CN1868120A - Electromechanical filter and electric circuit and electric apparatus employing it - Google Patents

Abstract

An electromechanical filter capable of being miniaturized by employing a micro-oscillator of a carbon nanotube, or the like, excellent in electric conductivity and capable of selecting a signal of a desired frequency. The electromechanical filter has an inner shell (106) of a carbon nanotube physically changed when a signal is inputted, and an outer shell (108) of a carbon nanotube arranged to cover the inner shell (106) through a micro-gap G. When a signal of a desired frequency is inputted to the inner shell (106) from a signal-input-side electrode part (110) connected therewith, the outer shell (108) detects oscillation of the inner shell (106) and delivers it through a signal-output-side electrode part (112) connected therewith.

Description

Electromechanical filter and the circuit and the electric equipment that adopt it

Technical field

The present invention relates to a kind of circuit and electric equipment that is provided with the electromechanical filter of microoscillator and adopts this electromechanical filter.

Background technology

Along with terminal, for example development of the compact degree of wireless terminal, the passive component of for example filter etc. of also wishing to be built in terminal enclosure is also microminiaturized.Particularly, in recent years, be widely used in the filter of electrical oscillator of LC etc. of radio communication in employing, the oscillator size depends on electrical length.This makes and is difficult to make filter little, and therefore seeks new signal Choice Theory.

Wherein, adopt the micro electronmechanical filter of MEMS (MEMS (micro electro mechanical system)) and NEMS (nano-electromechanical system) technology manufacturing to be hopeful as filter of future generation.

This electrical filter uses mechnical oscillator and this structure to depend on the quality and the spring constant of the oscillator of vibration.Therefore can reduce size by adopting electrical oscillator.For example, depend on shape and oscillation mode in the size of the oscillator of 1GHz vibration, but less than several microns magnitude.In addition, because the method that the size of this filter, needs to make the method for microoscillator less than several microns and surveys micro oscillation.

For example shown in the open case of Japan special permission flat 6-310976 number, have the electromechanical filter of the microoscillator that adopts prior art, wherein for example carbon nano-tube is used as microoscillator.Carbon nano-tube is the minimum tubular material of nanometer scale, and wherein carbon atom is joined together to form lattice.

Be used to electromechanical filter to select the mechanism hypothesis carbon nano-tube and the fullerene of signal to make in the open case of Japan special permission flat 6-310976 number by dielectric material.Particularly, adopt the electromechanical filter of prior art, the electrode that is connected with the input signal mouth and the electrode both who is connected with output signal port are arranged on the associated end of the carbon nano-tube of predetermined length.These electrodes are configured for providing to carbon nano-tube the input terminal and the outlet terminal of signal then.

Adopt this electromechanical filter, because in the piezoelectric effect that signal caused of input signal mouth input, carbon nano-tube is in the resonance frequency vibration of himself, then because this piezoelectric effect and can be voltage to the output of output signal port.In addition, for example the method for magnetomotive force (magnetomotive) and laser-Doppler interference technique also can be used as the method for the vibration of the microoscillator of surveying prior art.

Yet,, also ferroelectric insulator is not found the report of piezoelectric effect, but the report with superconductivity is arranged at present about carbon nano-tube and the fullerene shown in the patent document 1.Therefore the problem of the technology of patent document 1 is, it is owing to be difficult to enforcement about the hypothesis of the physical property of carbon nano-tube and fullerene.

In addition, in this electromechanical filter, in the method for the vibration of surveying the oscillator that is made of the micro-structural that adopts the magnetomotive force technology, need be used to produce the equipment of big external magnetic field, therefore for little coil manufacturing process and assurance space etc., this is problematic.Under the situation of the vibration of the oscillator of the prior art that survey to adopt the laser-Doppler interference technique, be difficult to have the oscillator of setting up target in focus, in addition, be difficult to obtain enough reverberation.In addition,, investigated such method, wherein be provided for the metal of reflector laser or silicon (Si) speculum to survey the vibration of this structure at the micro-structural tip as further oscillation detection method.Yet, in the method, comprise that the vibration of the structure of speculum is surveyed, and the detection of the oscillating characteristic of microoscillator self is difficult.

Summary of the invention

Therefore, the purpose of this invention is to provide a kind of electromechanical filter, adopt the circuit and the electric equipment of this electromechanical filter, it can realize overall microminiaturized and can select the signal of preset frequency by the microoscillator that adopts the carbon nano-tube that for example has superior electrical conductivity.

A technical problem that will solve according to the present invention, electromechanical filter adopt and comprise first element that changes physically because signal is imported and be arranged on second element that leaves the described first element preset distance place, surveys the physical change of first element when the signal of preset frequency is input to first element.

Description of drawings

Fig. 1 is the perspective view that the electromechanical filter structure of the first embodiment of the invention that adopts many wall constructions is shown;

Fig. 2 is the longitudinal sectional drawing that the electromechanical filter structure of the first embodiment of the invention that adopts multi-walled carbon nano-tubes is shown;

Fig. 3 is the longitudinal sectional drawing that constitutes the electromechanical filter of the first embodiment of the invention of improving example;

Fig. 4 is the horizontal sectional drawing that constitutes the electromechanical filter of the first embodiment of the invention of improving example;

Fig. 5 is the horizontal sectional drawing that constitutes the electromechanical filter of the first embodiment of the invention of improving example;

Fig. 6 A is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 6 B is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 6 C is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 6 D is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 7 A is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 7 B is the profile that the step of the electromechanical filter of making first embodiment of the invention is shown stage by stage;

Fig. 8 is the block diagram that adopts bank of filters (filter bank) circuit of electromechanical filter of the present invention;

Fig. 9 is the perspective view that the electromechanical filter structure of the many wall constructions that adopt second embodiment of the invention is shown;

Figure 10 is the longitudinal sectional drawing of structure that the electromechanical filter of the second embodiment of the invention that adopts many wall constructions is shown;

Figure 11 is the perspective view of structure that the electromechanical filter of the third embodiment of the invention that adopts many wall constructions is shown;

Figure 12 A is the profile that the step of the electromechanical filter of making third embodiment of the invention is shown stage by stage;

Figure 12 B is the profile that the step of the electromechanical filter of making third embodiment of the invention is shown stage by stage;

Figure 12 C is the profile that the step of the electromechanical filter of making third embodiment of the invention is shown stage by stage;

Figure 12 D is the profile that the step of the electromechanical filter of making third embodiment of the invention is shown stage by stage;

Figure 12 E is the profile that the step of the electromechanical filter of making third embodiment of the invention is shown stage by stage;

Figure 13 is the perspective view that the improvement example of electromechanical filter shown in Figure 11 is shown;

Figure 14 A is the view of example of method that the vibration of the oscillator of surveying electromechanical filter of the present invention is shown;

Figure 14 B is the view that the tunnel current that detects from the oscillator of Figure 14 A is shown;

Figure 15 is the perspective view of example application of oscillation detection method that the electromechanical filter of third embodiment of the invention is shown;

Figure 16 is the perspective view that the electromechanical filter structure of fourth embodiment of the invention is shown;

Figure 17 is the section plan of improvement example that the electromechanical filter of fourth embodiment of the invention is shown;

Figure 18 is the perspective view that the electromechanical filter structure of fifth embodiment of the invention is shown;

Figure 19 illustrates the view that concerns between the height of cylindrical oscillator and its natural mode shape; And

Figure 20 illustrates the view that concerns between probe amplitude and the oscillator resonance frequency.

Embodiment

In this embodiment, by comprise make as the self assembly (self-assembly) of carbon nano-tube, carbon nanohorn and the fullerene of the allotrope of carbon, have element about the central shaft symmetrical structure and promptly have axisymmetric element (particularly having element) and be used as configuration example such as micro radio terminal such as the micromechanics oscillator in the filter of the passive component of the communication terminal of mobile phone (after this being called microoscillator) about the rotating shaft symmetrical structure.When importing the signal of the preset frequency identical with himself resonance frequency, the selected output of this signal.

Particularly, also can adopt such micro-structural, it covers the microoscillator that forms by the self assembly of using wall shape element and forms, and this wall shape element constitutes with the material that the mode identical with described micromechanics oscillator formed by the self assembly that comprises carbon nano-tube, carbon nanohorn or fullerene.Signal by the input preset frequency identical with resonance frequency is to one of the microoscillator of this structure or wall shape element (being oscillator) herein, and it encourages owing to the electrostatic force that results from the gap location between microoscillator and the wall shape element causes significantly.Because the variation of electrostatic capacitance, this signal that causes preset frequency again is in another (being wall shape element herein) output.For example, the electromechanical filter of described first embodiment below adopting, the carbon nano-tube of several nanometers of diameter is as the microoscillator of this structure.

Below providing then (formula 1), the resonance frequency of establishing mechnical oscillator is f, and the length of this structure is L, and yang type modulus is E, and density is ρ.

