JP7550440B2 - Nanowire manufacturing apparatus and method - Google Patents

Description

The disclosure in this application relates to a nanowire manufacturing apparatus and a nanowire manufacturing method.

In various industrial fields such as the electronics, information, and electronics fields, there is a demand for metal nanowires, for example for nanoelectronic components, nanomagnetic materials, and wiring in integrated circuits, and research and development into these is being widely conducted.

In addition to being highly workable, with excellent thermal conductivity, ductility, and sinterability, metals also have characteristics such as a high strength-to-volume ratio and low environmental impact, making them easy to recycle and repair. For this reason, metal nanowires are expected to be used not only for wiring in integrated circuits, but also as mechanical materials that exhibit the properties of metals even at the nano- and micro-scale.

Furthermore, the use of longer metal nanowires is expected to lead to new industrial applications, such as filaments in electron microscopes, bonding wires in electronic components, medical nanoknives, and heat links as components of gravitational wave telescopes.

Patent Document 1 and Patent Document 2 describe a method of producing metal nanowires by electromigration (hereinafter sometimes referred to as "EM") by applying a high-density electron flow to metal wiring. In detail, they describe that (1) an electron flow called EM is generated in the metal wiring to move metal atoms, (2) the moved metal atoms accumulate and generate high pressure, and (3) that high pressure is used to physically restrain the metal atoms, aggregate them, and grow them to produce metal nanowires.

JP 2006-075961 A JP 2006-239790 A

Patent Document 1 and Patent Document 2 describe a device for manufacturing nanowires. The device has aluminum wiring provided between current input/output pads, and an insulating layer laminated on the aluminum wiring. The insulating layer of the device has an opening on the aluminum wiring.

Therefore, in the devices described in Patent Documents 1 and 2, applying a potential between the current input/output pads generates EM, causing aluminum nanowires to be ejected from the openings.

However, in the devices described in Patent Documents 1 and 2, the aluminum wiring material must be covered with an insulating layer in order for the nanowires to be ejected from the openings in the insulating layer. This creates a problem in that the amount of aluminum, which is the material used to form the nanowires, depends on the amount of aluminum wiring below the insulating layer. In addition, the insulating layers in the devices described in Patent Documents 1 and 2 are layered using thin-film formation techniques such as CVD. For this reason, it is difficult to remove the insulating layer after layering to supply aluminum, and there is a problem in that the devices described in Patent Documents 1 and 2 are difficult to reuse.

The present disclosure aims to provide a nanowire manufacturing device that can supply materials for forming metal nanowires at a desired timing. Other optional effects of the present disclosure will be made clear in the description of the invention.

(1) A nanowire manufacturing apparatus for manufacturing nanowires by atomic diffusion through electromigration, comprising:
The nanowire production apparatus includes a member having a space therein,
The components are:
A supply port for supplying a nanowire material to the space;
At least one ejection port for ejecting the nanowire material supplied into the space as nanowires;
Including,
Nanowire manufacturing equipment.
(2) When the space is viewed in the direction opposite the end of the component from the injection port, the cross-sectional area of the space perpendicular to that direction is
It is the same from the exit side to the end of the space.
or
Including a portion that gradually becomes larger from the injection port side toward the end of the space,
The nanowire manufacturing apparatus according to (1) above.
(3) further comprising a conductive film;
The conductive film includes a portion that is continuously laminated on the space side and the outside of the component through the injection port.
The nanowire manufacturing apparatus according to (1) or (2) above.
(4) The conductive film is laminated continuously from the portion laminated on the space side to the supply port.
The nanowire manufacturing apparatus according to (3) above.
(5) The member is
A first member including a supply port;
A second member including an injection port;
Including,
A space is defined by joining a second member to a first member;
The nanowire manufacturing apparatus according to (1) above.
(6) Further comprising a conductive film,
the second member includes a first surface joined to the first member;
the conductive film includes a portion that is continuously laminated on the space side and the outside through a portion of the first surface where the first member is joined;
The nanowire manufacturing apparatus according to (5) above.
(7) Further comprising a conductive film,
The second member is
A first surface joined to the first member;
a second surface opposite the first surface; and
Including,
the conductive film includes a portion continuously laminated from the first surface to the second surface via the injection port;
The nanowire manufacturing apparatus according to (5) above.
(8) The first member includes a third surface that defines a space,
the conductive film includes a portion that is continuously laminated from a position on the third surface where the second member is joined to the supply port;
The nanowire manufacturing apparatus according to (6) or (7) above.
(9) The ratio of the electrical conductivity of the nanowire material to the electrical conductivity of the conductive film is 5 to 20;
The nanowire manufacturing apparatus according to any one of (3), (4), (6) to (8) above.
(10) The conductive film is a titanium nitride film.
The nanowire manufacturing apparatus according to any one of (3), (4), (6) to (9) above.
(11) Further comprising an attachment,
The attachment is
an inlet into which the nanowire ejected from the ejection port enters;
An exit for the nanowires;
Including,
The outlet is different from the shape of the injection port.
The nanowire manufacturing apparatus according to any one of (1) to (10) above.
(12) There are multiple injection ports.
The nanowire manufacturing apparatus according to any one of (1) to (11) above.
(13) A method for producing nanowires using a nanowire production apparatus for producing nanowires by atomic diffusion due to electromigration, comprising the steps of:
The nanowire production apparatus includes a member having a space therein,
The components are:
A supply port for supplying a nanowire material to the space;
At least one ejection port for ejecting the nanowire material supplied into the space as nanowires;
Including,
The method for producing nanowires includes:
A supply step of supplying a nanowire material from a supply port into the space;
applying a current to the nanowire material to cause electromigration;
an ejection step of ejecting the nanowire from an ejection port by moving the nanowire material by electromigration;
A method for producing nanowires comprising:
(14) During the injection process, the nanowire material is fed into the space from the feed port;
The method for producing nanowires according to (13) above.

