Method for manufacturing spin wave excitation and detection structure

Abstract

To provide a method capable of manufacturing a spin wave excitation and detection structure improving a structure strength, improving the strength of a spin wave that can be excited, and widening a frequency bandwidth of the spin wave that can be excited.SOLUTION: The present invention relates to a method of manufacturing a spin wave excitation and a detection structure for exciting and detecting a spin wave. The manufacturing method of the spin wave excitation and detection structure includes the steps of: forming an insulation magnetic substance film on a donor substrate; manufacturing a laminated substrate by laminating a surface of the insulation magnetic substance film on the donor substrate with a surface of a support substrate while interposing a conductor film therebetween; removing the donor substrate from the laminated substrate; and forming a conductor line on the insulation magnetic substance film. Thus, the method manufactures the spin wave excitation and detection structure comprising the support substrate, the conductor film provided on the support substrate, the insulation magnetic substance film provided on the conductor film and the conductor line provided on the insulation magnetic substance film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a spin wave excitation and detection structure. [Background technology]

[0002] With the recent explosive growth in the amount of information handled on the Internet and elsewhere, there have been rapid developments in faster CPUs, faster medium- and long-distance communications using RF (radio frequency) and optical communications, increased data storage capacity, and the miniaturization of various components, but the bottlenecks to improving processing speeds are (1) the heat generation problem caused by performance improvements through miniaturization approaching physical limits, and (2) the slowdown in the development of data communication speeds (latency) between CPUs and memory.To address problem (1), there have been calls to switch to low-power carriers, but problem (2) is also becoming more pronounced with the recent development of related technologies.

[0003] For example, in the case of a group of sensors (so-called artificial skin) capable of detecting sensations at the same level as humans, enabling access using conventional electronic devices would require a huge number of transistors, leading to larger control units and communication delays. Furthermore, while high-resolution 3D displays in the medical and entertainment fields can be viewed by multiple people simultaneously by widening the viewing angle (ensuring approximately 45 degrees), constructing these displays using electronic devices would still require a huge number of transistors. As a result, communication delays and heat generation in the wiring cannot be ignored, raising concerns about burnt wiring and unstable operation due to heat.

[0004] As a result of the increasing number of situations in which large numbers of elements are required and the rapid increase in integration density, CMOS-based systems have become a bottleneck for all applications in terms of both speed and miniaturization.

[0005] There is a technology that uses spin waves to solve these problems in systems that use conventional CMOS.

[0006] Spin waves are phase waves created by magnetization (spin) in magnetic materials. They are also called magnetostatic waves. Magnetic materials contain many spins, as shown in Figure 6. The surface where the timing (phase) of the rotation of these spins is aligned creates a wavefront. When this wavefront propagates, information can be transmitted. This is a spin wave, and information can be transmitted without the movement of electric charge. Spin waves are a phenomenon related only to the magnetism of a material, and are not related to its electrical properties. In other words, they are waves that propagate through magnetic materials, whether they are conductors or insulators. For this reason, if an insulator is used, it is possible to create wiring through which electricity does not flow but spin waves do. Furthermore, because these spin waves are waves in the GHz (gigahertz) range, they are fast enough to be used for information processing.

[0007] Because spin waves are an information transmission method that does not require charge transfer, they are attracting attention as a potential next-generation, ultra-low-power information processing device. Basic logic circuits such as XNOR circuits [see Non-Patent Document 1], AND circuits, and OR circuits [see Non-Patent Document 2] have already been demonstrated and are currently in the research stage. With basic elements now demonstrated, more complex and practical circuits and applications are being proposed, demonstrated, and patented. Recently, research has been published that shows through calculations that compact address decoders can be created using spin waves (see Patent Document 1). In addition to functional advances, miniaturization is also progressing. It is expected that miniaturization to the micrometer and nanoscale will continue.

[0008] There are several methods for generating spin waves, but currently the most common method is to generate spin waves using an electric current.

[0009] Patent Document 2 describes a coplanar web guide type (a type that is completed in one layer) spin wave excitation structure. This is a spin wave excitation structure (antenna) of the type that has a signal level copper wire and a ground level copper wire made in one layer. A high frequency electrical signal can be input using a structure such as that described in Patent Document 2. As mentioned above, this structure is called a coplanar web guide structure, and is a widely known structure. It is widely used because the antenna part can be made in one layer and can be made small, down to the nanometer scale. However, there is a problem in that the frequency bandwidth of the spin waves (magnetostatic waves) that can be generated is narrow.

