Superconducting device and method for manufacturing the same

Abstract

To provide a superconducting device capable of disposing a non-contact coupling circuit of a superconducting integrated circuit chip and a non-contact coupling circuit of a circuit board more accurately with respect to design values.SOLUTION: A superconducting device comprises: a superconducting integrated circuit chip including on a surface a first electrode consisting of a first superconducting material and a first non-contact coupling circuit; and a circuit board including on a surface a second electrode consisting of a second superconducting material and a second non-contact coupling circuit and disposed oppositely with the superconducting integrated circuit chip. The second electrode includes a flat top face and includes a projection protruding toward the superconducting integrated circuit chip, and the first electrode includes a flat surface and a first recess which is disposed inside of the flat surface and of which the area is smaller than that of the top face. The first recess is disposed oppositely so as to be positioned inside of the top face, the top face and the flat surface are abutted, and a third superconducting material connecting the top face and the first recess is disposed inside of the first recess.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to superconducting devices and the like. [Background technology]

[0002] To integrate superconducting circuits, a structure in which a superconducting circuit integrated chip carrying an integrated circuit is flip-chip mounted on a circuit board is known. In this structure, it is necessary to suppress signal reflection and interference and ensure the required signal quality (transmission characteristics). For this purpose, non-contact coupling using capacitive coupling and inductive coupling, which can reduce the wiring layout in the integrated circuit, are considered promising.

[0003] In a specific structure, a required number of non-contact coupling circuits are arranged on the superconducting integrated circuit chip. For example, capacitive coupling circuits or inductive coupling circuits are used as the non-contact coupling circuits for inputting and outputting signals. The non-contact coupling circuit on the superconducting integrated circuit chip side and the non-contact coupling circuit on the circuit board side can be arranged facing each other. For the two non-contact coupling circuits to form a good non-contact coupling, a technique is required to couple the superconducting integrated circuit chip and the circuit board while maintaining a predetermined distance between them.

[0004] A technology that meets the above requirements is disclosed, for example, in Patent Document 1. In the technology of Patent Document 1, a second metal layer made of tin or tin and lead is laminated on the superconducting wiring provided on the circuit board, and the electrodes of the second metal layer are connected with solder to the electrodes of the superconducting element. That is, first, a second metal layer with good solder wettability is formed on the superconducting wiring, and then the electrodes of the superconducting element and the electrodes of the second metal layer are connected with solder. In this way, the electrodes of the superconducting element and the superconducting wiring of the electrode circuit board are connected via the second metal layer. This makes it possible to obtain a highly reliable connection between the superconducting element and the circuit board. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 2813093 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the structure disclosed in Patent Document 1 has a problem in that it is not possible to accurately control the distance between the non-contact coupling circuit of the superconducting integrated circuit chip and the non-contact coupling circuit of the circuit board, because there is a possibility that the mounting position of the non-contact coupling circuit of the superconducting integrated circuit chip or the non-contact coupling circuit of the circuit board may shift while the molten solder is solidifying.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a superconducting device etc. that can more accurately position the non-contact coupling circuit of a superconducting integrated circuit chip and the non-contact coupling circuit of a circuit board relative to the design values. [Means for solving the problem]

[0008] In order to solve the above problems, the superconducting device of the present invention comprises a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on its surface, and a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on its surface, and arranged to face the superconducting integrated circuit chip, wherein the second electrode has a flat upper surface and a protrusion that protrudes toward the superconducting integrated circuit chip, the first electrode has a flat surface and a first recess that is arranged inside the flat surface and has an area smaller than that of the top surface, the first recess is arranged opposite to be located inside the top surface, the top surface and the flat surface abut each other, and a third superconducting material that connects the top surface and the first recess is arranged inside the first recess.

[0009] Furthermore, the present invention provides a method for manufacturing a superconducting device, which includes a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on its surface, and a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on its surface, and which is arranged to face the superconducting integrated circuit chip, wherein the second electrode includes a flat upper surface and has a protrusion that protrudes toward the superconducting integrated circuit chip, the first electrode has a flat surface and a first recess that is located inside the flat surface and has an area smaller than that of the upper surface, a third superconducting material that connects the upper surface and the first recess is located inside the first recess, and the first recess is arranged opposite to and positioned inside the upper surface, and the upper surface and the flat surface are abutted against each other. [Effects of the Invention]

[0010] The effect of the present invention is to provide a superconducting device or the like that can more accurately position the non-contact coupling circuit of the superconducting integrated circuit chip and the non-contact coupling circuit of the circuit board relative to the design values. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing the configuration of a superconducting device of a first embodiment. [Figure 2] FIG. 3 is a cross-sectional view showing the configuration of a superconducting device according to a second embodiment. [Figure 3] FIG. 10 is a plan view showing an example of the configuration of a superconducting integrated circuit chip used in a superconducting device of a second embodiment. [Figure 4] 10 is a cross-sectional view showing a first configuration example of a superconducting integrated circuit chip used in a superconducting device of a second embodiment. FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a second configuration example of a superconducting integrated circuit chip used in a superconducting device of a second embodiment. [Figure 6] 10 is a cross-sectional view showing a third configuration example of a superconducting integrated circuit chip used in the superconducting device of the second embodiment. FIG. [Figure 7]FIG. 10 is a cross-sectional view showing a fourth configuration example of the superconducting integrated circuit chip used in the superconducting device of the second embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a fifth configuration example of a superconducting integrated circuit chip used in the superconducting device of the second embodiment. [Figure 9] FIG. 4 is a plan view showing a circuit board used in a superconducting device according to a second embodiment. [Figure 10] FIG. 4 is a cross-sectional view showing a first configuration example of a circuit board used in a superconducting device of a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a second configuration example of a circuit board used in a superconducting device of a second embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing a first example of the arrangement of a third superconducting material on a circuit board of the superconducting device of the second embodiment. [Figure 13] FIG. 10 is a cross-sectional view showing a second example of the arrangement of a third superconducting material on a circuit board of the superconducting device of the second embodiment. [Figure 14] FIG. 10 is a cross-sectional view showing a third configuration example of a circuit board used in the superconducting device of the second embodiment. [Figure 15] FIG. 10 is a cross-sectional view showing a fourth configuration example of a circuit board used in the superconducting device of the second embodiment. [Figure 16] FIG. 4 is a cross-sectional view showing a first state in a method for manufacturing a superconducting device according to a second embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing a second state in the method for manufacturing a superconducting device according to the second embodiment. [Figure 18] FIG. 10 is a cross-sectional view showing a third state in the method for manufacturing a superconducting device according to the second embodiment. [Figure 19] FIG. 10 is a cross-sectional view showing a modified example of the superconducting device of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments described below are limited to technically preferable aspects for carrying out the present invention, but are not intended to limit the scope of the invention. Note that similar components in each drawing are given the same reference numerals, and their description may be omitted.

