected with described electronics planar array detector, and described signal is adjustedReason and conversion circuit are being received after the control instruction that described timing generator circuit is sent described electronics faceThe image information of array detector gathers and transmits;
Described timing generator circuit receives after the triggering signal of described the first communication and control circuit, producesIntegration, transfer, conversion and the transmitted waveform of raw described electronics planar array detector;
Described the first communication and control circuit are electrically connected with described microcomputer.
In above-mentioned angle scanning photoemitted electron micro imaging system,
Described galvanometer comprises interconnective galvanometer motor and angular displacement sensor, described galvanometer motorFront axle is provided with described speculum, and the rear axle of described galvanometer motor is connected with described angular displacement sensor;
Described galvanometer controller comprises that galvanometer motor drive circuit, PID adjuster, sweep waveform occurCircuit, the second communication and control circuit, signal conditioning circuit, sensor interface circuitry and arithmetic unit;
Described the second communication and control circuit and described communication system, described the first communication and control circuitElectrical connection, described the second communication and control circuit are also electrically connected with described arithmetic unit, described arithmetic unit also withDescribed sweep waveform circuit for generating electrical connection; Described the second communication and control circuit are received described communication systemAfter the control instruction that transmission comes, control described sweep waveform circuit for generating and produce waveform;
Described angular displacement sensor is electrically connected with described sensor interface circuitry, described sensor interface electricityRoad is also electrically connected with described signal conditioning circuit, and described sensor interface circuitry is for passing described angular displacementThe signal data that sensor transmission comes carries out amplification and filtering and signal after treatment is transferred to described signalModulate circuit; Described signal conditioning circuit is used for the letter through described sensor interface circuitry filtering processingNumber process, finally obtain the signal of position, described galvanometer motor angle;
The telecommunications of the signal of telecommunication of described signal conditioning circuit output and the output of described sweep waveform circuit for generatingNumber do computing, operation result is exported to described PID adjuster, described PID adjuster and described galvanometer electricityDrive circuit electrical connection, described galvanometer motor drive circuit is electrically connected with described galvanometer motor, drives instituteState galvanometer and reach set angle.
In above-mentioned angle scanning photoemitted electron micro imaging system, described galvanometer motor is based on galvanometerThe servomotor of principle; Described angular displacement sensor adopts photo-electric angular displacement sensor or position, condenser type angleDisplacement sensor.
In above-mentioned angle scanning photoemitted electron micro imaging system, the speculum of described galvanometer is coated with opticsHigh-reflecting film; Between described galvanometer and described imaging lens, be also provided with optical polarizer.
In above-mentioned angle scanning photoemitted electron micro imaging system, described shaping mirror and described focus lamp canCarry out position adjustment along optical axis direction, for regulating the size of described vibration mirror reflected mirror surface hot spot.
In above-mentioned angle scanning photoemitted electron micro imaging system, the vacuum of described the second vacuum cavityHigher than the vacuum of described the first vacuum cavity.
A kind of angle scanning light transmitting electricity that utilizes above-mentioned angle scanning photoemitted electron micro imaging systemSub-micro imaging method, comprises the following steps,
S1, the exciting light of excitation source output is after shaping mirror and focus lamp, at the speculum table of galvanometerFace forms hot spot;
S2, described galvanometer, under the control of control system, is adjusted scanning within the scope of optics incident angleAngle, changes catoptrical incident angle and by incident angle location, galvanometer controller produces and gathers simultaneouslyThe triggering signal of image information;
S3, imaging lens will be imaged onto the surface of sample through the reverberation of described galvanometer;
S4, described sample surface electronic is subject to photon excitation, is meeting photoelectric effect occurrence conditionTime, sample surface, through electron microscopic system imaging, forms image information described in electron detachment;
S5, image information is gathered by data collecting system.