The materials for forming metal nanowires can be supplied at the desired time.

FIG. 1 is a diagram illustrating an example of a nanowire manufacturing apparatus according to a first embodiment. 13A to 13C are diagrams showing other configurations of the injection port. FIG. 4 is a schematic diagram showing a modification of the nanowire manufacturing apparatus according to the first embodiment. 1A to 1C are diagrams illustrating an example of a nanowire manufacturing method according to a first embodiment. FIG. 13 is a schematic diagram illustrating an example of a nanowire manufacturing apparatus according to a second embodiment. 5A to 5C are diagrams illustrating an example of a nanowire production method according to a second embodiment. FIG. 13 is a schematic diagram illustrating an example of a nanowire manufacturing apparatus according to a third embodiment. 10A to 10C are diagrams illustrating an example of a nanowire manufacturing method according to a third embodiment. A photograph substituted for a drawing: an electron microscope image of nanowires being ejected from the nozzle.

The nanowire manufacturing apparatus will be described in detail below with reference to the drawings. In this specification, components having the same functions are given the same or similar reference symbols. Furthermore, repeated descriptions of components given the same or similar reference symbols may be omitted.

In this specification, a numerical range expressed using "~" means a range that includes the numerical values before and after "~" as the lower and upper limits. In this specification, numerical values, numerical ranges, and qualitative expressions (e.g., expressions such as "same" and "the same") are to be interpreted as indicating numerical values, numerical ranges, and properties that include errors that are generally accepted in the technical field.

Note that the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc., in order to facilitate understanding. Therefore, the disclosure in this application is not necessarily limited to the position, size, range, etc., disclosed in the drawings.

(First embodiment of nanowire manufacturing apparatus)
A nanowire manufacturing apparatus 1 according to a first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1A is a diagram showing an example of the appearance of the nanowire manufacturing apparatuses 1a to 1c according to the first embodiment. FIG. 1B is a cross-sectional view showing an example of the nanowire manufacturing apparatus 1a in which the member 2 is made of a metallic material. FIG. 1C is a cross-sectional view showing an example of the nanowire manufacturing apparatus 1b in which the member 2 is made of a non-metallic material. FIG. 1D is a cross-sectional view showing an example of the nanowire manufacturing apparatus 1c in which the member 2 is made of a non-metallic material. FIGS. 1E and 1F are schematic views of the nanowire manufacturing apparatus as viewed from the supply port 4 to the injection port 5 in FIG. 1C. FIGS. 2A to 2D show examples of the injection port 5. FIGS. 3A to 3C are diagrams showing modified examples of the nanowire manufacturing apparatus 1 according to the first embodiment.

Nanowire manufacturing devices 1a to 1c each include a member 2 having a space 3 therein. The member 2 also includes a supply port 4 for supplying nanowire material to the space 3, and an ejection port 5 for ejecting the nanowires.

There is no particular limitation on the member 2 as long as it has a space 3 inside. For example, the space 3 may be defined by one member, or the space 3 may be defined by multiple members. In the example shown in FIG. 1A, the space 3 is defined by one member 2. In addition, there is no particular limitation on the material forming the member 2 as long as it can eject nanowires. Examples of materials forming the member 2 include metal materials such as stainless steel, titanium, chromium, and tungsten, and non-metal materials such as glass, silicon, and ceramics (e.g., alumina and titanium nitride). Metal materials are less likely to generate EM than nanowire materials, and are more preferably those that do not react with nanowire materials. If a metal material reacts with a nanowire material to form an intermetallic compound or the like, it may be welded and hinder the movement of the nanowire material. In the example shown in FIG. 1B, the member 2 is formed of a metal material. In the examples shown in FIGS. 1C and 1D, the member 2 is formed of a non-metal material. Although not shown in the figure, if member 2 is made of a metal material, the outer periphery of member 2 may be coated with an insulating material as necessary to prevent electrical leakage.

As will be described later, nanowires are produced by the nanowire production apparatus 1 according to the first embodiment using EM. Therefore, it is necessary to apply a current to the nanowire material held in the space 3. Therefore, when the member 2 is made of a nonmetallic material, the nanowire production apparatus 1 is provided with a conductive film 6 in order to apply a current to the nanowire material. In the examples shown in Figures 1C and 1D, the nanowire production apparatuses 1b and 1c are provided with a conductive film 6 because the member 2 is made of a nonmetallic material.