[0013] (First embodiment) FIG. 1 is a cross-sectional view showing a superconducting device 1 of this embodiment. The superconducting device 1 includes a superconducting integrated circuit chip 10 and a circuit board 20. The superconducting integrated circuit chip 10 has a first electrode 11 made of a first superconducting material and a first non-contact coupling circuit 12 on its surface. The circuit board 20 has a second electrode 21 made of a second superconducting material and a second non-contact coupling circuit 22 on its surface, and is disposed opposite the superconducting integrated circuit chip 10. Here, a superconducting material refers to a substance that exhibits superconductivity at so-called cryogenic temperatures near absolute zero (-273.15°C, which can also be expressed as 0 K). Superconducting substances can be broadly divided into metal-based substances with a critical temperature (the upper limit temperature at which the substance exhibits a superconducting state) of up to approximately 40 K, which are relatively low temperatures, and oxide-based substances with a critical temperature of around 100 K, which are relatively high temperatures. Examples of metal-based materials include mercury, vanadium, lead, niobium, niobium-titanium, niobium-tin, niobium-aluminum, vanadium-gallium, magnesium-boron, etc. Examples of oxide-based materials include yttrium-barium-copper-oxygen, bismuth-lead-strontium-calcium-copper-oxygen, etc.

[0014] The circuit board 20 has on its surface a second electrode 21 made of a second superconducting material and a second non-contact coupling circuit 22. The second electrode 21 includes a flat upper surface 21b and has a protrusion 21a that protrudes toward the superconducting integrated circuit chip 10.

[0015] The superconducting integrated circuit chip 10 has a first electrode 11 made of a first superconducting material and a first non-contact coupling circuit 12 on its surface. The first electrode 11 has a flat surface 11a and a first recess 11b that is located inside the flat surface 11a and has a smaller area than the top surface 21b. The first recess 11b is located opposite the inside of the top surface 21b. The top surface 21b and the flat surface 11a are in contact with each other. A third superconducting material 23 that connects the top surface 21b and the first recess 11b is located inside the first recess 11b.

[0016] With this configuration, the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 are arranged opposite to each other. Note that the circuit board 20 is designed so that the positioning of the upper surface 21b and the first recess 11b and the positioning of the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 are performed simultaneously in a direction parallel to the main surface of the circuit board 20.

[0017] In the above configuration, the upper surface 21b of the protrusion 21a abuts against the flat surface 11a of the first electrode 11, thereby setting the distance between the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 to a predetermined value determined by the height of the protrusion 21a. This means that a superconducting device 1 can be provided in which the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 are positioned more accurately relative to the design value. As a result, non-contact coupling can achieve input / output characteristics closer to the design value. The design value is a value that includes a predetermined tolerance from the reference value. Furthermore, because the first electrode 11 and the third superconducting material 23 are bonded at the first recess 11b, the area of ​​the bonding surface is increased compared to bonding flat surfaces, resulting in a stronger bond.

[0018] The superconducting device 1 of the first embodiment has been described above.

[0019] The superconducting device 1 of the first embodiment includes a superconducting integrated circuit chip 10 and a circuit board 20. The superconducting integrated circuit chip 10 has a first electrode 11 made of a first superconducting material and a first non-contact coupling circuit 12 on its surface. The circuit board 20 has a second electrode 21 made of a second superconducting material and a second non-contact coupling circuit 22 on its surface, and is disposed so as to face the superconducting integrated circuit chip 10. The circuit board 20 has a second electrode 21 made of a second superconducting material and a second non-contact coupling circuit 22 on its surface. The second electrode 21 includes a flat upper surface 21b and has a protrusion 21a that protrudes toward the superconducting integrated circuit chip 10. The superconducting integrated circuit chip 10 has a first electrode 11 made of a first superconducting material and a first non-contact coupling circuit 12 on its surface. The first electrode 11 has a flat surface 11a and a first recess 11b that is disposed inside the flat surface 11a and has a smaller area than the top surface 21b. The first recess 11b is disposed facing the top surface 21b so as to be located inside the top surface 21b. The top surface 21b and the flat surface 11a are in contact with each other. A third superconducting material 23 that connects the top surface 21b and the first recess 11b is disposed inside the first recess 11b.

[0020] In the above configuration, the upper surface 21b of the protrusion 21a abuts against the flat surface 11a of the first electrode 11, thereby setting the distance between the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 to a predetermined value determined by the height of the protrusion 21a. This means that a superconducting device 1 can be provided in which the first non-contact coupling circuit 12 and the second non-contact coupling circuit 22 are positioned more accurately relative to the design value. As a result, non-contact coupling can achieve input / output characteristics closer to the design value. The design value is a value that includes a predetermined tolerance from the reference value. Furthermore, because the first electrode 11 and the third superconducting material 23 are bonded at the first recess 11b, the area of ​​the bonding surface is increased compared to bonding flat surfaces, resulting in a stronger bond.

[0021] (Second embodiment) In this embodiment, a superconducting device 1000 will be described as a specific example of the configuration of the superconducting device 1 of the first embodiment.

