CN100544050C - Magnetore sistance effect element and manufacture method thereof - Google Patents

Magnetore sistance effect element and manufacture method thereof Download PDF

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Publication number
CN100544050C
CN100544050C CNB2004800176696A CN200480017669A CN100544050C CN 100544050 C CN100544050 C CN 100544050C CN B2004800176696 A CNB2004800176696 A CN B2004800176696A CN 200480017669 A CN200480017669 A CN 200480017669A CN 100544050 C CN100544050 C CN 100544050C
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electrode
metal conductor
effect element
conductor portion
magnetore sistance
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CN101061592A (en
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神间博
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Panasonic Holdings Corp
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Matsushita Electric Industrial Co Ltd
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Abstract

A kind of electronic device that does not have the conductance deviation is provided.Electronic device (100) comprising: electrode (2) and electrode (3); And the metal conductor thin film (7) that is electrically connected to electrode (2) and electrode (3).Metal conductor thin film (7) comprises metal conductor portion (1), and it is across the gap between electrode (2) and the electrode (3); Metal conductor portion (1) across length L be not more than electronics under the operating temperature of electronic device (100) in metal conductor portion (1) mean free path Λ.Form electronic device (100) in the following way: the gap of going up to have across length L at substrate (8) forms electrode (2) and electrode (3); Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across the supporter (4) in the gap between electrode (2) and the electrode (3); And by going up at supporter (4) and going up depositing metal conductor thin film (7) formation metal conductor portion (1) at electrode (2) and (3).

Description

Magnetore sistance effect element and manufacture method thereof
Technical field
The present invention relates to: have the electronic device of the precise shape of the nanometer scale of being controlled at, Magnetore sistance effect element with precise shape of the nanometer scale of being controlled at; Utilize magnetic head, recording/reproducing apparatus, memory element and the storage array of Magnetore sistance effect element; Be used to make the method for electronic device; With the method that is used to make Magnetore sistance effect element.
Background technology
Be used for the structure control of material has been be evaluated as information and the basic technology of communicating by letter etc. in the nanometer technology of nanometer scale, and researched and developed energetically.In recent years, the magnetic device and the electronic device of the precise shape of the nanometer scale of being controlled at have been proposed to have.
In the magnetic device field, because utilizing the MR of the conventional Magnetore sistance effect element (people such as M.N.Baibich " Phys.Rev.Lett.; Vol.61 " (1988) p.2472) of GMR (giant magnetoresistance effect) film only is about 10% than (magnetoresistance variation), so need show the Magnetore sistance effect element of higher MR ratio.At the Magnetore sistance effect element that utilizes TMR (tunnelling magnetoresistance) element that the demand proposed show about 50% high MR than (people's such as T.Miyazaki " J.Magn.Mater., Vol.139 " (1995), pL231).Square being inversely proportional to of the resistance of TMR element and TMR element width, the track width of described TMR element width and information recording carrier is proportional.Because packing density is high more and track width is narrow more, it is narrow more that the width of TMR element becomes, so the resistance of TMR element becomes high.Therefore, be difficult to the magnetic head of this element application in fine structure.
And, a kind of magnetoresistive memory (MRAM) that utilizes tmr film has been proposed.Yet utilizing the MR ratio of the magnetoresistive memory of tmr film is 50%, and this is not enough to as memory element.
In this case, someone attempts to make a kind of Magnetore sistance effect element, wherein between electrode, form the coupling part of precise shape with the nanometer scale of being controlled at and carry out in this coupling part can allow electronics by but the ballistic conduction (ballisticconduction) that is not scattered.In the photoetching technique of routine, very difficult formation is controlled at the precise shape of nanometer scale.By utilizing carbon nano-tube (hereinafter being referred to as CNT), a kind of structure (" Nature Vol.401 " (1999) that wherein forms the coupling part of the precise shape that is controlled at nanometer scale between electrode has been proposed, p572 hereinafter is referred to as it non-patent literature 3).In the document, a kind of Magnetore sistance effect element that is used for being electrically connected by carbon nano-tube two electrodes is disclosed.
In the field of electronic device, be called as the cross-sectional area that phenomenon that the quantum electricity leads is controlled wiring by utilization, propose wherein to eliminate the electronic device that electricity is led deviation (variation), in described quantum electricity was led, electricity was led the cross-sectional area stepped with respect to forming fine wiring.Leading cross-sectional area with respect to wiring when electricity produces electricity when changing continuously and leads deviation.At Adv.Mater.Vol.12,2000, propose to have the electronic device of this forming fine wiring that forms by carbon nano-tube among the p890, hereinafter the document is referred to as non-patent literature 4.
In addition, in the nanometer contact element that utilizes Ni whisker (whisker), it is reported that MR reaches 100,000% (referring to Physical Review B67,2003, p60401 hereinafter is referred to as it non-patent literature 5) than at room temperature.
Yet, depend on that hand levies (chirality), the conductance difference of carbon nano-tube becomes the hand steered chair type that shows metallic characteristic or shows the zigzag type of characteristic of semiconductor or show the chirality type of insulator characteristic to such an extent as to be difficult to control the carbon nano-tube of formation.
Therefore, in non-patent literature 3 in the structure of disclosed Magnetore sistance effect element, owing to not being controlled to be the conductance that connects the carbon nano-tube that two electrodes form, so the electrical characteristics instability.If carbon nano-tube can be formed the shape of the hand steered chair type that shows metallic conductivity, then the contact resistance between carbon nano-tube and two electrodes becomes high, is to be 15 to 30M Ω under the situation of Ni electrode at electrode for example.Therefore, this structure MR of having a Magnetore sistance effect element is than under extremely low temperature just only 10% and at room temperature can not obtain the problem of high MR ratio.
Obtain not have the electronic device of conductance deviation for the cross-sectional area that is controlled in the forming fine wiring of nanometer scale by control, same in the structure of wiring carbon nano-tube with non-patent literature 4, conductance that can not controlling carbon nanotube, as mentioned above.Owing to have the low problem of electronic stability, so be not suitable for practical application.In addition, the resistance height is to 10k Ω.
In document 5 in the nanometer contact element of disclosed employing Ni whisker, the nanometer contact portion that forms by plating have can not be controlled structure.Therefore, it can not practical application.
Summary of the invention
Based on noted earlier, the purpose of this invention is to provide: electronic device, magnetoresistance effect transistor with precise shape of the nanometer scale of being controlled at; Utilize magnetic head, recording/reproducing apparatus, memory element and the storage array of Magnetore sistance effect element; Be used to make the method for electronic device; With the method that is used to make Magnetore sistance effect element.
First electronic device of the present invention comprises: first electrode and second electrode; And the metal conductor thin film that is electrically connected to first electrode and second electrode.Metal conductor thin film comprises metal conductor portion, and this metal conductor portion is across (bridge) first electrode and second gaps between electrodes from seeing perpendicular to the direction of the basal surface of first electrode and second electrode; Metal conductor portion be no more than the mean free path Λ of the electronics in the metal conductor portion under the operating temperature of electronic device across length L.By: on substrate, form first electrode and second electrode with the gap that has across length L; Formation comprise be selected from the group formed by the wiring of nanotube and nanometer at least one supporter and across first electrode and second gaps between electrodes on direction, seen perpendicular to basal surface; With form metal conductor portion by method at depositing metal conductor thin film on the supporter and on first and second electrodes, make electronic device.
In specification, term " the mean free path Λ of electronics " represents that electronics wherein can be propagated and the distance that is not scattered.Term " metal conductor portion across length L " expression along central shaft from the some P1 that descends rapidly along the central shaft of electronic device at its cross-sectional area to the length of the some P2 that increases sharply at its cross-sectional area of locating electronic device.Especially, will describe the method for measuring metal conductor portion in an embodiment in detail across length L.
Owing to pass through: on substrate, form first electrode and second electrode, the described mean free path Λ that is no more than the electronics in metal conductor portion under the operating temperature of electronic device across length L with the gap that has across length L; Formation comprise be selected from the group formed by the wiring of nanotube and nanometer at least one and across first electrode of on direction, being seen and the supporter of second gaps between electrodes perpendicular to basal surface; Form metal conductor portion with the method for passing through at depositing metal conductor thin film on the supporter, on first electrode and second electrode, make according to first electronic device of the present invention, so can form the metal conductor portion across length L with the mean free path Λ that is no more than electronics on supporter, described supporter comprises at least one that is selected from the group be made up of the wiring of nanotube and nanometer.
In metal conductor portion across length L with the mean free path Λ that is no more than electronics, the phenomenon that the quantum electricity is led appears being called, and wherein electricity is led with respect to the cross-sectional area stepped.
Because metal conductor portion of the present invention is formed by metal, different with the carbon nano-tube that can not control conductance described in the non-patent literature 4, metal conductor portion of the present invention has stable conductance.In addition, the contact resistance with first electrode and second electrode becomes minimum.Therefore, electrical characteristics become stable.
Therefore, by utilizing the quantum electricity to lead to control the cross-sectional area of metal conductor portion, can obtain conductance is the situation of linear change with respect to cross-sectional area under, not produce the electronic device of conductance deviation.
Preferably, make electronic device by the depositing metal conductor thin film and the technology of removing supporter then.By removing the supporter that can not control conductance, the electrical characteristics of electronic device are more stable.
Can make electronic device by depositing metal conductor thin film and the technology of removing substrate then.When CNT is used for substrate, because the CNT substrate shows conductor, semiconductor and insulator three specific characters, so by removing the substrate that is made of CNT, the electrical characteristics of electronic device become more stable.
Preferably, first electrode and second electrode comprise magnetisable material.This is favourable, because can be with electronic device as Magnetore sistance effect element and memory element.
Preferably, first electrode and second electrode comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.This is favourable, because can obtain to have the Magnetore sistance effect element and the memory element of good magnetic characteristic.
Preferably, metal conductor thin film comprises magnetisable material.Because neticdomain wall is fixed to metal conductor portion, so can obtain whether to come the Magnetore sistance effect element of work according to the existence of neticdomain wall.
Preferably, metal conductor thin film comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.Neticdomain wall can be securely fixed on the metal conductor portion.
Preferably, the cross-sectional area S3 of the cross-sectional area S2 of the cross-sectional area S1 of first electrode, second electrode and metal conductor portion satisfies following relation:
S3＜S1 and S3＜S2.
Neticdomain wall is securely fixed on the metal conductor portion.
Preferably, the cross-sectional area S3 of metal conductor portion is not less than 1nm 2And be not more than 1.0 * 10 6Nm 2When cross-sectional area S3 less than 1nm 2The time, often be difficult to form the metal conductor portion that is controlled in nanometer scale with high reproducibility.When cross-sectional area S3 greater than 1.0 * 10 6Nm 2The time, often be difficult to realization quantum electricity and lead.
Preferably, supporter comprises carbon nano-tube.Adopt carbon nano-tube, can control the precise shape of supporter easily.In addition, can accurately control the shape of metal conductor portion in desirable mode.Because with comprise comparing of organic substance such as materials such as protein nano wirings, carbon nano-tube has high-fire resistance and has high mechanical strength, so make easily.
Preferably, the step of formation supporter comprises: will be used to promote that the formation catalyst for reaction of carbon nano-tube is arranged on first electrode and second electrode; And the supporter that comprises carbon nano-tube by the formation of chemical vapor deposition (CVD) method.Can make carbon nano-tube easily.
Preferably, the step that forms supporter comprises: form the supporter that comprises carbon nano-tube, apply different voltage to first electrode with second electrode respectively simultaneously.This is favourable, because provide electric field between first electrode and second electrode, makes it possible to easily form carbon nano-tube thus.
Preferably, first electrode and second electrode comprise magnetisable material; And catalyst comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.Because Fe, Co and Ni are magnetisable material, so, electrical characteristics and magnetic characteristic are worsened if magnetisable material is retained in first and second electrodes after making electronic device.
But supporter can comprise in wiring of self-organizing (self-organizable) protein nano and the wiring of silicon nanometer at least one.By the DNA of control protein nano wiring, can accurately control the precise shape of supporter.In addition, can be accurately the precise shape of metal conductor portion be controlled to desirable shape.
Preferably, the step that forms metal conductor portion comprises by the physical vapor deposition (PVD) method and comes the depositing metal conductor thin film.Adopt the physical vapor deposition (PVD) method, can easily form metal conductor portion.
Preferably, the operating temperature of electronic device is not less than 4.2K and is not more than 523K.If operating temperature, is used for the system of cooling electronic device less than 4.2K and is tending towards complicated, and because the expensive coolant of utilization such as liquid He, cost often significantly raises.If operating temperature is greater than 523K, then the ancillary equipment that can use under the operating temperature greater than 523K (be used in the electronic device combination such as ancillary equipment such as semiconductor element, magnetic mediums) is very restricted.Therefore, must use the good ancillary equipment of weatherability (thermal endurance etc.).When operating temperature is not less than 4.2K and is not more than 523K, lead the cross-sectional area of control metal conductor portion by utilizing the quantum electricity, utilize advantage of the present invention simultaneously, promptly, the conductance deviation that when conductance shows successive value with respect to the cross-sectional area of metal conductor portion, produces can be avoided, the performance of other ancillary equipment can be guaranteed.Therefore, can obtain the expected performance of equipment as a whole.
Second electronic device of the present invention comprises: first electrode and second electrode; And across the metallic conductor of first electrode and second gaps between electrodes.Metal conductor portion be not more than the mean free path Λ of electronics in metallic conductor under the operating temperature of electronic device across length L.By: on substrate, form first electrode and second electrode with the gap that has across length L; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across the supporter of first electrode and second gaps between electrodes; And on supporter the depositing metal conductor, make this electronic device.
In second electronic device of the present invention, on substrate, form first electrode and second electrode with the gap that has across length L; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across the supporter of first electrode and second gaps between electrodes; And depositing metal conductor on supporter.Can form have be no more than electron mean free path Λ across length L and direct first electrode and the metallic conductor of second electrode on the cross-over connection supporter, this supporter comprise be selected from by nanotube and nanometer connect up in the group of forming at least one and directly across between first electrode and second electrode.
In second electronic device of the present invention, similar to first electronic device of the present invention, in metallic conductor, the phenomenon that the quantum electricity is led appears being called as.This metallic conductor is different from the carbon nano-tube described in non-patent literature 4 and has stable conductance.In addition, the contact resistance with first electrode and second electrode reduces.Therefore, lead,, can obtain not have the electronic device of conductance deviation by the cross-sectional area of control metal conductor portion by utilizing the quantum electricity.
The 3rd electronic device of the present invention comprises: first electrode film; Be formed on the dielectric film on first electrode film; Be formed on second electrode film on the dielectric film; And the metallic conductor that penetrates dielectric film and first electrode film is electrically connected with second electrode film.The length L of metallic conductor is no more than the mean free path Λ of electronics in metallic conductor under the operating temperature of electronic device.By: on substrate, form first electrode film; Forming thickness on first electrode film is the dielectric film of the length L of metallic conductor; The field emission electron bundle irradiation dielectric film of the probe by being used to self-scanning tunnel microscope (STM), dielectric film with the through hole that arrives first electrode film is provided, and this scanning tunnel microscope comprises at least one that is selected from the group of being made up of nanotube and nanometer wiring; Use metallic conductor filling vias inboard; And on dielectric film and metallic conductor, form second electrode film, make electronic device.
In the 3rd electronic device of the present invention, by: first electrode film on substrate, formed; Forming thickness on first electrode film is the dielectric film of the length L of metallic conductor; The field emission electron bundle irradiation dielectric film of the probe by being used to self-scanning tunnel microscope (STM), dielectric film with the through hole that arrives first electrode film is provided, and this scanning tunnel microscope comprises at least one that is selected from the group of being made up of nanotube and nanometer wiring; Use metallic conductor filling vias inboard; And on dielectric film and metallic conductor, form second electrode film, make electronic device.Therefore, by being used to from comprising that at least one the field emission electron bundle of probe of STM that is selected from the group of being made up of the wiring of nanotube and nanometer shines in the through hole that forms, and can make the metallic conductor with the length L that is no more than electron mean free path Λ.