The space 3 of the member 2 is not particularly limited in shape as long as it can hold the nanowire material within the member 2. FIG. 1 shows an example of an approximately cylindrical shape in which the cross-sectional area of the space 3 perpendicular to the direction is the same from the ejection port 5 side to the supply port 4 when the space 3 is viewed in the direction opposite the ejection port 5 of the member 2 (the direction of the supply port 4 in the example shown in FIG. 1). Alternatively, the space 3 may be an approximately polygonal column shape, an approximately cubic shape, an approximately rectangular parallelepiped shape, or the like. As a further alternative, as shown in FIG. 3A, when the space 3 is viewed in the direction opposite the ejection port 5 of the member 2, the cross-sectional area of the space 3 perpendicular to the direction may include a portion 3a in which the cross-sectional area gradually increases from the ejection port 5 side toward the end of the space 3. Examples of the gradually increasing portion 3a of the space 3 include pyramid shapes such as cones and pyramids. Also, as shown in FIG. 3B, the gradually increasing portion 3a of the space 3 may be combined with a portion having the same cross-sectional area such as an approximately cylindrical shape.

The supply port 4 is for supplying the nanowire material to the space 3 and is connected to the space 3. The supply port 4 may be provided in any part of the member 2 as long as it does not prevent the nanowires from being ejected from the ejection port 5. In the example shown in FIG. 1, the supply port 4 is provided at the end of the member 2 facing the ejection port 5. Alternatively, as shown in FIG. 3C, the supply port 4 may be provided on the side of the space 3 of the member 2.

The ejection port 5 communicates with the space 3 and ejects the nanowires. Figures 2A to 2D are views of the ejection port 5 as viewed from the front side. The nanowires ejected from the ejection port 5 depend on the shape of the ejection port 5. In the example shown in Figure 1, the ejection port 5 is substantially circular. Alternatively, the ejection port 5 may be of any shape, such as a substantially square shape as shown in Figure 2A or a substantially pentagonal shape as shown in Figure 2B. In the example shown in Figure 1, there is only one ejection port 5. Alternatively, there may be multiple ejection ports 5 as shown in Figures 2C and 2D. If there are multiple ejection ports 5, multiple nanowires can be produced at once. In the example shown in Figures 2C and 2D, the multiple ejection ports 5 have the same shape. Alternatively, the multiple ejection ports 5 may have different shapes.

The size of the ejection port 5 may be set appropriately depending on the size of the nanowire to be manufactured. For example, it may be in the range of 700 nm to 10 μm. In this specification, the "size of the ejection port 5" means the diameter in the case of a circular shape, and means the longest distance when the ejection port 5 is sandwiched between two lines that are approximately parallel to each other in the case of a shape other than a circular shape.

In addition, in this specification, the ejection port 5 is defined as follows. As shown in Figures 1A to 1D and 3C, when there is a distance between the end of the space 3 and the point where the nanowires are ejected to the outside, the ejection port 5 refers to a through hole formed from the end of the space 3 to the point where the nanowires are ejected to the outside, in other words, penetrating from the first wall 21 to the second wall 22 of the member 2. On the other hand, as shown by the reference numeral 5 in Figures 3A and 3B, when the nanowires are ejected to the outside directly from the end of the space 3, the ejection port 5 refers to the boundary surface between the space 3 and the outside.

The conductive film 6 is laminated on the member 2 in order to apply a current to the nanowire material held in the space 3. As will be described later, in order to eject nanowires from the ejection port 5 by EM, it is preferable to apply a current to the nanowire material so that electrons moving in the nanowire material move toward the ejection port 5. Therefore, the conductive film 6 is laminated at least near the ejection port 5 and at a location that can be connected to an external power source. In the example shown in FIG. 1C, the conductive film 6 includes a portion that is continuously laminated on the space 3 side and the outside of the member 2 through the ejection port 5. In other words, the conductive film 6 is laminated from the first wall 21 on the space 3 side through the ejection port 5 to the second wall 22 on the outside. In other words, the conductive film 6 laminated on the first wall 21 is exposed to the space 3, and the conductive film 6 laminated on the second wall 22 is exposed to the outside of the nanowire manufacturing device 1b.

Note that the conductive film 6 may be extended and laminated to other parts of the member 2, so long as it is laminated at least near the injection port 5. In the example shown in FIG. 1D, the conductive film 6 is laminated from the first wall 21 through the injection port 5 to the second wall 22, and is optionally laminated to the third wall 23 that defines the space 3. By laminating the conductive film 6 on the third wall 23, the area of the conductive film 6 exposed to the space 3 is increased, and the contact area with the nanowire material held in the space 3 can be increased. Although not shown, the conductive film 6 laminated on the second wall 22 may be optionally extended to the outer wall facing the third wall 23.