[0022] 2 is a cross-sectional view showing the configuration of a superconducting device 1000 according to the second embodiment. The superconducting device 1000 is an example of the superconducting device 1.

[0023] Referring to FIG. 2, the superconducting device 1000 includes a superconducting integrated circuit chip 100 and a circuit board 200. The superconducting integrated circuit chip 100 has a first electrode 110 made of a first superconducting material and a first non-contact coupling circuit 120 on its surface. The circuit board 200 has a second electrode 210 made of a second superconducting material and a second non-contact coupling circuit 220 on its surface. The circuit board 200 is disposed opposite the superconducting integrated circuit chip 100. The second electrode 210 includes a flat upper surface 212 and has a protrusion 211 that protrudes toward the superconducting integrated circuit chip 100. The first electrode 110 has a flat surface 111 and a first recess 112 that is disposed inside the flat surface 111 and has an area smaller than that of the upper surface 212. The first recess 112 is disposed opposite the first recess 112 and is located inside the upper surface 212. The upper surface 212 and the flat surface 111 are in contact with each other. A third superconducting material 240 that connects the upper surface 212 and the first recessed portion 112 is disposed inside the first recessed portion 112.

[0024] Next, a configuration example of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment will be described. Fig. 3 is a plan view showing a configuration example of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment. Fig. 4 is a cross-sectional view showing a first configuration example of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment. Fig. 4 shows the A-A' cross section of Fig. 3.

[0025] 3 and 4, the superconducting integrated circuit chip 100 has a substrate 101. A first electrode 110 made of a first superconducting material and a first non-contact coupling circuit 120 are formed on the surface of the substrate 101. The first electrode 110 has a flat surface 111 and a first recess 112 provided inside the flat surface. The superconducting integrated circuit chip 100 is an example of the superconducting integrated circuit chip 10 of the first embodiment. The first electrode 110 is an example of the first electrode 11 of the first embodiment, the first non-contact coupling circuit 120 is an example of the first non-contact coupling circuit 12, the flat surface 111 is an example of the flat surface 11a, and the first recess 112 is an example of the first recess 11b.

[0026] The first electrode 110 is connected to a circuit such as a ground circuit (not shown). The first non-contact coupling circuit 120 is connected to a superconducting circuit (not shown). The first superconducting material constituting the first electrode 110 may be, for example, niobium, niobium nitride, aluminum, indium, lead, tin, rhenium, palladium, titanium, titanium nitride, tantalum, or an alloy containing any of these. The base material 101 may be, for example, silicon. The first non-contact coupling circuit 120 is, for example, a capacitive coupling circuit or an inductive coupling circuit for inputting and outputting signals to and from the circuit board 200. The base material 101 may be, for example, silicon. Although not shown, a first wiring layer may be provided below the first electrode 110.

[0027] As shown in FIG. 4, a thin film 110a of a first superconducting material is disposed on the surface of the first electrode 110. The thin film 110a of the first superconducting material has, for example, a uniform thickness. A recess-forming layer 113 is disposed below the thin film 110a of the first superconducting material. The recess-forming layer 113 is patterned, and the patterned thin film 110a of the first superconducting material is laminated thereon, thereby forming a flat surface 111 and a first recess 112. The recess-forming layer 113 can be formed, for example, using a wiring layer of a superconducting integrated circuit chip.

[0028] Next, a second configuration example of the superconducting integrated circuit chip 100 will be described as a modification of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment.

[0029] 5 is a cross-sectional view showing a second example configuration of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment. In the second configuration shown in FIG. 5, in addition to the configuration of FIG. 4, a first adhesion layer 110b is disposed below the thin film 110a of the first superconducting material. By providing the first adhesion layer 110b, the adhesion between the thin film 110a of the first superconducting material and the substrate 101 and the recess-forming layer 113 is improved. For example, titanium, titanium nitride, iridium, etc. can be used for the first adhesion layer 110b.

[0030] Next, a third configuration example of the superconducting integrated circuit chip 100 will be described as a modification of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment.

[0031] FIG. 6 is a cross-sectional view showing a third configuration example of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment. In the third configuration example, an uneven portion 112a is formed on the bottom of the first recess 112. The other configurations can be the same as the first configuration example of FIG. 4 or the second configuration example of FIG. 5. By providing the uneven portion 112a, the surface area of ​​the first recess 112 is increased, and therefore, when a bonding material is filled in the first recess 112, the bonding strength between the bonding material and the thin film 110a of the first superconducting material in the first recess 112 can be increased. Note that the uneven portion 112a can be formed, for example, by roughening the bottom surface of the first recess 112 by physical etching or chemical etching, or by patterning the recess-forming layer 113, but is not limited thereto.

[0032] Next, a fourth configuration example of the superconducting integrated circuit chip 100 will be described as a modification of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment.

[0033] FIG. 7 is a cross-sectional view showing a fourth configuration example of a superconducting integrated circuit chip used in the superconducting device of the second embodiment. As shown in FIG. 7 , in the fourth configuration example, a second recess 102 is disposed below the first electrode 110 in the first recess 112. The second recess 102 can be formed, for example, by digging into the substrate 101, as shown in FIG. 7 . The substrate 101 can be made of, for example, silicon. Various high-precision three-dimensional processing methods have been developed for silicon, and these methods can be used to accurately form the second recess 102. With the above configuration, it is easier to form a deeper first recess 112 than, for example, the method of forming the first recess 112 using the recess-forming layer 113 in the first configuration example. By deepening the first recess 112, the surface area of ​​the first recess 112 increases. Therefore, when a bonding material is filled in the first recess 112, the bonding strength between the bonding material and the thin film 110a of the first superconducting material in the first recess 112 can be enhanced.

[0034] Next, a fifth configuration example of the superconducting integrated circuit chip 100 will be described as a modification of the superconducting integrated circuit chip 100 used in the superconducting device 1000 of the second embodiment.

