CN102592914A - Method for controlling field emission electronic divergence angle by using nano carbon tube - Google Patents
Method for controlling field emission electronic divergence angle by using nano carbon tube Download PDFInfo
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- CN102592914A CN102592914A CN2012100463165A CN201210046316A CN102592914A CN 102592914 A CN102592914 A CN 102592914A CN 2012100463165 A CN2012100463165 A CN 2012100463165A CN 201210046316 A CN201210046316 A CN 201210046316A CN 102592914 A CN102592914 A CN 102592914A
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Abstract
The invention discloses a method for controlling a field emission electronic divergence angle by using a nano carbon tube. The method comprises the steps of: applying a voltage between the carbon tube and a positive pole to form electron field emission by using the multi-wall nano carbon tube as an electron source of field emission; and changing the electric-field distribution of a port of the nano carbon tube through regulating and selecting the length of the extracted outer wall of the nano carbon tube and the voltage applied to the nano carbon tube, controlling the field emission electronic divergence angle, collimation or convergence, and controlling the focusing distance of an electron beam. According to the invention, under the condition without any additional focusing device, the divergence, focusing or collimation of field-emitted electronics is controlled.
Description
Technical field
The present invention relates to CNT electronic field emission field, is a kind of method of utilizing the CNT controlling filed emitting electrons angle of divergence.
This patent needing can be used for high brightness electron source and processing of high-resolution electronics or imaging device.Like electric lithography, electron microscope and electron diffraction apparatus or the like.During particularly the near field was surveyed, the focus method of no additional electron lens can be eliminated the restriction of electron source with distance between the detection sample, thereby reduces the electron beam diffusion, greatly improves the resolution of electronic imaging device.
Background technology
Since CNT in 1991 came to light, because required bias voltage is very low and have very high characteristics such as emission, the electronic field emission device of CNT obtained extensive studies in global scope.After 2000, obtained preliminary commercialization based on the high brightness electron source or the x-ray source of CNT, there are flat panel display, cathode-ray lamp, X-ray tube or the like in the typical application field; Accordingly based on the high-resolution electron source equipment such as the electron beam lithography of CNT, electron microscopic and diffractive technology etc. are also among flourish.
The metal probe that in traditional feds, adopts nano-scale is as emission source, for example nanometer tungsten pin.Because CNT and nonmetal structure, but the atom of CNT exists with the combination of covalent bond, thereby can bear higher electric field than metal probe, reaches the electronic field emission requirement of the every nanometer of several volts.CNT has very little diameter, can improve several magnitudes at its terminal electric field owing to the geometry enhancement effect, thereby just can produce the electronics emission even add very low voltage (for example tens volts).Add that CNT has great Young's modulus and tensile strength, and chemically stable, a series of advantage of oxidation or hydrogenation or the like only just can take place under excessive temperature, make CNT become very desirable field emitting electronic source.
Structure according to CNT is different, and the angular distribution of field emission electron is also different.For example terminal single tube of uncapping possibly produce the electron beam of ring-type, and the end on hemisphere or plane can produce the electron beam of the different angles of divergence.And the CNT electrons emitted bundle of many walls generally has better cylinder symmetry and stability; At high temperature possibly present symmetry of five jiaos or hexagonal or the like according to the arrangement difference of carbon atom; Detailed introduction can be with reference to the comment document of Niels in 2004 [referring to document 1. Niels de Jonge and Jean-Marc Bonard; Carbon nanotube electron sources and applications
Phil. Trans. R. Soc. Lond. A(2004)
362, 2239-2266.].But in general because the diameter of CNT is very little, its electrons emitted quite comes from point source how much, thereby has the bigger angle of departure, and representative value is at several measurement levels.For the high-resolution electric lithography of needs or electronic imaging technology, the so big angle of divergence can't meet the demands, and need collimate or focuses on electron beam.
Though magnetic lens that traditional electron-beam convergence method for example adopts in the electron microscope or electrostatic lens technology development comparative maturity; But its structure and control relative complex; Cost an arm and a leg, and the more important thing is and in the near field that electron source and detection sample are pressed close to is very much surveyed, to use.
Summary of the invention
The technical problem that the present invention will solve is to overcome the problem that above-mentioned prior art exists; A kind of method of utilizing the CNT controlling filed emitting electrons angle of divergence is provided; Realize lensless electron beam collimation and focusing, can make the distance between electron source and the detection sample unrestricted simultaneously.