Therefore, in the metallic conductor of precise shape with the nanometer scale of being controlled at, be referred to as the phenomenon that the quantum electricity is led, wherein conductance (electricity is led) is with respect to the cross-sectional area stepped, and be referred to as the phenomenon of ballistic conduction, wherein electronics passes metallic conductor and scattering do not occur.
Because metallic conductor of the present invention is formed by metal, different with the carbon nano-tube that can not control conductance described in the non-patent literature 4, it has stable conductance.In addition, the contact resistance with first electrode film and second electrode film reduces widely.Therefore, electrical characteristics become stable.
Therefore, lead the cross-sectional area of control metallic conductor, can obtain to avoid the electronic device of the conductance deviation that taken place during with respect to the cross-sectional area linear change when conductance by utilizing the quantum electricity.In addition, by controlling the direction of magnetization of first electrode film and second electrode film,, can obtain to have the Magnetore sistance effect element of very high MR ratio owing to ballistic conduction.
Quadrielectron device according to the present invention comprises: first electrode and second electrode; And between first electrode and second electrode formed dielectric film that contacts with second electrode with first electrode.Dielectric film is provided with the groove that arrives second electrode from first electrode; This trench fill has metallic conductor, and it makes the electrode of winning contact with second electrode; And the length L of metallic conductor is no more than the mean free path Λ of electronics in metallic conductor under the operating temperature of electronic device.Make electronic device by on substrate, forming first electrode and second electrode that are provided with gap with length L.Dielectric film makes the electrode of winning contact with second electrode between first electrode and second electrode on the substrate.By being used to from comprising that at least one the field emission electron bundle of probe of scanning tunnel microscope (STM) that is selected from the group of being made up of the wiring of nanotube and nanometer shines dielectric film; And using the metallic conductor filling groove, dielectric film is provided with the groove that arrives second electrode from first electrode.
By on substrate, forming first electrode and second electrode that is provided with gap, make quadrielectron device of the present invention with length L.Dielectric film makes the electrode of winning contact with second electrode between first electrode and second electrode on the substrate.By being used to from comprising that at least one the field emission electron bundle of probe of scanning tunnel microscope STM that is selected from the group of being made up of the wiring of nanotube and nanometer shines dielectric film; And using the metallic conductor filling groove, dielectric film is provided with the groove that arrives second electrode film from first electrode film.Therefore, by being used to from comprising that at least one the field transmitted beam of probe of STM that is selected from the group of being made up of the wiring of nanotube and nanometer shines in the groove that forms, and can make the metallic conductor with the length L that is no more than electron mean free path Λ.
Therefore, in the metallic conductor of precise shape with the nanometer scale of being controlled at, be referred to as the phenomenon that the quantum electricity is led, wherein conductance (electricity is led) is with respect to the cross-sectional area stepped, and be referred to as the phenomenon of ballistic conduction, wherein electronics passes metallic conductor and scattering do not occur.
Because metallic conductor of the present invention is formed by metal, different with the carbon nano-tube that can not control conductance described in the non-patent literature 4, it has stable conductance.In addition, the contact resistance with first electrode film and second electrode film reduces widely.Therefore, electrical characteristics become stable.
Therefore, lead the cross-sectional area of control metallic conductor, can obtain to avoid the electronic device of the conductance deviation that taken place during with respect to the cross-sectional area linear change when conductance by utilizing the quantum electricity.In addition, by controlling the direction of magnetization of first electrode film and second electrode film,, can obtain to have the Magnetore sistance effect element of very high MR ratio owing to ballistic conduction.
Preferably, first electrode and second electrode comprise magnetisable material; And metallic conductor is provided with concave part.When electronic device being used for Magnetore sistance effect element, neticdomain wall can be securely fixed in the position of the concave part of metallic conductor by the formation concave part.By forming concave part, can in metal conductor portion, form the part that cross-sectional area wherein descends rapidly, and can be with the fixed-site of neticdomain wall on this position.When noise that needs reduce during electronic device operation to be produced, this structure is effective.The inventor determines and can form this concave part by utilizing STM.
Magnetore sistance effect element according to the present invention comprises: first electrode and second electrode that comprise magnetisable material; And the metal conductor thin film that is electrically connected to first electrode and second electrode.Metal conductor thin film comprises across first electrode of being seen on the direction perpendicular to the basal surface of first electrode and second electrode and the metal conductor portion of second gaps between electrodes.Metal conductor portion across length L be no more than be the length value of the electron spin in metal conductor portion diffusion under the operating temperature of Magnetore sistance effect element and under the operating temperature of Magnetore sistance effect element the value of the higher value in the value of the mean free path Λ of the electronics in the metal conductor portion.The cross-sectional area S3 of the cross-sectional area S1 of first electrode, the cross-sectional area S2 of second electrode and metal conductor portion satisfies following relational expression: S3＜S1 and S3＜S2.By: on substrate, form first electrode and second electrode with the gap that has across length L; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across first electrode of on direction, being seen and the supporter of second gaps between electrodes perpendicular to basal surface; And form metal conductor portion by method, make Magnetore sistance effect element at depositing metal conductor thin film on the supporter, on first electrode and second electrode.
" electron spin diffusion length " is that wherein electronics is keeping the following distance that can propagate of magnetized state (upwards spin states or spin states downwards) among the present invention.
In Magnetore sistance effect element according to the present invention, by: on substrate, form first electrode and second electrode with the gap that has across length L, should across length L be no more than be the length value of the electron spin in metal conductor portion diffusion under the operating temperature of Magnetore sistance effect element and under the operating temperature of Magnetore sistance effect element the value of the higher value in the value of the mean free path Λ of the electronics in the metal conductor portion; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across first electrode of on direction, being seen and the supporter of second gaps between electrodes perpendicular to basal surface; And form metal conductor portion by method, make Magnetore sistance effect element at depositing metal conductor thin film on the supporter, on first electrode and second electrode.Therefore, can have the metal conductor portion across length L of value for the higher value in the value at the mean free path Λ of the length value of electron spin diffusion and electronics making on the supporter, described supporter comprises and being selected from by connect up in the group of forming at least one of nanotube and nanometer.
In having this metal conductor portion across length L, be called as the phenomenon of ballistic conduction, wherein electronics passes metal conductor portion and scattering do not occur.
Because metal conductor portion of the present invention is formed by metal, different with the carbon nano-tube that can not control conductance described in the non-patent literature 3, it has stable conductance.In addition, the contact resistance between first electrode and second electrode becomes minimum.Therefore, electrical characteristics become stable.
Therefore, by controlling the direction of magnetization of first electrode and second electrode,, can obtain to have the Magnetore sistance effect element of very high MR ratio owing to ballistic conduction.
Preferably, by the depositing metal conductor thin film and remove supporter then and make Magnetore sistance effect element.By removing the supporter that can not control conductance, electrical characteristics are more stable.In addition, the contact resistance between first electrode and the metal conductor portion can be reduced, and the contact resistance between second electrode and the metal conductor portion can be reduced.
Can make Magnetore sistance effect element by the step of after the depositing metal conductor thin film, removing substrate.When CNT was used for substrate, the substrate of CNT showed conductor, semiconductor and insulator three specific characters, and by removing the substrate that is made of CNT, the electrical characteristics of Magnetore sistance effect element become more stable.
Preferably, first electrode comprises free layer, and wherein magnetization is rotated with respect to the external magnetic field easily; Second electrode comprises fixed bed, and wherein magnetization is not easy to rotate with respect to the external magnetic field; And the magnetization of free layer is a direction perpendicular to external magnetic field to be detected easily.Adopt this structure, can improve from the linearity of the signal of Magnetore sistance effect element output.
About free layer, " magnetization is easily with respect to the external magnetic field rotation ", and about fixed bed, " magnetization be not easy with respect to external magnetic field rotation " represents free layer respectively with respect to the external magnetic field that is applied to Magnetore sistance effect element rotation and the fixed bed rotation that is not magnetized that is magnetized.
Preferably, fixed bed comprises the antiferromagnetism film; And form magnetosphere and fixed by the antiferromagnetism film on the antiferromagnetism film, wherein magnetic film is electrically connected to metal conductor portion.According to this structure, the characteristic of Magnetore sistance effect element (MR ratio) is thermally-stabilised.
Preferably, supporter comprises carbon nano-tube.Adopt carbon nano-tube, can control the precise shape of supporter easily.In addition, the precise shape of metal conductor portion accurately can be controlled to desirable shape.Because compare with for example protein nano wiring as the material that comprises organic material, carbon nano-tube has high-fire resistance and high mechanical properties, so can easily make.
Preferably, the step of formation supporter comprises: will be used to promote that the formation catalyst for reaction of carbon nano-tube is arranged on first electrode and second electrode; And the supporter that comprises carbon nano-tube by the formation of chemical vapor deposition (CVD) method.Can form carbon nano-tube easily.
Preferably, the step that forms supporter comprises: form the supporter that comprises carbon nano-tube, apply different voltage to first electrode with second electrode respectively simultaneously.Can easily form carbon nano-tube by between first electrode and second electrode, forming electric field.
Preferably, catalyst comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.Because Fe, Co and Ni are magnetisable material, so even magnetisable material is retained in first and second electrodes after manufacturing, electrical characteristics and magnetic characteristic can not worsen yet.
But supporter can comprise the protein nano wiring of self-organizing and at least one in the wiring of silicon nanometer.By the DNA of control protein nano wiring, can accurately control the precise shape of supporter.In addition, can be accurately the precise shape of metal conductor portion be controlled to desirable shape.
Preferably, the step that forms metal conductor portion comprises by the physical vapor deposition (PVD) method and comes the depositing metal conductor thin film.Adopt the physical vapor deposition (PVD) method, can easily form metal conductor portion.
Preferably, metal conductor thin film comprises at least one that is selected from the group of being made up of Fe, Co and Ni.Neticdomain wall can be fixed firmly to metal conductor portion.
Preferably, first electrode and second electrode comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.Can obtain to have the Magnetore sistance effect element of good magnetic characteristic.
Preferably, the operating temperature of Magnetore sistance effect element is not less than 4.2K and is not more than 523K.If operating temperature, is used for the system of cooling electronic device less than 4.2K and is tending towards complicated, and because the expensive coolant of utilization such as liquid He, cost often significantly raises.If operating temperature is greater than 523K, then the ancillary equipment that can use under the operating temperature greater than 523K (be used in the electronic device combination such as ancillary equipment such as semiconductor element, magnetic mediums) is very restricted.Therefore, must use the good ancillary equipment of weatherability (thermal endurance etc.).When operating temperature is not less than 4.2K and is not more than 523K, utilize advantage of the present invention simultaneously, that is, can be easily and obtain the MR ratio safely, can guarantee the performance of other ancillary equipment.Therefore, can guarantee equipment expected performance as a whole.
Magnetic head according to the present invention comprises: according to Magnetore sistance effect element of the present invention; First goes between, and is electrically connected to first electrode of Magnetore sistance effect element; And second lead-in wire, be electrically connected to second electrode of Magnetore sistance effect element.
Magnetic head according to the present invention is provided with according to of the present invention has 100% or the Magnetore sistance effect element of higher high MR ratio.Therefore, can obtain very high sensitivity and very high output.
Recording/reproducing apparatus according to the present invention comprises: be used for the recording head in the magnetizing mediums recorded information; And the reproduction head that is used to reproduce the information that is recorded on the magnetizing mediums.Reproducing head is magnetic head of the present invention.
In recording/reproducing apparatus of the present invention, of the present invention have 100% or the Magnetore sistance effect element of higher high MR ratio be set to reproduce head.Therefore, can utilize recording head to carry out high output and easily and accurately reproduce with 100Gb/inch 2Or higher high record density is recorded in the information in the magnetizing mediums.
First memory element of the present invention comprises according to Magnetore sistance effect element of the present invention.First electrode of Magnetore sistance effect element comprises free layer, and wherein magnetization is rotated with respect to the external magnetic field easily; And second electrode comprises fixed bed, and wherein magnetization is not easy to rotate with respect to the external magnetic field.Memory element also comprises: produce the word line of external magnetic field, this external magnetic field can become parallel the direction of magnetization of free layer and fixed bed or antiparallel according to electric current; And the electric current supply device, be used to word line that electric current is provided.According to the external magnetic field that produces by word line, by being changed into, the direction of magnetization is parallel to each other or antiparallel, information is write in the Magnetore sistance effect element, and, read the information that writes in the Magnetore sistance effect element by measuring the resistance of Magnetore sistance effect element.
In first memory element of the present invention,, information is write in the Magnetore sistance effect element by make the direction of magnetization counter-rotating of free layer according to the external magnetic field that produces by word line.By measuring the resistance of Magnetore sistance effect element, can read the information that writes in the Magnetore sistance effect element.Because Magnetore sistance effect element is a Magnetore sistance effect element of the present invention,, can realize very high MR ratio so compare with conventional Magnetore sistance effect element with MR ratio of about 60%.
Second memory element of the present invention comprises that according to Magnetore sistance effect element of the present invention and electric current supply device it is used to provide the electric current that flows to the electric current of metal conductor portion or flow to metal conductor portion from second electrode towards first electrode towards second electrode from first electrode.By making the sense of current counter-rotating in the metal conductor portion that flows to Magnetore sistance effect element,, information is write Magnetore sistance effect element so that change into parallel or antiparallel with the direction of magnetization of second electrode first electrode; And, read the information that writes in the Magnetore sistance effect element by measuring resistance value according to first electrode Magnetore sistance effect element different with the direction of magnetization of second electrode.
In second memory element of the present invention, by the sense of current that flows to the metal conductor portion in the Magnetore sistance effect element being reversed and, information being write Magnetore sistance effect element by changing into parallel the direction of magnetization or antiparallel.By measuring resistance value, can read the information that writes in the magnetic effect element according to first electrode Magnetore sistance effect element different with the direction of magnetization of second electrode.Because Magnetore sistance effect element is a Magnetore sistance effect element of the present invention,, can realize very high MR ratio so compare with conventional Magnetore sistance effect element with MR ratio of about 60%.Because second memory element does not need word line as part,, can make structure little and simple as in first memory element of the present invention.Therefore, can realize having the memory element simple and structure that size is little, in this structure, cellar area is little, it is little and packing density is high to be used to install the interval of memory.
Preferably, the current density that supplies to the electric current of Magnetore sistance effect element by the electric current supply device is 1.0 * 10 5A/cm 2Or it is higher.When the current density of the electric current that supplies to Magnetore sistance effect element is 1.0 * 10 5A/cm 2Or when higher, can easily and safely information be write in the Magnetore sistance effect element.When current density less than 1.0 * 10 5A/cm 2The time, writing information safely.
Storage array of the present invention comprises: be arranged to matrix according to Magnetore sistance effect element of the present invention; Be used for independently information being write Magnetore sistance effect element and the wiring of reading information; R/w cell, be used for reversing so that change into parallel or antiparallel with the direction of magnetization of second electrode first electrode, come independently information to be write Magnetore sistance effect element through wiring by the sense of current that makes the metal conductor portion that flows to Magnetore sistance effect element; And reading unit, be used for depending on the direction of magnetization of first electrode and second electrode and the resistance value of different Magnetore sistance effect element reads the information that writes in the Magnetore sistance effect element independently by measurement.
In storage array of the present invention, provide the Magnetore sistance effect element of a plurality of second memory elements of the present invention.Similar to second memory element of the present invention, storage array does not need word line.Therefore, can realize having the memory element simple and structure that size is little, in this structure, cellar area is little, it is little and packing density is high to be used to install the interval of memory.