[0010] Patent Document 3 describes a microstrip line type spin wave excitation structure. The microstrip line is a structure in which a single copper wire (signal level) through which current flows is placed above a medium through which spin waves flow, and a ground level is provided below the medium through which spin waves flow (Patent Document 3 cites YIG (yttrium iron garnet) as an example).

[0011] The microstrip line type structure disclosed in Patent Document 3 has the advantage of being able to generate spin waves over a wide band. On the other hand, it has a multi-stage structure in which the signal level and ground level straddle the YIG, making it difficult to integrate.

[0012] As miniaturization and integration progress and microstrip lines become thinner, the distance between the signal level and ground level (= YIG thickness) remains the same, so a high-frequency rotating magnetic field cannot be created in the medium through which spin waves flow properly, and the strength of the spin waves decreases.The closer the signal level and ground level are, the more YIG there is between them, and the stronger the intensity of the spin waves that can be excited.

[0013] As the microstrip line becomes thinner, one way to maintain the spin wave strength is to simultaneously make the YIG thinner. However, if the thickness becomes less than 1 micrometer, the YIG cannot stand on its own (it will crack). For this reason, YIG is generally handled while on a substrate with a thickness of about 100 micrometers, and structural considerations are also carried out within that range.

[0014] Specifically, a conductor (usually copper wire) called a microstrip line, as shown in Figure 5(a), is used. A copper film is deposited on the entire surface of a Teflon substrate. The copper film is approximately 10 μm thick. The copper wire on the Teflon substrate is approximately 10 μm wide and 10 μm thick. When electricity is passed through this line, a rotating magnetic field is generated around the copper wire, rotating at a speed of approximately GHz. When a magnetic insulator (a material called YIG in Figure 5(a)) is placed in the area where this rotating magnetic field is generated while a DC magnetic field is applied, spin waves are excited by the rotating magnetic field. As a result, spin waves are transmitted from one microstrip line (input microstrip line) to the other microstrip line (output microstrip line). Conversely, at the output microstrip line, the rotating magnetic field generated by the spin waves generates a current within the microstrip line. That is, electricity is passed through the microstrip line to excite spin waves, resulting in spin wave propagation. During this propagation, calculations are performed, the calculation results are propagated, and the spin waves are converted to current and detected as an electrical signal. This process allows for the spin wave propagation spectrum shown by the "with magnetic field" line in Figure 5(b). The "without YIG" line in Figure 5(b) represents the spectrum obtained when the structure in Figure 5(a) does not contain YIG, while the "without magnetic field" line in Figure 5(b) represents the spectrum obtained when the structure in Figure 5(a) does not contain a DC magnetic field. Referring to Figure 5(a), the input microstrip line is the spin wave excitation structure, and the output microstrip line is the spin wave detection structure. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Japanese Patent Application Publication No. 2017-162937 [Patent Document 2] Special Publication No. 2006-504345 [Patent Document 3] Japanese Patent Application Publication No. 1-91514 [Non-patent literature]

[0016] [Non-Patent Document 1] Taichi Goto, Takuya Yoshimoto, Bungo Iwamoto, Kei Shimada, Caroline A. Ross, Koji Sekiguchi, Alexander B. Granovsky, Yuichi Nakamura, Hironaga Uchida and Mitsuteru Inoue, “Three-port logic gate using forward volume spin wave interference in a thin yttrium iron garnet film,” Scientific Reports, 9, 16472 (2019 / 11 / 11). [Non-patent document 2] Naoki Kanazawa, Taichi Goto, Koji Sekiguchi, Alexander B. Granovsky, Caroline A. Ross, Hiroyuki Takagi, Yuichi Nakamura, Hironaga Uchida and Mitsuteru Inoue, “The role of Snell's law for a magnonic majority gate,” Scientific Reports, 7, 7898 (2017 / 08 / 11). Summary of the Invention [Problem to be solved by the invention]

[0017] The spin wave devices that have been attracting attention as new information processing devices as described above also have a problem: the intensity of the spin waves is low.