$f\∝\frac{1}{L^2}\sqrt{\frac{E}{\mathrm{\ρ}}}$ ... (formula 1)

As shown in (formula 1), need to use higher yang type modulus E and than the material of low-density ρ so that resonance frequency f height.Carbon nano-tube is that magnitude is the material of the high yang type modulus of 1TPa, and is the material that is preferably used as the microoscillator that produces higher resonant frequency.

In addition, by being rolled into carbon plate cylindrical and forming surface element and be 3-D solid structure with carbon nanotube architecture.Therefore, should be noted that the definition of carbon nanotube density, but that element itself is extremely light and density that form the atom of oscillator is compared with other materials is low, makes density p low.If adopt Single Walled Carbon Nanotube rather than multi-walled carbon nano-tubes, density further reduces, and can expect and produce higher resonance frequency.

In the nanostructure of for example carbon nano-tube situation as mechnical oscillator, in order to survey its micro oscillation, need to form less than nanometer scale in nanostructure and to the vibration sniffer of the micro nano structure input signal microgap between the electrode etc. for example.The artificial retrofit technology of the existing force of employing photoetching technique etc., it is extremely difficult forming this microgap.Among described below each embodiment of the present invention, replace and use the Prosthesis, the method that provides a kind of self assembly manufacturing of using atom and molecule to be used as the micro-structural of oscillator and to be arranged on the vibration sniffer around the micro-structural, and the high frequency filter that adopts the nanometer mechanism with self assembly oscillator is provided.

Be detailed description below with reference to the accompanying drawing of the preferred embodiment of the present invention.

(first embodiment)

Fig. 1 is the perspective view that the electromechanical filter structure of first embodiment is shown, and Fig. 2 is the profile that the electromechanical filter structure of first embodiment is shown.Fig. 2 shows along the profile of the A-A ' of Fig. 1.Both all show the structure of the electromechanical filter that adopts carbon nano-tube.

Adopt electromechanical filter 100 illustrated in figures 1 and 2, be formed with in its surface provide by the inwall that carbon nano-tube constituted 106 that forms by self assembly on the substrate 104 of dielectric film 102 and cover the outer wall 108 of inwall 106, to the signal input side electrode part 110 of inwall 106 input signals, from signal outlet side electrode part 112 and the separator 114 of outer wall 108 to external output signal.

Substrate 104 is made by silicon etc., and dielectric film 102 is made by insulators such as for example silica.The core that signal input side electrode part 110 is arranged on the dielectric film 102, and signal outlet side electrode part 112 is arranged on around the signal input side electrode part 110 via separator 114.

Input signal mouth to signal input side electrode part 110 input signals is connected to signal input side electrode part 110, and output signal port is connected to signal outlet side electrode part 112.Signal outlet side electrode part 112 is arranged on dielectric film 102 on the substrate 104 via separator 114, and the result has avoided signal outlet side electrode part 112 and signal input side electrode part 110 bondings.

In addition, be used for catalysis material by the self-assembled growth carbon nano-tube.For example Fe (iron), Co (cobalt) or Ni (nickel) etc. form signal input side electrode part 110 and signal outlet side electrode part 112.

Be arranged on signal input side electrode part 110 surfaces with erectility with the terminal inwall 106 that is connected of base, and be arranged on the upper surface of signal outlet side electrode part 112 with erectility with the terminal outer wall 108 that is connected of base.

Inwall 106 and outer wall 108 are provided with header field, the tip of the body portion end of each cylinder that its sealing is provided with, thus inwall 106 is comprised in the outer wall 108.Inwall 106 and outer wall 108 have about the central shaft symmetrical structure.This central shaft is vertical about described substrate 104.

Between the inner surface of the outer surface of inwall 106 and outer wall 108, provide preset space length G (after this being called " gap ").Inwall 106 is the oscillators that vibrate when input prearranged signals frequency, and outer wall 108 is the electrodes that are used to survey vibration.

Gap length magnitude between the acquisition of signal gaps between electrodes G of the oscillator of inwall 106 and outer wall 108 and each wall of multi-walled carbon nano-tubes is identical, and is the microgap that utilizes the self assembly of carbon.The size of clearance G is the magnitude from several dusts to tens nanometers.Wall construction makes outer wall 108 cover inwall 106.Therefore outer wall 108 part that covers inwalls 106 makes that the occupied space of inwall 106 and outer wall 108 is littler, and the further microminiaturization of the overall size of electromechanical filter.

Then, the signal propagation of electromechanical filter 100 and the description of signal choice mechanism will be provided.

When the signal by input signal mouth input propagates into inwall 106, because the electrical potential difference between inwall 106 and the outer wall 108 and at microgap G place generation electrostatic force.Inwall 106 is encouraged by this electrostatic force that is produced then.When the signal of various frequencies during, the signal of preset frequency, promptly cause the significantly excitation of inwall 106 with the signal of the resonance frequency same frequency of inwall 106 by the input of input signal mouth.In Fig. 2, show the direction of vibration by arrow V1.

In the situation that inwall 106 significantly encourages, the clearance G between inwall 106 and the outer wall 108 narrows down, and causes the increase of electrostatic capacitance and reducing of impedance.For this reason, because impedance reduces, signal is selected to be propagated into outer wall 108 and propagates into output signal port by outer wall 108 and signal outlet side electrode part 112.This micro oscillation that is equivalent to inwall 106 is surveyed by the formed microgap G of the self assembly of material.

On the other hand, not that the signal of frequency of the resonance frequency of inwall 106 can not encourage the fluctuation of inwall 106, and can not realize reducing of impedance.This means and do not take place from the propagation of outer wall 108 to signal outlet side electrode part 112 and output signal port.

According to electromechanical filter 100, can select and export the signal of preset frequency and can intercept in addition signal.

That is, according to first embodiment, when the signal of preset frequency was input to inwall 106, outer wall 108 was surveyed the physical change of inwall 106, promptly surveyed vibration.Therefore can be by using since the micro element of the signal of input preset frequency and physical change for example carbon nano-tube or fullerene provide total microminiaturization as inwall 106, and can adopt outer wall 108 to select the signal of preset frequency.

Fig. 3 is the longitudinal sectional drawing of improvement example that the electromechanical filter of Fig. 1 and Fig. 2 is shown.Adopt electromechanical filter 100a shown in Figure 3, the dihedral carbon nanohorn replaces the outer wall 118 by the outer wall 108 of the vibration exploring electrode that constitutes electromechanical filter 100, this dihedral carbon nanohorn forms by self assembly, and an end seals and launches to constitute a kind of carbon nano-tube towards the bottom.Adopt the electromechanical filter 100a of Fig. 3, the element of this structure identical with electromechanical filter illustrated in figures 1 and 2 100 is given identical name and label and is not described.Outer wall 108 has about the central shaft symmetrical structure perpendicular to substrate 104.

Identical with electromechanical filter 100, electromechanical filter 100a is provided with signal input side electrode part 110 and signal outlet side electrode part 112a, the input signal mouth is connected to stimulus part 110 on the dielectric film 102 that is formed at substrate 104 surfaces, and output signal port is connected to signal outlet side electrode part 112a via separator 114a.

Signal input side electrode part 110 is provided with and is connected to its surperficial inwall 106, and signal outlet side electrode part 112a is provided with and is connected to its surperficial outer wall 118.Inwall 106 is with from the upright state setting of signal input side electrode 112a, and outer wall 118 so that the coaxial mode of the central shaft of its axle center and inwall 106 be provided with to cover inwall 106.The outer wall 118 that is connected to signal outlet side electrode part 112a is the conical carbon nanohorn that launches and have the sealing tip towards base end substantially.Therefore the clearance G between inwall 106 and the outer wall 118 is towards the terminal broadening of the base of outer wall 118.

As a result, the signal outlet side electrode part 112a that is connected to the base end of outer wall 118 makes up to be arranged on away from the position that is connected to the signal input side electrode part 110 on the dielectric film 102.Therefore the substrate 104 of composition signal input side electrode part 110 and signal outlet side electrode part 112a is simple to operate.

The signal choice mechanism of electromechanical filter 100a is identical with electromechanical filter 100, and does not therefore describe.

Can adopt many walls or Single Walled Carbon Nanotube as the carbon nano-tube or the carbon nanohorn that constitute inwall 106, outer wall 108 and outer wall 118.In addition, the inwall 106 that provides in this embodiment, outer wall 108 and outer wall 118 are the cylinder or the circular cone of hollow, but are not restrictive, and also can be other shapes, for example rod, taper shape, dihedral post or dihedral awl.

Fig. 4 and Fig. 5 are the profiles of improvement example that the electromechanical filter of first embodiment is shown.Electromechanical filter 100c shown in Figure 4 is that the inwall 106 of wherein electromechanical filter 100 is the example of rod inwall 106a.Electromechanical filter 100d shown in Figure 5 wherein is the example of rod inwall 106a as the inwall 106 among the electromechanical filter 100a of the improvement example of Fig. 3.Inwall 106a has about the central shaft symmetrical structure.The central shaft of inwall 106a is vertical about substrate 104.