In addition, the conductive film 6 may be provided on the entire surface of the above-mentioned laminated area (the conductive film 6 is laminated continuously without spacing at the area) or on a part of the area (the conductive film 6 is partially spaced at the area) as long as it can generate EM sufficient to emit nanowires by applying a current to the nanowire material held in the space 3. FIG. 1E shows an example in which the conductive film 6 is laminated on the first wall 21 in a roughly donut shape, in other words, an example in which the conductive film 6 is laminated continuously on the first wall 21 without spacing. On the other hand, FIG. 1F shows an example in which four conductive films 6 are radially laminated on the first wall 21, in other words, an example in which the conductive layers 6 are laminated at spacing at the laminated area. Although not shown, the conductive film 6 laminated on the ejection port 5, the second wall 22, and the third wall 23 may be similarly provided on the entire surface of the laminated area or on a part of the laminated area. Therefore, in this specification, for example, when it is stated that "a portion that is continuously laminated on the space side and the outside of the member through the injection port" it means that it includes at least a portion that is continuously laminated from the space 3 side of member 2 to the injection port 5 to the outside of member 2, in other words, laminated so that electricity flows. The same applies to "through the injection port" in other embodiments. As mentioned above, from the viewpoint of increasing the contact area with the nanowire material, it is more preferable to laminate the conductive film 6 over the entire surface at the place where it comes into contact with the nanowire material.

The material of the conductive film 6 is not particularly limited as long as it is a conductive material that is less likely to generate EM than the nanowire material and does not react with the nanowire material. In the example shown in FIG. 1D, if the conductive film 6 has a higher conductivity than the nanowire material, electrons will move through the conductive film 6 rather than through the nanowire material. This may result in fewer electrons moving through the nanowire material, which may reduce the efficiency of EM. Therefore, the conductive film 6 is preferably one that has a lower conductivity than the nanowire material. For example, the ratio of the conductivity of the nanowire material to the conductivity of the conductive film 6 is preferably 5 to 20, and more preferably 10 to 20. The lower conductivity of the conductive film 6 causes electrons to move through the nanowire material, which does not reduce the efficiency of EM. Although it depends on the nanowire material, examples of conductive films 6 that are less likely to generate EM than the nanowire material, do not react with the nanowire material, and have low conductivity include titanium nitride (TiN), chromium nitride (CrN), titanium aluminum nitride (TiAlN), boron nitride (BN), tungsten, and ruthenium dioxide ( _RuO2 ).

Even if the electrons moving through the nanowire material move to the conductive film 6, the conductivity of the conductive film 6 may be higher than that of the nanowire material, as long as the electrons in the nanowire material can be moved toward the injection port 5. In the example shown in FIG. 1C, the electrons in the nanowire material move toward the injection port 5 and to the conductive film 6. Therefore, the electrons in the nanowire material do not move in any direction other than the injection port 5. Therefore, although it depends on where the conductive film 6 is laminated, a material with a higher conductivity than the nanowire material can be used. In the example shown in FIG. 1C, for example, gold, silver, copper, tungsten, etc. may be used as the conductive film 6.

The conductive film 6 is layered on the member 2 by known thin film fabrication techniques, such as physical vapor deposition (PVD) (evaporation, sputtering, etc.), chemical vapor deposition (CVD) (atomic layer deposition, etc.), electroless plating, etc.

(First embodiment of nanowire manufacturing method)
The nanowire manufacturing method according to the first embodiment will be described with reference to Fig. 4. Fig. 4A is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1a according to the first embodiment in which the member 2 is made of a metallic material. Fig. 4B is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1b according to the first embodiment in which the member 2 is made of a non-metallic material. Fig. 4C is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1c according to the first embodiment in which the member 2 is made of a non-metallic material.

The nanowire manufacturing method according to the first embodiment includes (1) a supply step of supplying nanowire material 71 from a supply port 4 to a space 3, (2) a current application step of applying a current to the nanowire material 71 to cause electromigration, and (3) an ejection step of moving the nanowire material 71 by electromigration and ejecting the nanowire 7 from an ejection port 5. The above steps are carried out in the order of (1), (2), and (3).

The supply process is a process of supplying nanowire material 71 from the supply port 4 of the nanowire manufacturing device to the space 3. The nanowire material 71 supplied from the supply port 4 is held in the space 3.

The nanowire material 71 is a metal. EM is generated from any metal, so the material may be selected appropriately depending on the nanowire to be manufactured. Examples include metals such as aluminum, gold, silver, copper, nickel, cobalt, ruthenium, tin, bismuth, and tungsten, or alloys of these metals. The nanowire material 71 supplied to the supply port 4 may be in any shape, such as powder, small pieces, thin wires, or rods.

