JPS63265475A - Manufacture of superconducting electronic circuit - Google Patents

Abstract

PURPOSE:To manufacture a superconducting electronic circuit with a high transition temperature by a method wherein an energy beam is applied to the required region of a ceramics whose superconducting characteristics are varied in accordance with the composition and the ceramic is partially modified to form an electronic circuit. CONSTITUTION:An energy beam is applied to the required region of a ceramic whose superconducting characteristics are varied in accordance with the composition and the ceramic is partially modified to form an electronic circuit. As the superconducting characteristics of the ceramic are varied in accordance with the types and ratios of component elements, the superconducting transition temperature of the required region of the ceramic can be controlled by doping the region with the component elements or other elements. Therefore, the elements are so added as to draw a required pattern to make the pattern part superconducting or non-superconducting. With this constitution, as a wiring resistance R is practically zero in the integrated circuit, a delay in the wiring of the integrated circuit can be significantly reduced and a high speed operation can be realized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a superconducting electronic circuit, and particularly to a method for producing a superconducting electronic circuit using an oxide superconductor having a high superconducting transition temperature. It is.

[Prior art 1] Conventionally, niobium-based alloy materials have been the mainstream as superconducting materials, and are used in Josephson elements and the like. However, alloy-based superconducting materials have the disadvantage of having a low transition temperature and must be cooled with liquid helium.

Recent (La-5r) 21: uO, YBa2Cu30
It has been announced that oxide superconductors such as t have a high superconducting transition temperature. However, it is difficult to form electronic circuits using these superconducting oxides, and superconducting electronic circuits have not yet been realized.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems of the low superconducting transition temperature of alloy-based superconducting materials and the difficulty in forming electronic circuits in oxide superconducting materials. The purpose is to provide a method for creating conduction electronic circuits.

Means for Solving Problem E] In order to achieve such an object, the present invention partially modifies ceramics by irradiating an energy beam to a desired region of ceramics whose superconducting properties change depending on the composition. It is characterized by forming an electronic circuit by doing so.

[Function] The superconducting properties of oxide (ceramic) superconducting materials vary greatly depending on their composition, that is, the types and ratios of constituent elements. By adding , the superconducting transition temperature of that part can be controlled. Therefore, by adding elements in a predetermined pattern to make only that part a superconductor or only that part a non-superconductor, it is possible to create an oxide superconducting electron with a high superconducting transition temperature. You can get the circuit.

[Example J The present invention will be described in detail below with reference to the drawings.

111 Figures 1 to 3 show a first embodiment of the method for manufacturing a superconducting electronic circuit of the present invention.

Y2BaO produced by an appropriate method such as a sintering method.

A Cu layer 2 having a thickness of approximately 0.06 μm is formed on an insulating substrate 1 by sputtering, electroless plating, or the like (FIG. 1). Then, as shown in FIG. 2, a desired portion of the Cu layer 2 is irradiated with a laser beam 3.

As the laser beam, a double harmonic of Nd:YAG pulse laser (wavelength 0.53 μm) is used, and the beam diameter is approximately 2.
pm, peak power 10'W/cm', pulse width 0
．． When irradiated at 1 μm, the irradiated part of the Cu layer 2 melts,
It reacts with the Y28aOy insulating substrate 1 directly below it, and the thickness becomes 0.
A Y2BaCu, 07 layer 4 of about 25 μm is formed.

This YBa2u30t is a superconductor with a superconducting transition temperature of 93. When the zero-order unreacted Cu layer is removed by etching with sulfuric acid, Y2BaO is formed on the surface of the insulating substrate 1, as shown in FIG. A superconducting wiring pattern 4 can be obtained using Y2BaCu30.

Eligibility ■Yu FIG. 4 shows another embodiment of the invention.

A YJaCus07 insulator substrate 5 manufactured by a sintering method or the like is placed in an oxygen atmosphere, and the surface of the substrate 5 is scanned along a desired pattern with a laser beam 6. When irradiated under the same irradiation conditions as in Example 1, only the irradiated portion of the substrate 5 is heated and reacts with oxygen atoms in the atmosphere, forming an oxide layer 7 of composition Y2BaCu,02 with a thickness of approximately 0.2 μm. It is formed.

By irradiating the insulating substrate with a laser beam in this manner, the substrate can be modified and a desired wiring pattern can be obtained.

FIG. 5 shows an example of a microbridge type Josephson device manufactured by the method of the present invention.