In above-mentioned angle scanning photoemitted electron micro imaging method, in described step S2, comprise asLower step,
A. the given signal of required scanning angle is inputted the miniature calculating in described control system by userMachine;
B. described microcomputer is by the encode formation control instruction be by communication of given signalSystem (16) is sent to the second communication and the control circuit of described galvanometer controller;
C. described the second communication and control circuit are received after control instruction, and gated sweep circuit for generating producesSweep waveform;
D. the position of galvanometer motor is fed back by angular displacement sensor in real time, described angular displacement sensorOutput signal amplify and filtering through sensor interface circuitry, then process through signal conditioning circuit,Thereby obtain characterizing the signal of position, current described galvanometer motor angle, arithmetic unit is by position, described galvanometer motor angleThe signal of putting and given signal are compared, if any error, comparison result through PID controller calculate after,Control galvanometer motor drive circuit and drive described galvanometer motor rotation, until error concealment realizes incidence angleDegree location;
E. described the second communication and control circuit send triggering signal to the first communication and control circuit.
In above-mentioned angle scanning photoemitted electron micro imaging method, in described step S5, describedOne communication and control circuit are received after triggering signal, drive timing generator circuit to start working, and then described inTiming generator circuit control signal conditioning and conversion circuit complete electronics planar array detector signal collection andTransmission.
In above-mentioned angle scanning photoemitted electron micro imaging method, described optics incident angle scope isArbitrary interval in [90 degree, 90 degree].
Technique scheme of the present invention has the following advantages compared to existing technology.
(1) angle scanning photoemitted electron microscopy imaging system of the present invention, comprises that light beam sweepsRetouch system, electron microscopic system and control system, can meet in PEEM imaging enteringThe variation requirement of firing angle degree, realizes incident angle is regulated fast, accurately, andCan realize synchronized sampling, to avoid the impact of spurious signal, improve and measure signal to noise ratioAnd stability.
(2) angle scanning photoemitted electron microscopy imaging system of the present invention, has light beam and sweepsThe speed of retouching is fast, the feature of accurate positioning, synchronous acquisition, can realize PEEM imagingIn multiple requirement to incident angle of light, and can avoid light beam in position fixing process to trembleThe interference of the moving spurious signal causing, measures signal to noise ratio thereby improve.
(3) angle scanning photoemitted electron microscopy imaging system of the present invention, beam flying systemTurnkey is drawn together excitation source, shaping mirror, focus lamp, galvanometer and imaging lens, Qi ZhongzhenMirror is closed-loop system, can realize simultaneously and continue scanning and special angle location, continuesScan frequency<15kHz, angle orientation response>0.05ms, angle repetitive positioning accuracy< 100 μ rad, and prior art adopts stepper motor drive turntable motion and then changeIncident angle is realized the method for angle scanning, and angle repetitive positioning accuracy is about hundreds ofμ rad, this programme is better than prior art, and drives exciting light to carry out angle at galvanometerWhen degree scanning, sample surfaces facula position remains unchanged.
(4) angle scanning photoemitted electron microscopy imaging system of the present invention, beam flying systemShaping mirror, focus lamp, galvanometer, optical polarizer and the imaging lens of system are all positioned at clearlyIn clean vacuum environment, to reduce absorption of air and scattering exciting light.
(5) angle scanning photoemitted electron microscopy imaging system of the present invention, electron microscopic systemThe vacuum of the vacuum environment of living in of uniting is higher than the shaping mirror in optical beam scanning system, poly-The vacuum of Jiao Jing, galvanometer, optical polarizer and imaging lens vacuum environment of living in,Wherein imaging lens, except its optical effect, also plays the different vacuum level environment of isolationEffect.
(6) angle scanning photoemitted electron microscopy imaging system of the present invention, wherein sample stageBe connected with negative high voltage, electromagnetism object lens are connected with electromotive force ground, at sample and electromagnetismBetween object lens, form electronics accelerating field, thereby improve electron energy and reduce equivalenceAngular aperture.
(7) angle scanning photoemitted electron microscopy imaging system of the present invention is enhancing systemCompatibility, native system can add electronics between electromagnetism object lens and scene and projection lensBeam splitter, to facilitate the extra electron source of access, realizes low energy electron microscopy(LEEM, LowEnergyElectronMicroscope) function; At electronicsBetween beam splitter and electronics planar array detector, field lens and projection lens are also set, Neng GoushiAdjusting and the diffraction spectra imaging of existing enlargement ratio.