The method that is used to make electronic device of the present invention comprises: form first electrode and second electrode on substrate, have gap L therebetween; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across first electrode of on direction, being seen and the supporter of second gaps between electrodes perpendicular to the basal surface of first electrode and second electrode; And by on the supporter, form across first electrode of on direction, being seen and the metal conductor portion of second gaps between electrodes perpendicular to basal surface in the method for depositing metal conductor thin film on first electrode and second electrode.Gap L is no more than the mean free path Λ of the electronics in the metal conductor portion under the operating temperature of electronic device.
Therefore, can provide to have the metal conductor portion across length L that is no more than electron mean free path Λ on supporter, described supporter comprises at least one that is selected from the group of being made up of nanotube and nanometer wiring.
In metal conductor portion with the length L that is no more than electron mean free path Λ, be referred to as the phenomenon that the quantum electricity is led, wherein observe stepped with respect to the conductance (electricity is led) of the cross-sectional area of metal conductor portion.
Because metal conductor portion of the present invention is formed by metal, so different with the carbon nano-tube that can not control conductance described in the non-patent literature 4, it has stable conductance.In addition, reduce contact resistance between first electrode and second electrode greatly.Therefore, electrical characteristics become stable.
Therefore, by utilizing the quantum electricity to lead to control the cross-sectional area of metal conductor portion, can obtain to avoid the electronic device of the conductance deviation that produced during with respect to the cross-sectional area linear change when conductance.
The method that is used to make Magnetore sistance effect element of the present invention comprises: form first electrode and second electrode that comprises magnetisable material on substrate, have gap L therebetween; Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across first electrode of on direction, being seen and the supporter of second gaps between electrodes perpendicular to the basal surface of first electrode and second electrode; And by on the supporter, form across first electrode of on direction, being seen and the metal conductor portion of second gaps between electrodes perpendicular to basal surface in the method for depositing metal conductor thin film on first electrode and second electrode.Gap L be no more than be the length value of the electron spin in metal conductor portion diffusion under the operating temperature of Magnetore sistance effect element and under the operating temperature of Magnetore sistance effect element the value of the higher value in the value of the mean free path Λ of the electronics in the metal conductor portion.The cross-sectional area S3 of the cross-sectional area S1 of first electrode, the cross-sectional area S2 of second electrode and metal conductor portion satisfies following relation: S3＜S1 and S3＜S2.
Therefore, form on supporter that to have be the metal conductor portion across length L of the higher value in the value of the length value of electron spin diffusion and electron mean free path Λ, this supporter comprises at least one that is selected from the group of being made up of nanotube and nanometer wiring.
In having this metal conductor portion across length L, be referred to as the phenomenon of ballistic conduction, wherein electronics passes metal conductor portion and scattering do not occur.
Because metal conductor portion of the present invention is formed by metal, so different with the carbon nano-tube that can not control conductance described in the non-patent literature 3, it has stable conductance.In addition, the contact resistance with first electrode and second electrode becomes minimum.Therefore, electrical characteristics become stable.
Therefore, control the direction of magnetization of first and second electrodes, because ballistic conduction can be made the Magnetore sistance effect element with very high MR ratio.
According to the present invention, can provide electronic device, the Magnetore sistance effect element of precise shape with the nanometer scale of being controlled at; Utilize magnetic head, recording/reproducing apparatus, memory element and the storage array of Magnetore sistance effect element; Be used to make the method for electronic device; And the method that is used to make Magnetore sistance effect element.
The accompanying drawing summary
Figure 1A is the plane graph that illustrates according to the electronic device of embodiment 1;
Figure 1B is the cross-sectional view along the line 1B-1B intercepting of Figure 1A;
Fig. 1 C is the cross-sectional view along the line 1C-1C intercepting of Figure 1B;
Fig. 1 D is used to make cross-sectional view according to the method for the electronic device of embodiment 1 in order to explanation;
Fig. 1 E is used to make cross-sectional view according to the method for the electronic device of embodiment 1 in order to explanation;
Fig. 2 A illustrates to be used for illustrating the cross-sectional view across the electronic device of the method for length L that is used to measure according to the metal conductor portion of embodiment 1;
Fig. 2 B is used to measure the front view across the method for length L according to embodiment 1 in order to explanation;
Fig. 2 C is the curve chart across length L that is used to measure according to embodiment 1;
Fig. 2 D illustrates to be used for illustrating the cross-sectional view across the electronic device of the method for length L that is used to measure according to the metal conductor portion of embodiment 1;
Fig. 2 E illustrates to be used for illustrating the front view across another electronic device of the method for length L that is used to measure according to embodiment 1;
Fig. 2 F is another curve chart across length L that is used to measure according to embodiment 1;
Fig. 2 G is the another curve chart across length L that is used to measure according to embodiment 1;
Fig. 2 H is the curve chart again across length L that is used to measure according to embodiment 1;
Fig. 2 I to 2U illustrates according to the various shape of cross sections of the metal conductor portion of the electronic device of embodiment 1 and the view of central shaft;
Fig. 3 A is the plane graph that illustrates according to another electronic device of embodiment 1;
Fig. 3 B is the cross-sectional view along the line 3B-3B intercepting of Fig. 3 A;
Fig. 3 C is the cross-sectional view along the line 3C-3C intercepting of Fig. 3 B;
Fig. 3 D is the plane graph that illustrates according to another electronic device of embodiment 1;
Fig. 3 E is the front view that illustrates according to another electronic device of embodiment 1;
Fig. 3 F is the cross-sectional view along the line 3F-3F intercepting of Fig. 3 E;
Fig. 3 G is the plane graph that illustrates according to the another electronic device of embodiment 1;
Fig. 3 H is the front view that illustrates according to the another electronic device of embodiment 1;
Fig. 3 I is the cross-sectional view along the line 3I-3I intercepting of Fig. 3 H;
Fig. 3 J is the plane graph that illustrates according to another electronic device of embodiment 1;
Fig. 3 K is the cross-sectional view along the line 3K-3K intercepting of Fig. 3 J;
Fig. 3 L is the cross-sectional view along the line 3L-3L intercepting of Fig. 3 K;
Fig. 4 A is the plane graph that illustrates according to the Magnetore sistance effect element of embodiment 2;
Fig. 4 B is the front view that illustrates according to the Magnetore sistance effect element of embodiment 2;
Fig. 4 C is the cross-sectional view along the line 4C-4C intercepting of Fig. 4 B;
Fig. 4 D is in order to the plane graph of explanation according to the operation of the Magnetore sistance effect element of embodiment 2;
Fig. 4 E is in order to the plane graph of explanation according to the operation of the Magnetore sistance effect element of embodiment 2;
Fig. 5 A is the plane graph that illustrates according to the magnetic head of embodiment 3;
Fig. 5 B is the front view that illustrates according to the magnetic head of embodiment 3;
Fig. 6 is the front view that illustrates according to the recording/reproducing apparatus of embodiment 4;
Fig. 7 A is the plane graph that illustrates according to first memory element of embodiment 5;
Fig. 7 B is the front view that illustrates according to first memory element of embodiment 5;
Fig. 7 C is in order to the plane graph of explanation according to the operation of first memory element of embodiment 5;
Fig. 8 A is the plane graph that illustrates according to second memory element of embodiment 5;
Fig. 8 B is in order to the plane graph of explanation according to the operation of second memory element of embodiment 5;
Fig. 9 is the perspective view that illustrates according to the storage array of embodiment 5;
Figure 10 is the perspective view that illustrates according to the Magnetore sistance effect element of embodiment 6;
Figure 11 is used to make perspective view according to the method for the Magnetore sistance effect element of embodiment 6 in order to explanation;
Figure 12 A is in order to the perspective view of explanation according to the electronic device of embodiment 6;
Figure 12 B is used to make perspective view according to the method for the electronic device of embodiment 6 in order to explanation;
Figure 13 A is used to make plane graph according to the method for another electronic device of embodiment 6 in order to explanation;
Figure 13 B is used to make plane graph according to the method for another electronic device of embodiment 6 in order to explanation;
Figure 13 C is used to make plane graph according to the method for another electronic device of embodiment 6 in order to explanation.
Best executive mode of the present invention
Embodiment 1
Figure 1A is the plane graph that illustrates according to the electronic device 100 of embodiment 1; Figure 1B is the cross-sectional view along the line 1B-1B intercepting of Figure 1A; And Fig. 1 C is the cross-sectional view along the line 1C-1C explanation of Figure 1B.
Electronic device 100 has the electrode 2 and 3 that is formed on the rectangular shape on the substrate 8. Electrode 2 and 3 has relative separately from each other apparent surface 5 and 6.The material expectation that is used for electrode 2 and 3 is metal or alloy.
Electronic device 100 is provided with the cylinder supporter 4 that comprises the apparent surface 5 that is used for cross-over electrode 2 and the apparent surface's 6 of electrode 3 carbon nano-tube.Carbon nano-tube can be single-layer carbon nano-tube (SWCNT) or can be multilayer carbon nanotube (MWCHT).
Electronic device 100 has the metal conductor thin film 7 that is electrically connected to electrode 2 and 3.Metal conductor thin film 7 comprises metal conductor portion 1.When seeing perpendicular to the direction of the basal surface of electrode 2 and 3, metal conductor portion 1 along supporter 4 across the gap between electrode 2 and 3.Being not more than at the mean free path Λ of electronics in metal conductor portion 1 under the operating temperature of electronic device 100 of metal conductor portion 1 across length L.
The value of the mean free path Λ of electronics in metal conductor portion 1 depends on the operating temperature of electronic device 100 and is actually used in the material of metal conductor portion 1 of electronic device and difference.When material was pure Au, Ag and Cu, the mean free path Λ of electronics was 100m or bigger.Yet when material was pure Fe, Co, Ni etc., this value was on the order of magnitude of about 10nm.When the material of metal conductor portion 1 comprised impurity, the value of the mean free path Λ of electronics in metal conductor portion 1 was shorter than the mean free path value at pure material.Therefore, according to the chemical constituent of metal conductor portion 1, metal conductor portion 1 across length L for example at 1nm in the scope of 1000nm.
Preferably, the operating temperature of electronic device 100 is not less than 4.2K and is not more than 523K.In addition, consider that the cooling agent of electronic device 100 can be replace the liquid N of liquid He 2, and can reduce manufacturing cost and running cost, operating temperature is preferably and is not less than 77K and is not more than 523K.In addition, when equipment in conjunction with (for example according to the electronic device 100 of present embodiment and other electronic device, semiconductor device, magnetizing mediums etc.) time, consider the operating temperature of the electronic device except that the electronic device 100 of present embodiment if desired, then operating temperature can be for being not less than 273K and being not more than 523K.
The method that explanation is used to make the electronic device 100 of such structure.Fig. 1 D and 1E are the cross-sectional views that is used to make the method for electronic device 100 in order to explanation.At first, on substrate 8, form electrode 2 and 3, have the gap that has across length L therebetween.Then, on electrode 2 and 3, be provided for promoting carbon nano-tube to form catalyst for reaction 9.Then, for example, allow carbon nano-tube to begin growth,, and form supporter 4 thus so that across between electrode 2 and 3 from each catalyst 9 by chemical gas-phase deposition method.
Afterwards,, for example come depositing metal conductor thin film 7, and form metal conductor portion 1 along supporter 4 thus, so that finish the electronic device 100 shown in Figure 1A to 1C by gas-phase deposition method on the supporter 4 and on electrode 2 and 3.
When finishing the formation of metal conductor thin film 7, become unintelligible at junction interface between catalyst 9 and the metal conductor thin film 7 and the junction interface between catalyst 9 and electrode 2 and 3, and catalyst 9 integrates with metal conductor thin film 7 or electrode 2 and 3 thus.
Therefore, can make the electronic device 100 that is provided with metal conductor portion 1, this metal conductor portion 1 have be no more than electron mean free path Λ across length L.In this electronic device 100, the conduction that metal conductor portion 1 is responsible between the electrode 2 and 3.This metal conductor portion 1 is formed by metal.Therefore, different with the carbon nano-tube of the non-patent literature 4 that can not control conductance, metal conductor portion 1 has stable conductance.In addition, formed by metal because comprise the metal conductor thin film 7 of metal conductor portion 1, so different with the carbon nano-tube of non-patent literature 4, the contact resistance between electrode 2 and 3 becomes very little.Therefore, electrical characteristics are stable, and can solve the problem of the big contact resistance that produces between carbon nano-tube and electrode.
Hereinafter, with the specific method that is used to measure metal conductor portion 1 of explanation across length L.Fig. 2 A illustrates to be used for illustrating the cross-sectional view across the electronic device 100 of the method for length L that is used to measure metal conductor portion; Fig. 2 B is used to measure front view across the method for length L in order to explanation; And Fig. 2 C is the curve chart that is used to measure across length L.As mentioned above, term " metal conductor portion across length L " expression along central shaft from the some P1 that descends rapidly along the central shaft of electronic device at its cross-sectional area to the length of the some P2 that increases sharply at its cross-sectional area of locating electronic device.
At first, make under the same conditions and a plurality of electronic devices 100 that have the identical standard of identical shaped and size of preparation.Whether the shape and size of metal conductor portion 1 that can be by determining a plurality of electronic devices 100 such as the photographic analytical technology of utilizing TEM (transmission electron microscope) are identical.
Then, by utilizing in a plurality of electronic devices 100, adopt STM (scanning tunnel microscope) or three-dimensional TEM to cut electronic device 100, thereby can obtain to comprise simultaneously the cross section of metal conductor portion 1 and metal conductor thin film 7.Fig. 2 A illustrates an example of the shape of cross section that obtains by this cutting.
Then, according to the cross section that is obtained, determine the central shaft of metal conductor portion 1.Shape of cross section according to metal conductor portion 1 is determined central shaft X.In the example shown in Fig. 2 A, the shape of cross section of metal conductor portion 1 is a rectangle, and central shaft X is for connecting rectangle at the limit mid point of electrode 2 sides and straight line at the limit mid point of electrode 3 sides.
Then, by utilize in a plurality of electronic devices 100 at least another, determine along cross-sectional area S along central shaft X perpendicular to the electronic device 100 of the cross section of central shaft X.For example, along the cross section perpendicular to central shaft X, for example adopting, STM cuts electronic device 100.Then,, or analyze shape, obtain the cross-sectional area S of the cross section that obtained by cutting by the analytical technology of view data etc. by photomicrography such as STM, three-dimensional TEM etc.Therefore, the data of cross-sectional area S are determined and form the curve chart shown in Fig. 2 C along central shaft X, and in Fig. 2 C, central shaft X is shown transverse axis, and cross-sectional area S is shown the longitudinal axis.
Then, in formed curve chart, determine to locate the some P2 that cross-sectional area S increases sharply along the rapid some P1 that descends of central shaft X with at it at the cross-sectional area S of its place.From a P1, the cross-sectional area of electrode 2 is not included among the cross-sectional area S, causes cross-sectional area S to descend fast at a P1 place.From a P2, the cross-sectional area of electrode 3 is included among the cross-sectional area S, causes cross-sectional area S to increase sharply at a P2 place.For example, find out from the curve chart shown in Fig. 2 C that it is discontinuous to descend at a P1 cross-sectional area S, and increases discontinuous at a P2 cross-sectional area S.
Then, will be between a P1 and some P2 along the length of central shaft X be defined as metal conductor portion 1 across length.
Fig. 2 D illustrates to be used for illustrating the cross-sectional view across another electronic device 100P of the method for length L that is used to measure metal conductor portion; Fig. 2 E is its front view, and Fig. 2 F is another curve chart that is used to measure across length L.Shown in Fig. 2 D, the profile of the electrode 2P of electronic device 100P and 3P, metal conductor thin film 7P and metal conductor portion 1P comprise with at the different curve of example shown in Fig. 2 A to 2C.