Employing is extracted the outer wall of multiple-wall carbon nanotube out certain distance, adds the terminal electric field layer negatron lens effect that forms of outer wall behind the voltage, and field electrons emitted bundle is produced focusing effect.Thereby the angle of departure of controlling filed divergent bundle easily.
Technology implementation scheme of the present invention is following:
A kind of control method of utilizing CNT to the field emission electron angle of divergence, its characteristics are that this method comprises the following steps:
1. adopt existing conventional method to prepare multiple-wall carbon nanotube; Therefrom select a multiple-wall carbon nanotube; The one of which end is sticked on the fixing metal support with conductive silver glue, and an other end sticks on the piezoelectric ceramic displacement controller with nano-precision, adds a pulse voltage at the stiff end of multiple-wall carbon nanotube; The end of this CNT outer wall is opened, and this end becomes the carbon pipe of opening;
2. regulate the displacement of described piezoelectric ceramic displacement controller, extract the outer wall of described CNT out the distance suitable to the direction that connects piezoelectric ceramic with this CNT diameter;
3. the port at described CNT extraction outer wall adds a pulse voltage, and the outer wall of this port is also opened, and forms to have the CNT that the opening outer wall surrounds;
4. set up the CNT field emission apparatus: described CNT with the encirclement of opening outer wall is sticked on the metal probe with conductive silver glue; And with this probe stationary on a metallic support; This metallic support device is placed in the environment of ultra high vacuum, and vacuum degree is 10
-7～10
-12Mbar; Described metallic support is connected with a negative supply; The negative voltage that on the support of fixing metal probe, applies tens volts forms negative electrode, and anode is made up of the phosphor screen of the outer ground connection of certain distance, when the negative voltage that is applied when the port of described CNT forms the highfield that strengthens for how much; Cause the field emission of electronics, free electron is quickened to arrive described phosphor screen by added bias voltage;
The length of 5. extracting out through the outer wall of adjustment and selection CNT reaches the voltage that on CNT, is applied, and changes the Electric Field Distribution of described CNT port, and the controlling filed emitting electrons angle of divergence, collimation are perhaps assembled the focusing distance of controlling electron beam.
Described preparation multiple-wall carbon nanotube method is arc discharge method, laser ablation method or chemical vapour deposition technique.
Advantage of the present invention:
1, the present invention adopts the angle of divergence of the method controlling filed emitting electrons of extracting the CNT outer wall out, need not additional other electron focusing devices, makes whole electron source apparatus letter gather, and is cheap.
2, method of the present invention does not need the additional electron lens can realize the electron beam of high brightness collimation, helps improving the resolution of existing electronic diffraction equipment.
3, method of the present invention can realize that the electron beam of hundred nanometer focal lengths focuses on, and effectively suppresses the electron beam chromatic dispersion, improves the resolution of electron microscopic and photoetching technique.
,The present invention is through adjustment and select the length of the outer wall extraction of CNT to reach the voltage that on CNT, is applied; Can change the Electric Field Distribution of described CNT port; The controlling filed emitting electrons angle of divergence, collimation or convergence, the focusing distance of controlling electron beam.
Description of drawings
Fig. 1 is a multiple-wall carbon nanotube field emission apparatus sketch map
Fig. 2 is near the voltage distribution schematic diagram the CNT end
Fig. 3 is near the electric field absolute value distribution schematic diagram the CNT end
Fig. 4 is that the outer wall of CNT is extracted the corresponding electron-propagation path sketch map of different distance out
Fig. 5 is field emission electron bundle focal length and focused spot diameter extract distance with carbon pipe outer wall variation relation figure.
Embodiment
Below in conjunction with embodiment and accompanying drawing the present invention is described further, but should limit protection scope of the present invention with this.
