JPH09307148A - High-temperature superconducting single crystalline type vortex flow element and its forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize miniaturization, high speed and high frequency operation of a vortex flow element, by arranging a high-temperature superconducting single crystalline small object on the surface of a substrate, and arranging an ab surface containing an (a) axis and a (b) axis perpendicularly to the substrate. SOLUTION: Crystal is grown on the surface of an NdGaO3 single crystalline substrate 11, orientation rectangular to the (a) axis direction is generated to the substrate surface, YBa2 Cu3 O7-x is deposited, and the film thickness T is formed. Photoresist is spread on a superconducting single crystalline film, and patterning is performed perpendicularly to both ends of a vortex transition region 12 while containing a vortex driving current supplying line 13. A driving current supplying line 15 is patterned in parallel to the vortex transition region 12, perpendicularly intersecting both ends of an input signal line 14. The patterned superconducting single crystallin film is etched, and a vortex flow element structure is formed. Therefore, a superconducting vortex flow element having a small size.high output power.high response frequency and its peripheral circuit are provided by a simple method of low costs.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vortex flow device using an oxide high temperature superconductor single crystal. More specifically, the phenomenon that a magnetic flux quantum formed by a magnetic field intruding into a superconductor from the outside, that is, a vortex (vortex) moves at high speed in a high-temperature superconductor single crystal by a vortex drive current orthogonal to the magnetic field (vortex flow). The present invention relates to a high-temperature superconducting single-crystal vortex flow element as an operating principle and a method for manufacturing the same.

[0002]

2. Description of the Related Art Electronic devices using superconductors have essentially low power consumption and ultra-fast switching speeds. If a superconducting element that has the same operation method as a semiconductor transistor while utilizing this characteristic and that can amplify a weak electric signal is obtained, a high-performance superconducting circuit can be realized simply by replacing the element in the semiconductor circuit with a superconducting element. become.

The following three types have been proposed so far as superconducting amplifying elements having such a possibility. (1) An element that applies the electric field effect, (2) an element that applies carrier (charge) injection, and (3) an element that applies vortex. These control the electric field that carries the signal, the carrier, or the vortex to output the signal. It is an attempt to amplify. Hereinafter, each superconducting amplifier element will be described.

(1) Regarding the superconducting amplifying element based on the electric field effect, a report by Manhart et al. Is known.
(J. Mannhart et al .: Phys. Rev. Lett. 67 (1991) 2099)
. When the voltage V is applied to the MIS capacitor C in which the metal electrode M is provided on the semiconductor surface S via the insulator I, the charge Q = CV is induced on the semiconductor surface S. When this electric charge Q becomes about the same as the amount of electric charge originally existing on the semiconductor surface, the electric conduction on the semiconductor surface changes greatly with V,
Transistor operation becomes possible.

FIG. 9 shows an example of a field effect element utilizing this effect. The oxide high-temperature superconductor has a carrier density as low as 1/10 to 1/100 of metal, and the electric field effect is more likely to occur than metal. However, since it is 100 to 1000 times as large as that of a semiconductor, and it is difficult to control the junction surface of the MIS structure with good reproducibility, a sufficiently stable device has not been produced so far.

(2) Abe et al. Have reported a carrier injection type device. An example of the structure of this carrier injection type device is shown in FIG. 10 (H. Abe et al .: Supercon
d. Sci. & Technol. 4 (1991) 598). This is to replace the base region of the semiconductor bipolar transistor with a superconductor to reduce the electric resistance and obtain higher performance. For example, a grounded-emitter current amplification factor of 10 is obtained in an element in which an n-type semiconductor substrate doped with Nb is used as an emitter and a (Ba, Rb) BiO ₃ superconductor is used as a base. However, although three types of materials are used in the fabrication of this element, a technique for controlling two bonding interfaces is important, but there is still a problem in reproducibility. Also, the superconductor has a low critical temperature and cannot operate at the liquid nitrogen temperature.