With similar at the example shown in Fig. 2 A to 2C, determine central shaft X, determine cross-sectional area S along central shaft X, and the curve chart that forms the cross-sectional area S shown in Fig. 2 F.Then, determine to locate the some P2 that cross-sectional area S increases sharply along the rapid some P1 that descends of central shaft X with at it at the cross-sectional area S of its place.Will be between a P1 and some P2 along the length of central shaft X be defined as metal conductor portion 1 across length.The profile of the cross section of metal conductor portion 1P and metal conductor thin film 7P comprises curve, yet, because some P1 that descends rapidly at the cross-sectional area S of its place and the some P2 that increases sharply at the cross-sectional area S of its place appear in the curve chart in the example shown in Fig. 2 A to 2C, thus can measure a P1 with put between the P2 along central shaft X across length L.
Here it should be noted that shown in Fig. 2 G and 2H in formed curve chart, according to the shape of metal conductor portion and the shape of electrode, discontinuity point does not have appearance and cross-sectional area S to change continuously clearly.In this case, the corresponding point of deformation point D1 in the zone that will descend rapidly with cross-sectional area S therein is defined as a P1, and the corresponding point of deformation point D2 in the zone that will increase sharply with cross-sectional area S therein is defined as a P2, and measure then metal conductor portion 1 across length L
Fig. 2 I to 2U illustrates the various shape of cross sections of metal conductor portion 1 and the view of central shaft X.The cross section of metal conductor portion 1 can form the different shape shown in Fig. 2 I to 2U.As mentioned above, the shape of cross section according to metal conductor portion limits central shaft X.In Fig. 2 I to 2U, the left side of paper illustrates electrode 2 one sides, and the right side of paper illustrates electrode 3 one sides.
Metal conductor portion has the shape that comprises two basal surfaces and be formed on two cylinder side surfaces between the basal surface.Then, the shape of cross section of the metal conductor portion in this example can satisfy any one in the following condition [a] to [g].
That is to say that in the shape of cross section of above-mentioned metal conductor portion, the line (two lines in the vertical) that the periphery of metal conductor portion is shown is any one in following [a] to [g].
[a]: straight line with fixed width (length on the shorter direction);
[b]: width (length on the shorter direction) is dull straight line or the curve that descends from electrode 2 one sides to electrode 3 one sides;
[c]: width (length on the shorter direction) is dull straight line or the curve that descends from electrode 3 one sides to electrode 2 one sides;
[d]: the combination of above-mentioned [b] and [c];
[e]: the combination of above-mentioned [a] and [b];
[f]: the combination of above-mentioned [a] and [c]; And
[g]: the combination of above-mentioned [a], [b] and [c].
Fig. 2 I to 2U illustrates the example of shape of cross section, and these shape of cross sections only illustrate the metal part 1 that satisfies above-mentioned condition [a] to [g].The shape of cross section of the metal conductor portion 1 shown in Fig. 2 I is corresponding to referring to figs. 1A to the shape of cross section of the described metal conductor portion 1 of 1C and satisfy condition [a].Shape of cross section shown in Fig. 2 J is corresponding to reference to the shape of cross section of the described metal conductor portion 1P of figure 2D to 2E and satisfy condition [d].Shape of cross section shown in Fig. 2 K satisfy condition [g].Shape of cross section shown in Fig. 2 L satisfy condition [d].
Fig. 2 M satisfy condition [f].Fig. 2 N and 2O satisfy condition [c].Fig. 2 P and 2Q satisfy condition [f].Fig. 2 R satisfy condition [c].Fig. 2 S and 2T satisfy condition [d].Fig. 2 U satisfy condition [g].
The shape of the basal surface of the metal conductor portion in this example is not particularly limited.And the shape and size of two basal surfaces (on the surface of electrode 2 sides and electrode 3 sides) can be mutually the same or be differed from one another.In addition, to be formed on two side surfaces between the basal surface can be plane or curved surface or plane and the combining of curved surface.
In addition, consider the more reliable stability of acquisition, the cylindrical metal conductor part in the present embodiment has the shape that satisfies whole following conditions [h] to [l] simultaneously.
[h]: two basal surfaces are of similar shape;
[i]: two basal surfaces have area identical;
[j]: two basal surfaces are parallel to each other;
[k]: the central shaft of metal conductor portion is a straight line; And
[l]: two basal surfaces are with respect to vertical with the central shaft of above-mentioned [k] and comprise that the plane of the mid point of central shaft is mutually symmetrical.
Have simultaneously satisfy condition [h] and can comprise metal conductor portion to the example of the cylindrical metal conductor part of the shape of [l] with the shape of cross section shown in Fig. 2 I and the 2L.
The central shaft X of metal conductor portion 1 is generally straight line.Yet,, limit the central shaft X of metal conductor portion 1 with the shape of cross section shown in Fig. 2 P by in conjunction with two straight lines; And, limit the central shaft X of metal conductor portion 1 with the shape of cross section shown in Fig. 2 R by in conjunction with straight line and curve.Limit the central shaft X of metal conductor portion 1 with the shape of cross section shown in Fig. 2 O, 2S and the 2T by curved surface.
In addition, can form in concave part and the convex portions at least one by treatment technology such as STM.Yet, in this case, preferably, the shape of cross section of the metal conductor portion before forming concave part and convex portions (or hypothesis does not form the metal conductor portion of concave part and convex portions) has any in the above-mentioned shape [a] to [g].
As long as can form above-mentioned metal conductor portion 1, the shape of supporter 4 just is not particularly limited.
In the electronic device 100 of present embodiment, be responsible for being not more than at the mean free path Λ of electronics in metal conductor portion 1 under the operating temperature of electronic device of metal conductor portion 1 of conduction across length L.Therefore, be called as the phenomenon of ballistic conduction, it can allow electronics to pass metal conductor portion 1 and not be scattered, and is referred to as the phenomenon that the quantum electricity is led, and wherein conductance (electricity is led) is with respect to the cross-sectional area stepped of metal conductor portion 1.In the electronic device of present embodiment, the size of metal conductor portion is on the order of magnitude of nanometer, because metal conductor portion is formed on the carbon nano-tube, and also can observe ballistic conduction and the quantum electricity is led under higher relatively temperature.
When the quantum electricity in utilizing metal conductor portion 1 is led, by the cross-sectional area of control metal part 1, in large-scale production, the conductance deviation that electronic device is not produced when conductance changes continuously with respect to the cross-sectional area of metal conductor portion 1.
In Figure 1A, near metal conductor portion 1, grid part is set, and is used as source electrode and drain electrode by the film formed electrode 2 of magnetic and 3.Thus, can obtain spin transistor.In addition, if metal conductor portion 1 is separated with 3 with electrode 2 with supporter 4, then can obtain to utilize coulomb to block the single-electronic transistor of (coulomb brocade) phenomenon.
In the electronic device shown in Figure 1A to 1C 100, if electrode 2 and 3 is made of magnetisable material at least, then by utilizing the ballistic conduction in the metal conductor portion 1, can obtain to have the spin electric device (Magnetore sistance effect element) of high MR ratio, in this device, magnetoresistance changes on the direction of magnetization of electrode 2 and 3.In this case, metal conductor portion 1 is to be not more than the length value of under the operating temperature of the Magnetore sistance effect element electron spin in metal conductor portion diffusion and the value of the higher value in the value of the mean free path Λ of the electronics in the metal conductor portion under the operating temperature of Magnetore sistance effect element across length L.
In common material, the length value of electron spin diffusion is greater than electron mean free path Λ.For example, under the situation of Co, the length of electron spin diffusion is 5nm for about 50nm electron mean free path Λ.Therefore, usually can be with metal conductor portion 1 be arranged to be not more than the length of electron spin diffusion across length L.Yet, there is material such as Ni, its electron mean free path Λ is greater than the length of electron spin diffusion.When metal conductor portion 1 is formed by this material, can be set to be not more than electron mean free path Λ across length L.Here it should be noted that when the length of electron spin diffusion and electron mean free path Λ are equal to each other, can be set to be not more than this equal value across length L.
When metal conductor portion 1 and supporter 4 and electrode 2 and 3 are separated,, can not only utilize spin to block phenomenon and can also utilize above-mentioned coulomb to block phenomenon to realize spin electric device according to the spin condition of the metal conductor portion 1 of being separated and electrode 2 and 3.
When electrode 2 and 3 is made of magnetisable material, wish that catalyst 9 uses comprise metal/alloy particle or the film that is selected from least a atom in the group of being made up of Fe, Co and Ni.Think that these catalyst promote wherein to pass through to decompose CH when by formation carbon nano-tube such as CVD methods 4Be grown to the reaction of carbon nano-tube in the carbon that is produced (C).
After forming electronic device, can remove the supporter of making by carbon nano-tube with said method.Can optionally remove supporter 4 by oxygen ashing (oxygen asher).In addition, can remove supporter 4 by adopting laser radiation supporter 4.Yet, consider intensity, can keep supporter 4.In addition, after forming electronic device, can remove substrate 8 with said method.Especially, when CNT is used for substrate 8, because the substrate of CNT 8 shows conductor, semiconductor and insulator three specific characters, so by removing the substrate 8 that is formed by CNT, the electrical characteristics of electronic device become more stable.
Fig. 3 A is the plane graph that illustrates according to another electronic device 100A of embodiment 1; Fig. 3 B is the cross-sectional view along the line 3B-3B intercepting of Fig. 3 A; And Fig. 3 C is the cross-sectional view along the line 3C-3C intercepting of Fig. 3 B.Use identical reference marker to represent described same parts, and can omit repeat specification referring to figs. 1A to 1E.
On the surface of two electrodes, form supporter.On on the surface of the electrode 2 and surface of electrode 3, form the supporter 4A of electronic device 100A.When the side perpendicular to the basal surface of electrode 2 and 3 looks up, supporter 4A is across the gap between electrode 2 and 3.On electrode 2 and 3, form the metal conductor thin film 7A of electronic device 100A.When the side perpendicular to the basal surface of electrode 2 and 3 looks up, metal conductor portion 7A comprise along supporter 4A across electrode 2 and between the metal conductor portion 1A in gap.Metal conductor portion 1A is not more than at the mean free path Λ of electronics in metal conductor portion 1A under the operating temperature of electronic device 100A across length L.Gou Zao electronic device 100A has the effect identical with above-mentioned electronic device 100 like this.
Fig. 3 D is the plane graph that illustrates according to another electronic device 100B of embodiment 1; Fig. 3 E is the cross-sectional view along the line 3E-3E intercepting of Fig. 3 D; And Fig. 3 F is the cross-sectional view along the line 3F-3F intercepting of Fig. 3 E.Use identical reference marker to represent described same parts, and can omit repeat specification referring to figs. 1A to 1E.
Electrode can have the triangular prism shape.Electronic device 100B is provided with triangular prism electrode 2B and 3B.Form in the position respectively electrode 2B and 3B with box lunch when the side perpendicular to basal surface looks up, its surperficial summit is toward each other.The supporter 4B of electronic device 100B is across the gap between triangular prism shaped electrode 2B and the 3B.The metal conductor thin film 7B of electronic device 100B comprises across looking up along the metal conductor portion 1B in the gap of supporter 4B between electrode 2B and 3B from the side perpendicular to basal surface.Metal conductor portion 1B is not more than the mean free path Λ of electronics in metal conductor portion 1B across length.Gou Zao electronic device 100B also has the effect identical with above-mentioned electronic device 100 like this.
Fig. 3 G is the plane graph that illustrates according to the another electronic device 100C of embodiment 1; Fig. 3 H is the cross-sectional view along the line 3H-3H intercepting of Fig. 3 G; And Fig. 3 I is the cross-sectional view along the line 3I-3I intercepting of Fig. 3 H.Electrode can have cylindrical shape.Electronic device 100C has cylinder bodily form electrode 2C and 3C.The supporter 4C of electronic device 100C is across the gap between electrode 2C and the 3C.Electronic device 100C has the metal conductor thin film 7C that comprises metal conductor portion 1C.Metal conductor portion 1C is not more than the mean free path Λ of electronics in metal conductor portion 1C across length L.Gou Zao electronic device 100C also has the effect identical with above-mentioned electronic device 100 like this.
Fig. 3 J is the plane graph that illustrates according to another electronic device 100D of embodiment 1; Fig. 3 K is the cross-sectional view along the line 3K-3K intercepting of Fig. 3 J; And Fig. 3 L is the cross-sectional view along the line 3L-3L intercepting of Fig. 3 K.Can be formed for the apparent surface's of direct cross-over connection two electrodes metallic conductor.Electronic device 100D comprises: by the cylindrical body supports body of making across the carbon nano-tube between the apparent surface 6 of the apparent surface 5 of electrode 2 and electrode 34; And metallic conductor 1D, its along supporter 4 directly across between the apparent surface 6 of the apparent surface 5 of electrode 2 and electrode 3.On the surface of electrode 2 and 3, form metal conductor thin film 7D discretely with metallic conductor 1D.Metallic conductor 1D is not more than the mean free path Λ of electronics in metal conductor portion 1D across length L.Gou Zao electronic device 100D also has the effect identical with above-mentioned electronic device 100 like this.
Embodiment 2
Fig. 4 A is the plane graph that illustrates according to the Magnetore sistance effect element 200 of embodiment 2; Fig. 4 B is its front view; And Fig. 4 C is the cross-sectional view along the line 4C-4C intercepting of Fig. 4 B.Use identical reference marker to represent and the identical parts of embodiment 1 described those parts, and can omit repeat specification.
Magnetore sistance effect element 200 comprises electrode 2E and the 3E that is made by magnetisable material.Electrode 2E and 3E have apparent surface 5E respect to one another and 6E respectively.Electrode 2E and 3E comprise having width D is reduced to width d towards apparent surface 5E and 6E sweep respectively.
Magnetore sistance effect element 200 is provided with the cylindrical body supports body 4E that is made by the carbon nano-tube of the apparent surface 6E of the apparent surface 5E of cross-over electrode 2E and electrode 3E.
Magnetore sistance effect element 200 has the metal conductor thin film 7E that is electrically connected to electrode 2E and 3E.Preferably, metal conductor thin film 7E comprises magnetisable material.Metal conductor thin film 7E comprises metal conductor portion 1E.Metal conductor portion 1E across from see perpendicular to the direction of the basal surface of electrode 2E and 3E between electrode 2E and 3E along the gap of supporter 4E.Being not more than across length L of metal conductor portion 1E is the length value of the electron spin among metal conductor portion 1E diffusion under the operating temperature of Magnetore sistance effect element 200 and in the value of the higher value of electronics in the value of the mean free path Λ of metal conductor portion 1E under the operating temperature of Magnetore sistance effect element 200.
The cross-sectional area S3 of the cross-sectional area S1 of electrode 2E, the cross-sectional area S2 of electrode 3E and metal conductor portion 1E satisfies following relational expression:
S3＜S1 and S3＜S2.
Like this, when the cross-sectional area S3 of metal conductor portion is set to less than the cross-sectional area S1 of electrode and S2, when metal conductor portion 1E is made by magnetisable material, can easily neticdomain wall be fixed among the metal conductor portion 1E.In addition, same is not under the situation about being made by magnetisable material at metal conductor portion 1E, when the cross-sectional area S3 of metal conductor portion is set to less than the cross-sectional area S1 of electrode and S2, allow to realize the major part of the resistance of magnetoresistive element by metal conductor portion 1E.Cross-sectional area S1, S2 and S3 for along with the cross-sectional area that is used for determining the cross section that the central shaft across the metal conductor portion of length L described in the embodiment 1 is vertical.
The method that explanation is used to make the Magnetore sistance effect element 200 of such structure.At first, on substrate 8, form electrode 2E and the 3E that comprises magnetisable material therebetween with the gap that has across length L.Then, on electrode 2E and 3E, be provided for promoting carbon nano-tube to form catalyst for reaction.Then, for example allow carbon nano-tube to begin growth,, and form supporter 4E thus so that across between electrode 2E and 3E from each catalyst 9 by the chemical vapor deposition (CVD) method.Afterwards, on the supporter 4E and on electrode 2E and 3E, for example come depositing metal conductor thin film 7E, and form metal conductor portion 1E thus so that finish Magnetore sistance effect element 200 by gas-phase deposition method.