Provide the description of the method that is used for maker electrical filter 100 now.Fig. 6 A is the profile that illustrates the method for the electromechanical filter of making first embodiment of the invention stage by stage to 6D and Fig. 7 A and Fig. 7 B.

At first, as shown in Figure 6A, form to constitute the silica 202 (with reference to Fig. 2) of dielectric film 102 by thermal oxidation on silicon substrate 104, its thickness is 1 μ m magnitude, and it is thick to be formed into tens nm by the silica 214 that sputter will constitute separator 114 thereon.

Then, shown in Fig. 6 B,, form the photoresist 204 that uses photoetching composition in order to form silica 214 by dry etching.

Then silica 214 is carried out dry etching and removes photoresist 204 by ashing.After photoresist 204 was removed, the silica 214 on silicon substrate 104 constituted separator 114, shown in Fig. 6 C then.

Then, form each electrode part (signal input side electrode part 110 as shown in Figure 2 and signal outlet side electrode part 112 in this case).

Shown in Fig. 6 D, on the dielectric film 202 between separator 114 and the separator 114, electrode materials 205 such as Fe, Co and Ni are deposited to tens millimeters magnitudes.Form the photoresist 206 of the composition that is patterned into electrode pattern then thereon by photoetching.

Then, electrode material 205 is carried out dry etching, photoresist 206 is removed by ashing, and shown in Fig. 7 A, a part of electrode material 205 on the separator 114 forms electrode part (signal input side electrode part 110, signal outlet side electrode part 112).

Shown in Fig. 7 A, in electrode part (signal input side electrode part 110, signal outlet side electrode part 112) after the processing by electrode material 205 is formed on the separator 114, shown in Fig. 7 B, adopt CVD (chemical vapor deposition) technology to form the carbon structure (carbon nano-tube) that constitutes inwall 106 and outer wall 108, on signal input side electrode part 110 and signal outlet side electrode part 112, produce simultaneously along with the electric field of substrate 104 orthogonal directions, thereby use direction of growth control and form the many wall constructions 206 that have inwall 106 and cover the outer wall 108 of inwall 106.

As mentioned above, for CVD technology and sputtering technology etc., utilize deposition of materials condition (gaseous species, air pressure, throughput, RF (radio frequency) power, plasmoid, method of generating plasma, device electrode shape etc.) and current field condition (direction of an electric field, electric field strength) etc., can control the structure of the many wall constructions 206 that form by self assembly.Therefore about material, can control the size between inwall 106 and the outer wall 108, the size of clearance G, formation position, shape and the quantity of wall as the formation wall construction of carbon group material etc.

According to this embodiment, the catalyst material that is used for carbon nano-tube for example conducts such as Fe, Co, Ni is used to be connected respectively to inwall 106 and the signal input side electrode part 110 of outer wall 108 and the electrode material of signal outlet side electrode part 112 that is made of carbon nano-tube.Inwall 106 and the outer wall 108 that is made of carbon nano-tube is self assemblies respectively, and the required clearance G of vibration of surveying inwall 106 can easily form suitable dimension, do not need artificial adjustment.

The result, inwall 106,106a and 108 are micro-structurals, even and when the clearance G between inwall 106, the 106a and 108 be when being difficult to the artificial microgap that forms, by adopting signal input side electrode part 110 and signal outlet side electrode part 112, can easily make the micro electronmechanical filter 100 that to survey predetermined frequency signal as self-assembled growth inwall 106, the 106a and 108 of catalyst.

In addition, nanoprocessing that also can be by adopting nano-probe etc. or nanometer manufacturing form many wall constructions of being constructed by inwall 106 and 106a and outer wall 108,118.In the situation of the carbon family structure of for example this embodiment, by cover inwalls 106 with outer wall 108 or 118, pull out multi-walled carbon nano-tubes a wall, remove the lid of carbon nano-tube or pull out carbon nano-tube etc. and can form control.

Because the electric field that is used for inwall 106,106a and outer wall 108,118 is asymmetric, also can for example carry out pull out, sintering and inject not homoatomic step to the part of outer wall 108,118.In addition, the inwall 106 of electromechanical filter 100 and outer wall 108 adopt carbon nano-tube, but this limits anything but, and also can comprise carbon nanohorn, the metal of the semiconductor of the polymer of fullerene, for example protein, for example Si and for example Al etc. or other form the material of structure by self assembly.In addition, inwall 106 and outer wall 108 can comprise such material, and it comprises material and other atoms and molecule or complex compound that ion doping advances carbon nano-tube.For example the micro-material of carbon nano-tube can be with the material that acts on signal input side electrode part 110 and signal outlet side electrode part 112.

For electromechanical filter 100,100a, 100c, 100d, inwall 106,106a are taken as oscillator, and outer wall 108,118 is taken as the electrode that is used for acquisition of signal, but this limits anything but, and also can be connected to output signal port inwall 106 and inwall 106,106b are used as the acquisition of signal electrode, and the input signal mouth is connected to outer wall 108,118 and outer wall 108,118 is used as oscillator.In this case, for the structure of electromechanical filter 100,100a, output signal port can be connected to inwall 106,106a, and the input signal mouth can be connected to outer wall 108,118.

In addition,, all resonance modes be can use, swaying, vertical oscillation and torsional oscillation comprised as the inwall 106 of oscillator according to electromechanical filter 100,100a, 100c, 100d.In addition, a plurality of many wall constructions that are made of inwall 106 of the present invention, 106a and outer wall 108,118 of also can contacting or be connected in parallel to be forming electromechanical filter, thereby form band pass filter, band cut-off filter or bank of filters etc.

Fig. 8 is the block diagram that adopts the bank of filters circuit of electromechanical filter of the present invention.Bank of filters circuit 1000 has a plurality of electromechanical filters 700 and switch 800.A plurality of electromechanical filters 700 and electromechanical filter 100 are identical and have unlike signal according to each communication system and pass through frequency band. Electromechanical filter 100a, 100c or 100d can be used as electromechanical filter 700.The a plurality of of among electromechanical filter 100,100a, 100c or the 100d any one can be used as electromechanical filter 700, and perhaps the predetermined portions of these electromechanical filters 100,100a, 100c or 100d can be divided into predetermined number and suitably select.

Bank of filters circuit 1000 structures are selected each electromechanical filter 700 to use switch 800.Therefore this bank of filters circuit 1000 is well suited for being applied in many band wireless devices.Also can use for example plasma CVD technology etc. of other CVD technology.In addition, the external electric field of generation mechanism also can be as the electric field of the direction of growth that produces control inwall 106,106b and outer wall 108,118.In addition, can adopt and peel off the formation that (lift-off) technology is carried out separator 114,114a, signal input side electrode part 110 and signal outlet side electrode part 112,112a.

Second embodiment

Fig. 9 is the perspective view of structure that the electromechanical filter of second embodiment of the invention is shown, and Figure 10 is the profile of structure that the electromechanical filter of second embodiment is shown.Figure 10 shows along the profile of the B-B of Fig. 9.Fig. 9 and Figure 10 electromechanical filter shown in any one has shown the structure that adopts carbon nano-tube.

The electromechanical filter 200 of second embodiment and the electromechanical filter of first embodiment adopt same basic structure and manufacturing step.Therefore, in the description of electromechanical filter 200, the structure member identical with electromechanical filter illustrated in figures 1 and 2 100 gives same names and label and do not describe.

Difference between electromechanical filter 200 and the electromechanical filter 100 is that signal input side electrode part 110 is formed on separator 114b and goes up and be connected to outer wall 108, electrode part 311 is arranged on below the inwall 106 and voltage VP is applied to inwall 106, and separator 114b and separator 114 are divided in gap 201 between signal input side electrode part 110 and signal outlet side electrode part 112.Gap 201 can be in the manufacturing step of the electromechanical filter 100 of first embodiment forms the silica 214 shown in Fig. 6 B and Fig. 6 D and the mask pattern of electrode material 205 forms by changing.

Then, provide the signal propagation of electromechanical filter 200 and the description of signal choice mechanism.

When the signal by the input of input signal mouth propagates into outer wall 108, produce electrostatic force in clearance G owing to the electrical potential difference between inwall 106 and the outer wall 108.This electrostatic force of being produced of inwall 106 encourages then.When the signal of various frequencies during, the signal of preset frequency, promptly cause the significantly excitation of inwall 106 with the signal of the resonance frequency same frequency of the inwall 106 that constitutes by carbon nano-tube by the input of input signal mouth.In Figure 10, orientation of oscillation is illustrated by arrow V1.

Under the situation that inwall 106 significantly encourages, the clearance G between inwall 106 and the outer wall 108 narrows down, and causes the increase of electrostatic capacitance.Like this, the capacitance variations of the resonance frequency of inwall 106 takes place, and voltage VP is applied to inwall 106 by electrode 311.This resonance frequency signal that causes inwall 106 is energized at outer wall 108 places of signal output electrode part 112 sides.