(8) angle scanning photoemitted electron microscopy imaging system of the present invention, wherein burnt mirrorThe focal length of focal distance ratio shaping mirror is short, and the focus a of shaping mirror is positioned at focus lampBetween 1 times of focal length to 2 times focal length, so further compression light beam angular aperture,Reduce the aberration of subsequent optical system.
(9) angle scanning photoemitted electron microscopy imaging system of the present invention, wherein shaping mirror,Focus lamp and imaging lens are by CaF2Make, for improving the transmitance of ultraviolet light.
(10) angle scanning photoemitted electron micro imaging method of the present invention, has located at galvanometerAfter incident angle, the second communication and control circuit output triggering signal, synchronously to openMoving data collecting system, avoids the interference of spurious signal.
Brief description of the drawings
For content of the present invention is more likely to be clearly understood, below according to specific embodiment of the inventionAlso by reference to the accompanying drawings, the present invention is further detailed explanation for example, wherein,
Fig. 1 is the principle schematic of angle scanning photoemitted electron micro imaging system of the present invention;
Fig. 2 is the light of optical beam scanning system in angle scanning photoemitted electron micro imaging system of the present inventionLu Tu;
Fig. 3 is the principle frame of control system in angle scanning photoemitted electron micro imaging system of the present inventionFigure;
Fig. 4 is the letter of synchronized sampling mechanism in angle scanning photoemitted electron micro imaging system of the present inventionNumber figure;
Fig. 5 be angle scanning photoemitted electron micro imaging system of the present invention realize LEEM mode of operationSchematic diagram.
In figure, Reference numeral is expressed as: 1-the first vacuum cavity, 2-excitation source, 3-shaping mirror, 4-Focus lamp, 5-galvanometer, 5a-galvanometer motor, 5b-angular displacement sensor, 6-optical polarizer, 7-imagingMirror, 8-sample stage, 9-testing sample, 10-electromagnetism object lens, 11-electronics beam splitter, 12-field lens and throwingShadow mirror, 13-electronics planar array detector, 14-data collecting system, 14a-the first communication and control circuit,14b-timing generator circuit, 14c-signal condition and conversion circuit, 15-microcomputer, 16-communication systemSystem, 17-galvanometer controller, 17a-galvanometer motor drive circuit, 17b-PID adjuster, 17c-scanningWave generator circuit, 17d-the second communication and control circuit, 17e-signal conditioning circuit, 17f-sensorInterface circuit, 17g-arithmetic unit, 18-electron gun, 19-the second vacuum cavity.
Detailed description of the invention
As shown in Figure 1, be the preferred embodiment of angle scanning photoemitted electron micro imaging system of the present invention.Described angle scanning photoemitted electron micro imaging system comprises: optical beam scanning system, electron microscopic system,Three subsystems of control system.
As shown in Figure 2, described optical beam scanning system comprises: excitation source 2, shaping mirror 3, focus lamp4, galvanometer 5, optical polarizer 6 and imaging lens 7.
Described excitation source 2 is positioned at the first vacuum cavity 1 outside, excitation source 2 described in the present embodimentChoice for use deep ultraviolet lasers (DUV), for to the interior transmitting Ultra-Violet Laser of described the first vacuum cavity 1,In the present embodiment, the Ultra-Violet Laser that described excitation source 2 sends is collimation narrow beam laser, and this device swashsLight emitting source also can adopt other gas, arc sources etc. through shaping, as deuterium lamp, mercury lamp, helium lamp.Described shaping mirror 3 is positioned at described the first vacuum cavity 1 inside, for what described excitation source 2 was launchedUltra-Violet Laser carries out shaping, Ultra-Violet Laser after shaping is converged the focus a place of described shaping mirror 3 shapeBecome focal beam spot. Described focus lamp 4, described galvanometer 5 are positioned at described the first vacuum cavity 1 inside, useIn by focal beam spot imaging and be projected to the speculum pivot place of described galvanometer 5, in the present embodiment,The speculum degree of described galvanometer 5 has ultraviolet high-reflecting film. Described imaging lens 7 is positioned at the first vacuum cavity 1Portion, for by be imaged onto the surface of sample 9 through the ultraviolet light reverberation of described galvanometer 5, makesWhen incident beam carries out angle scanning, can guarantee that the facula position on described sample 9 surfaces keeps notBecome. Wherein, described shaping mirror 3, described focus lamp 4, described galvanometer 5 and described imaging lens 7 byCaF2Make, can increase uv transmittance. In the present embodiment, described shaping mirror 3 and described focusingMirror 4 can carry out position adjustment along optical axis direction, for regulating the large of described galvanometer 5 mirror surface hot spotsLittle.