By depositing metal conductor thin film 7E on the supporter 4E of carbon nano-tube, can form and have the metal conductor portion 1E that is not more than the value that is the higher value in the value of the length value of electron spin diffusion and electron mean free path Λ across length L.
This metal conductor portion 1E is responsible for conducting electricity between electrode 2E and 3E.This metal conductor portion 1E is made of metal, and therefore different with the carbon nano-tube of the non-patent literature 4 that can not control conductance, metal conductor portion 1E has stable conductance.In addition, formed by metal because comprise the metal conductor thin film 7 of metal conductor portion 1E, so different with the carbon nano-tube of non-patent literature 4, the contact resistance between electrode 2E and the electrode 3E becomes minimum.Therefore, it is stable that electrical characteristics become, and can solve the problem of the big contact resistance that produces between carbon nano-tube and electrode.
Among the metal conductor portion 1E across length L of the higher value in the value of length value with the electron spin of being not more than diffusion and electron mean free path Λ, observe the phenomenon that is called as ballistic conduction that can allow electronics to pass metal conductor portion 1E and not be scattered.When can control electrode 2E and during the direction of magnetization of 3E, because ballistic conduction, can obtain to have the Magnetore sistance effect element of very high MR ratio.
Fig. 4 D and Fig. 4 E are the plane graphs in order to explanation operation of Magnetore sistance effect element 200 when using magnetisable material to be used for metal conductor portion 1E.Shown in Fig. 4 D, when the direction of magnetization J1 antiparallel of direction of magnetization J2 that makes electrode 3E owing to external magnetic field H and electrode 2E, because neticdomain wall is fixed to metal conductor portion 1E, so electronics is uprised by neticdomain wall scattering and resistance.Shown in Fig. 4 E, when the direction of magnetization J2 that makes electrode 3E owing to external magnetic field H is parallel with the direction of magnetization J1 of electrode 2E,, carry out electron scattering and resistance step-down so can't help neticdomain wall because neticdomain wall disappears from metal conductor portion 1E.
In the metal conductor portion 1E across length L of length with the electron spin of being not more than diffusion and the higher value among the electron mean free path Λ, the ballistic conduction that is not scattered because taking place to allow electronics to pass metal conductor portion 1E is so be in electrode 2E and the resistance between the 3E under the antiparallel state shown in Fig. 4 D and be in electrode 2E under the parastate shown in Fig. 4 E and the difference between the resistance between the 3E becomes very big.As a result, can realize having 100% or higher MR than, promptly than the MR of conventional GMR element Magnetore sistance effect element than much bigger MR ratio.
Here it should be noted that when metal conductor portion 1E is made by namagnetic substance, on metal conductor portion 1E, do not produce neticdomain wall.Yet, similar in appearance to conventional GMR element, when the direction of magnetization of electrode 2 and 3 is parallel to each other, do not produce spin scattering and resistance step-down, and when the direction of magnetization of electrode 2 and 3 each other during antiparallel, produce spin scattering and resistance and uprise.In this case, different with conventional GMR element, in metal conductor portion 1E, produce ballistic conduction.Therefore, can obtain the MR ratio bigger than conventional GMR element.
In addition, do not adopt magnetisable material for two electrodes, when magnetisable material only is used for metal conductor portion 1E, can be by in metal conductor portion 1E, forming concave part so that capture neticdomain wall and make resistance keep high, determine that by allowing to show threshold value or higher electric current flow out so that suppress neticdomain wall and reduce resistance, obtain big MR ratio from one of electrode 2E and 3E then.
Preferably, the magnetisable material that is used for electrode 2E and 3E and metal conductor portion 1E is made of the semimetal magnetic material that comprises at least a element that is selected from the group of being made up of Fe, Co and Ni or have a big spin polarizability.
Here it should be noted that when allowing carbon nano tube growth simultaneously respectively when electrode 2E applies different voltage with 3E the direction of controlling carbon nanotube growth easily.Preferably, catalyst comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.
Embodiment 3
Fig. 5 A is the plane graph that illustrates according to the magnetic head 300 of embodiment 3; And Fig. 5 B is its front view.Use identical reference marker to represent and embodiment 1 and the identical parts of 2 described parts, and can omit repeat specification.
Magnetic head 300 comprises Magnetore sistance effect element 200A.Magnetore sistance effect element 200A comprises electrode 2F and the 3F that is made of magnetisable material. Electrode 2F and 3F have apparent surface 5F and 6F respectively.Electrode 2F and 3F comprise the sweep with the width D that reduces towards the width d of apparent surface 5F and 6F respectively.
Magnetore sistance effect element 200A is provided with the cylindrical body supports body 4F that makes by across the carbon nano-tube between the apparent surface 6F of the apparent surface 5F of electrode 2F and electrode 3F.
Magnetore sistance effect element 200A has the metal conductor thin film 7F that is electrically connected to electrode 2F and 3F.Metal conductor thin film 7F comprises magnetisable material.Metal conductor thin film 7F comprises metal conductor portion 1F.Metal conductor portion 1F across from see perpendicular to the direction of the basal surface of electrode 2F and 3F between electrode 2F and 3F along the gap of supporter 4F.Being not more than across length L of metal conductor portion 1F is the value of the higher value in the value of the length value of electron spin diffusion under the operating temperature of Magnetore sistance effect element 200A and the mean free path Λ of electronics in metal conductor portion 1F.
Magnetic head 300 comprises the electrode 2F that is electrically connected to Magnetore sistance effect element 200A and 3F and to the lead-in wire 10 of two electrode application voltage.
Electrode 3F comprises dielectric film 15, is made and be formed on the basement membrane (base film) 16 on the dielectric film 15 and be formed on the basement membrane 16 and have when applying external magnetic field H the free layer 11 of the direction of magnetization J2 of rotation easily by Ta etc.Even electrode 2F comprises dielectric film 33, made and be formed on the basement membrane 34 on the dielectric film 33 and be formed on the basement membrane 34 and have by Ta etc. and apply the fixed bed 12 that external magnetic field H does not allow voluble direction of magnetization J1 yet.Fixed bed 12 comprises the antiferromagnetism film that is formed on the basement membrane 34 14 and is formed on the antiferromagnetism film 14 and by the fixing magnetic film 13 of antiferromagnetism film 14.
The method that explanation is used to make the Magnetore sistance effect element 300 of such structure.At first, on substrate 8, form electrode 2F and 3F therebetween with the gap that has across length L.Then, lead-in wire 10 is connected respectively to electrode 2F and 3F.Then, on electrode 2F and 3F, be provided for promoting carbon nano-tube to form catalyst for reaction.Then, for example allow carbon nano-tube to begin growth,, and form supporter 4F thus so that across between electrode 2F and 3F from each catalyst by the chemical vapor deposition (CVD) method.Afterwards,, for example come depositing metal conductor thin film 7F, and form metal conductor portion 1F along supporter 4F thus by gas-phase deposition method on the supporter 4F and on electrode 2F and 3F.
By depositing metal conductor thin film 7F on the supporter 4F of carbon nano-tube, can form the metal conductor portion 1F across length L of the higher value in the value of length value with the electron spin of being not more than diffusion and electron mean free path Λ.
This metal conductor portion 1F is responsible for conducting electricity between electrode 2F and 3F.This metal conductor portion 1F is made of metal, and therefore different with the carbon nano-tube of the non-patent literature 4 that can not control conductance, metal conductor portion 1F has stable conductance.In addition, formed by metal because comprise the metal conductor thin film 7F of metal conductor portion 1F, so different with the carbon nano-tube of non-patent literature 4, the contact resistance between electrode 2F and the electrode 3F becomes minimum.Therefore, electrical characteristics are stable, and can solve the problem of the big contact resistance that produces between carbon nano-tube and electrode.
In the metal conductor portion 1F across length L of length with the electron spin of being not more than diffusion and the higher value among the electron mean free path Λ, observe the phenomenon that is called as ballistic conduction that can allow electronics to pass metal conductor portion 1F and not be scattered.By utilizing ballistic conduction, the direction of magnetization J2 of the direction of magnetization J1 of the electrode 2F by control fixed bed 12 and the electrode 3F of free layer 11 can obtain to have the Magnetore sistance effect element of very high MR ratio.
Shown in Fig. 5 A, when applying external magnetic field H, according to the size of external magnetic field H, do not make the direction of magnetization J1 rotation of the fixed bed 12 of electrode 2F, and make the direction of magnetization J2 rotation of the free layer 11 of electrode 3F.Therefore, the differential seat angle between direction of magnetization J1 and direction of magnetization J2 changes according to the size of the external magnetic field H that is applied, and changes resistance between electrode 2F and the 3F according to the differential seat angle between direction of magnetization J1 and the J2.As a result, according to the size of the external magnetic field H that is applied, change the electrode 2F of Magnetore sistance effect element 200A and the resistance between the 3F.
When fixed bed 12 constitutes by antiferromagnetism film 14 with by antiferromagnetism film 14 fixing magnetic films 13, can obtain to have the magnetic head of thermal stability property.
In addition, magnetic film 13 is fixed by antiferromagnetism film 14 in the example shown in Fig. 5 B, but it can comprise the synthetic film that has big coercitive hard magnetic film or be made of the hard magnetic film with big magnetic force and magnetic force.In this case, do not need antiferromagnetism film 14.
The direction of magnetization that is arranged on the magnetosphere 13 in the fixed bed 12 must be fixed in one direction.Yet, be used for wherein packing density greater than 100Gb/inch 2The magnetic head of application in, size of component is very fine, to such an extent as to the direction of magnetization of magnetosphere 13 is subjected to the influence of heat fluctuation, and becomes and is difficult to fixed magnetisation direction.Therefore, in this example, carry out the fixing of magnetic film 13 by using antiferromagnetism film 14, even and component size become meticulous, the direction of magnetization of magnetosphere 13 is not subjected to the influence of heat fluctuation yet.
Hope is arranged to the easy magnetizing axis 30 of free layer 11 vertical with the direction of external magnetic field H to be detected.Therefore, improve the linearity of the signal output of Magnetore sistance effect element 200A.A kind of method that obtains this purpose be provide in the both sides of free layer 11 permanent magnet and fixedly the easy magnetizing axis 30 of free layer 11 make it perpendicular to will be by the direction of the external magnetic field H of its bias magnetic field detection.The another kind of method that is used to obtain this purpose is to fix the part of free layer 11 both sides so that make the direction of the easy magnetizing axis 30 of free layer 11 perpendicular to magnetic field H by the antiferromagnetism film that separates setting with antiferromagnetism film 14.
In addition, free layer 11 is made of antiparallel exchange each other and the two-layer magnetic film that inserts nonmagnetic film therebetween.When representing two magnetospheric magnetization with M1 and M2 and representing film thickness with t1 and t2, (M1 * t1-M2 * t2) be not equal to zero.Thus, by exchange, can when component size becomes meticulous, improve with respect to the stability of heat fluctuation and improve because the sensitivity that the thickness of effective magnetic film reduces to cause with respect to the Magnetore sistance effect element of external magnetic field.
Identical with free layer 11, magnetic film 13 also can be made of antiparallel exchange each other and the two-layer magnetic film that inserts nonmagnetic film therebetween, improves the stability with respect to heat fluctuation thus.Under the situation of magnetic film 13, (M1X * t1X-M2X * t2X) can be zero, wherein M1X and M2X represent the magnetization of two respective magnetic films; And t1X and t2X represent thickness.
The material of wishing free layer 11 and magnetic film 13 is to comprise Fe, Co as main component and the metal/alloy of Ni.The object lesson of material comprises NiFe, CoFe and CoFeNi etc.As the material of antiferromagnetism film 14, expectation use comprise as main component be selected from least a element in the group of forming by Pt, Pd and Ir and the alloy film of Mn element, for example, PtMn, IrMn and PtPdMn.Dielectric film 15 and 33 can be by for example SiO 2Constitute.Needn't form dielectric film 15 and 33.Yet under the situation that forms dielectric film 15 and 33, CNT can grow smoothly.
Here it should be noted that by allowing carbon nano-tube across so that form supporter 4F, 10 apply the voltage that differs from one another by going between simultaneously, direction that can the controlling carbon nanotube growth to electrode 2F and 3F.
Embodiment 4
Fig. 6 is the front view that illustrates according to the recording/reproducing apparatus 400 of embodiment 4.Recording/reproducing apparatus 400 comprises recording head part 17 and reproduces head part 18.Recording head part 17 has winding part 31.When electric current flows on winding part 31, leakage field from the G1 of interrecord gap (IGP), and utilize this leakage field, record the information in the magnetic recording medium 19.
Reproducing head part 18 has two shieldings (shield) part 32 that comprises magnetisable material and is arranged on the magnetic head 300 according to embodiment 3 between the masked segment 32.Be arranged to the clearance G 2 that reads between the masked segment 32 narrower than the twice that is recorded in the bit length BL in the magnetic recording media 19.The Magnetore sistance effect element 200A of the magnetic head 300 by embodiment 3 come detection record in magnetic recording media 19 information and it is read (referring to Fig. 5 A) via lead-in wire 10.
The magnetic head 300 of the reproduction head part 18 of embodiment 4 comprises the Magnetore sistance effect element 200A of embodiment 3.Magnetore sistance effect element 200A comprises metal conductor portion 1F (referring to Fig. 5 A and 5B).Because metal conductor portion 1F's is the value that is not more than the higher value in the value of the length value of electron spin diffusion and the mean free path Λ of electronics in metal conductor portion 1F across length L, so can realize ballistic conduction at metal conductor portion 1F.Therefore, if use the magnetic head 300 that reproduces head part 18, then because 100% MR is more higher than comparing with conventional GMR element or TMR element, so can realize having greater than 100Gb/inch 2Splendid highdensity recording/reproducing apparatus.
Embodiment 5
Fig. 7 A is the plane graph that illustrates according to first memory element 500 of embodiment 5; Fig. 7 B is its front view; And Fig. 7 C is in order to the plane graph of explanation according to the operation of first memory element 500 of embodiment 5.Use identical reference marker to represent and the identical parts of embodiment 1 to 4 described parts, and can omit repeat specification.
Memory element 500 comprises with reference to figure 5A and 5B at the Magnetore sistance effect element 200A described in the embodiment 3.Magnetore sistance effect element 200A comprises: electrode 3F, and it comprises and wherein magnetizes the free layer 11 that is rotated easily with respect to external magnetic field H; Electrode 2F, it comprises and wherein magnetizes the fixed bed 12 that is not easy to be rotated with respect to external magnetic field H; And the metal conductor thin film 7F that comprises metal conductor portion 1F.Fixed bed 12, free layer 11 and metal conductor portion 1F are made of magnetisable material.
Among the metal conductor portion 1F across length L of the higher value in the value of length value with the electron spin of being not more than diffusion and electron mean free path Λ, observe the phenomenon that is called as ballistic conduction that can allow electronics to pass metal conductor portion 1F and not be scattered.By utilizing ballistic conduction, the direction of magnetization J2 of the direction of magnetization J1 of the fixed bed 12 by control electrode 2F and the free layer 11 of electrode 3F can obtain to have the Magnetore sistance effect element of very high MR ratio.
Memory element 500 also comprises being used for producing according to any one of electric current 21A and 21B makes the external magnetic field H1 of direction of magnetization J2 counter-rotating of free layer 11 or the word line 20 of H2; And any one electric current supply device 22 that is used for providing electric current 21A and 21B to word line 20.
Shown in Fig. 7 A, when electric current supply device 22 when word line 20 provides electric current 21A, word line 20 produces external magnetic field H1.Externally do not magnetize the direction of magnetization J1 of rotation fixed bed 12 on the direction of magnetic field H 1, and externally magnetize the direction of magnetization J2 that rotates free layer 11 on the direction of magnetic field H 1.Therefore, the direction of magnetization J1 antiparallel of the direction of magnetization J2 of free layer 11 and fixed bed 12.