[0018] A cross-sectional view of a currently used electrical spin wave excitation structure (also known as a transducer or antenna) (which can also be used as a spin wave detection structure as described above) is shown in Figure 4. A conventional spin wave excitation and detection structure 200 has a copper film 24 below a dielectric substrate 22, and a YIG film 26 is mounted on a copper wire 28 together with a gadolinium gallium garnet substrate 25. This structure is not suitable for miniaturization and integration. This is because simply scaling down the structure to make it smaller results in extremely low excitation efficiency and extremely narrow bandwidth.

[0019] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a method for manufacturing a spin wave excitation detection structure that has high structural strength, a high intensity of spin waves that can be excited, and a wide frequency bandwidth of spin waves that can be excited. [Means for solving the problem]

[0020] In order to achieve the above object, the present invention provides a method for manufacturing a spin wave excitation detection structure that excites and detects spin waves, comprising the steps of: forming an insulating magnetic film on a donor substrate; bonding a surface of the insulating magnetic film on the donor substrate to a surface of a support substrate via a conductive film to form a bonded substrate; removing the donor substrate from the bonded substrate; and forming a conductive wire on the insulating magnetic film, thereby manufacturing a spin wave excitation detection structure that includes the support substrate, the conductive film provided on the support substrate, the insulating magnetic film provided on the conductive film, and the conductive wire provided on the insulating magnetic film.

[0021] In this method for manufacturing a spin wave excitation / detection structure, the surface of the insulating magnetic film and the surface of the support substrate can be joined via a conductive film by a simple bonding method. Furthermore, the spin wave excitation / detection structure manufactured by this method has high structural strength and can excite high spin waves. Furthermore, the frequency bandwidth of the spin waves that can be excited is wide.

[0022] In this case, the conductive film can be formed on the support substrate, and the conductive film formed on the support substrate can be bonded to the surface of the insulating magnetic film.

[0023] Alternatively, the conductive film may be formed on the insulating magnetic film, and the conductive film formed on the insulating magnetic film may be bonded to the surface of the support substrate.

[0024] It is also possible to form the conductive film on both the support substrate and the insulating magnetic film, and then bond the first conductive film formed on the support substrate to the second conductive film formed on the insulating magnetic film.

[0025] Any of these bonding methods can easily bond the surface of the insulating magnetic film on the donor substrate to the surface of the support substrate via the conductive film.

[0026] Preferably, the insulating magnetic film is made of magnetic garnet, and more preferably, the insulating magnetic film is made of yttrium iron garnet.

[0027] By using such a type of insulating magnetic film, it is possible to excite good spin waves, and also to detect the spin waves without any problems.

[0028] Furthermore, in this case, it is preferable that the donor substrate is a substrate made of paramagnetic garnet.

[0029] In this way, by using a paramagnetic garnet as the donor substrate and using a magnetic garnet as the insulating magnetic film formed on the donor substrate, the garnets have similar structures, and therefore a magnetic garnet film, which is an insulating magnetic material, can be formed as having a good structure.

[0030] In the method for manufacturing a spin wave excitation and detection structure of the present invention, the step of removing the donor substrate from the bonded substrate stack can be performed by grinding and polishing.

[0031] Furthermore, the method for manufacturing a spin wave excitation detection structure of the present invention may further include a step of forming an ion-implanted surface by implanting ions into the insulating magnetic film after forming the insulating magnetic film on the donor substrate, and the step of removing the donor substrate from the bonded substrate may be performed by dividing the bonded substrate at the ion-implanted surface after fabricating the bonded substrate.

[0032] The donor substrate can be removed from the bonded substrate by any of these methods.

[0033] The conductive film and conductive wire may contain at least one of copper, aluminum, gold, silver, platinum, iron, a transparent conductor, a superconductor, graphene, and a conductive magnetic material.

[0034] In the method for manufacturing a spin wave excitation and detection structure of the present invention, the above-mentioned types of conductors can be used in addition to copper as the conductor component.

[0035] The support substrate may be at least one of a silicon substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate.