(3) A report by Marten et al. Is known about an element to which vortex is applied. Fig. 11 is an example of the device structure using this vortex motion (J.
S. Martens et al .: IEEE Trans.Appl.Supercond. 1 (199
1) 95). The two superconductors are weakly coupled (weakly coupled) by the finely processed superconductor. When a bias current is made to flow between the two superconductors and a current is made to flow in the input signal line, a magnetic field is induced, but this magnetic field becomes a vortex and penetrates into the weak coupling part. Since the Lorentz force acts on the vortex by the vortex drive current, the vortex flows at a high speed through the weak coupling portion, and the vortex flow voltage V _f is generated between the two superconductors. Since V _f is proportional to the vortex flow velocity and the vortex density, the magnitude of V _f can be controlled by the input signal.

That is, an amplifier which receives a current signal and outputs a vortex flow voltage can be realized. V _f
Although a device having a voltage of 10 mV has been obtained as a result, there is a problem that the device size increases to several mm.
As described above, although there is a problem in reducing the size of the element, it is possible to obtain a power gain, which is closer to practical use than other terminals.

On the other hand, recently, the principle of a new superconducting element having an amplification characteristic has been proposed (T. Yamashita and M. Ta.
chiki: Proc. of International Superconductive Ele
ctronic Conference (ISEC95) Sept. 18-21 (1995)).
This utilizes the anisotropic crystal structure and physical properties and vortex peculiar to a high-temperature superconductor single crystal, and FIG. 12 shows the device structure and operation principle.

First, a vortex drive current is made to flow in advance in the c-axis direction of a single crystal small piece made of a high-temperature superconductor, and a magnetic field is generated by causing a current I _c to flow in an input signal current line wound around the small piece. The generated magnetic field is a
It enters as an anisotropic vortex parallel to the b-plane. If there is no fine crystal defect that is a pinning point of the vortex in the small piece, the vortex will flow in the ab plane at high speed due to the Lorentz force. Thus, a vortex flow voltage V _f is generated at both ends of the small piece. In a high-temperature superconductor single crystal, the vortex flow rate is high, so V _f is also large, and by controlling this with an input signal, a high amplification function can be realized.

The principle of this element is similar to the above (3) vortex flow element, but the element can be downsized, the output can be increased, and the speed can be increased as compared with the conventional element. That is, the width (W) in the ab plane direction of the single crystal piece that becomes the vortex traveling region is more than twice the magnetic field penetration length λ _c when a magnetic field is applied parallel to the c axis, and the length in the c axis direction ( L) may be at least twice the magnetic field penetration length λ _ab when a magnetic field is applied parallel to the ab plane.

Here, as a material, La _2-x Sr _x Cu _{3 is used.}
O (LSCO) has been proposed, but in this case λ _ab =
Since the device size is as small as 0.08 μm and λ _c = 0.8 μm, the device size is about 2 μm, and the device can be made much smaller than the vortex flow device. Further, since the critical current value in the c-axis direction also does not use weak coupling, it is -10 ¹¹ A / m ^2, which is an order of magnitude larger than that of the conventional device, and high output can be achieved. Furthermore, as a feature of high-temperature superconductivity, the vortex flow speed in the ab plane is -10 ⁶ m / s, so the switching speed becomes faster along with the miniaturization of the device, enabling higher speeds and higher frequencies. The characteristics of the vortex flow element will be greatly exceeded.

[0013]

However, there are many problems to be solved in order to realize the high temperature superconductor type vortex flow element of this principle. That is, in order to realize the device, a good-quality single crystal piece that can be energized in the c-axis direction and has a width of about 2λ _c, which is a vortex traveling region, and a vortex drive current supply line are joined to this, and a c It is necessary to have an element structure in which an input signal line for introducing a vortex is arranged orthogonally to the axial direction. Further, the drive current supply line and the input signal line need to be made of a high temperature superconductor itself rather than a metal normal conductor in consideration of the problems of heat loss and signal distortion.

A method for producing the above-mentioned device at a low cost by a simple method has not been disclosed in the above literature and is still in a search state.