Then, shown in Fig. 7 C, when electric current supply device 22 when word line 20 is provided at the electric current 21B that flows on the opposite direction of electric current 21A, word line 20 produces the external magnetic field H2 opposite with external magnetic field H1 direction.Then, the direction of magnetization J2 of rotation free layer 11 on the direction of magnetic field H 2 externally.Therefore, the direction of magnetization J2 of free layer 11 is parallel with the direction of magnetization J1 of fixed bed 12.
Thus, thereby rotate the direction of magnetization J2 of free layer 11 on word line 20, can obtain parastate and antiparallel state by electric current 21A or electric current 21B are flowed.
Shown in Fig. 7 A, as the direction of magnetization J1 of two electrode 2F and 3F and J2 each other during antiparallel, when magnetisable material was used for metal conductor portion 1F, neticdomain wall was fixed.Therefore, since electronics by the neticdomain wall scattering, so the resistance between two electrode 2F and the 3F uprises.Shown in Fig. 7 C, when the direction of magnetization J1 of two electrode 2F and 3F and J2 were parallel to each other, neticdomain wall disappeared from metal conductor portion 1F.Therefore, since electronics not by the neticdomain wall scattering, so the resistance step-down between two electrode 2F and the 3F.
When metal conductor portion 1F is made of namagnetic substance, in metal conductor portion 1F, do not produce neticdomain wall.Yet when the direction of magnetization of electrode 2F and 3F was parallel to each other, metal conductor portion 1F showed ballistic conduction; And when the direction of magnetization of electrode 2F and 3F each other during antiparallel, the spin scattering takes place.Therefore, be parallel or antiparallel each other according to the direction of magnetization of electrode 2F and 3F, can obtain than the big magnetic resistance change rate of conventional GMR element.
Among the metal conductor portion 1F across length L of the higher value in the value of length value with the electron spin of being not more than diffusion and electron mean free path Λ, can realize to allow electronics to pass metal conductor portion 1F and the phenomenon that is called as ballistic conduction that is not scattered.Therefore, resistance under the antiparallel state shown in Fig. 7 A and the difference between the resistance under the parastate shown in Fig. 7 C become very big.Therefore, compare, can realize very high MR ratio with the MR ratio of conventional Magnetore sistance effect element with maximum MR ratio of about 60%.
When allowing electric current 21A or electric current 21B to flow into word line 20, can be with in the free layer 11 that writes electrode 3F with the state information corresponding " 1 " shown in the state shown in Fig. 7 A and Fig. 7 C or " 0 " respectively.When the resistance measured between two electrode 2F and the 3F, can be according to being that high resistance or low resistance read the information that is write.
Fig. 8 A is the plane graph that illustrates according to second memory element 600 of embodiment 5; Fig. 8 B is the plane graph in order to the operation that second memory element 600 is described.
Memory element 600 comprises Magnetore sistance effect element 200A.As in above-mentioned memory element 500, among the metal conductor portion 1F across length L of the higher value in the value of length value with the electron spin of being not more than diffusion and electron mean free path Λ, observe can allow electronics to pass metal conductor portion 1F and be not scattered be called as ballistic conduction.By utilizing ballistic conduction, the direction of magnetization J2 of the direction of magnetization J1 of the fixed bed 12 by control electrode 2F and the free layer 11 of electrode 3F compares with the TMR element with conventional GMR element, can obtain to have the Magnetore sistance effect element of very high MR ratio.
Memory element 600 is provided with electric current supply device 25.Electric current supply device 25 is provided among the metal conductor portion 1F from electrode 2F to Magnetore sistance effect element 200A and flows to the electric current 23 of electrode 3F and flow to the electric current 24 of electrode 2F from electrode 3F among metal conductor portion 1F.Basic structure in the present embodiment is except that not providing identical with the memory element 500 shown in Fig. 7 A to 7C the word line.
When metal conductor portion 1F is non-magnetic conductor, shown in Fig. 8 A, by allowing electric current 23 from comprising the electrode 2F side inflow of fixed bed, the direction of magnetization J1 antiparallel of the fixed bed of the direction of magnetization J2 of the free layer of electrode 3F and electrode 2F.Shown in Fig. 8 B, by allowing electric current 24 from comprising the electrode 3F side inflow of free layer, make electrode 3F free layer direction of magnetization J2 counter-rotating and be in antiparallel state with respect to the direction of magnetization J1 of the fixed bed of electrode 2F.In addition, when metal conductor portion 1F is magnetisable material, flow into from electrode 3F or electrode 2F by allowing electric current, can be with respect to the fixing neticdomain wall or remove neticdomain wall of metal conductor portion 1F from metal conductor portion 1F.
When allowing electric current 23 or 24 on Magnetore sistance effect element 200A, to flow, can will write in the free layer of electrode 3F with state information corresponding " 1 " or " 0 " shown in the state shown in Fig. 8 A and Fig. 8 B.When the resistance between measurement electrode 2F and the 3F, can be according to being that high resistance or low resistance read the information that writes.
For by electric current 23 or 24 being flowed make the direction of magnetization J2 counter-rotating of electrode 3F, electric current 23 and 24 current density are at least 1 * 10 5A/cm 2Or higher, and wish to be 1 * 10 for stable operation 6A/cm 2Or it is higher.
When utilizing conventional photoetching technique to make this magnetoresistance element, because the width of metal conductor portion increases, so must flow into big electric current in order to increase current density.Therefore, be difficult to obtain can conserve energy Magnetore sistance effect element.
In the present embodiment, because on CNT, form metal conductor portion, so can be easily the width of metal conductor portion be reduced to 1 to 10nm.Therefore, even do not allow to flow into big electric current, also can realize above-mentioned current density.Preferably, electric current 23 and 24 current density are 1 * 10 8A/cm 2Or it is lower.If current density is higher than this upper limit, then memory element may be damaged during operation.
Different with the memory element 500 shown in Fig. 7 A to 7C, the memory element 600 shown in Fig. 8 A and the 8B does not need word line.Under the situation of the magnetization inversion that is undertaken by the external magnetic field H that utilizes word line, when memory element diminished, the needed word line current of magnetization inversion increased, and this is serious problem.This memory element 600 does not have this problem.
Because memory element 600 does not need aforesaid word line, so it has simple and undersized structure.Therefore, can realize having the memory element simple and structure that size is little, in this structure, cellar area is little, and it is little and packing density is high to be used to install the interval of memory.According to memory element 600, compare than MR ratio with maximum MR wherein for about 60% conventional Magnetore sistance effect element, can obtain very high MR ratio.
Here it should be noted that can utilize be arranged under the fixed bed 11 or on the antiferromagnetism film fix the fixed bed 11 of the memory element shown in Fig. 7 A to 7C, 8A and the 8B.Preferably, this antiferromagnetism film comprises and is selected from least a element in the group of being made up of Pt, Pd and Ir and contains the alloy film of Mn element as main component, for example PtMn, IrMn and PtPdMn.
Fig. 9 is the perspective view that illustrates according to the storage array 700 of embodiment 5.
As shown in Figure 9, will be arranged to matrix with reference to the memory element of figure 8A and described this embodiment of 8B can record the information on the single memory element and the memory element of the structure of sense information from single memory element so that make to have.Therefore, can realize that density is higher than the storage array of 1Gb.
In storage array 700, Magnetore sistance effect element 200A is arranged to matrix (m capable * n row).Along the Magnetore sistance effect element 200A that on column direction, is provided with, provide M bar lead X1, X2 ... X (m-1), Xm.To be used to connect connecting line CL (i, i) (1≤i≤m and 1≤i≤n) and m bar lead X1, the X2 of the electrode 3F of each Magnetore sistance effect element 200A ... X (m-1), Xm are arranged to matrix.N bar lead Y1, the Y2 of the electrode 2F that is connected to the Magnetore sistance effect element 200A that is provided with on line direction are provided then ... Y (n-1), Yn.
Storage array 700 comprises r/w cell 35.By making sense of current counter-rotating among the metal conductor portion 1F that flows into Magnetore sistance effect element 200A so that change over parallel the direction of magnetization of electrode 2F and 3F or antiparallel, writing unit 35 writes on information on the Magnetore sistance effect element 200A independently through lead and connecting line.
Storage array 700 comprises reads unit 36.By measuring and the electrode 2F of different Magnetore sistance effect element 200A and the resistance value between the 3F are read unit 36 and read the information that writes Magnetore sistance effect element 200A independently according to the direction of magnetization of electrode 2F and 3F.
(i j) upward flows with lead Yi, carries out the information record at lead Xi, connecting line CL can to pass through to allow relatively large electric current.At this moment, depend on that the direction that wherein allows electric current to flow is from lead Xi side inflow or from lead Yj side inflow, the direction of magnetization of electrode 2F and 3F becomes parastate or antiparallel state.If magnetisable material is used for metal conductor portion 1F, under the situation of antiparallel state, neticdomain wall is fixed to metal conductor portion and resistance uprises; And under parastate, remove neticdomain wall and resistance step-down from metal conductor portion 1F.When metal conductor portion 1F is made of namagnetic substance, neticdomain wall is not arranged among the metal conductor portion 1F.Yet when the direction of magnetization of electrode 2F and 3F was parallel to each other, metal conductor portion 1F showed ballistic conduction and resistance step-down; And when the direction of magnetization each other during antiparallel, spin diffusion and resistance take place uprise.
Then, measure the resistance between two electrode 2F and the 3F and be height or hang down the information that writes of reading according to measured resistance value.
Lead by the electricity that metal conductor portion 1F sets up between electrode 2F and the 3F.This metal conductor portion 1F is made of metal.Therefore, different with the carbon nano-tube that can not control conductance in the non-patent literature 4, metal conductor portion 1F has stable conductance.Be made of metal because comprise the metal conductor thin film of metal conductor portion 1F, so different with the carbon nano-tube of non-patent literature 4, the contact resistance between electrode 2F and electrode 3F becomes very little.Therefore, electrical characteristics are stable, and can solve the problem of the big contact resistance that produces between carbon nano-tube and electrode.
Metal conductor portion 1F is not less than higher value in the value of the length value of the electron spin diffusion among the metal conductor portion 1F and electron mean free path Λ across length L, observes the phenomenon that is called as ballistic conduction that can allow electronics to pass metal conductor portion 1F and not be scattered.By utilizing ballistic conduction, compare with the TMR element with conventional GMR element, can obtain to have the Magnetore sistance effect element (BMR (towards cunning MR)) of very high MR ratio.Therefore, can realize showing the storage array 700 of the output higher than conventional MRAM.
Embodiment 6
Figure 10 is the perspective view that illustrates according to the Magnetore sistance effect element 800 of embodiment 6; And Figure 11 is used to make perspective view according to the method for the Magnetore sistance effect element 800 of embodiment 6 in order to explanation.
Magnetore sistance effect element 800 comprise be not easy with respect to the external magnetic field be magnetized the rotation fixed bed (first electrode film) PL.Fixed bed PL comprises antiferromagnetism film AF and is formed on that antiferromagnetism film AF goes up and by the fixing magnetic film ML of antiferromagnetism film AF.On magnetic film ML, form non-magnetic insulating film NL.On non-magnetic insulating film NL, form free layer (second electrode film) FL that is magnetized easily and rotates with respect to the external magnetic field.Free layer FL is made of magnetic film.
Magnetore sistance effect element 800 comprises and penetrates nonisulated film NL and be electrically connected magnetic film ML and the cylindrical metal conductor C of free layer FL.Metallic conductor C is made of magnetisable material or namagnetic substance.The length of metallic conductor C from magnetic film ML to free layer FL is not more than the electron mean free path Λ of metallic conductor C under the operating temperature of magnetoresistance element 800.
The method that explanation is used to make the Magnetore sistance effect element 800 of such structure.At first, on substrate 8, form antiferromagnetism film AF and magnetic film ML successively.Then, forming thickness on magnetic film ML is the non-magnetic insulating film NL of the length of metallic conductor C.
Then, shine and form the through hole 27 that arrives magnetic film ML by being used to the field emission electron bundle of probe 26 from the scanning tunnel microscope (STM) that comprises carbon nano-tube.Use metallic conductor C filling vias 27 then.Then, on non-magnetic insulating film NL and metallic conductor C, form free layer FL.
Be used to adopt the probe 26 of the STM of field emission electron bundle irradiation to form, and can carry out meticulous safely and processing accurately by visiting nanotube.Therefore, can form and have 1nm to the 1000nm particularly fine size of 1nm to 100nm and the through hole 27 of shape.Therefore, can obtain to adopt magnetisable material to fill so that have the metallic conductor C of fine size and shape.
In having the metallic conductor C of the length L that is not more than electron mean free path A, observe can allow the phenomenon that is called as ballistic conduction that electronics is not scattered by metallic conductor C and wherein conductance with respect to the cross-sectional area of metallic conductor C and stepped be called as the phenomenon that the quantum electricity is led.
By utilizing ballistic conduction, by the direction of magnetization J2 of control free layer FL and the direction of magnetization J1 of fixed bed PL, magnetic head, record and reproducer, memory element and the storage array that can obtain to have the Magnetore sistance effect element of very high MR ratio and utilize this Magnetore sistance effect element.
As shown in figure 10, if magnetisable material is used for metallic conductor C, then when the direction of magnetization J1 antiparallel of the direction of magnetization J2 of free layer FL and fixed bed PL, neticdomain wall is fixed among the metallic conductor C that is made by magnetisable material, increases the resistance between free layer FL and the fixed bed PL thus.When the direction of magnetization J2 of free layer FL was parallel with the direction of magnetization J1 of fixed bed PL, neticdomain wall disappeared from metallic conductor C, and reduced the resistance between free layer FL and the fixed bed PL thus.When namagnetic substance is used for metallic conductor C, in metal conductor portion, do not produce neticdomain wall.According to the direction of magnetization of free layer FL and fixed bed PL is parallel to each other or antiparallel each other, that is, and and when the direction of magnetization is parallel to each other, the resistance step-down of metallic conductor C, show ballistic conduction, and when the direction of magnetization each other during antiparallel, resistance is owing to the generation of spin scattering uprises.Therefore, can obtain to have the Magnetore sistance effect element of high MR ratio.
Rotate so that cause the magnetization of free layer FL by the size that changes the external magnetic field, the differential seat angle of change between the direction of magnetization J2 of the free layer FL of the fixed magnetisation direction J1 of fixed bed PL and the rotation that is magnetized, and therefore change resistance between free layer FL and the fixed bed PL.By utilizing Magnetore sistance effect element 800, can be configured to the magnetic head of detection signal from magnetizing mediums.
In addition, by allow big electric current from free layer FL side inflow or from fixed bed PL side inflow so that make the parallel to each other or antiparallel each other of the direction of magnetization J1 of the direction of magnetization J2 of free layer FL and fixed bed PL, come writing information.By utilizing resistance between free layer FL and the fixed bed PL according to direction of magnetization J1, the J2 of free layer FL and fixed bed PL still antiparallel parallel to each other and the different facts is come sense information, and can realize memory element thus.
In addition, if the Magnetore sistance effect element 200A that is arranged to matrix shown in Figure 9 is replaced by Magnetore sistance effect element 800, then can realize big capacity storage array.This is owing to allow current vertical in the use of the Magnetore sistance effect element 800 of film Surface runoff, can obtain usually than allowing electric current to be parallel to the high density of Magnetore sistance effect element 200A of film Surface runoff.
By utilizing the quantum electricity to lead, the cross-sectional area by control metallic conductor C can obtain the electronic device the conductance deviation that produces under the situation of conductance with respect to the cross-sectional area linear change in large-scale production.
In addition, can use the semiconductor film that wherein electric current only flows in metallic conductor C when electric current flows on Magnetore sistance effect element 800 to replace non-magnetic insulating film NL with higher relatively resistance.
Figure 12 A is in order to the perspective view of explanation according to the electronic device 900 of embodiment 6.Figure 12 B is the perspective view that is used to make the method for electronic device 900 in order to explanation.