Described in the focal distance ratio of described focus lamp 4, the focal length of shaping mirror 3 is short, and Jiao of described shaping mirror 3Point a, between 1 times of focal length to 2 times focal length of described focus lamp 4, is compressed into irradiating light beam angular aperture,Reduce the aberration of subsequent optical system. In use, by regulating described shaping mirror 3 can regulate focusThe position of a, and then coordinate the described focus lamp 4 of adjusting, make it to meet imaging relations, i.e. adjustable instituteState the size of galvanometer 5 mirror surface hot spots, thereby regulate described sample 9 surface light of final projectionThe size of spot.
Described electron microscopic system is positioned at described vacuum cavity the second vacuum cavity 19 inside, for to instituteState sample 9 surface light electronics and carry out imaging. Described electron microscopic system sample stage 8, electromagnetism object lens10, electronics beam splitter 11, field lens and projection lens 12 and electronics planar array detector 13.
Described sample stage 8 is multiple degrees of freedom displacement platform, is connected, for putting with negative high voltage (30kV～0)Put described sample 9. Is connected described electromagnetism object lens 10 and electromotive force, at described sample 9 andBetween described electromagnetism object lens 10, form electronics accelerating field, thereby improve electron energy and reduce equivalenceAngular aperture, has avoided, due to ultraviolet light photons energy lower (being conventionally less than 7eV), therefore excitingEnergy of photoelectron is lower, and because the angle of divergence is larger, thereby the problem that cannot carry out high-quality imaging.In the present embodiment, to adopt ESEM angle be the taper object lens of 45 degree to described electromagnetism object lens 10.Described in described electronics planar array detector 13, imaging lens 7 is by the ultraviolet reflectance photoimaging through described galvanometer 5Behind the surface of sample 9, described sample 9 surface electronics are subject to ultraviolet photon and excite, fullWhen foot photoelectric effect occurrence condition, described electromagnetism thing is passed through on sample 9 surfaces successively described in electron detachmentMirror 10 projects imaging on described electronics planar array detector 13. In the present embodiment, described electronics beam splittingMirror 11 is arranged between described electromagnetism object lens 10 and described electronics planar array detector 13, described field lens andProjection lens 12 is arranged between described electronics beam splitter 11 and described electronics planar array detector 13, electronicsDepart from described sample 9 surfaces pass through successively described electromagnetism object lens 10, described electronics beam splitter 11,Described field lens and projection lens 12 project imaging on described electronics planar array detector 13. Add described field lensTo realize adjusting and the diffraction spectra imaging of enlargement ratio with the object of projection lens 12. Add described electronics to divideThe object of bundle mirror 11 is the compatibility in order to strengthen system, and the extra electron source of convenient access, realizes lowEnergy electron microscope (LEEM, LowEnergyElectronMicroscope) function, described electronicsBeam splitter 11 can adopt WienFilter, multi-layer double-pole magnetic lenses etc., as shown in Figure 5.
The vacuum of described the second vacuum cavity 19 is higher than the vacuum of described the first vacuum cavity 1,In the present embodiment, the vacuum of described the second vacuum cavity 19 is about 10-8～10-9Handkerchief, described first trueThe vacuum of cavity body 1 is about 10-3Handkerchief; Described imaging lens 7 plays the different vacuum level environment of isolationEffect.