This pumping signal propagates into output signal port by signal outlet side electrode part 112.This is equivalent to by the micro oscillation of the inwall 106 that is detected by the formed microgap G of the self assembly of material.

On the other hand, frequency is not the vibration that the signal of the resonance frequency of inwall 106 does not encourage the peak swing of inwall 106, and can not obtain the variation of electrostatic capacitance.Therefore, not propagation from the outer wall 108 of signal outlet side electrode part 112 sides to signal outlet side electrode part 112 or output signal port.

According to electromechanical filter 200, can select and export the signal of preset frequency, and intercept signal in addition.

That is, according to second embodiment, when the signal of preset frequency was input to inwall 106, outer wall 108 was surveyed the physical change of inwall 106, promptly surveyed vibration.Therefore can be by adopting since the micro component of the signal of input preset frequency and physical change for example carbon nano-tube or fullerene provide whole microminiaturization as inwall 106, and can use outer wall 108 to select the signal of preset frequencies.

Outer wall 108 is separated by electricity between singal input electrode part 110 sides and signal output electrode part 112 sides.Therefore by pull out, sintering and to outer wall 108 parts inject not homoatomic or on the part of outer wall 108 the deposit dielectric film, may cause that insulation or electrical conductance are local reduces.Also can form insulator in 201 places in the gap.

The 3rd embodiment

Figure 11 is the perspective view that the structure of the electromechanical filter that is used for third embodiment of the invention is shown.

Adopt electromechanical filter 300 shown in Figure 11, on silicon substrate 302, form the dielectric film 304 that constitutes by silica, on this dielectric film 304, via separator 306 electrode part 310,312 and 314 is set separatedly with preset space length.

Electrode part 310,312 and 314 Fe (iron), Co (cobalt) or Ni formations such as (nickel) by the catalyst material that is configured for carbon nano tube growth, and be provided with not contact with each other by separator 306.

The input signal mouth is connected to the electrode part 310 of electrode part 310,312 and 314.Long cylindrical oscillator 316 is installed between this electrode part (after this being called " signal input side electrode part ") 310 and the electrode part 312.In addition, partly (after this being called " signal outlet side electrode part ") 314, be arranged on oscillator 316 sides to the electrode that will export through the signal that oscillator 316 vibrations input, oscillator 316 cause.

Separator 306 is formed by silica, and is prevented the phase mutual interference of the molecular separating force etc. of the surface of base that is made of dielectric film 304 by the electrode part 310,312 that catalyst material forms.

Oscillator 316 is made of the carbon nano-tube identical with the material of above-mentioned inwall 106.When the signal of preset frequency was imported via electrode part 310, signal outlet side electrode part 314 produced electrostatic force, thereby oscillator 316 is by this electrostatic force excitation.The detection of this vibration causes signal outlet side electrode part 314 from oscillator 316 inputs and the signal that is input to the signal same frequency of oscillator 316.Oscillator 316 has about the central shaft symmetrical structure, and in this case, this central shaft is the trunnion axis that is parallel to silicon substrate 302.

Then, provide the description of operation of the electromechanical filter 300 of the 3rd embodiment.

Propagate into the oscillator 316 that constitutes by carbon nano-tube from the signal of input signal mouth input by signal input side electrode part 310.In this case, the potential energy of oscillator 316 causes the electrostatic force of signal outlet side electrode part 314 to change owing to this signal changes.Oscillator 316 is owing to the variation of this electrostatic force is energized, and the clearance G 2 between oscillator 316 and the signal outlet side electrode 314 narrows down.

The mechanical oscillation of oscillator 316 causes taking place between oscillator 316 and the signal outlet side electrode part 314 increase of electrostatic capacitance and reducing of impedance.Therefore the frequency signal identical with the resonance frequency of oscillator 316 is sent to signal outlet side electrode part 314 and propagates into output signal port.That is, be with the signal that passes to outer frequency can not be transmitted to signal outlet side electrode part 314.

At electromechanical filter 300, form the isostructural formation of shape that control comes control example such as carbon nano-tube by the carbon nano-tube that adopts the hot CVD technology, this nanotube constitutes single wall or many walls and is the oscillator 316 of anisotropic graphite, carbon nano-tube, carbon nanohorn in the direction of growth.The following formation of the structure of this carbon nano-tube.

Then, provide the description of the method for the electromechanical filter of making the 3rd embodiment.

Figure 12 A is the profile that illustrates the step of the electromechanical filter that is used to make third embodiment of the invention stage by stage to Figure 12 E.

At first, shown in Figure 12 A, it is thick that the silica 404 (with reference to Figure 11) that will constitute dielectric film 304 on silicon substrate 302 forms about 1 μ m, and the silica 406 (with reference to Figure 11) that adopts sputtering method will constitute separator 306 thereon to form about 1 μ m thick.

Then, shown in Figure 12 B, the silica 406 that is formed on the silica 404 forms by dry etching.Then in order to form separator 306, form at silica 406 on the upper surface of part of separators 306 and form photoresist 408 by the composition that adopts photoetching.

In Figure 12 B, the silica 404 of Figure 12 A forms silicon substrate 302 lip-deep dielectric films 304.

Then, silica 406 is carried out dry etching, and eliminate photoresist 408 by ashing.

As a result, shown in Figure 12 C, remove the photoresist 408 (with reference to Figure 12 B) of the silica 406 (with reference to Figure 12 B) on the dielectric film 304, be arranged on photoresist 408 following parts and be formed on the dielectric film 304 as separator 306 by adopting ashing.

Then, form the electrode part.That is, shown in Figure 12 D, for example Fe, Co, Ni etc. are tens nm thickness by the sputtering method deposit with the electrode material 410 that constitutes the catalyst in the carbon nano tube growth.Photoresist 412 forms by being patterned on the electrode pattern then, and it adopts the photoetching on the part of the electrode material 410 that is deposited on the separator 306.After the dry etching of electrode material 410, adopt ashing to remove photoresist 412.

As a result, the part of the electrode material 410 of deposit photoresist 412 forms the electrode 310,312,314 (with reference to Figure 11) on the separator 306.Electrode part 310,312 and 314 each with between preset space length form.The setting that faces with each other of signal input side electrode part 310 and electrode part 312.Signal outlet side electrode part 314 is provided with along the direction that is orthogonal to this line from the line center that connects signal input side electrode part 310 and electrode part 312 at interval with preset space length (clearance G 2) then.Figure 12 D is the view that electrode material 410 parts that constitute signal input side electrode part 310 and electrode part 312 are shown.

After the formation of signal input side electrode part 310 and electrode part 312 etc. is finished, shown in Figure 12 E, adopt the hot CVD technology to form carbon nano-tube, simultaneously between signal input side electrode part 310 and electrode part 312, apply voltage, thereby adopt the direction of growth to control the carbon nano-tube that is grown in bridge joint between the electrode part 310.Therefore micromechanics oscillator 316 is installed between signal input side electrode part 310 and the electrode part 312.Methane gas can be with acting on the gas that adopts in the hot CVD technology.The growth temperature of oscillator (carbon nano-tube) 316 will be about 850 degrees centigrade in this case.

Herein, the method of the growth of the oscillator 316 that control is made of carbon nano-tube applies voltage between signal input side electrode part 310 and electrode part 312, be horizontal direction and produce electric field along the equidirectional with oscillator 316 directions of growth with the direction of growth of control generator 316.Herein, oscillator 316 is made as from 310 growths of signal input side electrode part.

As a result, carbon nano-tube is subjected to the Coulomb attraction power along direction of an electric field, begins growth along direction of an electric field, and obtains the state of bridge joint between signal input side electrode part 310 and electrode part 312.

If controlling carbon nanotube growth time in this type of step as shown in figure 13, can be configured to cantilever design to the carbon nano-tube of the oscillator 316a that constitutes electromechanical filter 300a.The oscillator structure of this electromechanical filter 300a is different from electromechanical filter 300, but the miscellaneous part of this structure is identical.The parts that this structure is identical give same names and label and do not describe.

As mentioned above, for CVD technology and sputtering technology etc., can adopt deposition of materials condition (gas type, air pressure, throughput, RF power, plasmoid, method of generating plasma, device electrode shape etc.) and current field condition (direction of an electric field, electric field strength) to wait to control the structure (with reference to Figure 11) of the oscillator 316 that forms by self assembly.Therefore about material as the formation layer structure of carbon group material etc., size that can control generator 316, formation position, shape and the number of the size of clearance G 2, wall.

According to this embodiment, the catalyst material that is used for carbon nano tube growth for example conducts such as Fe, Co, Ni is connected to the electrode material of the signal input side electrode part 301 and the signal outlet side electrode part 314 of the oscillator 316 that is made of carbon nano-tube.Oscillator 316 self assemblies that constitute by carbon nano-tube respectively, and the required clearance G 2 of vibration of surveying oscillator 316 can easily form appropriate size, do not need artificial adjustment.