In the current application process, a current is applied to the nanowire material 71 so that EM is generated in the direction of the injection port 5. In the example of the nanowire manufacturing apparatus 1a shown in FIG. 4A, the member 2 is made of a metal material. Therefore, the positive electrode of the external power supply is connected to the second wall 22 of the member 2. When the negative electrode of the external power supply is connected to the member 2, no current flows through the nanowire material 71, so it is directly connected to the nanowire material 71. Therefore, electrons from the negative electrode of the external power supply move in the direction of the injection port 5 through the nanowire material 71. In the example of the nanowire manufacturing apparatus 1b shown in FIG. 4B, the positive electrode of the external power supply is connected to the conductive film 6 laminated on the second wall 22 of the member, and the negative electrode is connected to the nanowire material 71. Therefore, in the nanowire manufacturing apparatus 1b, electrons move in the same way as in the nanowire manufacturing apparatus 1a. Also, as in the example of the nanowire manufacturing apparatus 1c shown in FIG. 4C, when the conductive film 6 is optionally laminated on the third wall 23 that defines the space 3, the negative pole of the external power supply can be connected to the conductive film laminated on the third wall 23. Of course, when using the nanowire manufacturing apparatus 1c, the negative pole of the external power supply may be directly connected to the nanowire material 71. In the example shown in FIG. 4C, electrons from the negative pole of the external power supply move to the conductive film 6 laminated on the third wall 23. Then, when the conductive film 6 laminated on the third wall 23 comes into contact with the nanowire material 71, the electrons move to the nanowire material 71. This is because the conductivity of the conductive film 6 is lower than that of the nanowire material 71. The electrons that have moved to the nanowire material 71 then move toward the injection port 5.

The amount of current flowing through the nanowire material 71 is not particularly limited as long as EM is generated, but a current density of 1×10 ⁶ A/m ² or more is preferable, and a current density of 1×10 ⁸ A/m ² or more is more preferable.

The ejection process is a process in which the nanowire material 71 is moved by the EM generated by applying a current, and the nanowire 7 is ejected from the ejection port 5. EM is a phenomenon in which metal atoms are transported in the direction of electron movement by atomic diffusion when the current density flowing through metal wiring increases. First, as shown in the example shown in Figures 4A to 4C, electrons move toward the ejection port 5 by applying a current. Next, the nanowire material 71 held in the space 3 of the nanowire manufacturing devices 1a to 1c moves toward the ejection port 5 by atomic diffusion caused by the EM. The nanowire material 71 that has moved toward the ejection port 5 accumulates, generating high pressure near the ejection port 5. As a result, the high pressure ejects and produces the nanowire 7 from the ejection port 5.

The nanowire manufacturing apparatuses 1a to 1f and the nanowire manufacturing method according to the first embodiment have the following advantages.
(1) Nanowire manufacturing apparatuses 1a to 1f each include a supply port 4. Therefore, nanowire material 71 can be supplied from supply port 4 at a desired timing even while a current is being applied to nanowire material 71. Therefore, since nanowire material 71 lost through the production of nanowires 7 can be replenished, there is no limit to the amount of nanowire material 71 as in the prior art. Note that nanowire material 71 may be supplied with the current turned off.
(2) Since the nanowire material 71 can be supplied from the supply port 4, long nanowires 7 can be manufactured according to the amount of supply.
(3) Since the nanowire material 71 can be supplied from the supply port 4, the nanowire manufacturing apparatuses 1a to 1f can be used repeatedly.
(4) Since the nanowire material 71 can be supplied from the supply port 4, nanowires 7 having different metal compositions can be manufactured. For example, nanowires 7 are manufactured using a first metal material, and then a second metal material different from the first metal material is supplied from the supply port 4, thereby manufacturing nanowires 7 having different metal compositions in which the first metal material and the second metal material are continuous.
(5) Nanowires 7 can be easily manufactured. For example, manufacturing nanowires by applying pressure to a molten metal material and ejecting it from an ejection port requires complicated procedures such as melting the material, applying high pressure, and controlling temperature. However, the nanowire manufacturing apparatuses 1a to 1f according to the first embodiment can manufacture nanowires 7 by supplying nanowire material 71 and applying a current to the nanowire material 71, eliminating the need for complicated procedures.
(6) When multiple injection ports 5 are provided, multiple nanowires 7 can be produced at once.
(7) When the conductive film 6 is laminated from the first wall 21 to the supply port 4 via the third wall 23 of the member 2, an external power source can be connected to the conductive film 6. Therefore, a current can be applied to the nanowire material 71 without directly connecting an external power source to the nanowire material 71.

(Second embodiment of nanowire manufacturing apparatus)
Nanowire manufacturing apparatuses 1g to 1j according to a second embodiment will be described with reference to Fig. 5. Fig. 5A is a schematic diagram showing an example of the external appearance of the nanowire manufacturing apparatuses 1g to 1j. Fig. 5B is a schematic cross-sectional view showing an example of the nanowire manufacturing apparatus 1g in which the second member 25 is made of a metallic material. Fig. 5C is a schematic cross-sectional view showing an example of the nanowire manufacturing apparatus 1h in which the member 2 is made of a non-metallic material. Fig. 5D is a schematic cross-sectional view showing an example of the nanowire manufacturing apparatus 1i in which the member 2 is made of a non-metallic material. Fig. 5E is a schematic cross-sectional view showing an example of the nanowire manufacturing apparatus 1j in which the member 2 is made of a non-metallic material.

In the nanowire manufacturing apparatuses 1a to 1f according to the first embodiment, the space 3 of the member 2 is defined by a single member. On the other hand, the nanowire manufacturing apparatuses 1g to 1j according to the second embodiment differ from the first embodiment in that the space 3 of the member 2 is defined by joining the second member 25 to the first member 24. Therefore, for the nanowire manufacturing apparatuses 1g to 1j according to the second embodiment, the differences from the first embodiment will be mainly described, and a repetitive description of matters already described in the first embodiment will be omitted. Therefore, it goes without saying that matters already described in the first embodiment can be adopted even if they are not explicitly described in the second embodiment.