[0035] 8 is a cross-sectional view showing a fifth configuration example of a superconducting integrated circuit chip used in the superconducting device of the second embodiment. In the fifth configuration example, a through-hole 103 is formed in the substrate 101 at a position corresponding to the first recess 112, and the through-hole 103 is filled with a filler 104 to a predetermined depth, thereby forming the second recess 102. This makes it easy to form a deep first recess 112. Therefore, as in the fourth configuration example, the surface area of ​​the first recess 112 is increased, and when a bonding material is filled in the first recess 112, the bonding strength between the bonding material and the thin film 110a of the first superconducting material in the first recess 112 can be increased.

[0036] In the above description, an example was described in which the shape of the first recess 112 is cylindrical, but the shape of the first recess 112 is not limited to this and may be, for example, a polygonal prism, a cone, a polygonal pyramid, a truncated cone, a truncated polygonal pyramid, etc.

[0037] Next, the configuration of the circuit board 200 used in the superconducting device 1000 of the second embodiment will be described. Fig. 9 is a plan view showing the circuit board 200 used in the superconducting device 1000 of the second embodiment. Fig. 10 is a cross-sectional view showing a first configuration example of the circuit board 200 used in the superconducting device of the second embodiment. Fig. 11 is a cross-sectional view showing the first configuration example of the circuit board 200 used in the superconducting device of the second embodiment.

[0038] As shown in FIGS. 9 and 10 , circuit board 200 has substrate 201. A second electrode 210 made of a second superconducting material and a second non-contact coupling circuit 220 are formed on the surface of substrate 201. Second electrode 210 has a protrusion 211 of a predetermined height and a flat upper surface 212. Here, circuit board 200 is an example of circuit board 20 of the first embodiment. Second electrode 210 is an example of second electrode 21, second non-contact coupling circuit 220 is an example of second non-contact coupling circuit 22, protrusion 211 is an example of protrusion 21a, and upper surface 212 is an example of upper surface 21b.

[0039] The substrate 201 of the circuit board 200 is made of, for example, silicon. The second superconducting material may be, for example, niobium, niobium nitride, aluminum, indium, lead, tin, rhenium, palladium, titanium, titanium nitride, tantalum, or an alloy containing any of these. The second electrode 210 is connected, for example, to a ground circuit (not shown). The second non-contact coupling circuit 220 is connected, for example, to an electronic circuit (not shown). Although not shown, a second wiring layer may be provided below the second electrode 210.

[0040] FIG. 10 is a cross-sectional view showing a circuit board 200 used in the superconducting device of the second embodiment. FIG. 10 is a cross-sectional view taken along the line BB′ in FIG. 9. As shown in FIG. 10, a protrusion 230 having a predetermined height and a flat upper surface is formed on a substrate 201. The protrusion 230 is covered with a thin film 210a of a second superconducting material, thereby forming a second electrode 210. The thin film 210a of the second superconducting material has, for example, a uniform thickness. The thin film 210a of the second superconducting material can be formed of, for example, niobium, niobium nitride, aluminum, lead, tin, rhenium, palladium, titanium, titanium nitride, tantalum, or an alloy containing any of these. The protrusion 230 can be formed of a material different from the thin film 210a of the second superconducting material, such as copper, silver, gold, platinum, or an alloy containing any of these.

[0041] Some superconducting materials, such as niobium, are difficult to process, making it difficult to form a three-dimensional structure such as the protrusion 230. Therefore, by using a material that is easy to process, the protrusion 230 can be easily formed. Furthermore, by using a material that is easy to process, the height of the protrusion 230 can be accurately controlled and the upper surface can be made flat. Then, by stacking a thin film 210a of a second superconducting material with an accurately controlled film thickness on the protrusion 230, the height of the protrusion 211 can be accurately controlled and the upper surface 212 can be made flat. Furthermore, by processing the above-mentioned stacked film using photolithography, etching, or the like, the second electrode 210 and the protrusion 211 can be easily formed.

[0042] Next, a second configuration example of the circuit board 200 will be described as a modification of the circuit board 200 used in the superconducting device of the second embodiment.

[0043] 11 is a cross-sectional view showing a second configuration example of circuit board 200 used in the superconducting device of the second embodiment. In the second configuration example of circuit board 200, in addition to the first configuration example of FIG. 10, a second adhesion layer 213 is laminated below thin film 210a of second superconducting material. By providing second adhesion layer 213, the adhesion between thin film 210a of second superconducting material and substrate 201 and protrusion 230 is improved. For example, titanium, titanium nitride, iridium, etc. can be used for second adhesion layer 213.

[0044] Next, as a modification of the arrangement of the third superconducting material 240 on the circuit board 200 used in the superconducting device of the second embodiment, a first example of the arrangement of the third superconducting material 240 on the circuit board 200 will be described.

[0045] FIG. 12 is a cross-sectional view showing a first example of the arrangement of the third superconducting material 240 on the circuit board 200 of the superconducting device 1000 of the second embodiment. The third superconducting material 240 connects the upper surface 212 of the protrusion 211 and the first recess 112 of the superconducting integrated circuit chip 100. When manufacturing the superconducting device 1000, the circuit formation surface of the superconducting integrated circuit chip 100 and the circuit formation surface of the circuit board 200 are brought into close proximity to each other, and the upper surface 212 of the protrusion 211 is brought into contact with the flat surface 111 of the first electrode 110. At this time, the first recess 112 is aligned so as to fit inside the upper surface 212. The third superconducting material 240 is then bonded to the thin film 110a of the first superconducting material in the first recess 112 and the thin film 210a of the second superconducting material on the upper surface 212.

[0046] In the above configuration, it is desirable that the volume of the third superconducting material 240 is close to the volume of the first recess 112 so that the third superconducting material 240 contacts the entire inner surface of the first recess 112. On the other hand, it is desirable that the third superconducting material 240 does not protrude into the contact area between the upper surface 212 of the protrusion 211 and the flat surface 111 of the first electrode 110. For this reason, for example, the volume of the third superconducting material 240 can be set to be smaller than the volume of the first recess 112 by a predetermined margin. After setting it in this way, the third superconducting material 240 is arranged in a bump shape on the upper surface 212.