The result, oscillator 316 is micro-structurals, even and the clearance G 2 between oscillator 316,316a and the signal outlet side electrode part 314 is to be difficult to the artificial microgap that forms, by with signal input side electrode part 301 and signal outlet side electrode part 314 as the self assembly of the catalyst oscillator 316 of growing, can easily make the electromechanical filter 300 that can survey predetermined frequency signal.

According to this embodiment, be input under the situation of oscillator 316 from the input port through signal input side electrode part 310 at input signal, when signal is the identical frequency of resonance frequency with oscillator 316, oscillator 316 is energized, and the increase of electrostatic capacitance and reducing of impedance take place in signal outlet side electrode part 314, thereby signal propagates into signal outlet side electrode part 314, and can select and export the signal of preset frequency.Therefore can select and export the signal of preset frequency.

Also can be by the control electrode part that is connected to the control signal power supply further being provided in the position in the face of signal outlet side electrode part 314 and oscillator 316 being sandwiched wherein and the vibration of control generator 316.

In addition, oscillator 316 at electromechanical filter 100 places adopts carbon nano-tube, but this limits anything but, and also can comprise carbon nanohorn, the metal of the semiconductor of the polymer of fullerene, for example protein, for example Si and for example Al etc. or other form the material of structure by self assembly.

In addition, oscillator 316 can comprise material and other atoms and molecule, the perhaps complex compound of ion doping in the carbon nano-tube.Micro-material for example carbon nano-tube can be as the material of signal input side electrode part 301, signal outlet side electrode part 314 and electrode part 312.

In addition, in Figure 11 and Figure 13, oscillator 316,316a are depicted as individual unit, but also can adopt a plurality of structures are set.Can adopt many walls or Single Walled Carbon Nanotube or many walls or single wall carbon nanohorn as the carbon nano-tube that constitutes oscillator 316.

In addition, the oscillator 316 that this embodiment provides is depicted as hollow cylinder, but this limits anything but, and also can be other shapes, for example rod, taper shape, dihedral post or dihedral awl.In addition,, all resonance modes be can use, swaying, vertical oscillation and the distortion vibration of oscillator 316,316a comprised according to electromechanical filter 300,300a.

In addition, also can adopt a plurality of electromechanical filters 300, the 300a polyphone of this embodiment wherein or together the electromechanical filter of being connected in parallel, to constitute band pass filter, band cut-off filter or bank of filters etc.

For example, the bank of filters circuit 1000 shown in the bank of filters circuit of employing Fig. 8, a plurality of electromechanical filters 700 can or be connected in parallel with electromechanical filter 300,300a polyphone.The result of this structure of bank of filters circuit 1000 with adopt electromechanical filter 100,100a, 100c, 100d identical as the situation of electromechanical filter 700, therefore do not describe.

In addition, when making oscillator 316,316a, adopt the hot CVD technology, but this limits anything but, and also can adopt for example plasma CVD technology etc. of other vapor phase epitaxy techniques in the mill.In addition, the external electric field of generation mechanism also can be as the electric field of the method that produces the direction of growth that is used for control generator 316,316a.In addition, also can adopt stripping technology to carry out the formation of separator 306 and each electrode part 310,312 and 314.

(surveying the method for the vibration of the carbon nano-tube that constitutes by inwall 106, outer wall 108 and oscillator 316,316a)

Figure 14 is the view of example of method that illustrates the vibration of the oscillator that is used to survey electromechanical filter of the present invention.Figure 14 A is the profile that illustrates the vibration of the carbon nano-tube of surveying the inwall in the electromechanical filter that is used as among first embodiment, and Figure 14 B is the view that the tunnel current that Figure 14 A is detected is shown.

Vibration as the carbon nano-tube of inwall 106 among each above-mentioned micro electronmechanical filter 100,100a, 300, the 300a and oscillator 316 is the micrometric displacement vibration.In this case, each of this vibration surveyed and all to be adopted the use tunnel current to carry out as the scanning tunnel microscope (after this being called " STM ") of a part of probe.

Electromechanical filter 100b shown in Figure 14 A is an electromechanical filter shown in Figure 2 100 of removing outer wall 108, separator 114 and signal outlet side electrode part 112.Therefore the element of the structure identical with electromechanical filter 100 gives same label and does not describe.

At electromechanical filter 100b, inwall 106 is arranged on dielectric film 102 surfaces that are formed on the silicon substrate 104 with erectility via signal input side electrode part 110, as the oscillator that is made of carbon nano-tube etc.

STM (not shown) probe tip 502 be arranged on inwall 106 around, inwall 106 constitutes oscillator as electromechanical filter 100b by carbon nano-tube.Distance between probe tip 502 and the inwall 106 is the scope (tens dusts) that tunnel current 504 flows.The change detection of distance is the variation of tunnel current 504 between probe tip 502 and the inwall 106 when inwall 106 vibrations (orientation of oscillation is illustrated by arrow V1).

As a result, as shown in Figure 14B, the vibration of inwall 106 is surveyed and to be the vibration of tunnel current, and the frequency of oscillation of tunnel current 504 is frequencies of oscillation of the inwall 106 that is made of carbon nano-tube.The inwall 106 that demonstrates the vibration of Gigahertz band is micro-structurals of nanometer scale.The displacement of this vibration also is small and is tens dusts.The magnitude of this displacement is identical magnitude with the resolution of the STM that surveys accurate atom magnitude surface texture.Preferably in the detection of micro oscillation, use the STM theory, measure because can carry out pinpoint accuracy.

The method of surveying vibration also can be applied to the structure of the electromechanical filter 300 of the 3rd embodiment.Figure 15 is the perspective view of example of method that illustrates the vibration of the electromechanical filter that is used to survey the 3rd embodiment.

Electromechanical filter 300b shown in Figure 15 is an electromechanical filter shown in Figure 11 300 of removing signal outlet side electrode part 314.Therefore give same numeral with the element of the identical structure that is used for electromechanical filter 300 and do not describe.

This electromechanical filter 300b is provided with signal input side electrode part 310 and the electrode part of separating with preset space length by the separator 306 that is formed on dielectric film 304 surfaces on the silicon substrate 302 312, and is installed between signal input side electrode part 310 and the electrode part 312 by the oscillator 316 that carbon nano-tube constitutes.

For the electromechanical filter 300b of structure like this, the probe tip 502 of STM (not shown) is arranged on the detection that oscillator 316 tops are carried out the vibration of oscillator 316 simultaneously.During vibration in explorer electrical filter 100a, the distance between probe tip 502 and the oscillator 316 is the scope (tens dusts) that tunnel current flows through.The variation of distance is detected as the variation of tunnel current between the oscillatory process middle probe most advanced and sophisticated 502 of the oscillator 316 of vertical direction (by the orientation of oscillation shown in the arrow V2) and oscillator 316.Like this, control signal power supply 505 can be connected to each of bottom electrode part 310,312 and silicon substrate 302, to produce the vibration of vertical direction.

Being provided with of the probe tip 502 of STM can be undertaken by the equipment of combination S TM and scanning electron microscopy (after this being called " SEM ").If the electron beam of SEM causes that interference also can not use SEM when worrying the tunnel current in surveying STM-SEM.

According to the inwall of making by carbon nano-tube 106 of electromechanical filter 100b, 300b and the oscillation detection method of oscillator 316, when adopting the probe tip 502 of STM, tunnel current between inwall 106 and oscillator 316 and the probe tip 502 is detected, can the direct detection micro oscillation.This and magnetomotive force technology, laser-Doppler interference technique and use the difference of the metal of reflector laser or the detection method of silicon (Si) speculum etc. to be: a large amount of space that does not need to produce the large equipment of the external magnetic field of surveying usefulness and be used for exploration operation, do not adopt the detection of the vibration that comprises speculum of speculum situation, and can survey the oscillating characteristic of little inwall 106 and oscillator 316 itself.

The 4th embodiment

Figure 16 is the perspective view that the electromechanical filter structure of fourth embodiment of the invention is shown.

In electromechanical filter shown in Figure 16 600, on silicon substrate 602 surfaces, form the dielectric film 604 that constitutes by silica.Electrode part 608,610 is arranged on the dielectric film 604 with the preset space length separation through the separator 606 that is made of silica.

The input signal mouth of input signal is connected to electrode part 608 and is connected to electrode part 610 from the output signal port of electrode part 610 output signals.

The oscillator 612 that is made of carbon nano-tube, extend in the direction that is orthogonal to electrode part 608,610 faces direction is arranged between the electrode part 608,610, makes signal propagate into electrode part 610 by the vibration of oscillator 612.These oscillator 612 supported element (not shown) support.In addition, oscillator 612 has about the central shaft symmetrical structure, and in the case, this central shaft is the trunnion axis that is parallel to silicon substrate 602.

The oscillator 612 that is made of carbon nano-tube is provided with in its surface from electrode part 608,610 positioned at intervals ground with preset space length, and the electrostatic force that is created between oscillator 612 and the electrode part 608,610 when being input to electrode part 608 when signal encourages.In addition, when having when being transmitted to electrode part 610 with the input of the signal of resonance frequency same frequency and its, oscillator 612 is energized.