In the nanowire manufacturing apparatuses 1g to 1j according to the second embodiment, the member 2 includes a first member 24 and a second member 25. The second member 25 is joined to the first member 24 to define the space 3. The first member 24 includes a supply port 4, and the second member 25 includes an injection port 5.

The first member 24 has at least an opening that becomes the supply port 4 (hereinafter, sometimes referred to as the "first opening") and an opening that is covered by joining with the second member 25 (hereinafter, sometimes referred to as the "second opening"), and these openings are in communication with each other. The first member 24 may have the first opening and the second opening in any location on the first member 24, so long as the first opening and the second opening are in communication with each other via the space 3. In the example shown in FIG. 5, the first opening and the second opening are opposed to each other and are in communication with each other. Alternatively, the first member 25 may have the first opening and the second opening in positions that are not opposed to each other and are in communication with each other via the space 3.

The second member 25 is joined to the first member 24 to define the space 3. The second member 25 also has an injection port 5. The surface of the second member 25 that is joined to the first member 24 is the first surface 26, and the first surface 26 is joined to the first member 24 to define the space 3. The surface of the second member 25 facing outward and opposite the first surface 26 is the second surface 27. There are no particular limitations on the shape or size of the second member 25, as long as it is joined to the first member 24 to define the space 3 and has an injection port 5. In the example shown in FIG. 5, the second member 25 is a circle with a uniform thickness. Alternatively, the second member 25 may be an ellipse or polygon, or may have a non-uniform thickness.

There is no particular limit to the method of joining the first member 24 and the second member 25. Examples of the joining method include joining with an adhesive, joining with a fixing member such as a screw, welding, anodic joining, or a combination of these. There is also no particular limit to the adhesive used for joining. Examples of adhesives include carbon paste, silver paste, nickel paste, epoxy resin, acrylic resin, and phenolic resin.

The materials forming the first member 24 and the second member 25 can be the same as the materials forming the member 2 described in the first embodiment above. In the example shown in Figures 5A to 5E, the first member 24 is formed from a non-metallic material, but it may alternatively be formed from a metallic material. In the example shown in Figure 5B, the second member 25 is formed from a metallic material. In the example shown in Figures 5C to 5E, the second member 25 is formed from a non-metallic material.

In the nanowire manufacturing apparatus 1 according to the second embodiment, as in the first embodiment, it is necessary to apply a current to the nanowire material held in the space 3. For this reason, the nanowire manufacturing apparatuses 1h to 1j shown in Figures 5C to 5E, in which the first member 24 and the second member 25 are made of a nonmetallic material, are provided with a conductive film 6.

As in the first embodiment, the conductive film 6 may be laminated at least near the ejection port 5 and at a location where an external power source can be connected. In the example shown in FIG. 5C, the conductive film 6 includes a portion that is continuously laminated from the space 3 side to the outside through the location where the first member 24 is joined on the first surface 26 of the second member 25. That is, the conductive film 6 is exposed to the space 3 at a portion on the space 3 side from the location where the second member 25 is joined to the first member 24, and is exposed to the outside of the nanowire manufacturing device 1h at an outer portion. Alternatively, as described in the first embodiment, the conductive film 6 may include a portion that is continuously laminated from the first surface 26 on the space 3 side to the second surface 27 on the outside through the ejection port 5 provided in the second member 25. FIG. 5D shows an example in which the conductive film 6 is continuously laminated from the first surface 26 to the second surface through the ejection port 5.

As shown in the example of FIG. 5E, the conductive film 6 may be laminated continuously from the space 3 side to the outside through the place where the second member 25 is joined to the first member 24, and may also be optionally laminated on the third surface 28 that defines the space 3 of the first member 24. By laminating the conductive film 6 on the third surface 28, the contact area with the nanowire material held in the space 3 can be increased. Although not shown, the conductive layer 6 may be laminated continuously from the first surface 26 to the second surface 27 through the injection port 5, and may also optionally extend from the first surface 26 to the third surface 28.

Furthermore, when the conductive film 6 is laminated continuously from the space 3 side to the outside through the place where the second member 25 is joined to the first member 24, the conductive film 6 may optionally extend to the outer surface opposite the third surface 28.

(Second embodiment of nanowire manufacturing method)
The nanowire manufacturing method according to the second embodiment will be described with reference to Fig. 6. Fig. 6A is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1g according to the second embodiment in which the second member 25 is made of a metal material. Fig. 6B is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1h according to the second embodiment. Fig. 6C is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1i according to the second embodiment. Fig. 6D is a diagram showing an example of the nanowire manufacturing method using the nanowire manufacturing apparatus 1j according to the second embodiment.