First, a superconducting layer 12 of YBaxCu 30 having a thickness of approximately 1 μm is formed on the entire surface of a Si substrate 11 by an appropriate method such as sputtering, and is used as a ground layer. Next, for example, a CVD method is used to form an insulating layer 13 of about 1 .mu.m thick of Sin, and a YBa2Cu3O7 superconducting layer is formed thereon by a sputtering method or the like, and the layer is formed into the shape of a Josephson element 14 by photoetching. Next, Josephson element 1
Ni1i15 having a width of about 1 μm and a thickness of about 0.06 μm is formed on the narrow portion of the substrate 4. At this time, only the central portion 14^ is covered with a resist layer having a width of 0.1 μI formed in advance by electron beam exposure or ion beam exposure, and N
i is not brought into contact with the YBa2Cu3O7 surface. Do it N
The i-film is scanned with a Nd:YAG pulse laser with a beam diameter of about 1 μm. In this way, the laser irradiated area 1
5 melts and reacts with YBa2Cu3O7 directly below, modifying its composition and losing its superconductivity, but the central part 1
Only in 4A, there is no Ni intrusion, and superconductivity is not lost.

When the remaining Ni is etched and removed, the central part 14A
A microbridge-type Josephson element 14 in which superconductors are connected is formed.

Although not shown, wiring for driving the Josephson element 14 can be provided by, for example, the methods shown in Example 1.2. Further, it is possible to form an integrated Josephson element by forming elements and circuits necessary for operating the Josephson element 14 on the St substrate 11.

Laser beams include not only the above-mentioned Nd:YAG laser, but also ultraviolet lasers such as excimer lasers,
An infrared laser such as a C02 laser can be used. The energy of ultraviolet lasers is absorbed by the electronic system of ceramics, and the energy of infrared lasers is absorbed by the lattice imaging of ceramics. By selecting the laser wavelength, the depth of energy penetration into the ceramic can be adjusted.

Ceramics can also be modified by using an electron beam as an energy beam to heat ceramics or a thin film formed on ceramics to cause a reaction.

When using an electron beam, the penetration depth can be adjusted by adjusting the accelerating voltage.

The application target of the present invention is not limited to the above-mentioned YBa2u3O7, but also (La-5r) 2CuOx, (La-Ba) a
cuoll, (y-sr) 2cuo.

Needless to say, the present invention can be widely applied to other oxide superconductors.

The circuit pattern width according to the present invention can be formed as narrow as a minimum of 0.1 μm.

[Effects of the Invention] According to the present invention, new high-speed devices such as Josephson devices and superconducting transistors can be realized using oxide superconductors with high superconducting transition temperatures.Electronic circuits according to the present invention When applied to an integrated circuit, the wiring resistance (R)
is virtually 0, so the wiring delay of integrated circuits (mainly C
(determined by XR) is extremely small, and high speed can be achieved.

Further, since the wiring resistance is substantially 0, the line width and thickness of the wiring can be reduced, so that it is possible to increase the density of elements and wiring. Furthermore, since the heat generation of the element is small, even higher density is possible.

[Brief explanation of the drawing]

1 to 3 are process diagrams illustrating a method for manufacturing a superconducting wiring pattern in an embodiment of the present invention, FIG. 4 is a perspective view illustrating another embodiment of the present invention, and FIG. 5 is a microbridge FIG. 2 is a perspective view illustrating a method for manufacturing a Josephson type Josephson element. 1... Y2BaOt substrate, 2... Cu layer, 3... Laser beam, 4... Y, BaCu, 07 wiring layer, 5---Y2B
aCu, O, substrate, 6...laser beam, 11-5 i-substrate, 12...YBa, Cu30. Ground layer, 13...Si
n, layer, 14...Josephson element, 15...1 film, 16...laser beam. Designated agent Director, Electronics Technology Research Institute, Agency of Industrial Science and Technology → Figure 2 Figure 3 Figure 4 Ryo 1

Claims (1)

[Claims] 1) An electronic circuit is formed by partially modifying the ceramic by irradiating an energy beam to a desired region of the ceramic whose superconducting properties change depending on the composition. A method for creating superconducting electronic circuits. 2) The composition of the ceramic before energy beam irradiation is such that it does not exhibit superconductivity at a predetermined temperature, and only the energy beam irradiated portion is modified to have superconductivity at the predetermined temperature. A method for producing a superconducting electronic circuit according to claim 1. 3) The composition of the ceramic before energy beam irradiation is a composition that exhibits superconductivity at a predetermined temperature, and only the energy beam irradiated portion is modified so that it does not exhibit superconductivity at the predetermined temperature. A method for producing a superconducting electronic circuit according to claim 1. 4) The method for producing a superconducting electronic circuit according to any one of claims 1 to 3, wherein the energy beam is a laser beam. 5) The method for producing a superconducting electronic circuit according to any one of claims 1 to 3, wherein the energy beam is an electron beam. 6) forming a thin film in close contact with the surface of the ceramic;
Claims 1 to 5, characterized in that the ceramic is modified by the elements constituting the thin film.
A method for producing a superconducting electronic circuit as described in any of the following paragraphs. 7) Creation of a superconducting electronic circuit according to any one of claims 1 to 5, characterized in that the ceramic is modified with an element constituting a fluid medium surrounding the ceramic. Law.