Electronic device 900 comprises electrode 2G and the 3G that is formed on the substrate 8; And be formed on the dielectric film 28 that contacts with 3G with electrode 2G between electrode 2G and the 3G.
On dielectric film 28, form the groove 29 that arrives electrode 3G from electrode 2G.With making metallic conductor 1G come filling groove 29 with electrode 2G contacts with 3G.The length of metallic conductor 1G is not more than at the mean free path Λ of electronics in metallic conductor 1G under the operating temperature of electronic device 900.
The method that explanation is used to make the electronic device 900 of such structure.At first, with the gap that has length L therebetween electrode 2G and 3G and formation dielectric film 28 on substrate 8 are set.Then, on dielectric film 28, form the groove 29 that arrives electrode 3G from electrode 2G by the mobile simultaneously probe 26 of the STM of carbon nano-tube that comprises of exposure field divergent bundle.Use metallic conductor 1G filling groove 29 then.
Receive when forming by spy when the probe 26 of the STM that is used to adopt the irradiation of field emission electron bundle, can carry out meticulous safely and processing accurately than pipe.Therefore, can form to have and be controlled at 1nm to the 1000nm particularly fine size of 1nm to 100nm magnitude and the groove 29 of shape.Therefore, can obtain to have the metallic conductor 1G that the employing magnetisable material of fine size and shape is filled.
In having the metallic conductor 1G of the length L that is not more than electron mean free path Λ, observe the quantum electricity and lead and ballistic conduction.
By utilizing the quantum electricity to lead, by the cross-sectional area of control metallic conductor 1G, in large-scale production, electronic device does not have the conductance deviation under the situation of conductance with respect to the cross-sectional area linear change.By utilizing ballistic conduction, by the direction of magnetization of control electrode 2G and 3G, magnetic head, record and reproducer, memory element, the storage array that can obtain to have the Magnetore sistance effect element of very high MR ratio and utilize this Magnetore sistance effect element.
Metallic conductor 1G is provided with concave part.Here, the concave part of metallic conductor is wherein along perpendicular to the cross-sectional area of the cross section of the metallic conductor length L direction part less than the cross-sectional area of other parts.The inventor determines and can form concave part by utilizing STM.As shown in FIG. 13A, simultaneously at probe, groove 39 is formed on basically the center of dielectric film 28 by use divergent bundle irradiation dielectric film 28 from electrode 2G side mobile STM on the direction of arrow 38; Then,, simultaneously at probe groove 41 is formed on the dielectric film 28 by use divergent bundle irradiation dielectric film 28, so that the top of groove 41 arrives the top of groove 39 from electrode 3G side mobile STM on the direction of arrow 40.Therefore, form groove 29A with the convex portions 37 shown in Figure 13 B.Afterwards, come filling groove 29A with metallic conductor 1G so that form metallic conductor 1G with concave part 37A.By forming concave part 37A, when electronic device is used for Magnetore sistance effect element,, then neticdomain wall is securely fixed on the position of concave part 37A of metallic conductor 1G if magnetisable material is used for metallic conductor 1G.
Example 1
On the Si substrate, SiO is set 2Layer.At SiO 2On the layer, come to form the pair of electrodes of making by Mo/Au with the interval of 50nm by sputter and EB photoetching.Then, on electrode, apply the catalyst of the fine granular that comprises Ni with about 5nm diameter.Then, under 800 ℃ by utilizing CH 4The CVD method grow in the horizontal and have the 50nm length and the about CNT of 1nm diameter so that across between two electrodes and form supporter.On CNT and two electrodes, the Au film that deposit 1nm is thick, thus on CNT, form metal conductor portion, and form electronic device thus.
Then, by the diameter of CNT is changed into 2nm, 5nm, 10nm and 20nm, prepare electronic device.Particularly, preparation: be to form the thick electronic device that metal conductor portion obtained of 2nm on the supporter of CNT of 2nm by growth diameter therein; Be to form the thick electronic device that metal conductor portion obtained of 5nm on the supporter of CNT of 5nm by growth diameter therein; Be to form the thick electronic device that metal conductor portion obtained of 5nm on the supporter of CNT of 10nm by growth diameter therein; And be to form the thick electronic device that metal conductor portion obtained of 5nm on the supporter of CNT of 20nm by growth diameter therein.When applying voltage and measure electricity when leading to these electronic devices under the operating temperature at 77K, demonstrate the quantum electricity and lead and be G=2e 2The integral multiple of/h, G=2e 2/ h depends on the size of the CNT that will use in described formula, wherein G represents conductance (electricity is led); E represents electron charge; And h represents Planck's constant.
Example 2
On the Si substrate, SiO is set 2Layer.At SiO 2On the layer, come to form electrode of making by Ta/NiFe/CoFe and the electrode of making by Ta/PtMn/CoFe with the interval of 10nm by sputter and EB photoetching.Then, deposit has the Co film of the thickness of 0.5nm as catalyst on these electrodes.Then, under 400 ℃ by utilizing CH 4The CVD method grow in the horizontal and have the 10nm length and the about CNT of 20nm diameter, thereby across between two electrodes and form supporter.
On CNT and two electrodes, the Co film that deposit 3nm is thick, thus on CNT, form metal conductor portion, and form the Magnetore sistance effect element 200A shown in Fig. 5 A and the 5B thus.So form Magnetore sistance effect element, to such an extent as to the Breadth Maximum of two electrodes is set to 120nm and width reduces towards metal conductor portion.Lead-in wire is connected to these electrodes and prepares the magnetic head 300 shown in Fig. 5 A and the 5B thus.When apply under the operating temperature at 300K specific voltage and external magnetic field from 1kOe change to-during 1kOe, demonstrate MR than being about 500%.
Example 3
By utilizing the magnetic head of preparation in example 2, preparation has the reproduction head part that 120nm reproduces track width.Prepare the recording/reproducing apparatus with recording head part and reproduction head part shown in Figure 6.Adopt CoCrPt-SiO 2Based perpendicular magnetic recording media is as magnetic recording media.Demonstrate under the operating temperature of 300K, can reproduce head part from this and reproduce with 200Gb/inch 2Packing density be recorded in information on the magnetic recording media.
Example 4
On the Si substrate, SiO is set 2Layer.At SiO 2On the layer, form electrode of making by Ta/NiFe/CoFe and the electrode of making by Ta/PtMn/CoFe with the interval of 15nm by sputter and EB photoetching.Then, deposit has the Co film of the thickness of 0.5nm as catalyst on these electrodes.Then, under 450 ℃ by utilizing CH 4The CVD method grow in the horizontal and have the 15nm length and the about CNT of 6nm diameter, thereby across between two electrodes and form supporter.
On CNT and two electrodes, the Co film that deposit 3nm is thick, thus on CNT, form metal conductor portion, and form the Magnetore sistance effect element 200A shown in Fig. 5 A and the 5B thus.So form Magnetore sistance effect element, to such an extent as to the Breadth Maximum of two electrodes is set to 80nm and width reduces towards metal conductor portion.Lead-in wire is connected to these electrodes and prepares Fig. 5 A and the shown magnetic head 300 of 5B thus.When apply under the operating temperature at 77K specific voltage and external magnetic field from 1kOe change to-during 1kOe, demonstrate MR than being about 1000%.
Example 5
On the Si substrate, form electrode of making by Ta/NiFe/CoFe and the electrode of making by Ta/PtMn/CoFe with the interval of 50nm by sputter.Then, deposit has the Co film of 0.5nm thickness on these electrodes.Then, under 450 ℃ by utilizing CH 4The CVD method grow in the horizontal and have the 50nm length and the about CNT of 20nm diameter, thereby across between two electrodes and form supporter.Here it should be noted that the thickness of two electrodes is made about 20nm.
On CNT and two electrodes, the Cu film that deposit 10nm is thick, thus on CNT, form metal conductor portion, and prepare the Magnetore sistance effect element 200A shown in Fig. 5 A and the 5B thus.So prepare Magnetore sistance effect element 200A, to such an extent as to the Breadth Maximum of two electrodes is set to 200nm and width reduces towards metal conductor portion.Lead-in wire is connected to these electrodes and prepares magnetic head thus.When apply under the operating temperature at 77K specific voltage and external magnetic field from 1kOe change to-during 1kOe, demonstrate MR than being about 100%.
By utilizing this magnetic head, preparation has the reproduction head part that 200nm reproduces track width.Prepare the recording/reproducing apparatus that head part and recording head part are reproduced in shown in Figure 6 having.Adopt CoCrPt-SiO 2Based perpendicular magnetic recording media is as magnetic recording media.Demonstrate under the operating temperature of 300K, can reproduce head part from this and reproduce with 120Gb/inch 2Packing density be recorded in information on the magnetic recording media.
Example 6
In example 4 on Fig. 5 A and the electrode 3F of the Magnetore sistance effect element 200A shown in the 5B of preparation, form the word line of making by Cu with electrode 3F insulation, and prepare the memory element 500 shown in Fig. 7 A to 7C thus.By changing the direction wherein allow electric current to flow into word line, information " 1 " or " 0 " are write among the electrode 3F, and detect resistance between two electrodes of Magnetore sistance effect element then.The information that demonstrates resistance basis " 1 " or " 0 " changes; The information that writes is non-volatile; This memory element can read to non-destructive and can repeat 10 10Inferior or more times information is write among the electrode 3F.
Example 7
Prepare the memory element 600 shown in Fig. 8 A and the 8B by Fig. 5 A and the Magnetore sistance effect element 200A shown in the 5B that utilizes preparation in example 4.Under operating temperature, be about 1.0 * 0 by making the current density that flows into metal conductor portion at 300K 7A/cm 2, and, write the information of " 1 " or " 0 " by shown in Fig. 8 A, allowing electric current 23 from electrode 2F side inflow or by shown in Fig. 8 B, allowing electric current 24 from having the electrode 3F side inflow of free layer with fixed bed.When the resistance value of check electrode 2F of Magnetore sistance effect element and 3F, demonstrate resistance and change according to the information of " 1 " or " 0 "; The information that writes is non-volatile.This memory element can read to non-destructive and can repeat 10 10Inferior or more times information is write in the Magnetore sistance effect element.
Example 8
As shown in Figure 9, the Magnetore sistance effect element 200A of the memory element 600 that will prepare in example 7 is arranged to matrix, so that prepare big capacity storage array 700.Under the operating temperature of 300K, by suitably select m capable * among the n row Magnetore sistance effect element 200A one, be about 1.0 * 10 by the density that makes the electric current that flows into lead and connecting line 7A/cm 2, and by allowing electric current, the information of " 1 " or " 0 " is write selected Magnetore sistance effect element 200A from the electrode 2F side inflow of Magnetore sistance effect element 200A or from its electrode 3F side inflow.When the resistance value of two electrodes of check Magnetore sistance effect element, demonstrate resistance and change according to the information of " 1 " or " 0 "; The information that writes is non-volatile.This memory element can read to non-destructive and can repeat 10 10Inferior or more times information is write in the Magnetore sistance effect element.
Example 9
On substrate, form the Ta basement membrane by sputter, thereby form antiferromagnetism film AF that makes by PtMn and the magnetic film ML preparation fixed bed PL that makes by CoFe.Then, on magnetic film ML, form the Al film by sputter, and utilize its autoxidation, preparing is the Al with 3nm thickness 2O 3The non-magnetic insulating film NL of oxide-film.
Then, as shown in figure 11, by to Al 2O 3The non-magnetic insulating film NL of oxide-film applies voltage, forms the meticulous hole with 5nm diameter by adopting field emission electron bundle from the probe 26 of the STM that comprises carbon nano-tube to shine.Then, form the CoFe film thereon with formation free layer FL by sputter, and simultaneously, be filled in above-mentioned Al with CoFe 2O 3The hole that forms on the oxide-film is to form metallic conductor C.Free layer FL and fixed bed PL are electrically connected to each other thus.The width that this element is patterned into 80nm by the EB photoetching is to prepare Magnetore sistance effect element shown in Figure 10 800.
Then, on the free layer FL of Magnetore sistance effect element 800, the word line of making by Cu through the dielectric film setting.Under the operating temperature of 300K, allow electric current to flow to word line causes the magnetization inversion of free layer FL with generation magnetic field then.When measuring the resistance of Magnetore sistance effect element 800, demonstrating resistance is parallel according to the direction of magnetization of the direction of magnetization of free layer FL and fixed bed PL or antiparallel changes.Determine that this element is as 500 operations of the memory element shown in Fig. 7 A and 7C.
Then, allow electric current flowing, so that current density is about 1.0 * 10 by filling with CoFe on the formed metallic conductor C in meticulous hole 7A/cm 2According to the direction that allows electric current to flow is from free layer FL side inflow or from fixed bed PL side inflow, determines to make the direction of magnetization counter-rotating of free layer FL; Change the fixed bed PL of this element and the resistance between the free layer FL; And this element is as 600 operations of the memory element shown in Fig. 8 A to 8B.
Example 10
On substrate, form the thick Ta basic unit of 5nm by the method identical, thereby form thick antiferromagnetism film AF of the 20nm that makes by PtMn and the thick magnetic film ML preparation fixed bed PL of 3nm/0.7nm/3nm that makes by CoFe/Ru/CoFe with example 9.Then, on magnetic film ML, form the Al film by sputter, and utilize its autoxidation, be prepared as Al with 5nm thickness 2O 3Oxide-film is as non-magnetic insulating film NL.
Then, as shown in figure 11, by to by Al 2O 3The non-magnetic insulating film NL of oxide-film applies voltage, forms the meticulous hole with 10nm diameter by adopting field emission electron bundle from the probe of the STM that comprises carbon nano-tube to shine.Then, by sputter Cu film thereon.Be formed on above-mentioned Al with the Cu filling 2O 3Hole on the oxide-film is to form metallic conductor C.Then, has the CoFe/NiFe/Ru/NiFe film of 1nm/2nm/0.4nm/2nm thickness to form free layer FL by sputter formation.This free layer FL and fixed bed PL are electrically connected to each other.The width that this element is patterned into 160nm by the EB photoetching is to prepare Magnetore sistance effect element shown in Figure 10 800.
Lead-in wire is connected to free layer FL and fixed bed PL, thus the preparation magnetic head.When apply fixed voltage and external magnetic field from 1kOe change to-during 1kOe, demonstrate MR than being about 200%.
By utilizing this magnetic head, preparation has the reproduction head part that 160nm reproduces track width.Prepare the recording/reproducing apparatus that head part and recording head part are reproduced in shown in Figure 6 having.Adopt CoCrPt-SiO 2Based perpendicular magnetic recording media is as magnetic recording media.Demonstrate under the operating temperature of 300K, can reproduce head part from this and reproduce with 150Gb/inch 2Packing density be recorded in information on the magnetic recording media.
On the free layer FL of Magnetore sistance effect element 800, the word line of making by Cu through the dielectric film setting.Then, under the operating temperature of 77K, allow electric current to flow to word line causes the magnetization inversion of free layer FL with generation magnetic field.When measuring the resistance of Magnetore sistance effect element 800, demonstrating resistance is parallel according to the direction of magnetization of the direction of magnetization of free layer FL and fixed bed PL or antiparallel changes.Determine that this element is as 500 operations of the memory element shown in Fig. 7 A to 7C.
Then, allow electric current flowing, so that current density is about 1.0 * 10 by filling with Cu on the formed metallic conductor C in meticulous hole 7A/cm 2Determine that according to the direction that allows electric current to flow be from free layer FL side inflow or from fixed bed PL side inflow, change the direction of magnetization of free layer FL; Change the fixed bed PL of this element and the resistance between the free layer FL; And with this element as the memory element shown in Fig. 8 A to 8B 600 operation.
Example 11
On dielectric substrate, form the Au film by sputter.Thereby the Au film is carried out composition form electrode 2G and 3G, shown in Figure 12 A with 100nm interval.Then, comprise SiO by sputtering to form between electrode 2G and the 3G 2The dielectric film 28 of film.