[0036] In the method for manufacturing a spin wave excitation / detection structure of the present invention, the above-mentioned types of substrates can be used as the support substrate in addition to a silicon substrate. [Effects of the Invention]

[0037] The method for manufacturing a spin wave excitation detection structure of the present invention can bond the surface of an insulating magnetic film and the surface of a support substrate via a conductive film using a simple bonding method. Furthermore, a spin wave excitation detection structure manufactured by such a manufacturing method has high structural strength and can excite spin waves with high intensity. Furthermore, the frequency bandwidth of the spin waves that can be excited is wide. More specifically, a spin wave excitation detection structure manufactured by the manufacturing method of the present invention has a conductive film between the insulating magnetic film and the support substrate, and has the wide excitation bandwidth characteristic of a microstrip line. Furthermore, the signal level and ground level are close to each other, and the insulating magnetic film, which is a region between them where spin waves flow, provides high intensity of the excited spin waves. Furthermore, because the insulating magnetic film is bonded to the support substrate via the conductive film, the structure has high mechanical strength and is easy to handle. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a flow chart showing an example of a method for manufacturing a spin wave excitation detection structure according to the present invention. [Figure 2] FIG. 10 is a flow chart showing another example of the method for manufacturing the spin wave excitation detection structure of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of a spin wave excitation detection structure manufactured by a method for manufacturing a spin wave excitation detection structure according to the present invention. [Figure 4] FIG. 1 is a schematic cross-sectional view showing an example of the structure of a conventional spin wave excitation and detection structure. [Figure 5] (a) is a perspective view showing a conventional microstrip spin wave excitation and detection structure, and (b) is the spin wave propagation spectrum thereof. [Figure 6] FIG. 1 is a schematic diagram for explaining a spin wave. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, the present invention will be described in detail with reference to the preferred embodiments, but the present invention is not limited to these.

[0040] As mentioned above, the currently used electrical spin-wave excitation structure (also known as a transducer or antenna) shown in Figure 4 is not suitable for miniaturization and integration. Simply scaling down the structure results in extremely low excitation efficiency and extremely narrow bandwidth. Specifically, if the upper copper wire 28 is made thinner and thinner to achieve miniaturization and integration, the spin wave intensity weakens. This is because the upper copper wire 28 and the lower copper film 24 are too far apart. Therefore, one approach would be to thin the dielectric substrate 22, but doing so would prevent the generation of a rotating magnetic field in the upper YIG film 26. Therefore, the YIG film 26 must be located between the upper copper wire 28 and the lower copper film 24. Furthermore, if the sample is too thin, it will fall apart, so a substrate (dielectric substrate 22) is necessary.

[0041] The inventors of the present invention have proposed the usefulness of the structure shown in Fig. 3 based on the problems of the conventional spin wave excitation and detection structure 200 shown in Fig. 4, and have found this to be useful through calculations. Based on this, we propose the structure of the spin wave excitation and detection structure 100 shown in Fig. 3.

[0042] FIG. 3 shows an example of a spin wave excitation / detection structure 100 manufactured by the manufacturing method of the present invention. The spin wave excitation / detection structure 100 is capable of exciting spin waves and detecting spin waves. The spin wave excitation / detection structure 100 comprises a support substrate 12, a conductive film 14 provided on the support substrate 12, an insulating magnetic film 16 provided on the conductive film 14, and a conductive wire 18 provided on the insulating magnetic film 16. That is, the support substrate 12, the conductive film 14, the insulating magnetic film 16, and the conductive wire 18 are stacked in this order.

[0043] The spin wave excitation detection structure 100 excites spin waves in the insulating magnetic film 16 by passing a high-frequency signal in the gigahertz range between the upper conductive wire 18 at an electrical signal level and the lower conductive film 14 at an electrical ground level.

[0044] The spin wave excitation / detection structure 100 shown in FIG. 3 is manufactured by a method including the steps of forming an insulating magnetic film on a donor substrate, bonding the surface of the insulating magnetic film on the donor substrate to the surface of a support substrate via a conductive film to form a bonded substrate, removing the donor substrate from the bonded substrate, and forming a conductive wire on the insulating magnetic film.

[0045] An example of a method for manufacturing a spin wave excitation and detection structure of the present invention is shown in Figure 1. Each step will be explained in more detail below.

[0046] In the method for manufacturing the spin wave excitation and detection structure of the present invention, first, as shown in step S11 of FIG. 1, an insulating magnetic film 16 is formed on a donor substrate 15.