Because the influence of worrying the oscillator 612 of formation base and the molecular separating force between the dielectric film 604 is exerted one's influence to the drive characteristic of the oscillator 612 that is made of carbon nano-tube and separator 606 is set.That is, thus because each electrode part 608,610 need be set to be faced with each other carbon nano-tube is clipped in the middle, separator 606 is each electrode part 608,610 and dielectric film 604 insulation.

At this electromechanical filter 600, when the signal of preset frequency when the input signal mouth is imported, this signal is transmitted to the oscillator 612 that is made of carbon nano-tube via electrode part 608.In this case, owing to cause this signal of changing with the electrostatic force of electrode part 610, the potential variation of oscillator 612.Oscillator 612 is owing to this variation of electrostatic force is energized, and 612 and electrode part 610 between gap turn narrow.As the result of gap turn narrow, take place that electrostatic capacitance increases and the impedance reduction between oscillator 612 and the electrode part 610, propagate into electrode part 610 with the signal of oscillator 612 resonance frequency same frequencys, and be sent to output signal port.That is, band passes to outer frequency signal and can not propagate into signal outlet side electrode part 610.

According to electromechanical filter 600, can select to export the signal of preset frequency.

Figure 17 is the section plan of improvement example that the electromechanical filter of the 4th embodiment is shown.

The structure that the structure difference of electromechanical filter 600a shown in Figure 17 is oscillator is different with the corresponding electromechanical filter 600 of the 4th embodiment shown in Figure 16, but the miscellaneous part of this structure and electromechanical filter 600 have same structure.Therefore different parts has only been described in the description of having omitted same section.

The structure of electromechanical filter 600a is to be used to drive the method for carbon nano-tube as the mechanical actuator of oscillator that adopt, and wherein inwall 614 is vibrated by this inwall 614 as multi-walled carbon nano-tubes and outer wall 616.Inwall 614 and outer wall 618 have about the central shaft symmetrical structure.Herein, this central shaft is the trunnion axis parallel with the dielectric film 602 on the silicon substrate.

Multi-walled carbon nano-tubes 618 structures of electromechanical filter 600a move inwall 614 vertically in outer wall 616, there is lid the terminal one or both ends unlimited, a side of this outer wall.

Particularly, multi-walled carbon nano-tubes 618 makes the coaxial setting in the center of cylinder shape inner wall 614 in cylindrical outer wall 616, and the two ends of inwall 614 are the shape outwards outstanding from outer wall 616 two ends.

In addition, the side periphery of the outer wall 616 of multi-walled carbon nano-tubes 618 part (basic horizontal is in the axle of outer wall 616 and be arranged on the outer surface part of orthogonal direction) is connected to each electrode part 618,610, and input signal mouth and output signal port are connected to described electrode part.

At electromechanical filter 600a, when the signal from the input signal mouth was imported into electrode part 608, this signal was propagated into outer wall 616 from electrode part 608.Between the atom on the surface that outer wall 616 outstanding modes contact with each other, produce molecular separating force (Van der Waals for) with the two ends of inwall 614 at outer wall 616 and inwall 614 then.Inwall 614 is drawn into outer wall 616 then, and moves to from outer wall 616 1 is distolateral that another is distolateral.

When potential energy was in stable state owing to molecular separating force is minimum, inwall 614 put on the kinetic energy maximum of outer wall 616.In addition, at the inwall 614 instantaneous states that stop at opposite side, because molecular separating force, potential energy becomes maximum once more, and the kinetic energy vanishing.

End of outer wall 616 and the other end are repeated this and are moved, and therefore inwall 614 demonstrates identical mobile of the simple harmonic oscillation of the oscillator that moves with potential energy curve along bottom protrusion in outer wall 616.

That is, inwall 614 with reciprocating manner in outer wall 616 along the moving axially of inwall 614 and outer wall 616, i.e. inwall 614 vibrations.In order to control the vibration of inwall 614, employing ion doping and molecule injection etc. give the carbon nano-tube of inwall 614 with dielectric property, thereby produce vibration by external electrical field.

In addition, between electrode part 608 that is connected to outer wall 616 and electrode part 610, produce external electrical field.The electrostatic capacitance of inwall 614 is owing to the displacement that inwall 614 moving in outer wall 616 caused changes, and therefore the signal that causes of electric coupling propagates into output signal port via electrode part 610.

When the gap between the carbon nano-tube of the inwall 614 that is made of oscillator and signal outlet side electrode part are divided is narrow, also can adopt signal outlet side electrode part branch be arranged on multi-walled carbon nano-tubes 618 vertically and this signal be transmitted to the selection aspect of signal outlet side electrode part.

In addition, the dielectric film that forms when bonding also can be arranged on the border, field of outer wall 616, signal input side electrode part 608 and signal outlet side electrode part 610.In addition, because the electric field of inwall 614 and outer wall 616 is asymmetric, also can for example pull out, sintering and inject not homoatomic step to outer wall 616 parts.

In addition, the inwall 614 of electromechanical filter 600a and outer wall 616 adopt carbon nano-tube, but this limits anything but, and also can comprise carbon nanohorn, the metal of the semiconductor of the polymerization of fullerene, for example protein, for example Si and for example Al etc. and form other materials of structure by self assembly.

In addition, inwall 614 and outer wall 616 can be the composition of complexity, and it comprises the material that ion doping advances the material of carbon nano-tube and comprises other atoms and molecule.For example the material of carbon nano-tube can be with the material that acts on signal input side electrode part 608 and signal outlet side electrode part 610.

In Figure 16, oscillator 612 is depicted as individual unit, but also can adopt a plurality of structures is set.In addition, in Figure 17, constitute inwall 614 and the carbon nano-tube of outer wall 616 and the multi-walled carbon nano-tubes that carbon nanohorn is depicted as three walls, but this limits anything but, and also can adopt the wall of other numbers, many walls or Single Walled Carbon Nanotube and many walls or single wall carbon nanohorn.In addition, inwall 614 that provides among this embodiment and outer wall 616 are the cylindrical or conical of hollow, but this limits anything but, and also can adopt other shapes, for example rod, taper shape, dihedral post or dihedral awl.

In addition, electrode part 608 and electrode part 610 also can be by for example Fe (iron), Co (cobalt) and Ni (nickel) make as the material of the catalyst material of carbon nano tube growth.The electromechanical filter for preparing a plurality of carbon nano-tube 618 is also passable, and each connection of all contacting of these a plurality of multi-walled carbon nano-tubes 618, thereby input and output lateral electrode part 608,610 connects in two side portions.In addition, electromechanical filter 600a also can be connected in parallel.

In addition, the many wall constructions that are made of inwall 614 and outer wall 616 also can form by nanoprocessing or the nanometer manufacturing of adopting nano-probe etc.Under the situation of the carbon family structure in this embodiment for example, by cover inwalls 614 with outer wall 616, pull out multi-walled carbon nano-tubes wall, remove the top cover of carbon nano-tube, perhaps catch carbon nanotube etc. and forming.

In addition,, can in inwall 616, use inwall 614 all resonance modes, comprise longitudinally vibration, along perpendicular to vibration, rotational oscillation and the torsional oscillation of direction longitudinally as oscillator according to electromechanical filter 600a.In addition, a plurality of many wall constructions that the inwall 614 of the embodiment thus of also can contacting or be connected in parallel and outer wall 616 constitute forming electromechanical filter, thereby form band pass filter, band cut-off filter or bank of filters etc.For example, adopt the bank of filters circuit 1000 of Fig. 8, also can make up a plurality of signals by the different electromechanical filter 700 of frequency band according to each communication system by a plurality of many wall constructions of polyphone or be connected in parallel inwall 614 and outer wall 616 formations.In addition, can use stripping technology to carry out the formation of separator 606, signal input side electrode part 608 and signal outlet side electrode part 610.

The 5th embodiment

Figure 18 shows the perspective view of the structure of the electromechanical filter that is used for the fifth embodiment of the present invention.

Electromechanical filter 400 shown in Figure 180 comprises having and the resonance part 401 of the electromechanical filter 100b same structure of Figure 14, the probe tip 402 and being used to of surveying the vibration of resonance part 401 are adjusted the adjustment member 403 of probe tip 402 and the distance between the part 401 of resonating.

Resonance part 401 is constructed in the mode identical with electromechanical filter shown in Figure 14 100.Signal input side electrode part 110 is provided with and is formed with from the teeth outwards on the silicon substrate 104 of dielectric film 102.Oscillator 106b is arranged on the upper surface of singal input electrode part 110 with erectility then.

Signal input side electrode part 110 is to oscillator 106b input signal.In addition, oscillator 106b is identical with the inwall 106 as oscillator shown in Figure 14, and comprises the self assembly carbon nano-tube.In addition, oscillator 106b has about the central shaft symmetrical structure, and central shaft is a vertical axis about silicon substrate 104 in this case.