Shown in Figure 12 B, so that adopt field emission electron bundle irradiation dielectric film 28 that the probe 26 of the STM that comprises the CNT with 1nm diameter is scanned, form the groove with 2nm degree of depth 29 that arrives electrode 3G from electrode 2G by applying voltage on dielectric film 28 thereby remove SI semi-insulation film 28 to dielectric film 28.Then, form the Au film on the dielectric film 28 and fill the groove 29 that is formed on the dielectric film 28 by sputtering at, thereby form the metallic conductor 1G that is electrically connected to electrode 2G and 3G with the Au film.Thus, form electronic device 900.
In addition, by the diameter of the CNT of the probe 26 of STM is changed into 2nm, 4nm, 6nm, 8nm and 10nm, form electronic device.Particularly, preparation: have the electronic device that the probe of STM of the CNT of 2nm diameter forms the dark groove of 2nm and obtains with the metallic conductor filling groove by employing; Has the electronic device that the probe of STM of the CNT of 4nm diameter forms the dark groove of 2nm and obtains with the metallic conductor filling groove by employing; Has the electronic device that the probe of STM of the CNT of 6nm diameter forms the dark groove of 5nm and obtains with the metallic conductor filling groove by employing; The probe of STM that has the CNT of 8nm diameter by employing forms the electronic device that the dark groove of 5nm obtains; Form the electronic device that the dark groove of 5nm obtains with the probe of the STM of the CNT that has the 10nm diameter by employing.
When applying voltage to these electronic devices and measure each electricity when leading, determine to demonstrate the size that depends on metallic conductor separately, the quantum electricity is led and is G=2e 2The integral multiple of/h.
In addition, definite direction of magnetization by control electrode 2G and 3G changes the resistance between electrode 2G and the 3G, and electronic device is operated as Magnetore sistance effect element and memory element with high MR ratio.
Example 12
On substrate, form the Ta basement membrane by sputter, thereby form the antiferromagnetism film AF that makes by PtMn and form fixed bed PL by the magnetic film ML that NiFe makes.Then, on magnetic film ML, form the Al film by sputter, and utilize its autoxidation, prepare Al with 3nm thickness 2O 3Oxide-film is as non-magnetic insulating film NL.
Then, as shown in figure 11, by to Al 2O 3The non-magnetic insulating film NL of oxide-film applies voltage, shines and forms the meticulous hole with 5nm diameter by being used to the field emission electron bundle of probe from the STM that comprises carbon nano-tube.Then, form NiFe thereon with formation free layer FL by sputter, and simultaneously, be formed on above-mentioned Al with the NiFe filling 2O 3Hole on the oxide-film to be forming metallic conductor C, and free layer FL and fixed bed PL are electrically connected to each other then.The width that this element is patterned into 80nm by the EB photoetching is to prepare the Magnetore sistance effect element 800 shown in Figure 10.
Then, on the free layer FL of Magnetore sistance effect element 800, arrange the word line that constitutes by Cu via dielectric film.Under the operating temperature of 300K, allow electric current to flow to word line causes the magnetization inversion of free layer FL with generation magnetic field then.When measuring the resistance of Magnetore sistance effect element 800, it is parallel demonstrating the direction of magnetization according to the direction of magnetization of free layer FL and fixed bed PL or antiparallel changes resistance.Determine that this element is as 500 operations of the memory element as shown in Fig. 7 A to 7C.
Then, allow electric current flowing, so that current density is about 1.0 X 10 by filling with CoFe on the formed metallic conductor C in meticulous hole 7A/cm 2According to allowing electric current is from free layer FL side inflow or from fixed bed PL side inflow, determines the direction of magnetization of counter-rotating free layer FL, changes the resistance between fixed bed PL and the free layer FL; And with this element as the memory element as shown in Fig. 8 A to 8B 600 operation.
Can apply the present invention to: have the electronic device of the precise shape of the nanometer scale of being controlled at, Magnetore sistance effect element with precise shape of the nanometer scale of being controlled at; Utilize magnetic head, record/playback device, memory element and the storage array of this Magnetore sistance effect element; Be used to make the method for electronic device; With the method that is used to make Magnetore sistance effect element.

Claims (37)

1, a kind of electronic device comprises:
First electrode and second electrode; And
Be electrically connected to the metal conductor thin film of described first electrode and described second electrode,
Wherein, described metal conductor thin film comprises metal conductor portion, and it is across described first electrode and described second gaps between electrodes from seeing perpendicular to the direction of the basal surface of described first electrode and described second electrode;
Described metal conductor portion be not more than the mean free path Λ of the electronics in the described metal conductor portion under the operating temperature of described electronic device across length L;
Make described electronic device by following step:
On substrate, form described first electrode and described second electrode to have described gap across length L;
Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across from described first electrode seen perpendicular to the direction of described basal surface and the supporter of described second gaps between electrodes;
By forming metal conductor portion in the described metal conductor thin film of deposit on the described supporter and on described first electrode and described second electrode; And
Remove described supporter after the described metal conductor thin film of deposit.
2, electronic device according to claim 1 is wherein made described electronic device by the described metal conductor thin film of deposit and the technology of removing described substrate then.
3, electronic device according to claim 1 and 2, wherein said first electrode and described second electrode comprise magnetisable material.
4, electronic device according to claim 1 and 2, wherein said first electrode and described second electrode comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.
5, electronic device according to claim 1 and 2, wherein said metal conductor thin film comprises magnetisable material.
6, electronic device according to claim 1 and 2, wherein said metal conductor thin film comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.
7, electronic device according to claim 1 and 2, the cross-sectional area S3 of the cross-sectional area S1 of wherein said first electrode, the cross-sectional area S2 of described second electrode and described metal conductor portion satisfies following relation:
S3＜S1 and S3＜S2.
8, electronic device according to claim 7, the cross-sectional area S3 of wherein said metal conductor portion is not less than 1nm 2And be not more than 1.0 * 10 6Nm 2
9, electronic device according to claim 1 and 2, wherein said supporter comprises carbon nano-tube.
10, electronic device according to claim 9, the step that wherein forms described supporter comprises: will be used to promote that the formation catalyst for reaction of described carbon nano-tube is arranged on described first electrode and described second electrode; And the supporter that comprises described carbon nano-tube by the formation of chemical vapor deposition (CVD) method.
11, electronic device according to claim 10, the step of the described supporter of wherein said formation comprise that formation comprises the described supporter of described carbon nano-tube, applies different voltage to described first electrode with described second electrode respectively simultaneously.
12, according to claim 10 or 11 described electronic devices, wherein said first electrode and described second electrode comprise magnetisable material; And described catalyst comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.
13, electronic device according to claim 1 and 2, but wherein said supporter comprises the protein nano wiring of self-organizing and at least one of silicon nanometer wiring.
14, electronic device according to claim 1 and 2, the step that wherein forms described metal conductor portion comprises by the physical vapor deposition (PVD) method comes the described metal conductor thin film of deposit.
15, electronic device according to claim 1 and 2, the operating temperature of wherein said electronic device are not less than 4.2K and are not more than 523K.
16, a kind of electronic device comprises:
First electrode and second electrode; And
Metallic conductor is across described first electrode and described second gaps between electrodes;
Wherein, described metallic conductor is not more than the mean free path Λ of the electronics in the described metallic conductor under the operating temperature of described electronic device across length L;
Make described electronic device by following method:
On substrate, form described first electrode and described second electrode to have described gap across length L;
Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across the supporter of described first electrode and described second gaps between electrodes;
The described metallic conductor of deposit on described supporter; And
Remove described supporter behind the described metallic conductor of deposit.
17, a kind of Magnetore sistance effect element comprises:
First electrode and second electrode that comprise magnetisable material; And
Be electrically connected to the metal conductor thin film of described first electrode and described second electrode,
Wherein said metal conductor thin film comprises across from described first electrode seen perpendicular to the direction of the basal surface of described first electrode and described second electrode and the metal conductor portion of described second gaps between electrodes;
Described metal conductor portion be not more than the length value of under the operating temperature of the described Magnetore sistance effect element electron spin in described metal conductor portion diffusion and the higher value in the value of the mean free path Λ of the electronics in the described metal conductor portion under the operating temperature of described Magnetore sistance effect element across length L;
The cross-sectional area S3 of the cross-sectional area S1 of described first electrode, the cross-sectional area S2 of described second electrode and described metal conductor portion satisfies following relation: S3＜S1 and S3＜S2;
Make this Magnetore sistance effect element by following method:
On substrate, form described first electrode and described second electrode to have described gap across length L;
Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across from described first electrode seen perpendicular to the direction of described basal surface and the supporter of described second gaps between electrodes;
By on the described supporter, the described metal conductor thin film of deposit forms described metal conductor portion on described first electrode and described second electrode; And
Remove described supporter after the described metal conductor thin film of deposit.
18, Magnetore sistance effect element according to claim 17 is wherein made described Magnetore sistance effect element by the described metal conductor thin film of deposit and the technology of removing described substrate then.
19, Magnetore sistance effect element according to claim 17, wherein said first electrode comprises free layer, wherein magnetization is rotated with respect to the external magnetic field easily; Described second electrode comprises fixed bed, and wherein magnetization is not easy to rotate with respect to the external magnetic field; And the magnetization of described free layer is a direction perpendicular to described external magnetic field to be detected easily.
20, Magnetore sistance effect element according to claim 19, wherein said fixed bed comprises the antiferromagnetism film; And be formed on the described antiferromagnetism film and by the fixing magnetic film of described antiferromagnetism film, wherein said magnetic film is electrically connected to described metal conductor portion.
21, Magnetore sistance effect element according to claim 17, wherein said supporter comprises carbon nano-tube.
22, Magnetore sistance effect element according to claim 21, the step that wherein forms described supporter comprises: will be used to promote that the formation catalyst for reaction of carbon nano-tube is arranged on described first electrode and described second electrode; And the described supporter that comprises described carbon nano-tube by the formation of chemical vapor deposition (CVD) method.
23, Magnetore sistance effect element according to claim 22, the step of the described supporter of wherein said formation comprise that formation comprises the described supporter of described carbon nano-tube, applies different voltage to described first electrode with described second electrode respectively simultaneously.
24, according to claim 22 or 23 described Magnetore sistance effect elements, wherein said catalyst comprises at least a element that is selected from the group of being made up of Fe, Co and Ni.
25, Magnetore sistance effect element according to claim 17, but wherein said supporter comprises the protein nano wiring of self-organizing and at least one in the wiring of silicon nanometer.
26, Magnetore sistance effect element according to claim 17, the step that wherein forms described metal conductor portion comprises by the physical vapor deposition (PVD) method comes the described metal conductor thin film of deposit.
27, Magnetore sistance effect element according to claim 17, wherein said metal conductor thin film comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.
28, Magnetore sistance effect element according to claim 17, wherein said first electrode and described second electrode comprise at least a element that is selected from the group of being made up of Fe, Co and Ni.
29, Magnetore sistance effect element according to claim 17, the operating temperature of wherein said Magnetore sistance effect element are not less than 4.2K and are not more than 523K.
30, a kind of magnetic head comprises:
As any described Magnetore sistance effect element in the claim 17 to 29;
First goes between, and is electrically connected to described first electrode of described Magnetore sistance effect element; With
Second goes between, and is electrically connected to described second electrode of described Magnetore sistance effect element.
31, a kind of record and/or reproducer comprise:
Be used for recording head in the magnetizing mediums recorded information; And
Be used to reproduce the reproduction head of the information that is recorded on the magnetizing mediums,
Wherein said reproduction head is a magnetic head as claimed in claim 30.
32, a kind of memory element comprises: Magnetore sistance effect element as claimed in claim 17,
Described first electrode of wherein said Magnetore sistance effect element comprises free layer, and wherein magnetization is rotated with respect to the external magnetic field easily, and
Described second electrode comprises fixed bed, and wherein magnetization is not easy with respect to the rotation of described external magnetic field,
Described memory element also comprises:
Produce the word line of external magnetic field according to electric current, this external magnetic field becomes parallel the direction of magnetization of described free layer and described fixed bed or antiparallel; And
The electric current supply device is used for providing described electric current to described word line,
Wherein, be parallel to each other or antiparallel, information is write described Magnetore sistance effect element by the direction of magnetization is changed into according to the external magnetic field that from described word line, is produced; And
By measuring the resistance of Magnetore sistance effect element, read the information that writes described Magnetore sistance effect element.
33, a kind of memory element comprises:
As any described Magnetore sistance effect element in the claim 17 to 29, and
The electric current supply device, be used for to described Magnetore sistance effect element be provided at described metal conductor portion from described first electrode stream to the electric current of described second electrode or described metal conductor portion from the electric current of described second electrode stream to described first electrode,
Wherein by making the sense of current counter-rotating of the described metal conductor portion that flows to described Magnetore sistance effect element, changing into parallel or antiparallel with the direction of magnetization of described second electrode described first electrode, thereby information is write described Magnetore sistance effect element; And by measuring and the resistance value of different described Magnetore sistance effect elements is read the information that writes described Magnetore sistance effect element according to the direction of magnetization of described first electrode and described second electrode.
34, memory element according to claim 33 is 1.0 * 10 by the current density that described electric current supply device offers the electric current of described Magnetore sistance effect element wherein 5A/cm 2Or it is higher.
35, a kind of storage array comprises:
Be arranged to matrix as any described Magnetore sistance effect element in the claim 17 to 29;
The wiring that is used for independently information being write described Magnetore sistance effect element and reads described information;
R/w cell, be used for reversing to change into parallel or antiparallel with the direction of magnetization of described second electrode described first electrode, independently information write described Magnetore sistance effect element through described wiring by the sense of current that makes the described metal conductor portion that flows into described Magnetore sistance effect element; And
Read the unit, be used for by measuring and the resistance value of each different Magnetore sistance effect elements is read the information that writes described Magnetore sistance effect element independently through described wiring according to the direction of magnetization of described first electrode and described second electrode.
36, a kind of method that is used to make electronic device, this method comprises:
On substrate, form first electrode and second electrode, have gap L therebetween;
Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across from described first electrode seen perpendicular to the direction of the basal surface of described first electrode and described second electrode and the supporter of described second gaps between electrodes; And
Form across described first electrode of on direction, being seen and the metal conductor portion of described second gaps between electrodes by method perpendicular to described basal surface at depositing metal conductor thin film on the described supporter, on described first electrode and described second electrode;
Wherein said gap L is not more than the mean free path Λ at the electronics in described metal conductor portion under the operating temperature of described electronic device;
Remove the technology of described supporter by the described metal conductor thin film of deposit then and make described electronic device.
37, a kind of method that is used to make Magnetore sistance effect element, this method comprises:
On substrate, form first electrode and second electrode that comprises magnetisable material, have gap L therebetween;
Formation comprise be selected from the group of forming by the wiring of nanotube and nanometer at least one and across from described first electrode seen perpendicular to the direction of the basal surface of described first electrode and described second electrode and the supporter of described second gaps between electrodes; And
By on the described supporter, form across described first electrode of on direction, being seen and the metal conductor portion of described second gaps between electrodes perpendicular to the basal surface of described first electrode and described second electrode in the method for depositing metal conductor thin film on described first electrode and described second electrode
Wherein said gap L is not more than the higher value in the value at the mean free path Λ of the electronics of described metal conductor portion under the length value of the electron spin in described metal conductor portion diffusion under the operating temperature of described Magnetore sistance effect element and the operating temperature at described Magnetore sistance effect element; And
The cross-sectional area S3 of the cross-sectional area S1 of described first electrode, the cross-sectional area S2 of described second electrode and described metal conductor portion satisfies following relation: S3＜S1 and S3＜S2;
Remove the technology of described supporter by the described metal conductor thin film of deposit then and make described Magnetore sistance effect element.
CNB2004800176696A 2003-06-25 2004-06-24 Magnetore sistance effect element and manufacture method thereof Expired - Fee Related CN100544050C (en)

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