JP2956521B2 - Method for manufacturing high-temperature superconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-temperature superconductor and a method for manufacturing the same.

[0002]

Conventionally, the critical temperature of the superconductor by Y ₁ Ba ₂ Cu ₃ O ₇ is about 90 ° K, also, Y ₁ Ba ₂ Cu ₃
The contact structure of a ceramic-based superconductor such as O ₇ was generally formed by contacting and connecting a silver film.

[0003]

However, according to the above-mentioned prior art, there are a problem that the critical temperature does not rise and a problem that the critical temperature is not stabilized.

An object of the present invention is to solve the problems of the prior art and to provide a ceramic high-temperature superconductor structure, a processing method, and a contact structure having a stable critical temperature above room temperature at 100 ° K or more. And

[0005]

In order to solve the above problems SUMMARY OF THE INVENTION The method for producing a high-temperature superconductor of the present invention, Y ₁ Ba ₂ Cu
A step of forming a coating on the surface of a ceramic-based superconductor such as ₃ O _7, a step of forming a contact hole in the coating,
At least a step of forming a conductive nitride film in the contact hole, a step of implanting oxygen ions through the coating, and a step of annealing after the step are included. Further, the present invention provides a method as described above, wherein the coating is made of Si ₃ N ₄
It is characterized by being. Further, the present invention is characterized in that the conductive nitride film is a film selected from a TiN film, a WN film, a MoN film, and an NbN film.

[0006]

[Action] Y ₁ Ba ₂ the action of oxygen ion implantation to Cu ₃ O ₇ or the like ceramic superconductors, inter alia Y ₁ Ba ₂ Cu ₃
O ₇ has an action of introducing radical oxygen into the oxygen-deficient position of the oxygen-deficient perovskite crystal structure, and the spin direction of the electron of the radical oxygen changes with the electron of the radical ion such as Cu ion and oxygen ion (bonded oxygen). And the spin interaction of these electrons (or holes) can be a driving force to generate the high-temperature superconductivity phenomenon. The introduction acts to increase the critical temperature to about room temperature or more by increasing the hole density.

The formation of the Si ₃ N ₄ film is carried out by using Y ₁ Ba ₂ Cu ₃
It has the effect of applying compressive stress to ceramic superconductors such as O ₇ , shortening the distance between oxygen radicals and copper ions,
In addition to the action of raising the critical temperature, the Si ₃ N ₄ film also has an action of preventing the escape of oxygen radicals and has an action of stabilizing the critical temperature.

Further, when a conductive nitride film such as a TiN film is used for the contact portion, the contact resistance can be reduced, and the critical temperature can be increased and stabilized similarly to the Si ₃ N ₄ film. There is.

[0009]

The present invention will be described below in detail with reference to examples.

FIG. 1 shows a high-temperature superconductor structure showing one embodiment of the present invention. That is, a substrate 1 made of glass or metal
A Si ₃ N ₄ film (l) 2 is formed on the surface of the substrate by a CVD method, and a Y ₁ Ba ₂ Cu ₃ O ₇ film 3 is formed on the Si ₃ N ₄ film (l) 2.
Is formed by a sputtering method or the like, and the surface of the Y ₁ Ba ₂ Cu ₃ O ₇ is coated with a Si ₃ N ₄ film (2) 4 by a CVD method or the like, and from the surface of the Si ₃ N ₄ film (2) 4 Oxygen ion implantation 5 is performed by a high energy ion implantation device, and Y ₁
Oxygen ions are implanted into the Ba ₂ Cu ₃ O ₇ film 3, and the implanted oxygen is fixed in a radical state between lattices at oxygen-deficient positions and the like by subsequent annealing. In addition, Y ₁ Ba ₂ Cu
_{The 3} O ₇ film 3 may be a simple substance (shape, linear shape, etc.) of Y ₁ Ba ₂ Cu ₃ O ₇ , and the Si ₃ N ₄ film may cover the surface of these simple substances, and the base may be SiO 2. ₂ films and A ₂₃ film may be formed. Further, the oxygen ion implantation 5 is performed using Y ₁ Ba ₂ Cu
It may be driven into the vicinity of the surface of ₃ O ₇ alone and not into the center. Further, the Si ₃ N ₄ film is not limited to the film but may be a coating, and a sintered body may be formed on the surface.

FIG. 2 shows a contact structure of a high-temperature superconductor showing another embodiment of the present invention.
_{A 3} N ₄ film (l) 12 is formed, and the Si ₃ N ₄ film (l) 12
The surface of the Y ₁ Ba ₂ Cu ₃ O ₇ film l3 is formed, the Y ₁
On the Ba ₂ Cu ₃ O ₇ film, a Si ₃ N ₄ film (2) 14 is coated, and a contact hole is formed in the Si ₃ N ₄ film (2) 14 so that the contact A TiN film 15 is formed in the hole by a sputtering method or the like, and an A film 16 is formed on the TiN film 15. In the case of this example, the TiN film needs to have a structure that completely fills the connection hole.
An iN film 15 is formed on the Y ₁ Ba ₂ Cu ₃ O ₇ film, a Si ₃ N ₄ film (2) 14 is formed thereon, and a connection of the Si ₃ N ₄ film on the TiN film 15 is formed. A structure and method such as making a hole may be adopted, and the A film 16 may be made of another conductive material such as an Ag film. Further, the TiN film 15 is made of WN, MoN,
Another conductive nitride film such as NbN may be used. It goes without saying that oxygen ion implantation may be performed on the Y ₁ Ba ₂ Cu ₃ O ₇ film after the formation of the connection electrode, followed by annealing.

_{Furthermore, Y 1 Ba 2 Cu 3 O} 7 film l3 may be another ceramic superconducting film, single not film structure only (rod-like, linear, and rated shaped, etc.) have a structure Needless to say good things.

[0013]

According to the present invention, there is an effect that a ceramic high-temperature superconductor having a critical temperature of 100 K or more and a normal temperature or more can be stably supplied without fluctuation of the critical temperature. Furthermore, according to the present invention, since the conductive nitride film is formed in the contact hole, there is an advantageous effect that the escape of oxygen from the contact portion can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a high-temperature superconductor structure showing one embodiment of the present invention.

FIG. 2 is a view showing a connection structure of a high-temperature superconductor according to another embodiment of the present invention.

[Explanation of symbols]

········· Substrate 2, 12 · 4 · 14 ··· Si ₃ N ₄ film 3 · 13 ····· Y ₁ Ba ₂ Cu ₃ O ₇ film 5 ··· ···· Oxygen ion implantation 15 ··········· TiN film 16 ········ A film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 39/24 H01B 12/02 H01B 13/00 565 H01L 39/02 H01L 39/00 H01L 39/22 H01L 39 / 06

Claims (3)

(57) [Claims] A step of forming a coating on the surface of a ceramic superconductor such as Y ₁ Ba ₂ Cu ₃ O ₇ , a step of forming a contact hole in the coating, and a step of forming a conductive nitride on at least the contact hole. A method for manufacturing a high-temperature superconductor, comprising a step of forming a film, a step of implanting oxygen ions through the coating, and a step of annealing after the step. 2. The method according to claim 1, wherein said coating is made of Si ₃ N ₄ . 3. The method according to claim 1, wherein the conductive nitride film is a TiN film, a WN film,
2. The method for manufacturing a high-temperature superconductor according to claim 1, wherein the high-temperature superconductor is a film selected from an oN film and an NbN film.