[0047] The third superconducting material 240 is crushed inside the first recess 112 to connect the first superconducting material thin film 110a and the second superconducting material thin film 210a. For this reason, it is desirable to use a material for the third superconducting material 240 that is more malleable than the first superconducting material thin film 110a and the second superconducting material thin film 210a. To meet this condition, it is desirable to select the third superconducting material 240 depending on the materials used for the first superconducting material thin film 110a and the second superconducting material thin film 210a. For example, if the first superconducting material thin film 110a and the second superconducting material thin film 210a are both niobium, the third superconducting material 240 can be indium.

[0048] Next, a second example of the arrangement of the third superconducting material on the circuit board 200 will be described as a modification of the arrangement of the third superconducting material on the circuit board 200 used in the superconducting device of the second embodiment.

[0049] 13 is a cross-sectional view showing a second example of the arrangement of a third superconducting material on the circuit board of the superconducting device of the second embodiment. In the second example of FIG. 13, in addition to the configuration of the first example of FIG. 12, a third adhesion layer 241 is provided between the third superconducting material 240 and the upper surface 212. The third adhesion layer 241 can be formed of, for example, titanium, titanium nitride, or iridium. By providing the third adhesion layer 241, the adhesion between the third superconducting material 240 and the upper surface 212 can be improved.

[0050] Next, a third configuration example of the circuit board 200 will be described as a modification of the circuit board 200 used in the superconducting device of the second embodiment.

[0051] Fig. 14 is a cross-sectional view showing a third configuration example of circuit board 200 used in the superconducting device of the second embodiment. In the example of Fig. 14, thin film 210a of second superconducting material has opening 214 on the inside of upper surface 212. Opening 214 can be formed by, for example, photolithography. For example, if the adhesion between third superconducting material 240 and thin film 210a of second superconducting material is poor but the adhesion between third superconducting material 240 and protrusion 230 is good, providing opening 214 can improve the adhesion.

[0052] Next, a fourth configuration example of the circuit board 200 will be described as a modification of the circuit board 200 used in the superconducting device of the second embodiment.

[0053] Fig. 15 is a cross-sectional view showing a fourth configuration example of a circuit board used in the superconducting device of the second embodiment. In the fourth configuration example of Fig. 15, in addition to the third configuration example of Fig. 14, a fourth adhesion layer 242 is provided between the third superconducting material 240 and the protrusion 230. By providing the fourth adhesion layer 242, it is possible to improve the adhesion of the third superconducting material 240 to the protrusion 211. For example, titanium, titanium nitride, or iridium can be used for the fourth adhesion layer 242.

[0054] Next, a method for manufacturing a superconducting device according to a second embodiment will be described. Fig. 16 is a cross-sectional view showing a first state in the method for manufacturing a superconducting device according to the second embodiment. Fig. 17 is a cross-sectional view showing a second state in the method for manufacturing a superconducting device according to the second embodiment. Fig. 18 is a cross-sectional view showing a third state in the method for manufacturing a superconducting device according to the second embodiment.

[0055] First, as shown in Fig. 16, the superconducting integrated circuit chip 100 and the circuit board 200 are placed in a vacuum chamber (not shown) with their circuit forming surfaces facing each other, and the chamber is evacuated. At this time, the superconducting integrated circuit chip 100 is fixed by a chip fixing jig (not shown), and the circuit board 200 is fixed by a substrate fixing jig (not shown). As a fixing method, for example, a clamping method or an electrostatic chuck method can be applied. The degree of vacuum in the chamber is, for example, 10 -6 A value of about Pa is preferred.

[0056] 17, an activation device 300 is used to remove adsorbed materials and oxides from the flat surface 111 of the first electrode 110 and the surface of the first recess 112, which will be the bonding portion of the superconducting integrated circuit chip 100, thereby activating the bonding portion. The activation device 300 for activation may be, for example, a device that irradiates ions or a neutral atomic beam. Similarly, the activation device 300 is used to remove adsorbed materials and oxides from the surfaces of the protrusion 211 and the third superconducting material 240, which will be the bonding portion of the circuit board 200, thereby activating the bonding portion.

[0057] Next, as shown in FIG. 18 , the superconducting integrated circuit chip 100 and the circuit board 200 are aligned so that the first non-contact coupling circuit 120 and the second non-contact coupling circuit 220 face each other. At this time, the third superconducting material 240 arranged in a bump shape on the upper surface 212 is aligned so that it faces the inside of the first recess 112. Then, while maintaining the vacuum, the superconducting integrated circuit chip 100 and the circuit board 200 are brought close to each other so that the flat surface 111 of the first electrode 110 and the upper surface 212 of the protrusion 211 come into contact with each other. Furthermore, the superconducting integrated circuit chip 100 and the circuit board 200 are brought close to each other so that the flat surface 111 of the first electrode 110 and the upper surface 212 of the protrusion 211 come into close contact with each other. Furthermore, a force is applied in a direction that brings the superconducting integrated circuit chip 100 and the circuit board 200 close to each other, and a predetermined pressure is applied to the contact portions between them. At this time, the temperatures of the first recess 112 and the third superconducting material 240 are controlled within a range of, for example, room temperature, 25° C. to 100° C. By performing bonding at a low temperature of 100° C. or less, positional deviation during bonding caused by changes in the state of the superconducting element due to heating and thermal expansion of the members can be reduced, and bonding can be performed with accurate positioning.

[0058] By applying pressure as described above, the malleable third superconducting material 240 is inserted into the first recess 112 and bonded to the first recess 112, conforming to the surface roughness of the inner surface. A portion of the flat surface 111 of the first electrode 110 and the outer periphery of the upper surface 212 of the protrusion 211 are also bonded. In this bonding, an amorphous layer is formed at the bonding interface between the thin film 110a of the first superconducting material and the third superconducting material 240, resulting in a strong bond between them. Similarly, an amorphous layer is also formed at the bonding interface between the thin film 110a of the first superconducting material and the thin film 210a of the second superconducting material, resulting in a strong bond between them. While not shown, the superconducting integrated circuit chip 100 and the circuit board 200 can be aligned by, for example, providing alignment marks on each of them and adjusting their positions using a transmission image captured by an infrared camera.