In view of the above problems, the present invention aims to provide a novel and practical structure of a vortex flow element and a method for manufacturing the vortex flow element based on the principle of vortex flow, using a high-quality high-temperature superconductor single crystal. And

[0016]

In order to solve the above problems, a high temperature superconducting single crystal body type vortex flow element according to the present invention (hereinafter referred to as "vortex flow element").
Then, a high-temperature superconductor single crystal body and a pair of electrodes bonded to both ends of the high-temperature superconductor single crystal body in the c-axis direction,
A high-temperature superconductor, comprising: an exciting means for applying a magnetic field to the single-crystal small body of the high-temperature superconductor in a direction orthogonal to the c-axis; and a current flowing in the superconducting state between the pair of electrodes by the exciting means. In a vortex flow element that generates a voltage between the pair of electrodes when a magnetic field is applied to the small body, the high temperature superconductor single crystal small body is provided on a substrate surface, and the a-axis of the high temperature superconductor single crystal small body is provided. And an ab plane including the b-axis are provided orthogonal to this substrate.

The high-temperature superconductor single crystal body in the vortex flow device of the present invention has a crystal structure (unit cell) in which the a and b axes are substantially equal in length and the c axis is long. The CuO ₂ layer in which the superconducting carriers can move freely extends in the a and b axis directions, but this C
It has a structure in which a uO ₂ layer and a semiconductor block layer are stacked, and exhibits anisotropic electrical characteristics in which the superconducting carriers are hard to move in the c-axis direction. As shown in FIG. 12, when a vortex driving current is made to flow in the c-axis direction of the high-temperature superconductor single crystal body in advance and a magnetic field is applied by the excitation means placed outside the body, the magnetic field becomes an anisotropic vortex. Then, it penetrates parallel to the ab plane of the single crystal. In this case, the vortex is very easy to move in the a and b axis directions due to the anisotropic property described above, and the ab at high speed due to the Lorentz force.
Flow in the plane. As a result, a large vortex flow voltage V _f is generated across the c-axis of the small body.

In the present invention, the high temperature superconductor single crystal small body to which a magnetic field is applied by the exciting means is provided on the substrate surface so that the ab plane of the small body is orthogonal to the substrate. As a result, a high-temperature superconductor single crystal body (that is, a vortex traveling region) to which a magnetic field is applied by the exciting means of the vortex flow element can be provided on the substrate plane, so that the width of the vortex traveling region (W ) And the length (L) of the vortex traveling region are easily processed, and the manufacturing is easy, and mass production at low cost is possible.

In the vortex flow element of the present invention, the width (W) in the direction orthogonal to the c-axis of the high temperature superconductor single crystal small body (that is, the vortex traveling region) to which the magnetic field is applied by the exciting means and the c-axis direction. The length (L) needs to satisfy a certain condition. Under the conditions shown in FIG. 12, the width (W) in the ab in-plane direction of the single crystal piece that becomes the vortex traveling region is twice the magnetic field penetration length λ _c when a magnetic field is applied parallel to the c-axis. As described above, the length (L) in the c-axis direction is ab
It is sufficient if it is at least twice the magnetic field penetration length λ _ab when a magnetic field is applied parallel to the plane. However, in the present invention, as a result of intensive studies, the width (W) of the vortex traveling region satisfies W ≦ 5λ _c with respect to the magnetic field penetration length λ _c when a magnetic field is applied parallel to the c-axis, In addition, if the length (L) of the vortex region satisfies the condition that L ≧ λ _ab with respect to the magnetic field penetration length λ _ab when a magnetic field is applied parallel to the ab plane, a sufficient critical current density is obtained. It has been confirmed that high performance such as ultra high speed switching characteristics can be realized.

The exciting means in the vortex flow element of the present invention may be any one that applies a magnetic field in a direction orthogonal to the c-axis of the high temperature superconducting body, and surrounds the vortex traveling region of the body on the substrate. All you need is a position. For example, since a magnetic field is generated around a conducting wire,
An exciting means may be provided by providing a conductor wire parallel to the vortex traveling region. Such a conductive wire can be easily obtained by patterning on the substrate. Preferably, the exciting means is provided on the same substrate surface on which the high temperature superconductor single crystal bodies are provided. Further, the exciting means may be provided so as to overlap the high-temperature superconductor single-crystal small body with the insulating layer interposed therebetween.