[0047] Various materials can be used for the donor substrate 15 and the insulating magnetic film 16. Among them, it is preferable to use a substrate made of paramagnetic garnet for the donor substrate 15. For example, gadolinium gallium garnet (Gd3Ga5O) is used as the paramagnetic garnet. 12 A paramagnetic garnet substrate such as (GGG) can be used. The insulating magnetic film 16 is preferably made of magnetic garnet. In particular, the insulating magnetic film 16 is preferably made of yttrium iron garnet (YIG). Yttrium iron garnet is Y3Fe5O 12 The insulating magnetic film 16 can be made of a magnetic garnet, particularly yttrium iron garnet, and the spin wave excitation and detection structure 100 shown in FIG. 3 can excite good spin waves. Furthermore, spin waves can be detected without any problems.

[0048] The step of forming an insulating magnetic film on a donor substrate is preferably performed by liquid phase epitaxy. For example, gadolinium gallium garnet (Gd3Ga5O) is preferably formed by liquid phase epitaxy. 12 Yttrium iron garnet, Y3Fe5O, produced by liquid epitaxial growth on a paramagnetic garnet substrate such as (GGG) 12 The insulating magnetic film 16 can be formed from a single crystal of (YIG).

[0049] Although there are no particular limitations on the thickness of the donor substrate 15, a thickness of 100 μm or more ensures mechanical strength, more preferably 300 μm or more, and particularly preferably 500 μm or more.

[0050] There is no particular limitation on the thickness of the insulating magnetic film 16 formed on the donor substrate 15. As will be described later, it is preferable that the insulating magnetic film 16 has a thickness of 10 μm or less when the spin wave excitation detection structure 100 is finally formed. The thickness of the insulating magnetic film 16 formed on the donor substrate 15 at this stage can be determined taking into consideration, for example, economic efficiency, and can be, for example, 200 μm or less.

[0051] After forming the insulating magnetic film 16 on the donor substrate 15 as described above, as shown in step S12 of Figure 1, the surface of the insulating magnetic film 16 on the donor substrate 15 is bonded to the surface of the support substrate 12 via the conductive film 14 to produce a bonded substrate.

[0052] The support substrate 12 can be at least one of a silicon substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate. As described above, various support substrates can be used. Among these, a silicon substrate is preferable as the support substrate 12 because it is inexpensive and of high quality. Examples of insulating substrates include glass, quartz, sapphire, aluminum nitride, and alumina. A paramagnetic garnet substrate can also be used as a non-magnetic substrate. The thickness of the support substrate 12 is preferably 100 μm or more and 500 μm or less. If the thickness of the support substrate 12 is 100 μm or more, the mechanical strength of the spin wave excitation detection structure 100 to be manufactured is high and handling is easier. Furthermore, if the thickness of the support substrate 12 is 500 μm or less, sufficient mechanical strength can be ensured in the spin wave excitation detection structure 100 to be manufactured.

[0053] It is desirable to mirror-polish the support substrate 12 before bonding. It is also desirable to flatten the surface of the insulating magnetic film 16 formed on the donor substrate 15 by polishing.

[0054] Various methods can be used for bonding. For example, a conductive film can be formed only on the support substrate 12, and the conductive film formed on the support substrate 12 can be bonded to the surface of the insulating magnetic film 16. Alternatively, a conductive film can be formed only on the insulating magnetic film 16, and the conductive film formed on the insulating magnetic film 16 can be bonded to the surface of the support substrate 12. Alternatively, a conductive film can be formed on both the support substrate 12 and the insulating magnetic film 16, and a first conductive film formed on the support substrate 12 and a second conductive film formed on the insulating magnetic film 16 can be bonded to each other.

[0055] In either case, the conductive film can be formed by sputtering or the like. Depending on the material of the conductive film, bonding can be performed by simply pressing at room temperature. Heating may also be performed as necessary. An adhesive may also be used.

[0056] Next, as shown in step S13 of FIG. 1 , the donor substrate 15 is removed from the bonded substrate stack. The donor substrate 15 can be removed from the bonded substrate stack by grinding and polishing. After the donor substrate 15 is removed, the insulating magnetic film 16 is preferably reduced in thickness to 10 μm or less by grinding and polishing, etc. The thickness of the insulating magnetic film 16 is more preferably 5 μm or less, and particularly preferably 1 μm or less. In this way, the insulating magnetic film 16 in the spin wave excitation detection structure 100 to be manufactured can be made thin, at 10 μm or less.

[0057] 1, the conductor wires 18 are formed on the insulating magnetic film 16. There are no particular restrictions on the method for forming the conductor wires 18, and photolithography or the like can be used as appropriate.