The nanowire manufacturing method according to the second embodiment differs from the nanowire manufacturing method according to the first embodiment in that the nanowires are manufactured using nanowire manufacturing apparatuses 1g to 1j in which the space 3 of the member 2 is defined by joining a first member 24 to a second member 25, but in other respects is the same as the nanowire manufacturing method according to the first embodiment. Therefore, in the nanowire manufacturing method according to the second embodiment, the differences from the nanowire manufacturing method according to the first embodiment will be mainly described, and repetitive descriptions of matters already described in the nanowire manufacturing method according to the first embodiment will be omitted. Therefore, it goes without saying that matters already described in the nanowire manufacturing method according to the first embodiment can be adopted even if they are not explicitly described in the nanowire manufacturing method according to the second embodiment.

In the current application process, a current is applied to the nanowire material 71 so that EM is generated in the direction of the injection port 5. In the example of the nanowire production device 1g shown in FIG. 6A, the second member 25 is formed of a metal material. Therefore, the positive electrode of the external power supply is connected to the second surface 27 of the second member 25. The negative electrode of the external power supply is directly connected to the nanowire material 71. Therefore, electrons from the negative electrode of the external power supply move in the direction of the injection port 5 via the nanowire material 71.

In the example of the nanowire manufacturing device 1h shown in FIG. 6B, the conductive film 6 is continuously laminated on the space 3 side and the outside through the place where the second member 25 is joined to the first member 24. Therefore, the conductive film 6 laminated on the space 3 side of the place where the second member 25 is joined to the first member 24 contacts the nanowire material 71. The conductive film 6 laminated on the outside of the place where the second member 25 is joined to the first member 24 is connected to the positive electrode of the external power source. The negative electrode of the external power source is directly connected to the nanowire material 71. When a current is applied to the nanowire material 71, the conductive film 6 is laminated at the end on the injection port 5 side of the space 3, so that the electrons move in the direction of the injection port 5.

The example using the nanowire manufacturing apparatus 1i shown in FIG. 6C is similar to the electrode connection when the nanowire manufacturing apparatus 1b according to the first embodiment is used. In the example of the nanowire manufacturing apparatus 1j shown in FIG. 6D, the conductive film 6 is laminated on the space 3 side and the outside through the place where the second member 25 is joined to the first member 24 on the first surface 26, and optionally on the third surface 28. Therefore, the negative electrode of the external power supply can be connected to the conductive film 6 laminated on the third surface 28. Of course, when the nanowire manufacturing apparatus 1j is used, the negative electrode of the external power supply may be directly connected to the nanowire material 71.

Therefore, in the nanowire manufacturing devices 1g to 1j, the electrons moving through the nanowire material 71 flow in the direction of the injection port 5, and EM is generated in the direction of the injection port 5. Therefore, in the injection process, the generated EM moves the nanowire material 71, and the nanowire 7 is injected from the injection port 5.

The nanowire manufacturing apparatuses 1g to 1j and the nanowire manufacturing method according to the second embodiment provide the following synergistic effects in addition to the effects provided by the nanowire manufacturing apparatuses 1a to 1f and the nanowire manufacturing method according to the first embodiment.
(1) By providing the first member 24 and the second member 25, it is possible to connect to an external power source via the location where the first member 24 and the second member 25 are joined.
(2) Since the second member 25 is joined to the first member 24, it is possible to join the second member 25 having an injection port 5 of a desired shape.

(Third embodiment of nanowire manufacturing apparatus)
A nanowire manufacturing apparatus 1k according to a third embodiment will be described with reference to Fig. 7. Fig. 7A is a cross-sectional view showing an example of the nanowire manufacturing apparatus 1k according to the third embodiment. Fig. 7B is a diagram showing an example of the attachment 8 as viewed from the front with the outlet 82. Fig. 7C is a diagram showing a cross-sectional view of the attachment 8 taken along line XX' in Fig. 7B. Fig. 7D is a diagram showing a shape of the nanowire 7 emitted from the outlet 82 of the attachment 8.

The nanowire manufacturing apparatus 1k according to the third embodiment differs from the first embodiment in that it is provided with an attachment 8, but is otherwise the same as the first embodiment. Therefore, for the nanowire manufacturing apparatus 1k according to the third embodiment, the differences from the first embodiment will be mainly described, and repetitive descriptions of matters already described in the first embodiment will be omitted. Therefore, it goes without saying that matters already described in the first embodiment can be adopted even if they are not explicitly described in the third embodiment. Also, although the example shown in FIG. 7 is described with reference to the first embodiment, it goes without saying that matters already described in the second embodiment can also be adopted in the third embodiment.

As explained in the first embodiment above, the shape of the nanowire emitted from the ejection port 5 depends on the shape of the ejection port 5. However, when attempting to produce a nanowire that is hollow, for example, it may not be possible to produce it by simply changing the shape of the ejection port 5. Therefore, in order to produce nanowires of shapes that are difficult to produce by simply changing the shape of the ejection port 5, as shown in FIG. 2, the nanowire production apparatus 1k according to the third embodiment is equipped with an attachment 8.

The attachment 8 changes the shape of the nanowires ejected from the ejection port 5. The attachment 8 has an entrance 81 and an exit 82. The entrance 81 is where the nanowires ejected from the ejection port 5 are introduced. The exit 82 is where the nanowires introduced into the attachment 8 are ejected.