The electrodes in the vortex flow device of the present invention can also be easily obtained by patterning on the substrate. Therefore, preferably, the electrode is provided on the same substrate surface on which the high-temperature superconductor single crystal body is provided.

In the method of manufacturing a vortex flow element according to the present invention, a high-temperature superconductor single crystal body, a pair of electrodes bonded to both ends of the high-temperature superconductor single crystal body in the c-axis direction, and a high-temperature superconductor body. Exciting means for applying a magnetic field to the single crystal body in a direction orthogonal to the c-axis, and a high-temperature superconductor single crystal small body is provided by the exciting means while a current is flowing in a superconducting state between the pair of electrodes. In a method of manufacturing a vortex flow element that generates a voltage between a pair of electrodes when a magnetic field is applied to a body, a high-temperature superconductor single crystal film has an ab plane including an a-axis and a b-axis on the substrate. The film is formed so as to be orthogonal to.

That is, a single crystal film is formed on a suitable substrate so that the ab plane of the high temperature superconducting single crystal film is orthogonal to the substrate surface. In this case, the superconducting single crystal film needs to be a single crystal film epitaxially grown on the substrate with very few defects.

Therefore, preferably, a high-temperature superconductor single crystal film is formed on the surface of a substrate having at least a predetermined crystal orientation by a liquid-phase epitaxial method or a vapor-phase epitaxial method to form an a-axis and a b-axis. It is obtained by forming a film so that the surface to be formed is orthogonal to the surface of the substrate.

Therefore, in the substrate on which the high-temperature superconductor single crystal film is formed, a crystal plane that promotes liquid-phase or vapor-phase epitaxial growth should be exposed so that the ab plane of the high-temperature superconductor single crystal film is orthogonal to the substrate surface. . For example, in addition to the one in which the (110) plane of the NdGaO ₃ single crystal substrate is exposed, LaGaO
₃ , SrTiO ₃ , LaAlO ₃ or a specific surface of a single crystal substrate, in which a small amount of another element, such as Gd, is added to these to improve the substrate characteristics, is used. In this case, a crystal structure having a lattice constant close to that of the high-temperature superconducting single crystal, a thermal expansion coefficient close to that of the high-temperature superconducting single crystal, and no phase transition at a crystal deposition temperature or lower is preferable. Also, PrBa ₂ Cu ₃ O _7-x , which has the same crystal structure as the high-temperature superconductor but does not exhibit superconducting properties, and the high-temperature superconductor single crystal itself that controls the carrier to suppress the critical temperature T _c are used. You can

As the high temperature superconducting material in the vortex flow element of the present invention, a material having an anisotropic crystal structure, physical properties and the like peculiar to the high temperature superconductor single crystal is appropriately selected. In particular, a superconductor having a perovskite type crystal structure is preferably used. From the viewpoint of speeding up and downsizing of the device, a material having a high critical temperature and a small penetration length λ _ab , λ _c is desirable. Therefore, for example, LSCO type, YBa ₂ Cu ₃
O _7-x (YBCO), RBa ₂ in which Y is replaced by another element
Cu ₃ O _7-x (R = rare earth) and the like are promising. In addition to these, Y- and R-based 124 structural materials and Bi-based (for example, Bi-based
₂ Sr ₂ CaCu ₂ O ₈ ), Tl-based (eg, Tl ₂ B
_{a 2 Ca n-1 Cu n} O y (n = 1,2,3,4)), H
A g-type (for example, Hg ₂ Ba ₂ Ca ₂ Cu ₃ O _{8 + x} ) or the like is also used depending on the application.

The formed film is subjected to fine processing to form a vortex traveling region. Here, the vortex drive current flowing in the vortex travel region is made to flow in the c-axis direction, and the width W of the travel region satisfies W ≦ 5λ _c and the length L thereof satisfies L ≦ λ _ab .