[0058] By the method for manufacturing a spin wave excitation detection structure according to the above steps S11 to S14, the spin wave excitation detection structure 100 shown in FIG. 3 can be manufactured.

[0059] In the present invention, the conductive film 14 and the conductive wires 18 may be made of at least one of copper, aluminum, gold, silver, platinum, iron, transparent conductors, superconductors, graphene, and conductive magnetic materials. Among these, copper is particularly preferred. Other conductors may also be used as the material for the conductive film 14 and the conductive wires 18, such as carbon nanotubes and organic conductive materials. The conductive film 14 and the conductive wires 18 are preferably made of materials with higher conductivity than the supporting substrate 12 and the insulating magnetic film 16. The components of the conductive film 14 and the conductive wires 18 may be the same or different.

[0060] Of these, the conductive wire 18 preferably has a thickness of 1 μm or less and a width of 5 μm or less. The thickness is more preferably 0.5 μm or less, and particularly preferably 0.1 μm or less. The width is more preferably 2 μm or less, and particularly preferably 0.5 μm or less. There is no particular lower limit to the thickness of the conductive wire 18, but if it is too thin, the wires will separate and conductivity will not be maintained, so a thickness of 0.01 μm or more is preferred. One upper conductive wire 18 is sufficient. However, two or more may be used.

[0061] The thickness of the conductive film 14 is preferably 1 μm or less. This thickness is more preferably 0.5 μm or less, and particularly preferably 0.1 μm or less. There is no particular lower limit to the thickness of the conductive film 14, but if the thickness is too thin, the film will separate completely and will not maintain conductivity, so a thickness of 0.01 μm or more is preferred.

[0062] The dimensions of the components of the spin wave excitation and detection structure 100 manufactured by the manufacturing method of the present invention are preferably as listed above, and the spin wave excitation and detection structure 100 can be made smaller.

[0063] In the method for manufacturing a spin wave excitation and detection structure of the present invention, the donor substrate can be removed from the bonded substrates in step S13 as shown in FIG.

[0064] 2, step S11 is the same as the embodiment of Fig. 1, in which an insulating magnetic film 16 is formed on a donor substrate 15. Thereafter, a step of implanting ions into the insulating magnetic film 16 to form an ion-implanted surface (ion-implanted layer) 17 is further included ("additional step" in Fig. 2). Hydrogen ions or helium ions can be used as the ions to be implanted.

[0065] Thereafter, the bonding step S12 is performed in the same manner as in the embodiment of FIG. 1. In the next step S13, the donor substrate 15 is removed from the bonded substrate by dividing the bonded substrate at the ion-implanted surface 17. This allows the donor substrate 15 to be removed from the bonded substrate. Furthermore, part of the insulating magnetic film 16 formed on the donor substrate 15 also remains on the donor substrate 15. This division can be performed by applying a mechanical impact to the ion-implanted surface 17. Heating may also be performed at the same time.

[0066] After the separation (peeling), the surface of the insulating magnetic film 16 may be polished or the like at the separated surface.

[0067] Simultaneously with the removal of the donor substrate 15, the thickness of the insulating magnetic film 16 can be adjusted by adjusting the depth of ion implantation in the ion implantation step described above. The thickness of the insulating magnetic film 16 is more preferably 5 μm or less, and particularly preferably 1 μm or less. In this way, the insulating magnetic film 16 in the spin wave excitation detection structure 100 to be manufactured can be as thin as 10 μm or less.

[0068] In this method, for example, the insulating magnetic film on the peeled donor substrate 15 can be mirror-finished again and subjected to ion implantation, allowing it to be subjected to the same process again.

[0069] After the bonded substrate is divided, the surface can be polished as appropriate. Thereafter, the conductive wires 18 are formed on the insulating magnetic film 16 in the same manner as in FIG.

[0070] The spin wave excitation detection structure manufactured by the manufacturing method of the present invention as described above is expected to become an essential component as a spin wave excitation structure (electricity-spin wave conversion element) in spin wave computers, which are said to be the next generation of CPUs.

[0071] Spin waves are phase waves that propagate with electrons fixed in place, so the Joule heat loss that would normally occur when charge moves is theoretically zero. Furthermore, YIG in particular is a magnetic oxide material, so it is an insulator and does not generate eddy currents. In this way, spin waves, which have theoretically zero losses in both steady-state currents and eddy currents, have the potential to replace all of the wiring and logic elements such as NAND and NOR that are realized in CMOS. In other words, by combining them with nanotechnology, it is expected that we will be able to realize cool computers that do not generate heat.