The present invention utilizes the control method of CNT to the field emission electron angle of divergence, comprises the following steps:
The preparation multiple-wall carbon nanotube [see also document [2]. John Cumings and A. Zettl, Low-friction nanoscale linear bearing realized from multiwall carbon nanotubes, Science (2000)
289602-604.]: with the single taking-up of multiple-wall carbon nanotube of conventional method (like arc discharge method, laser ablation method, chemical vapour deposition technique or the like) preparation; The one of which end is sticked on the fixing metal support with conductive silver glue, and an other end sticks on the piezoelectric ceramic displacement controller with nano-precision.Stiff end at the carbon pipe adds a pulse voltage, and the end of the outer wall of CNT is opened, and this end becomes the carbon pipe of opening; The displacement of the described piezoelectric ceramic of regulating and controlling is extracted the outer wall of described CNT and the suitable distance of carbon pipe diameter out to the direction that connects piezoelectric ceramic; Port extracting outer wall out adds a pulse voltage, and the outer wall of this port is also opened; After CNT taken off, the port of this CNT formed the shape shown in dotted ellipse shape subgraph among Fig. 1.The outer wall 1 of carbon pipe is extracted the distance of carbon pipe diameter magnitude with respect to carbon inside pipe wall 2, said distance from the straight tube top of carbon inside pipe wall 2 as starting point.
2. CNT field emission apparatus: shown in Fig. 1, the multiple-wall carbon nanotube of above-mentioned preparation is sticked on the metal probe 3 with conductive silver glue, and with this probe stationary on a metallic support 4.Form negative electrode connecting the negative voltage that adds tens volts on the support 4 of fine needle 3, anode is by phosphor screen 5 formations of the ground connection of certain distance outer (typical case at several microns to several centimetres), with the bundle shape of spot of observation field emission electron.Added voltage forms the highfield that geometry strengthens at the port of carbon pipe, causes the field emission of electronics, and free electron is quickened arrival phosphor screen 5 by added bias voltage.Because electron motion receives the influence of molecule in the air, whole device need be placed in the environment of ultra high vacuum (10 easily
-7～10
-12Mbar).
3. near the voltage the carbon pipe distributes and Electric Field Distribution: find the solution Poisson's equation 2 φs=0 of electrostatic field as boundary condition through Finite Element Method with the applied voltage on carbon pipe and the anode, obtain carbon pipe neighbouring electromotive force and Electric Field Distribution, φ is an electromotive force.Because the axial symmetry characteristics of carbon pipe, above equation can be found the solution under two axisymmetric cylindrical coordinatess.The carbon pipe that it is 10 nanometers that simulated conditions are set to a diameter adds-bias voltage of 10V, and outer wall is extracted 10 nanometers out.The analog result of typical two-dimensional columns symmetrical coordinates is as shown in Figure 2, and the voltage that left figure has provided amended carbon pipe distributes, and the voltage that right figure provides general carbon pipe under the similarity condition distributes.Obviously visible general carbon pipe Potential Distributing layer is semi-circular outwards to be dispersed, and forms the voltage that is similar to convergence and distributes and outer wall extracted out after 10 nanometers extracting the part annex out.Fig. 3 provides electric field (absolute value) corresponding under two kinds of situation and distributes, and there is a very strong electric field 4.6G V/m in the end that left figure outer wall is extracted out (mark arrow place), and the electronics of the internal wall emission of this electric field has the effect of convergence.Though carbon pipe end also can emitting electrons in this highfield, its emission area is very little, and directional divergence, and arriving behind the anode with respect to the carbon inner tube layer electrons emitted after assembling is a very weak background noise, can ignore.Right figure is near an Electric Field Distribution situation general carbon pipe end, does not have the electric field that can cause electronics to be assembled.
4. carbon pipe outer wall electric field is to the converging action of field emission electron: trajectory of electron motion is as shown in Figure 4 in above-mentioned electric field, and wherein a figure is that outer wall is taken out 10 nanometers, and electronics emission back is converged to the near field by the highfield of outer wall, and focal length is between 10 to 20 nanometers; Figure b extracts outer wall out 8 nanometers, and most of electronics emission can produce very little beam spot, about 5 nanometers of Simulation result in the far field after the highfield collimation of outer wall presents the propagation parallel with symmetry axis.A spot of carbon tube edges electrons emitted is converged to the near field, but because fringe field a little less than, the emitting electrons probability is little a lot of than the center, its intensity can be ignored.Provided the general carbon pipe electrons emitted track that is emission type as comparison diagram c.Fig. 5 has provided the relation that electron beam focal length length and focused spot diameter and carbon pipe outer wall extract distance, with the diameter of carbon pipe as unit.It is thus clear that along with the extraction reduced distances, the focal length length of side, it is big that focused spot diameter becomes.When the electron beam shown in the figure b was tending towards collimation, focal length became infinity, and focused spot diameter is about the half the of carbon pipe diameter.