The exciting means, electrodes and the like may be formed by microfabrication on a single crystal film formed at the same time as the running region, or after forming the running region, a separate vapor phase method or liquid phase method may be used. It may be used in combination with the running area. In the latter case, it is not necessary that the high-quality single crystal film is used for forming the exciting means and the electrode, as long as the critical current density is high. In this way, a high-quality high-temperature superconducting single crystal film with a-axis or b-axis orientation can be used to manufacture a vortex flow element based on a novel principle.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a high-temperature superconductor single crystal small body is provided on a substrate surface, and an ab plane including the a-axis and the b-axis of this high-temperature superconductor single-crystal small body is formed on this substrate. In contrast, they are provided orthogonally. As a result, the vortex traveling region of the vortex flow element can be provided on the plane of the substrate. Therefore, in manufacturing, the width W in the direction orthogonal to the c-axis and the length L of the vortex traveling region in the c-axis direction L.
Can be easily processed and easily manufactured, and can be mass-produced at low cost.

To form a specific high-temperature superconductor single crystal body, a high-temperature superconductor single crystal film may be formed on a substrate so that the ab plane including the a-axis and the b-axis is perpendicular to the substrate surface. .
This film formation is preferably performed by a liquid phase epitaxial method or a vapor phase epitaxial method. Therefore, as the substrate, a substrate in which a crystal plane that promotes liquid phase or vapor phase epitaxial growth is exposed so that the ab plane of the high temperature superconducting single crystal film is orthogonal to the substrate surface is used.

Further, a pair of electrodes joined to both ends of the high-temperature superconductor single crystal body in the c-axis direction, and an excitation means for applying a magnetic field to the high-temperature superconductor single crystal body in a direction orthogonal to the c-axis. Can be arranged on the same substrate, and can be easily manufactured by processing such as ordinary patterning and etching.

In the vortex flow element constructed as described above, the flow voltage generated in the vortex traveling region is proportional to the product of the number of vortexes flowing in the traveling region and the flow velocity. The number of vortexes is controlled by the input signal current, and the flow velocity is determined by the magnitude of the vortex drive current flowing in the traveling area and the viscous resistance in the superconductor. The superconducting critical current value in the traveling region is proportional to the critical current density in the c-axis direction in the traveling region and the width and thickness of the traveling region.

Therefore, by appropriately setting the magnitude of the drive current,
By changing the input signal, a large modulated flow voltage can be taken out across the traveling region. It is also possible to fabricate a device with higher output by increasing the number of traveling regions or fabricating a device having a thickness or length appropriately changed.

[0034]

The present invention will be described below in more detail with reference to examples. Example 1 (Manufacturing 1 of Vortex Flow Element) FIG. 1 is an explanatory diagram showing the configuration of an example of the vortex flow element of the present invention. As shown in the figure, on the (110) plane of the NdGaO ₃ single crystal substrate (11), a crystal was grown by a liquid phase epitaxial method and a-axis oriented (orientation orthogonal to the substrate surface in the a-axis direction) YBa. ₂ Cu ₃ O
Deposit _7-x (hereinafter referred to as YBCO single crystal thin film) to 5 μm,
Then, the film thickness (T) was set to 1 μm by polishing and etching. Therefore, the obtained YBCO single crystal film was b
It has a crystal structure in which the axis and the c-axis are parallel to the substrate surface.

A photoresist is applied on this superconducting single crystal film, and the photoresist is formed by ordinary photolithography.
5 μm length (L) and desired width (W) as shown
A vortex running area (12) having and this running area
Patterning was performed into a substantially U-shape including the vortex drive current supply line (13) arranged orthogonally to both ends of (12). At the same time, the input signal line (14) arranged in parallel with the vortex traveling region (12) and the drive current supply line (15) arranged orthogonal to both ends of the input signal line (14) were patterned.

The patterned superconducting single crystal film was etched to form a vortex flow element structure. The critical temperatures of the high temperature superconductors forming the obtained devices were all in the range of 88 to 92K. The width (W) of the vortex travel region was variously changed within the range of 0.3 μm to 8 μm, and samples were prepared, and the width (W ′) of the input signal line (14) was W ′ ≧ W.