[0072] The spin wave excitation and detection structure of the present invention has the following ripple effects in related fields.

[0073] (1) Computer This technology will have a ripple effect on all fields currently using computers, as well as on devices equipped with CPUs and other computing elements. It will be particularly useful in situations where computers are needed on the millimeter or micrometer scale, such as in mobile devices, wearable devices, and sensors and microchips that are being installed in home appliances.

[0074] (2) High frequency, wireless, and communications fields Spin waves, like microwaves, are waves that respond on the order of GHz, but by converting them into waves that propagate through magnetic materials, their wavelengths can be shortened by more than 100 times. In terms of device (element) size, this means that the entire chip can be made 100 times smaller. Until now, there has been little progress in miniaturizing analog high-frequency devices, and they are far from being portable. Therefore, the realization of spin wave devices, including spin-wave phase modulation elements, is expected to lead to the miniaturization of high-frequency devices. [Example]

[0075] EXAMPLES The present invention will be explained in more detail below by showing examples of the present invention, but the present invention is not limited to these examples.

[0076] [Example 1] A spin wave excitation detection structure was manufactured according to the method for manufacturing a spin wave excitation detection structure of the present invention shown in FIG.

[0077] A 3-inch (7.62 cm) diameter GGG (GdGaO 12 On this donor substrate 15, a single crystal ((BiYLu)3(FeM)5O) magnetic garnet film was grown as an insulating magnetic film 16 by the LPE (liquid phase epitaxial) method. 12 ) was grown to a thickness of 100 μm (step S11). Here, M is an element that can substitute for Fe in the garnet structure, and examples thereof include Ga, Al, Sc, and In, but specifically Ga was used here. The single crystal film formation method at this time conformed to the method disclosed in Japanese Patent Laid-Open Publication No. 03-223199. Thereafter, the surface of the insulating magnetic film 16 was mirror-polished. After mirror-polishing, a copper (Cu) film was formed to a thickness of 100 nm as the conductive film 14 by sputtering.

[0078] Meanwhile, a mirror-polished Si substrate having a diameter of 3 inches (7.62 cm) was prepared as a support substrate 12 (carrier substrate). On this support substrate 12, a copper (Cu) film was formed as a conductor film 14 to a thickness of 100 nm by sputtering.

[0079] Thereafter, the copper film-formed surfaces of both substrates were stacked in a vacuum chamber, and pressure and heat were applied to obtain a structure (bonded substrate) in which the support substrate 12, donor substrate 15, insulating magnetic film 16, and conductive film 14 were integrated (step S12).

[0080] The donor substrate 15 (GGG substrate) side of the bonded substrate taken out from the apparatus was ground, and then polished to make the magnetic garnet film, which is the insulating magnetic film 16, have a thickness of 1 to 10 μm (step S13).

[0081] Thereafter, a copper wire was formed as the conductor wire 18 on the insulating magnetic film 16 (step S14), thereby obtaining a spin wave excitation and detection structure 100.

[0082] [Example 2] A spin wave excitation detection structure was manufactured according to the method for manufacturing a spin wave excitation detection structure of the present invention shown in FIG.

[0083] A 3-inch (7.62 cm) diameter GGG (GdGaO 12 On this donor substrate 15, a single crystal ((BiYLu)3(FeM)5O) magnetic garnet film was grown as an insulating magnetic film 16 by the LPE (liquid phase epitaxial) method. 12 ) was grown to a thickness of 110 μm (step S11). Here, M was Ga. The single crystal film formation method at this time conformed to the method disclosed in JP-A-03-223199. Thereafter, the surface of the insulating magnetic film 16 was mirror-polished. Ion implantation was performed on the mirror-polished surface. The ion species was hydrogen ions. The method at this time conformed to that disclosed in JP-A-2020-043591. Thereafter, a copper (Cu) film was formed to a thickness of 100 nm as the conductive film 14 on the mirror-polished surface (ion-implanted surface) by sputtering.

[0084] Meanwhile, a mirror-polished Si substrate surface with a diameter of 3 inches (7.62 cm) was prepared as a support substrate (carrier substrate) 12. On this support substrate 12, a copper (Cu) film was formed as a conductor film 14 to a thickness of 100 nm by sputtering.