[0059] Next, a modified example of the superconducting device 1000 will be described. Fig. 19 is a cross-sectional view showing a modified example of the superconducting device 1000 described in Fig. 18. In this modified example, the superconducting integrated circuit chip 100 shown in Fig. 6 has an uneven portion 112a at the bottom of the first recess 112. By using this superconducting integrated circuit chip 100, the contact area between the third superconducting material 240 filled in the first recess 112 and the first recess 112 increases, thereby enabling the superconducting integrated circuit chip 100 and the circuit board 200 to be firmly bonded together.

[0060] The superconducting device and the like according to the second embodiment of the present invention have been described above.

[0061] A superconducting device 1000 of the second embodiment includes a superconducting integrated circuit chip 100 and a circuit board 200. The superconducting integrated circuit chip 100 has a first electrode 110 made of a first superconducting material and a first non-contact coupling circuit 120 on its surface. The circuit board 200 has a second electrode 210 made of a second superconducting material and a second non-contact coupling circuit 220 on its surface, and is disposed opposite the superconducting integrated circuit chip 100. The second electrode 210 further includes a flat upper surface 212 and has a protrusion 211 that protrudes toward the superconducting integrated circuit chip 100. The first electrode 110 has a flat surface 111 and a first recess 112 that is disposed inside the flat surface 111 and has an area smaller than that of the upper surface 212. The first recess 112 is arranged opposite to the upper surface 212 so as to be located inside the upper surface 212, the upper surface 212 and the flat surface 111 abut against each other, and a third superconducting material 240 connecting the upper surface 212 and the first recess 112 is arranged inside the first recess 112.

[0062] In the above configuration, the upper surface 212 of the protrusion 211 abuts against the flat surface 111 of the first electrode 110, thereby setting the distance between the first non-contact coupling circuit 120 and the second non-contact coupling circuit 220 to a predetermined value determined by the height of the protrusion 211. In other words, it is possible to provide a superconducting device 1000 that allows the first non-contact coupling circuit 120 and the second non-contact coupling circuit 220 to be positioned more accurately with respect to the design values. As a result, it is possible to obtain input / output characteristics closer to the design values ​​through non-contact coupling. Furthermore, because the first electrode 110 and the third superconducting material 240 are bonded at the first recess 112, the area of ​​the bonding surface is increased compared to when flat surfaces are bonded together, resulting in a stronger bond.

[0063] Moreover, according to one embodiment, in superconducting device 1000, thin film 110a of a first superconducting material is disposed on the surface of first electrode 110. In this configuration, by disposing thin film 110a of first superconducting material with a uniform thickness, first recess 112 can be formed along the shape formed by underlying recess-forming layer 113.

[0064] According to one embodiment, at least one first adhesion layer 110b is disposed below the thin film 110a of the first superconducting material in the superconducting device 1000. By providing the first adhesion layer 110b, it is possible to improve the adhesion between the thin film 110a of the first superconducting material and the underlying layer such as the substrate 101.

[0065] According to one embodiment, in the superconducting device 1000, the second recess 102 is disposed below the first electrode 110 at a position corresponding to the first recess 112. By providing the second recess 102, the first recess 112 can be formed using a thin film 110a of the first superconducting material with a uniform thickness.

[0066] According to one embodiment, in the superconducting device 1000, the second recess 102 is provided in the substrate 101 of the superconducting integrated circuit chip 100. By providing the second recess 102 in the substrate 101, it becomes easier to form the deeper first recess 112.

[0067] According to one embodiment, in the superconducting device 1000, the second recess 102 is formed by filling the through-hole 103 provided in the substrate 101 of the superconducting integrated circuit chip 100 with a first material different from the substrate 101 to a predetermined depth. This configuration makes it easy to form a deeper second recess 102, and also makes it easy to form a corresponding deeper first recess 112.

[0068] According to one embodiment, the surface of the second electrode 210 is formed of a thin film 210a of a second superconducting material in the superconducting device 1000. By using the thin film 210a of the second superconducting material, the second electrode 210 can be obtained with excellent characteristics and workability.

[0069] According to one embodiment, at least one second adhesion layer 213 is disposed below the thin film 210a of the second superconducting material in the superconducting device 1000. By providing the second adhesion layer 213, it is possible to improve the adhesion between the thin film 210a of the second superconducting material and the underlying layer such as the substrate 201.

[0070] Furthermore, according to one aspect, in superconducting device 1000, protrusion 230 made of a second material different from the second superconducting material is disposed inside thin film 210a of the second superconducting material in protrusion 211. By forming protrusion 230 from a material that is easy to process and different from the second superconducting material, protrusion 230 having a desired shape can be formed, and protrusion 211 having a desired shape can be easily formed.

[0071] Furthermore, according to one embodiment, in superconducting device 1000, thin film 210a of second superconducting material has opening 214 inside upper surface 212, and third superconducting material 240 is disposed at a position corresponding to opening 214. With this configuration, when the adhesion between third superconducting material 240 and thin film 210a of second superconducting material is poor compared to the adhesion between third superconducting material 240 and the material of protrusion 230, it is possible to improve the adhesion.

[0072] Furthermore, according to one embodiment, in the superconducting device 1000, a fourth adhesion layer 242 is formed in the opening 214 to improve adhesion between the second material and the third superconducting material 240. The effect of the fourth adhesion layer 242 can improve adhesion between the third superconducting material 240 and the protrusion 230.

[0073] According to one embodiment, the superconducting device 1000 includes a third adhesion layer 241. The third adhesion layer 241 enhances adhesion between the third superconducting material 240 and at least a portion of the upper surface 212. In this configuration, the action of the third adhesion layer 241 can improve adhesion between the third superconducting material 240 and the upper surface 212.