Example 2 (Verification of W Dependence of Vortex Flow Element) FIG. 2 is a line showing the dependence of the critical current density of each vortex running region on the width (W) of the vortex running region under liquid nitrogen temperature and zero magnetic field. In the figure, the vertical axis represents the critical current density (10 ¹⁰ A / m ² ), and the horizontal axis represents W / λ _c . As shown in the figure, the critical current density increased as W became smaller. Especially, when λ _c = 0.7 μm, this change is W /
It was remarkable in λ _c ≦ 5. The increase in critical current density shown in the figure is a kind of size effect.

Example 3 (Characteristics of Vortex Flow Element) Next, the characteristics of the vortex flow element were evaluated at the temperature of liquid nitrogen. FIG. 3 is a circuit diagram showing an outline of the measurement system when evaluating the vortex flow element characteristics. The evaluation was performed using the circuit shown in FIG. As a sample, W = 1 μm
Element was selected. Vortex drive current I _d = 22m
A is made to flow in advance, and an input current I _c = 1 m is applied to the input signal line.
When A was energized, a vortex flow voltage V _f = 4 mV was generated at both ends of the device. Also, the internal resistance of the element R _i =
The resistance was 0.22 ohms and the transresistance R _{m was} 10 ohms. The generation of V _f corresponds to the conversion of the input signal into the voltage signal, and the power gain G _p can be obtained by adjusting the additional resistance R ₂ .

In the case of the circuit of FIG. 3, the power gain G _p can be approximated as G _p = R _m ² R ₂ / R ₁ (R _i + R ₂ ) ² with the inductance component neglected in the low frequency region. In order to increase the gain, it is important that R _m is large and R _i is small. In addition, R ₁ = R ₂
= R _i = 0.22 ohm, G _p = 770 is obtained. From the above results, it was shown that this device can be easily used as an amplification device for electric signals.

Example 4 (AC Characteristics of Vortex Flow Element) On the other hand, the AC characteristics of the present vortex flow element were examined.
FIG. 4 is a circuit diagram of a measurement system used to verify the AC characteristics of the vortex flow element. In the circuit shown in the figure, a direct current of 2.8 mA and a carrier current (frequency of 10 kHz, amplitude of 0.2 mA) were input to the signal input line in an overlapping manner with this current. Direct current 21.5 mA and signal wave current (frequency 1 kHz, amplitude 0.5 mA) were input to the vortex running region. At this time, an amplitude-modulated voltage signal with a maximum amplitude of 2 mV was generated at both ends of the element. As a result, it was shown that a modulation / demodulation circuit can be easily manufactured using the vortex flow element.

Example 5 (Oscillation Characteristics of Vortex Flow Element) Further, an oscillation circuit was produced using this vortex flow element, and a high frequency signal was generated. FIG. 5 is an explanatory diagram showing an outline of an oscillation circuit using a vortex flow element. DC current I _d = 21.5 mV to the input signal line of the element
And DC current I _c = 1.5 mA in the vortex travel area
Was input, and part of the voltage generated at both ends of the element was positively fed back and input to the input signal line. At this time, oscillation of a GHz-class frequency was observed in the LC resonance part in the element, and it was found that a high-frequency signal oscillation circuit could be easily manufactured using this element.

The maximum response frequency of this element is several hundreds.
Since it is expected to reach several THz from GHz, by optimizing the element in the future, other than this, passive elements for millimeter-wave / submillimeter-wave band ultra-high frequencies and picosecond-class ultra-high-speed switching are also available. Elements and the like can be considered as applications.

Embodiment 6 (Manufacturing 2 of Vortex Flow Element) FIG. 6 is an explanatory view showing the constitution of another embodiment of the vortex flow element of the present invention. NdGaO ₃ Single Crystal Substrate (61)
On the (110) plane of
An axially oriented YBCO single crystal thin film was deposited to a thickness of 5 μm. Then, the film thickness (T) was set to 1 μm by polishing and etching.

A photoresist is applied on this superconducting single crystal thin film, and the photoresist is patterned by ordinary photolithography so as to correspond to the vortex traveling region (62) as shown in the figure, and then etched by ion milling. A vortex traveling region (62) in the vortex flow element structure was produced. Running areas formed (62)
Has a length (L) of 10 μm and a width (W) of 1 μm.
After that, a photoresist is applied to the entire substrate and the resist is photolithographically applied to the vortex drive current line (63),
It was patterned into a shape corresponding to the input signal line (64) and the drive current supply line (65).