In sum, utilize outer wall with multiple-wall carbon nanotube to extract the method with the suitable distance of carbon pipe diameter, can be in the emission of the field of electronics the effective angle of divergence of control electronics, form and assemble or the beam spot of collimation, high brightness electron source is provided.(beyond several centimetres) can keep the size of carbon pipe diameter magnitude to the beam spot of collimation in the far field, thereby than the electron beam that is divergence form of general carbon pipe emission more much higher brightness are arranged, and this will greatly improve the resolution of electronic diffraction equipment.And can shorten to below 100 nanometers through its focal length of focused beam that this method obtains, this can't realize with traditional electron focusing method.Under so short distance; The electron beam chromatic dispersion in communication process that is brought by the Coulomb repulsion effect of the electric charge of electronics and electronics initial velocity and energy uncertainty can be suppressed greatly; Thereby strengthen to improve the image quality of electronic imaging device such as electron microscope, and this is for just among develop actively, with time-resolved electronic imaging device the meaning of particular importance being arranged.
Claims (2)
1. utilize the control method of CNT, it is characterized in that this method comprises the following steps: the field emission electron angle of divergence
1. adopt existing conventional method to prepare multiple-wall carbon nanotube; Therefrom select a multiple-wall carbon nanotube; The one of which end is sticked on the fixing metal support with conductive silver glue, and an other end sticks on the piezoelectric ceramic displacement controller with nano-precision, adds a pulse voltage at the stiff end of multiple-wall carbon nanotube; The end of this CNT outer wall is opened, and this end becomes the carbon pipe of opening;
2. regulate the displacement of described piezoelectric ceramic displacement controller, the outer wall of described CNT is extracted out and the suitable distance of this carbon pipe diameter to the direction that connects piezoelectric ceramic;
3. the port at described CNT extraction outer wall adds a pulse voltage, and the outer wall of this port is also opened, and forms one and has the CNT that the opening outer wall surrounds;
4. set up the CNT field emission apparatus: described CNT with the encirclement of opening outer wall is sticked on the metal probe with conductive silver glue; And with this probe stationary on a metallic support; This metallic support device is placed the environment of ultra high vacuum, and vacuum degree is 10
-7～10
-12Mbar; Described metallic support with communicate with a negative supply; The negative voltage that on the support of fixing metal probe, applies tens volts forms negative electrode, and anode is made up of the phosphor screen of the outer ground connection of certain distance, when the negative voltage that is applied when the port of described CNT forms the highfield that strengthens for how much; Cause the field emission of electronics, free electron is quickened to arrive described phosphor screen by added bias voltage;
The length of 5. extracting out through the outer wall of adjustment and selection CNT reaches the voltage that on CNT, is applied, and changes the Electric Field Distribution of described CNT port, and the controlling filed emitting electrons angle of divergence, collimation are perhaps assembled the focusing distance of controlling electron beam.
2. the control method of utilizing CNT to the field emission electron angle of divergence according to claim 1 is characterized in that described preparation multiple-wall carbon nanotube method is arc discharge method, laser ablation method or chemical vapour deposition technique.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111413727A (en) * | 2020-04-15 | 2020-07-14 | 中国科学院电工研究所 | Electron beam divergence angle measuring device and preparation method and measuring method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101261916A (en) * | 2008-04-08 | 2008-09-10 | 北京大学 | A single carbon nano electronic field emission cathode and its making method |
| JP2009117367A (en) * | 2007-11-02 | 2009-05-28 | Qinghua Univ | Field emission electron source, and manufacturing method thereof |
| CN102024639A (en) * | 2010-11-29 | 2011-04-20 | 清华大学 | Method for manufacturing electron emitter |
| CN102290304A (en) * | 2011-08-07 | 2011-12-21 | 张研 | Carbon nanotube field emission array with focusing gate |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009117367A (en) * | 2007-11-02 | 2009-05-28 | Qinghua Univ | Field emission electron source, and manufacturing method thereof |
| CN101261916A (en) * | 2008-04-08 | 2008-09-10 | 北京大学 | A single carbon nano electronic field emission cathode and its making method |
| CN102024639A (en) * | 2010-11-29 | 2011-04-20 | 清华大学 | Method for manufacturing electron emitter |
| CN102290304A (en) * | 2011-08-07 | 2011-12-21 | 张研 | Carbon nanotube field emission array with focusing gate |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111413727A (en) * | 2020-04-15 | 2020-07-14 | 中国科学院电工研究所 | Electron beam divergence angle measuring device and preparation method and measuring method thereof |
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