[0074] According to one embodiment, the superconducting device 1000 has a first joint where the flat surface 111 and the upper surface 212 are directly joined at least in part of the area where they abut. The joining of the flat surface 111 and the upper surface 212 makes it possible to more firmly join the superconducting integrated circuit chip 100 and the circuit board.

[0075] According to one embodiment, the first joint in the superconducting device 1000 has an amorphous layer containing the first superconducting material and the second superconducting material. By forming the amorphous layer, the thin film 110a of the first superconducting material and the thin film 210a of the second superconducting material can be more firmly joined.

[0076] Furthermore, according to one embodiment, the superconducting device 1000 has a second joint portion in which the thin film 110a of the first superconducting material located in the first recess 112 is directly joined to the third superconducting material 240. In this configuration, the thin film 110a of the first superconducting material in the first recess 112 is joined to the third superconducting material 240, thereby making the joint stronger.

[0077] According to one embodiment, in the superconducting device 1000, the second joint has an amorphous layer including the first superconducting material and the third superconducting material 240. This configuration enables the joint between the thin film 110a of the first superconducting material and the third superconducting material 240 to be more firmly joined.

[0078] According to one embodiment, in the superconducting device 1000, an uneven portion 112a is formed on the bottom surface of the first recess 112. The uneven portion 112a increases the contact area between the thin film 110a of the first superconducting material and the third superconducting material 240, thereby making the bond stronger.

[0079] According to one embodiment, the third superconducting material 240 is a material that is more ductile than the first superconducting material in the superconducting device 1000. With this configuration, a strong bond can be achieved even if the first recess 112 is miniaturized.

[0080] The method for manufacturing a superconducting device 1000 of the second embodiment includes joining a superconducting integrated circuit chip 100 and a circuit board 200. The superconducting integrated circuit chip 100 has a first electrode 110 made of a first superconducting material and a first non-contact coupling circuit 120 on its surface. The circuit board 200 has a second electrode 210 made of a second superconducting material and a second non-contact coupling circuit 220 on its surface, and is disposed opposite the superconducting integrated circuit chip 100. The second electrode 210 includes a flat upper surface 212 and has a protrusion 211 that protrudes toward the superconducting integrated circuit chip 100. The first electrode 110 has a flat surface 111 and a first recess 112 that is disposed inside the flat surface 111 and has an area smaller than that of the upper surface 212. In the method for manufacturing the superconducting device 1000 of the second embodiment, a third superconducting material 240 that connects the upper surface 212 and the first recessed portion 112 is placed inside the first recessed portion 112. Furthermore, the first recessed portion 112 is placed facing the upper surface 212 so as to be located inside the upper surface 212, and the upper surface 212 and the flat surface 111 are brought into contact with each other.

[0081] According to one embodiment, in the method for manufacturing the superconducting device 1000, the superconducting integrated circuit chip 100 and the circuit board 200 are bonded together in a vacuum chamber. This configuration allows the flat surface 111 to be bonded to the upper surface 212, and the first recess 112 to be bonded to the third superconducting material 240.

[0082] Furthermore, according to one embodiment, the method for manufacturing superconducting device 1000 activates the surface of first recess 112 and the surface of third superconducting material 240 before bringing flat surface 111 and upper surface 212 into contact with each other, and then brings flat surface 111 and upper surface 212 into contact with each other. This configuration can further strengthen the bond between flat surface 111 and upper surface 212 and the bond between first recess 112 and third superconducting material 240.

[0083] According to one embodiment, the method for manufacturing the superconducting device 1000 brings the flat surface and the upper surface into contact with each other by controlling the temperature of the first recess 112 and the temperature of the third superconducting material 240 within a range of room temperature, 25°C to 100°C. By performing bonding at a low temperature of 100°C or less, positional deviation during bonding due to changes in the state of the superconducting element caused by heating or thermal expansion of the members is small, and bonding can be performed with accurate positioning.

[0084] According to one embodiment, the method for manufacturing superconducting device 1000 sets the arithmetic mean roughness of flat surface 111 and the arithmetic mean roughness of upper surface 212 to 1 nm or less. This configuration allows the two to be bonded more firmly.

[0085] The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above-described embodiment. In other words, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

[0086] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on its surface; a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on its surface, the circuit board being disposed so as to face the first non-contact coupling circuit; Equipped with the second electrode includes a flat upper surface and a protrusion protruding toward the superconducting integrated circuit chip; the first electrode has a flat surface and a first recessed portion that is disposed inside the flat surface and has an area smaller than that of the upper surface; the first recesses are arranged opposite to each other so as to be located inside the upper surface, the upper surface and the flat surface abut against each other, a third superconducting material connecting the upper surface and the first recess is disposed inside the first recess; A superconducting device characterized by: (Appendix 2) a thin film of the first superconducting material disposed on a surface of the first electrode; 2. The superconducting device according to claim 1, (Appendix 3) At least one first adhesive layer is disposed under the thin film of the first superconducting material. 3. The superconducting device according to claim 2, (Appendix 4) a second recess is disposed in a lower layer of the first electrode at a position corresponding to the first recess; 4. The superconducting device according to claim 2 or 3, (Appendix 5) the second recess is provided in a substrate of the superconducting integrated circuit chip; 5. The superconducting device according to claim 4, (Appendix 6) the second recess is formed by filling a through hole provided in the substrate of the superconducting integrated circuit chip with a first material different from the substrate to a predetermined depth; 5. The superconducting device according to claim 4, (Appendix 7) the surface of the second electrode is formed of a thin film of the second superconducting material; 7. The superconducting device according to any one of claims 1 to 6, (Appendix 8) At least one second adhesive layer is disposed beneath the thin film of the second superconducting material. 8. The superconducting device according to claim 7,