A YBCO polycrystal film was deposited to 0.5 μm by magnetron sputtering from the above, and then the photoresist was removed to produce the vortex flow device shown in FIG. The drive current line (63) overlaps both ends of the vortex traveling region (62), and the input signal line (64) is formed in parallel with the vortex traveling region (62).

The critical current density of the vortex traveling region (62) is 77 K, and 2.4 × 10 ¹⁰ A / m ² under zero magnetic field.
Met. When a vortex drive current I _d = 22.3 mA was made to flow and I _c = 1 mA was applied to the input signal line, a vortex flow voltage V _f = 4.5 m was applied to both ends of the element.
V occurred. In this case, the element R _i = 0.20Ω, R
It was _{m to 10} Ω.

As described above, the basic characteristics similar to those of Example 1 were confirmed in the element to which the vortex driving current line and the input signal line of the element were added later by the vapor phase method.

Embodiment 7 (Manufacturing 3 of Vortex Flow Element) FIG. 7 is an explanatory view showing the constitution of still another embodiment of the vortex flow element of the present invention. NdGaO ₃ single crystal substrate
On the (110) plane of (71), an a-axis oriented YBCO single crystal thin film was deposited to a thickness of 5 μm by a liquid phase epitaxial method. Then, the film thickness (T) was set to 1 μm by polishing and etching.

A photoresist is applied onto the YBCO single crystal thin film, the photoresist is patterned by ordinary photolithography, and then ion milling is performed to etch the single crystal, which is longer than the vortex travel region (72) in the vortex flow element structure. A body (80) was created. Further, a photoresist was coated on this again, and the resist was patterned by photolithography. A 0.5 μm thick c-axis oriented YBCO polycrystalline film was deposited on the resist by magnetron sputtering, and then the photoresist was removed. As a result, the vortex drive current line (73) is formed so as to overlap the entire surface of the single crystal body (80), and the input signal line (74) is formed at a position parallel to the vortex travel region (72). The drive current supply line (75) was formed by arranging it at both ends of (74).

Here, the YBCO polycrystalline film laminated on the vortex traveling region (72) is finely processed and removed by the focused ion beam method, and a small vortex traveling region (72) as shown in FIG. 7 is formed. A device having the above was manufactured. The vortex running area (72) had a length (L) of 5 μm and a width (W) of 1 μm.

The length of this microfabrication corresponds to L in Examples 1 and 6, and an element in which L was changed in the range of 0.1 μm to 1 μm was manufactured.

FIG. 8 shows the transresistance (R
It is a diagram which shows the relationship between _m ) and a vortex running area length (L). As shown in FIG. 8, R _m has a substantially proportional relationship with L, but when L = 0.1 μm, it largely deviates from the straight line and greatly decreases, and when R _m becomes too small, power gain cannot be obtained. confirmed. For YBCO single crystal, λ
_{Since ab} = 0.14 μm and λ _c = 0.7 μm, it was confirmed that L ≧ λ _ab was required to obtain the device according to the present invention.

[0053]

As described above, according to the present invention,
By subjecting a high-temperature superconducting single crystal film formed so that the ab plane is vertical to the substrate to fine processing, a vortex flow element based on a new principle can be manufactured, which is simple and low cost. By the method, it is possible to supply a superconducting vortex flow element having a small size, a high output and a high response frequency and its peripheral circuit.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a vortex flow device of the present invention.

FIG. 2 is a diagram showing the width (W) dependence of the critical current density of each vortex travel region under liquid nitrogen temperature and zero magnetic field, where the vertical axis represents the critical current density (10 ¹⁰ A / m). ² ), the horizontal axis is W / λ _c .

FIG. 3 is a circuit diagram showing an outline of a measurement system for evaluating characteristics of a vortex flow element.

FIG. 4 is a circuit diagram of a measurement system used for verification of AC characteristics of a vortex flow element.

FIG. 5 is an explanatory diagram showing an outline of an oscillation circuit using a vortex flow element.