On the other hand, probe tip 402 is identical with probe tip 502 shown in Figure 14, and this probe tip 402 is adjusted part 403 along towards moving with direction away from resonator part 401.The moving through the power that acts between probe tip 402 and the oscillator 106b of probe tip 402 and changing, and cause that the natural mode shape of oscillator 106b changes.In addition, probe tip 402 has the identical effect of operation with the outer wall 108 of first embodiment.

That is, probe tip 402 serves as the electrode of the vibration of surveying resonance part 401, thereby when the signal of preset frequency was input to the oscillator 106b of resonance part 401, the physical change among the oscillator 106b was detected and outputs to the output signal port (not shown).Though not shown, signal output has structure and the operation identical with the signal output of each the foregoing description, and therefore do not describe.

Adjustment member 403 for example is a cantilever, thereby and is included in the base end that front end is provided with the body of rod 403a of probe tip 402 and is connected to body of rod 403a and causes the movable body part 403b that body of rod 403a moves.Body of rod 403a has flexibility and follows the vibration of probe tip 402 and vibrate.

In addition, movable body part 403b moves body of rod 403a along forming the direction that contacts with elimination with oscillator 106b, and changes the distance between probe tip 402 and the oscillator 106b.For example, movable body part 403b is fixed to the precalculated position of electromechanical filter.Then, adopt stepper motor that body of rod 403a is moved about movable body part 403b, thereby body of rod 403a itself is moved along the direction away from oscillator 106b.

As shown in figure 18, making the distance between oscillator 106b and the probe tip (probe) 402 is L, and the amplitude of probe tip 402 vibration is A, distance L is changed, and the result that body of rod 403a moves about movable body part 403b changes amplitude A.

That is, changing distance L causes the distance L 1 between probe tip 402 and the oscillator 106b to change.

By changing this distance L 1 promptly by causing that distance L changes the natural mode shape that changes microoscillator 106b.

Provide the description of the natural mode shape of oscillator 106b now.Adopt the natural mode shape of the size decision microoscillator 106b of above-mentioned oscillator itself.As a result, if can not form the oscillator 106b of desired size, can not realize having the electromechanical filter of expectation resonance frequency.Herein, oscillator 106b is cylindrical (is in particular and has the cylindrical of the header field that is arranged at cylindrical lid and nappe front end), and provides the description of cylindrical oscillator herein.

Figure 19 illustrates the figure that concerns between cylindrical oscillator height and the natural mode shape thereof.As shown in figure 19, from above-mentioned (formula 1), resonance frequency is oscillator length-2 a time power.This means that slight errors in the oscillator manufacturing will cause the skew of resonance frequency.When the expectation resonance frequency was 1GHz, this depended on the oscillator material and difference, but under the situation of carbon nano-tube, the height of oscillator is 0.06 μ m substantially.

Exist from 0.06 μ m of expectation at the height of oscillator under the situation of 1% error (0.0606 μ m), resonance frequency changes 2%, become 1.02GHz, and centre frequency has changed 20MHz.Be used under the situation of wireless system as the filter in electromagnetic wave reception and the emission process at the electromechanical filter with this oscillator, the permissible dose that departs from from the oscillator centre frequency depends on this wireless system.Yet the wireless system that the centre frequency of permission 20MHz departs from is not typical, and bias is the value that can not ignore.

Therefore, preferably be provided for making the accuracy method of oscillator, perhaps the mechanism of frequency adjustment oscillator 106b.Said structure causes the electromechanical filter 400 of this 5th embodiment can realize the high accuracy frequency adjustment.

Then, provide the description of the frequency adjustment that the electromechanical filter 400 of this embodiment realized.

Typically, the words of known employing cantilever (non-patent document " atom and molecule nano machinery ", the 53rd page to the 56th page of Maruzen Corporation), if the distance between cantilever and the sample surfaces changes, the direction and the size that act on the power on cantilever and the sample surfaces change, and therefore resonance frequency changes.The amount that resonance frequency changes promptly is known as Δ v from the amount that the natural mode shape of oscillator 106b departs from.

$\mathrm{\Δv}=\frac{1}{2\mathrm{\πKA}}\underset{0}{\overset{2\mathrm{\π}}{\∫}}F(L+A\cos \mathrm{\ψ})\cos \mathrm{\ψd\ψ}$ ... (equation 2)

Herein, v, A and L illustrate the resonance frequency of cantilever, the amplitude of vibration and the parallel position of cantilever and sample surfaces respectively.

Power F between Δ v and cantilever and the sample is proportional through the weighted average of one-period.Short arc limit A＜＜L, the power F and the Δ v that act between probe tip 402 and oscillator 106b are proportional.

That is, can adopt the size that acts on the power between probe tip 402 and the oscillator 106b to change the resonance frequency of oscillator 106b.Like this, adjustment member 403 is served as and is proofreaied and correct because the bias of the resonance frequency that the error of manufacturing oscillator 106b etc. takes place.

The size of power F is changed by the mechanism that produces power between probe tip 402 and oscillator 106b.This is determined by the relative position relation between probe tip 402 and the oscillator 106b.

If oscillator 106b fully separates with probe tip, between oscillator 106b and probe tip 402, do not disturb, and power F does not produce.Yet when probe tip 402 during near oscillator 106b, between produces attraction and the power of generation F.-2 powers of attraction and distance are proportional.Therefore power F also becomes big when the distance between probe tip 402 and the oscillator 106b diminishes.In addition, when probe tip 402 becomes when shortening near the distance between oscillator 106b and probe tip 402 and the oscillator 106b, the direction of generation repulsive force and power F is reversed between oscillator 106b and probe tip 402.

Therefore can change the size and Orientation that acts on the power on both by the distance that changes between oscillator 106b and the probe tip 402.

Figure 20 illustrates the view that concerns between the resonance frequency of the oscillation amplitude of probe tip 402 and oscillator 106b.

Figure 20 shows along the amplitude of vertical axis with along the resonance frequency of the oscillator 106b of trunnion axis, and each figure Q, R, S illustrate the feature of each respective area.Herein, in Figure 20, q, r and s illustrate the amplitude of same angular frequency (ω d).Yet in figure S, zone shown by dashed lines is that range of instability and actual spectrum are illustrated by solid line.That is, in curve S, lower frequency side and high frequency side change in discontinuous mode.

As shown in figure 20, under the position of probe tip 402 and the situation that fully separates the position of oscillator 106b, do not act on by the power F shown in the figure Q in the drawings and therefore oscillator 106b in its natural mode shape vibration.

If probe tip 402 is near oscillator 106b, attraction force acts is between probe tip 402 and oscillator 106b, and resonant frequency shift is to lower frequency side, shown in the figure R among the figure.

In addition, thereby enter under the situation in repulsive force district near oscillator 106b at probe tip 402, the opposite orientation of power F, and the resonant frequency shift of oscillator 106b is to high frequency side, shown in the figure S among the figure.

In the 5th embodiment, as among the 3rd embodiment, the method for most advanced and sophisticated 402 vibrations of exploratory probe also can be to survey electrostatic capacitance change, survey tunnel current or for example adopt atomic force microscope (AFM) to survey the method for light.

In addition, adopting the electromechanical filter 400 of the 5th embodiment, is not only to compensate the error of making among the oscillator 106b, can compensate because the variation of the resonance frequency that other reasons causes yet.At electromechanical filter 400, can change the logical centre frequency of band.Therefore, under the situation of using wireless terminal device, channel is selected and band is selected to be fine, and also is fine as the application of tunable filter.

According to the electromechanical filter of above-mentioned each embodiment, can realize whole microminiaturization by the microoscillator of using the carbon nano-tube that for example has superior electrical conductivity, and can select the signal of preset frequency.

In addition, in above-mentioned each embodiment, can be by using the microminiaturization of adopting carbon nano-tube to realize passive component in the high-frequency circuit as the electromechanical filter of microoscillator, therefore making can provide next generation communication equipment and tend to high electrostatic capacitance, high-speed communication, it improves employed band frequency, and the compatibility with microminiaturized terminal is provided.

According to a first aspect of the invention, adopted and comprised first element of physical change and the structure of second element along with the signal input, this second element is arranged on the preset space length place of leaving first element, surveys the physical change of first element when the signal of preset frequency is input to first element.

According to this structure, second element is surveyed the physical change of first element when predetermined frequency signal is input to first element.Therefore, by using since the microcomponent of the input of the signal of preset frequency and physical change for example carbon nano-tube or fullerene etc. can provide whole microminiaturized, and can use second element to select the signal of preset frequency.

In a second aspect of the present invention, in said structure, first element has the central shaft symmetrical structure about first element, and owing to the signal input is vibrated, and second element is surveyed the vibration of first element when the signal of preset frequency is input to first element.

According to this structure, when the signal of preset frequency was input to first element that has about the central shaft symmetrical structure of first element, second element was surveyed the vibration of first element.Therefore can only use first element to select the signal of preset frequency.For example, for example carbon nano-tube or fullerene etc. can provide whole microminiaturization and can use second element to select the signal of preset frequency as first element by using the micro element that vibrates owing to the signal of importing preset frequency.