Described control system is positioned at the outside of described the first vacuum cavity 1 and described the second vacuum cavity 19,For controlling the operation of described optical beam scanning system and described electron microscopic system. Described control system comprises:Data collecting system 14, microcomputer 15, communication system 16 and galvanometer controller 17.
Described data collecting system 14 is electrically connected with described electronics planar array detector 13, for gather fromThe image information forming on described electronics planar array detector 13. Described microcomputer 15 and described dataAcquisition system 14 is electrically connected, image information and the use transmitted for receiving described data collecting system 14The operation information at family. Described communication system 16 is electrically connected with described microcomputer 15, for acceptingState the command information that microcomputer 15 sends. Described galvanometer controller 17 and described communication system 16,Described galvanometer 5 is electrically connected, and described galvanometer controller 17 receives described miniature by described communication system 16The command information that computer 15 sends, and then control described galvanometer 5 and rotate, to realize adjustment scan angleThe object of degree.
As shown in Figure 3, described galvanometer 5 comprises interconnective galvanometer motor 5a and angular displacement sensor5b; Described galvanometer motor 5a is the servomotor based on galvanometer principle, before described galvanometer motor 5aAxle is provided with described speculum, and the rear axle of described galvanometer motor 5a is connected with described angular displacement sensor 5b;Described angular displacement sensor 5b can adopt photo-electric angular displacement sensor or capacitive angular sensor,Described angular displacement sensor 5 is high-resolution circle grating in the present embodiment.
Described data collecting system 14 comprise successively the signal condition of electrical connection and conversion circuit 14c, timeOrder circuit for generating 14b and the first communication and control circuit 14a. Described signal condition and conversion circuit 14cBe electrically connected with described electronics planar array detector 13, described signal condition and conversion circuit 14c are receivingState the image to described electronics planar array detector 13 after the control instruction that timing generator circuit 14b sendsInformation and transmission. Described timing generator circuit 14b receives described the first communication and controls electricityAfter the triggering signal of road 14a, produce described electronics planar array detector 13 integration, transfer, conversion andTransmitted waveform, in the present embodiment for producing CCD integration, transfer, conversion and transmitted waveform. DescribedOne communication and control circuit 14a are electrically connected with described microcomputer 15.
Described galvanometer controller 17 comprises galvanometer motor drive circuit 17a, PID adjuster 17b, scanningWave generator circuit 17c, the second communication and control circuit 17d, signal conditioning circuit 17e, sensorInterface circuit 17f and arithmetic unit 17g.
Described the second communication and control circuit 17d and described communication system 16, described the first communication and controlCircuit 14a electrical connection processed, described the second communication and control circuit 17d are also electrically connected with described arithmetic unit 17gConnect, described arithmetic unit 17g is also electrically connected with described sweep waveform circuit for generating 17c; Described the second communicationAnd control circuit 17d receives that described communication system 16 transmits after next control instruction, controls described scanningWave generator circuit 17c produces waveform. Described angular displacement sensor 5b and described sensor interface circuitry17f electrical connection, described sensor interface circuitry 17f is also electrically connected with described signal conditioning circuit 17e,Described sensor interface circuitry 17f enters for the signal data that described angular displacement sensor 5b transmission is comeRow amplification and filtering also transfer to described signal conditioning circuit 17e by signal after treatment; Described signal is adjustedReason circuit 17e for by carry out through described sensor interface circuitry 17f filtering the signal processed shaping andPhase locking frequency multiplying, finally obtains the signal of position, described galvanometer motor 5a angle, shakes described in the present embodimentThe signal of position, mirror motor 5a angle is data signal. The signal of telecommunication of described signal conditioning circuit 17e outputDo computing with the signal of telecommunication of described sweep waveform circuit for generating 17c output, due to described galvanometer motor 5aThe signal of position, angle is data signal, the signal of telecommunication of signal conditioning circuit 17e described herein output with described inThe signal of telecommunication of sweep waveform circuit for generating 17c output does logic and subtracts computing, described in operation result is exported toPID adjuster 17b, described PID adjuster 17b is electrically connected with described galvanometer motor drive circuit 17a,Described galvanometer motor drive circuit 17a is electrically connected with described galvanometer motor 5a, drives described galvanometer 5 to reachTo set angle.