FIG. 6 is an explanatory diagram showing the configuration of another embodiment of the vortex flow element of the present invention.

FIG. 7 is an explanatory view showing the constitution of still another embodiment of the vortex flow element of the present invention.

FIG. 8 is a diagram showing the relationship between the transresistance (R _m ) of each element and the vortex travel region length (L).

FIG. 9 is an explanatory diagram showing a configuration of a superconducting amplifier element based on a field effect.

FIG. 10 is an explanatory diagram showing the structure of a carrier injection type element.

FIG. 11 is an explanatory diagram showing a structure of an element utilizing the motion of vortex.

FIG. 12 is an explanatory view showing the structure of a vortex flow element using a high temperature superconductor single crystal.

[Explanation of symbols]

(11) (61) (71)… NdGaO ₃ single crystal (substrate) (12) (62) (72)… Vortex traveling region (high temperature superconductor single crystal body) (13) (63) (73)… Vortex Drive current line (electrode) (14) (64) (74) ... Input signal line (excitation means) (15) (65) (75) ... Drive current supply line (excitation means)

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshihiko Maeda 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (6)

[Claims] 1. A high-temperature superconductor single crystal body, a pair of electrodes joined to both ends of the high-temperature superconductor single crystal body in the c-axis direction, and a c-axis for the high-temperature superconductor single crystal body. Exciting means for applying a magnetic field in a direction orthogonal to each other, between the pair of electrodes when a magnetic field is applied to the high temperature superconductor body by the exciting means in a state where a current is flowing in a superconducting state between the pair of electrodes. In a high-temperature superconducting single crystal body type vortex flow element for generating a voltage, the high-temperature superconductor single crystal body is provided on a substrate surface,
Ab including the a-axis and the b-axis of this high-temperature superconductor single crystal body
A high-temperature superconducting single-crystal vortex flow element having a surface orthogonal to this substrate. 2. The high-temperature superconducting single crystal body type vortex flow element according to claim 1, wherein a width W perpendicular to the c-axis of the high-temperature superconductor single crystal body to which a magnetic field is applied by the exciting means is the c-axis. The length L in the c-axis direction of the high temperature superconductor single crystal body to which the magnetic field is applied by the exciting means is set to be 5 times or less of the magnetic field penetration length λ _c when the magnetic field is applied in parallel to the ab plane. A high-temperature superconducting single-crystal vortex flow element characterized by having a magnetic field penetration length of λ _ab or more when a magnetic field is applied. 3. The high-temperature superconducting single crystal body type vortex flow element according to claim 1, wherein the exciting means is provided on the same substrate surface on which the high-temperature superconductor single crystal bodies are provided. High-temperature superconducting single crystal body type vortex flow element. 4. The high-temperature superconducting single-crystal vortex flow element according to claim 1, wherein the electrodes are provided on the same substrate surface on which the high-temperature superconductor single-crystal bodies are provided. A high-temperature superconducting single crystal body type vortex flow element. 5. A high-temperature superconductor single crystal body, a pair of electrodes bonded to both ends of the high-temperature superconductor single crystal body in the c-axis direction, and a c-axis for the high-temperature superconductor single crystal body. An exciting means for applying a magnetic field in a direction orthogonal to each other, the pair of electrodes when a magnetic field is applied to the high temperature superconductor single crystal body by the exciting means in a state where a current is flowing in a superconducting state between the pair of electrodes. In a method of manufacturing a high-temperature superconducting single crystal body type vortex flow element for generating a voltage between electrodes, an ab plane including a high-temperature superconductor single-crystal film on the substrate, the a-plane including the a-axis and the b-axis is orthogonal to the substrate surface. A method for manufacturing a high-temperature superconducting single crystal body type vortex flow element, which is characterized in that 6. The method for producing a high-temperature superconducting single crystal body type vortex flow element according to claim 5, wherein the high-temperature superconductor single-crystal film is formed on at least the surface of the substrate having a predetermined crystal orientation. A high-temperature superconducting single-crystal vortex flow element, which is obtained by a liquid phase epitaxial method or a vapor phase epitaxial method so that a plane formed by the a-axis and the b-axis is orthogonal to each other.