In a third aspect of the present invention, adopt wherein one of first element and second element structure for the wall shape element that covers another element.

According to this structure, first element and second element one of be the wall shape element that covers another element.First element and second element constitute wall construction, and can reduce part that one of first element and second element cover another element for example first element cover the occupied space of part of second element, and the overall size of electromechanical filter can further reduce.

In a fourth aspect of the present invention, adopting wherein, said structure also comprises: be connected to the structure of the input side electrode of first element, by cause the excitation of first element to the first element input signal; And the outlet side electrode that is connected to second element, the output signal identical when second element is surveyed the vibration of first element with the signal frequency that is input to first element.

According to this structure, when the signal of preset frequency when the input side electrode is input to first electrode, second element is surveyed the physical change as first element of vibration, and output of outlet side electrode and the signal that is input to the signal same frequency of first element.Therefore can selectively export preset frequency.

In a fifth aspect of the present invention, adopt a kind of structure, wherein said structure also comprises the input side electrode, it leaves the first element setting with preset space length, causes that first element is owing to input signal is energized.Herein, second element is the outlet side electrode of signal of output and the signal same frequency that is input to first element when second element is surveyed the vibration of first element.

According to this structure, second element is surveyed the vibration of first element when the signal of preset frequency is input to the input side electrode, and second element is as the signal of outlet side electrode and output and input signal same frequency.Therefore can selectively export the signal of preset frequency.

According to a sixth aspect of the invention, second element is the wall shape element that covers first element, and said structure also comprises: be connected to the input side electrode of second element, cause that first element is owing to the signal that is input to second element is energized; And be connected to first element and apply the electrode of voltage and be connected to the outlet side electrode of second element to first element, its when second element is surveyed the vibration of first element to the output signal identical with the signal frequency that is input to first element.

According to this structure, second element covers first element, and when the signal of preset frequency from the input side electrode when second element is imported, second element is surveyed the vibration as the first element physical change, and output of outlet side electrode and the signal that is input to the signal same frequency of second element.Therefore first element and the not parallel setting of second element and therefore can use microstructure more selectively to export the signal of preset frequency.Therefore can realize being in the micro-filter of sheared edge on the structure.

In a seventh aspect of the present invention, adopt a kind of structure, wherein in said structure, first element and second element are made of the material that forms by self assembly one of at least, comprise carbon nano-tube, carbon nanohorn or fullerene, and described preset space length is by the formed microgap of the self assembly of at least the first element.

According to this structure, first element that constitutes oscillator is formed by the material that forms by self assembly at least, and preset space length is the microgap that is formed by self assembly.Therefore do not need artificially to form preset space length, and directly form the structure that first element and second element are provided at predetermined intervals.For example, even predetermined space is to be difficult to the artificial little spacing that forms, the self assembly that can easily pass through first element forms.

In a eighth aspect of the present invention, adopt such structure, in said structure, first element and second element constitute by the growth of using catalyst material one of at least, and are connected to by the electrode part that electrode material constituted that comprises catalyst material.

According to this structure, first element and second element are connected to one of at least the electrode that comprises catalyst material.Therefore can realize growth by simply first element being connected to the electrode part.

In a ninth aspect of the present invention, adopt such structure, wherein in said structure, first element and second element constitute by comprising that complexity that ion doping advances the material of carbon nano-tube and comprises the material of other atoms and molecule is formed.

According to this structure, first element and second element constitute by comprising that complexity that ion doping advances the material of carbon nano-tube and comprises the material of other atoms and molecule is formed.Therefore first element and second element have dielectric property.Therefore thereby first element is energized by the electric field institute physical change between first element and second element.Second element also resonates when the signal of preset frequency is input to first element.Therefore can selectively export the signal of the preset frequency that is input to first element by second element.

In a tenth aspect of the present invention, adopt such structure, wherein in said structure, adopt artificial first element and second element of forming of retrofit technology.

According to this structure, adopt artificial first element and second element of forming of retrofit technology.Therefore can manually use the artificial constructed electromechanical filter that can selectively export predetermined frequency signal of retrofit technology.

In a eleventh aspect of the present invention, adopt such structure, wherein in said structure, the physical change of first element is vibration, and the probe that is connected to the electrode that the signal that is input to first element is exported by use is surveyed the tunnel current that flows through between first element and electrode, thereby carries out the detection of first element vibration.

According to this structure, survey the detection that the tunnel current that flows through carries out the vibration of first element by using probe between first element and electrode, and therefore can easily survey micro oscillation.

In a twelveth aspect of the present invention, adopt such structure, wherein in said structure, the physical change of first element is vibration, and the adjusting part also is provided, and it causes the preset space length between first element and second element, and causes the variation of resonant frequency of first element.

According to this structure, regulate part by changing the resonance frequency that preset space length between first element and second element changes first element.Therefore, also can regulate resonance frequency that part changes first element and at the signal of second element output preset frequency by adopting even foozle takes place.In addition, the logical centre frequency of the band that can use wireless receiver equipment to wait to change first element and carry out that channel is selected and band is selected.

A thirteenth aspect of the present invention adopts the bank of filters that comprises the electromechanical filter that adopts said structure.

A fourteenth aspect of the present invention adopts the structure of the circuit with said structure.

According to said structure, the electromechanical filter of said structure can be applied to the circuit that comprises bank of filters and have the electric equipment of circuit.Can be applied in band pass filter for example, band cut-off filter and in the circuit of the bank of filters of transmissions such as many bands wireless terminal, and in the electric equipment such as miniature high-performance wireless device.

Japanese patent application 2004-141641 number that this specification on May 11st, 2003-292669 number 1 was submitted to based on the Japanese patent application of submitting on August 12nd, 2003 and the Japanese patent application of submitting on August 5th, 2004 2004-229731 number, its whole contents is quoted herein as a reference.

Industrial applicability

The present invention is useful as the electromechanical filter that is provided with microoscillator, and it is by adopting for example carbon The microcomponent of the physical change owing to import predetermined frequency signal such as nanotube or fullerene is as first yuan Part and can make whole size microminiaturization.

Claims (14)

1, a kind of electromechanical filter comprises:

First element is because signal is imported and physical change; With

Second element is arranged with predetermined space and the described first element branch, surveys the physical change of described first element when the signal of preset frequency is input to described first element.

2, electromechanical filter according to claim 1, wherein:

Described first element has the central shaft symmetrical structure about described first element, and owing to the signal input is vibrated; With

Described second element is surveyed the vibration of described first element when the signal of preset frequency is input to described first element.

3, electromechanical filter according to claim 1, one of wherein said first element and second element are another the wall shape elements that covers in described first element and second element.

4, electromechanical filter according to claim 1 also comprises:

The input side electrode is connected to described first element, by cause described first element excitation to the described first element input signal; With

The outlet side electrode is connected to described second element, output and the signal that is input to the described first element same frequency when described second element is surveyed the vibration of described first element.

5, electromechanical filter according to claim 1 also is equipped with the input side electrode, and it separates setting with preset space length with described first element, causes described first element owing to the signal input is energized,

Wherein said second element is the outlet side electrode, output and the signal that is input to the described first element same frequency when described second element is surveyed the vibration of described first element.

6, electromechanical filter according to claim 1, wherein said second element are the wall shape elements that covers described first element, and also comprise:

The input side electrode is connected to described second element, causes that described first element is owing to the signal that is input to described second element is energized;

Electrode is connected to described first element, to described first element apply voltage and

The outlet side electrode is connected to described second element, output and the signal that is input to the signal same frequency of described first element when described second element is surveyed the vibration of described first element.

7, electromechanical filter according to claim 1, described at least first element is made up of the material that comprises carbon nano-tube, carbon nanohorn or fullerene that forms by self assembly in wherein said first element and second element, and described preset space length is by the formed microgap of the self assembly of described at least first element.

8, electromechanical filter according to claim 1, described at least first element constitutes by the growth of adopting catalysis material in wherein said first element and second element, and is connected to by the electrode part that electrode material constituted that comprises described catalysis material.

9, electromechanical filter according to claim 1, wherein said first element and second element are made up of complexity and are constituted, and comprise that ion doping advances the material of carbon nano-tube and comprises the material of other atoms and molecule described complicated the composition.

10, electromechanical filter according to claim 1, wherein said first element and second element adopt precision processing technology manually to form.

11, electromechanical filter according to claim 1, the physical change of wherein said first element comprises vibration, and carry out the detection of first vibration of element by adopting probe to survey the tunnel current that flows between described first element and electrode, described probe is connected to the electrode of the signal output that is input to first element.

12, electromechanical filter according to claim 1, the physical change of wherein said first element comprises vibration, and comprises that also the preset space length that causes between described first element and second element changes and cause the adjustment member of the variation of resonant frequency of described first element.

13, a kind of circuit, it comprises the bank of filters that adopts electromechanical filter according to claim 1.

14, a kind of electric equipment, it has circuit according to claim 13.

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