[0085] Thereafter, the copper film-formed surfaces of both substrates were stacked in a vacuum chamber, and pressure and heat were applied to obtain a structure (bonded substrate) in which the support substrate 12, donor substrate 15, insulating magnetic film 16, and conductive film 14 were integrated (step S12).

[0086] The bonded substrate having an integral structure was heated and mechanical impact was applied from the side, so that the substrate was divided at the ion implanted surface and peeled off (step S13). After that, the surface of the insulating magnetic film 16 was mirror-finished to form a magnetic garnet film having a thickness of 0.3 to 2 μm.

[0087] Thereafter, a copper wire was formed as the conductor wire 18 on the insulating magnetic film 16 (step S14), thereby obtaining a spin wave excitation and detection structure 100.

[0088] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention. [Explanation of symbols]

[0089] 12...support substrate, 14...Conductive film, 15...donor substrate, 16...insulating magnetic film, 17...ion-implanted surface, 18...Conductor wire, 100...spin wave excitation and detection structure, 22...Dielectric substrate, 24...copper film, 25...Gadolinium gallium garnet substrate, 26...YIG film, 28...Copper wire, 200...Conventional spin wave excitation and detection structure.

Claims

1. A method for manufacturing a spin wave excitation and detection structure for exciting and detecting spin waves, comprising: forming an insulating magnetic film on a donor substrate; a step of forming a bonded substrate by bonding a surface of the insulating magnetic film on the donor substrate to a surface of a support substrate via a conductive film, the step being performed by forming the conductive film on the insulating magnetic film and bonding the conductive film formed on the insulating magnetic film to the surface of the support substrate; removing the donor substrate from the bonded substrate stack; forming a conductive wire on the insulating magnetic film; whereby the support substrate and the conductive film provided on the support substrate; the insulating magnetic film provided on the conductive film; the conductive wire provided on the insulating magnetic film; 1. A method for manufacturing a spin wave excitation detection structure, comprising:

2. A method for manufacturing a spin wave excitation and detection structure for exciting and detecting spin waves, comprising: forming an insulating magnetic film on a donor substrate; a step of forming a bonded substrate by bonding a surface of the insulating magnetic film on the donor substrate to a surface of a support substrate via a conductive film, the conductive film being formed on both the support substrate and the insulating magnetic film, and bonding a first conductive film formed on the support substrate to a second conductive film formed on the insulating magnetic film; removing the donor substrate from the bonded substrate stack; forming a conductive wire on the insulating magnetic film; whereby the support substrate and the conductive film provided on the support substrate; the insulating magnetic film provided on the conductive film; the conductive wire provided on the insulating magnetic film; 1. A method for manufacturing a spin wave excitation detection structure, comprising:

3. 3. The method for manufacturing a spin wave excitation and detection structure according to claim 1, wherein the insulating magnetic film is made of magnetic garnet.

4. 4. The method for manufacturing a spin wave excitation and detection structure according to claim 3, wherein the insulating magnetic film is made of yttrium iron garnet.

5. 5. The method for manufacturing a spin wave excitation / detection structure according to claim 3, wherein the donor substrate is made of paramagnetic garnet.

6. removing the donor substrate from the bonded substrate stack; 6. The method for manufacturing the spin wave excitation / detection structure according to claim 1, wherein the method is carried out by grinding and polishing.

7. After forming the insulating magnetic film on the donor substrate, the method further includes a step of implanting ions into the insulating magnetic film to form an ion-implanted surface; 7. The method for manufacturing a spin wave excitation detection structure according to claim 1, wherein the step of removing the donor substrate from the bonded substrate is carried out by dividing the bonded substrate at the ion implantation surface after the bonded substrate is produced.

8. 8. The method for manufacturing a spin wave excitation detection structure according to claim 1, wherein the conductive film and conductive wire contain at least one of copper, aluminum, gold, silver, platinum, iron, a transparent conductor, a superconductor, graphene, and a conductive magnetic material.

9. 9. The method for manufacturing a spin wave excitation detection structure according to claim 1, wherein the support substrate is at least one of a silicon substrate, a dielectric substrate, a conductive substrate, an insulating substrate, a magnetic substrate, a non-magnetic substrate, a wood substrate, and a stone substrate.

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