The main waveform that described in technical scheme of the present invention, control system produces, as shown in Figure 4, comprising:The step scanning ripple a of described scanning wave generation circuit 17c output, described signal conditioning circuit 17e outputThe position signalling b of described galvanometer motor 5a, described the second communication and control circuit 17d shake describedThe triggering signal c of output after mirror motor 5a locates successfully, and sequence circuit 14b is receiving triggering letterThe CCD integration, transfer, conversion and the transmitted waveform d that after number, produce.
The angle scanning photoemitted electron of angle scanning photoemitted electron micro imaging system of the present inventionMicro imaging method: comprise the following steps:
S1, the exciting light that described excitation source 2 is exported is through described shaping mirror 3 and described focus lamp 4After, form hot spot in the mirror surface of described galvanometer 5.
S2, described galvanometer 5 is under the control of described control system, within the scope of optics incident angleAdjust scanning angle, change catoptrical incident angle and by incident angle location, shake described in simultaneouslyMirror controller 17 produces the triggering signal that gathers image information, and described optics incident angle scope is[90 degree, 90 degree], are preferably 70 ± 5 degree in the present embodiment; Concrete steps are:
A. the given signal of required scanning angle is inputted described microcomputer 15 by user;
B. described microcomputer 15 by given signal encode formation control instruction and pass through described inCommunication system 16 is sent to described the second communication and control circuit 17d;
C. described the second communication and control circuit 17d receive after control instruction, control described scanningCircuit for generating 17c produces sweep waveform;
D. the position of described galvanometer motor 5a is fed back by angular displacement sensor 5b in real time, described inThe output signal of angular displacement sensor 5b is amplified and filtering through described sensor interface circuitry 17f,Carry out shaping and phase locking frequency multiplying through described signal conditioning circuit 17e again, thereby obtain characterizing current instituteState the data signal of position, galvanometer motor 5a angle, described arithmetic unit 17g is by described galvanometer motor 5aThe data signal of position, angle and given signal are compared, if any error, described in comparison result warpPID controller 17b controls described galvanometer motor drive circuit 17a and drives described galvanometer electricity after calculatingMachine 5a rotation, until error concealment realizes incident angle location;
E. described the second communication and control circuit 17d send out to described the first communication and control circuit 14aGo out triggering signal.
S3, the ultraviolet reflectance photoimaging through described galvanometer 5 is arrived described detected sample by described imaging lens 7The surface of product 9.
S4, described sample 9 surface electronics are subject to photon excitation, are meeting photoelectric effect generationWhen condition, sample 9 surfaces are through described electron microscopic system imaging, shape described in electron detachmentBecome image information.
S5, image information is gathered by described data collecting system 14, and concrete steps are: described firstCommunication and control circuit 14a receive after triggering signal, drive described timing generator circuit 14b to startWork, and then described timing generator circuit 14b controls described signal condition and conversion circuit 14c is complete
Become collection and the transmission of electronics planar array detector 13 signals.
In other embodiments, can be according to system imaging needs, do not arrange described optical polarizer 6,Described electronics beam splitter 11 and described field lens and projection lens 12.
In other embodiments, demand per sample, adopts other excitation sources such as deuterium lamp, mercury lampAs system source.
In other embodiments, if the signal of position, described galvanometer motor 5a angle is analog signal, instituteState the signal of telecommunication of signal conditioning circuit 17e output and the telecommunications of described sweep waveform circuit for generating 17c outputNumber will carry out simulation trial.
In other embodiments, signal conditioning circuit 17e can also be to filtering through sensor interface circuitry 17fRipple the signal of processing carry out other processing.
Obviously, above-described embodiment is only for example is clearly described, and not to embodimentRestriction. For those of ordinary skill in the field, can also do on the basis of the above descriptionGo out other multi-form variation or variation. Here without also giving exhaustive to all embodiments.And the apparent variation of being extended out thus or variation still the protection domain in the invention itIn.