[0087] a protrusion made of a second material different from the second superconducting material is disposed inside the thin film of the second superconducting material in the protruding portion; 8. The superconducting device according to claim 6 or 7, (Appendix 9) the thin film of the second superconducting material has an opening on the inside of the upper surface, and the third superconducting material is disposed at a position corresponding to the opening; 9. The superconducting device according to claim 8, (Appendix 10) a third adhesion layer for enhancing adhesion between the second material and the third superconducting material is formed in the opening; 10. The superconducting device according to claim 9, (Appendix 11) a fourth adhesion layer is disposed between the third superconducting material and at least a portion of the upper surface to enhance adhesion therebetween; 11. The superconducting device according to any one of claims 1 to 10. (Appendix 12) a first bonding portion where the flat surface and the upper surface are directly bonded to each other in at least a portion of the area where the flat surface and the upper surface are in contact with each other; 12. The superconducting device according to any one of claims 1 to 11, (Appendix 13) The first junction has an amorphous layer including the first superconducting material and the second superconducting material. 13. The superconducting device according to claim 12, (Appendix 14) a second joint portion in which the first superconducting material located in the first recess and the third superconducting material are directly joined; 14. The superconducting device according to any one of claims 1 to 13, (Appendix 15) The second junction has an amorphous layer including the first superconducting material and the third superconducting material. 15. The superconducting device according to claim 14, (Appendix 16) A concave-convex portion is formed on the bottom surface of the first recessed portion. 16. The superconducting device according to any one of claims 1 to 15, (Appendix 17) the third superconducting material is more ductile than the first superconducting material; 17. The superconducting device according to any one of claims 1 to 16, (Appendix 18) A method for manufacturing a superconducting device comprising: a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on a surface thereof; and a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on a surface thereof, the circuit board being disposed so as to face the first non-contact coupling circuit, the second electrode includes a flat upper surface and a protrusion protruding toward the superconducting integrated circuit chip; the first electrode has a flat surface and a first recessed portion that is disposed inside the flat surface and has an area smaller than that of the upper surface; a third superconducting material is disposed inside the first recess, the third superconducting material connecting the upper surface and the first recess; The first recesses are disposed opposite each other so as to be located inside the upper surface, The upper surface and the flat surface are brought into contact with each other. A method for manufacturing a superconducting device. (Appendix 19) The superconducting integrated circuit chip and the circuit board are bonded in a vacuum chamber. 19. A method for manufacturing a superconducting device according to claim 18, (Appendix 20) activating a surface of the first recess and a surface of the third superconducting material before the flat surface and the upper surface are brought into contact with each other; The flat surface and the upper surface are brought into contact with each other. 20. A method for manufacturing a superconducting device according to claim 19, (Appendix 21) the flat surface and the upper surface are brought into contact with each other while controlling the temperature of the first recess and the temperature of the third superconducting material within a range of 25°C to 100°C; 21. A method for manufacturing a superconducting device according to claim 20. (Appendix 22) The arithmetic mean roughness of the flat surface and the arithmetic mean roughness of the upper surface are set to 1 nm or less. 22. A method for manufacturing a superconducting device according to any one of claims 17 to 21. [Explanation of symbols]

[0088] 1,1000 Superconducting Device 10, 100 Superconducting integrated circuit chip 11, 110 first electrode 11a, 111 flat surface 11b, 112 first recess 12, 120 First non-contact coupling circuit 20, 200 circuit board 21, 210 second electrode 21a, 211 protrusion 21b, 212 top surface 22, 220 Second non-contact coupling circuit 23, 240 The third superconducting material 101 Base material 201 Substrate 230 protrusion 300 activation device

Claims

1. a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on its surface; a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on its surface, the circuit board being disposed so as to face the superconducting integrated circuit chip; Equipped with the second electrode includes a flat upper surface and a protrusion protruding toward the superconducting integrated circuit chip; the first electrode has a flat surface and a first recessed portion disposed inside the flat surface and having an area smaller than that of the upper surface; the first recesses are disposed opposite to each other so as to be located inside the upper surface; the upper surface and the flat surface abut against each other, a third superconducting material connecting the upper surface and the first recess is disposed inside the first recess; A superconducting device characterized by:

2. a thin film of the first superconducting material disposed on a surface of the first electrode; 2. The superconducting device according to claim 1.

3. a second recess is disposed in a lower layer of the first electrode at a position corresponding to the first recess; 3. The superconducting device according to claim 1 or 2.

4. the second recess is provided in a substrate of the superconducting integrated circuit chip; 4. The superconducting device according to claim 3.

5. a protrusion made of a second material different from the second superconducting material is disposed inside the thin film of the second superconducting material in the protruding portion; 5. A superconducting device according to claim 1, wherein the superconducting device comprises: a first insulating layer;

6. the thin film of the second superconducting material has an opening on the inside of the upper surface, and the third superconducting material is disposed at a position corresponding to the opening; 6. The superconducting device according to claim 5.

7. an adhesion layer is disposed between the third superconducting material and at least a portion of the upper surface to enhance adhesion therebetween; 7. A superconducting device according to claim 1, wherein the superconducting device comprises: a first insulating layer;

8. a second joint portion in which the first superconducting material located in the first recess and the third superconducting material are directly joined; 8. A superconducting device according to claim 1, wherein the superconducting device comprises:

9. the third superconducting material being more ductile than the first superconducting material; 9. A superconducting device according to claim 1, wherein the superconducting device comprises:

10. A method for manufacturing a superconducting device comprising: a superconducting integrated circuit chip having a first electrode made of a first superconducting material and a first non-contact coupling circuit on a surface thereof; and a circuit board having a second electrode made of a second superconducting material and a second non-contact coupling circuit on a surface thereof, the circuit board being disposed so as to face the superconducting integrated circuit chip, the second electrode includes a flat upper surface and a protrusion protruding toward the superconducting integrated circuit chip; the first electrode has a flat surface and a first recessed portion disposed inside the flat surface and having an area smaller than that of the upper surface; a third superconducting material connecting the upper surface and the first recess is disposed inside the first recess; The first recesses are disposed opposite each other so as to be located inside the upper surface, The upper surface and the flat surface are brought into contact with each other. A method for manufacturing a superconducting device.

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