The shape of the nanowire emitted from the attachment 8 depends on the shape of the outlet 82 of the attachment 8. There are no particular limitations on the shape of the outlet 82, and it may be adjusted as appropriate to match the shape of the nanowire to be produced. Figures 7B and 7C show examples of attachments 8 that produce hollow nanowires. Figure 7D also shows hollow nanowires 7 emitted from the attachment 8.

The material forming the attachment 8 can be the same as the material forming the member 2 described in the first embodiment above. In addition, although not shown, when the attachment 8 is formed from a nonmetallic material, the attachment 8 may be provided with a conductive film from the inlet 81 to the outlet 82 of the attachment 8.

The attachment 8 is joined to the second wall 22 of the member 2 so that the nanowires emitted from the injection port 5 are introduced into the inlet 81. There are no particular limitations on the method of joining the attachment 8 to the second wall 22. For example, the joining method can be the same as the joining method for the first member 24 and the second member 25 described in the second embodiment above.

(Third embodiment of nanowire manufacturing method)
A nanowire manufacturing method according to a third embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram showing an example of a nanowire manufacturing method using a nanowire manufacturing apparatus 1k according to a third embodiment having an attachment 8 made of a metal material.

The nanowire manufacturing method according to the third embodiment differs from the nanowire manufacturing method according to the first embodiment in that the nanowire is manufactured using a nanowire manufacturing apparatus 1k equipped with an attachment 8, but is otherwise the same as the nanowire manufacturing method according to the first embodiment. Therefore, in the nanowire manufacturing method according to the third embodiment, the differences from the nanowire manufacturing method according to the first embodiment will be mainly described, and repetitive descriptions of matters already described in the nanowire manufacturing method according to the first embodiment will be omitted. Therefore, it goes without saying that the matters already described in the nanowire manufacturing method according to the first embodiment can be adopted even if they are not explicitly described in the nanowire manufacturing method according to the third embodiment. It also goes without saying that the matters already described in the nanowire manufacturing method according to the second embodiment can be adopted in the nanowire manufacturing method according to the third embodiment.

In the current application process, a current is applied to the nanowire material so that EM is generated in the direction of the ejection port 5. In the example shown in FIG. 8, the attachment 8 is made of a metal material. As shown in FIG. 8, the attachment 8 is brought into contact with the conductive film 6 laminated on the member 2 or the second wall 22 made of a metal material, and is electrically connected. Therefore, by connecting the positive electrode of an external power source to the attachment 8, EM can also be generated in the nanowire material moving through the attachment 8. Note that, if the distance between the ejection port 5 and the exit 82 of the attachment 8 is short, the positive electrode of the external power source may be connected to the conductive film 6 laminated on the member 2 or the second wall 22 made of a metal material, even if the attachment 8 is made of a metal material. If the distance between the ejection port 5 and the exit 82 of the attachment 8 is short, even if EM is not generated within the attachment 8, the nanowire 7 is ejected from the ejection port 5 by high pressure, and therefore the nanowire 7 can be ejected from the exit 82 by the pressure.

In addition, when the attachment 8 is formed of a non-metallic material and has a conductive film from the entrance 81 to the exit 82, the conductive film of the attachment 8 may be brought into contact with the conductive film 6 laminated on the member 2 or the second wall 22 formed of a metallic material. Then, by connecting the positive electrode of an external power source to the conductive film of the exit 82, EM can also be generated in the nanowire material moving through the attachment 8. Note that, when the distance between the ejection port 5 and the exit 82 of the attachment 8 is short, the positive electrode of an external power source may be connected to the conductive film 6 laminated on the member 2 or the second wall 22 formed of a metallic material. In this case, the attachment 8 does not need to have a conductive film. As described above, when the distance between the ejection port 5 and the exit 82 of the attachment 8 is short, the nanowire 7 can be ejected from the exit 82 even if EM is not generated within the attachment 8.

In the ejection process, the nanowire 7 is ejected from the ejection port 5 by the generated EM. The nanowire 7 is then introduced into the entrance 81 of the attachment 8. Even after the nanowire 7 is introduced into the entrance 81, the nanowire 7 continues to be ejected from the ejection port 5, so pressure is applied to the nanowire 7 as it passes from the entrance 81 to the exit 82. Therefore, in the nanowire manufacturing method according to the third embodiment, it is possible to manufacture a nanowire 7 having a shape similar to the shape of the exit 82 of the attachment 8. The attachment 8 may also be heated in the ejection process. Pressure and heat are applied to the nanowire 7 as it passes through the attachment 8, making it easier to deform the nanowire 7.

The nanowire manufacturing apparatus 1k and nanowire manufacturing method according to the third embodiment synergistically achieves the following effects in addition to the effects achieved by the nanowire manufacturing apparatuses 1a to 1j and nanowire manufacturing methods according to the first and second embodiments.
(1) By providing the attachment 8, it is possible to produce nanowires in shapes that are difficult to produce using the injection port 5.

Example 1
[Preparation of Nanowire Manufacturing Apparatus]
A nanowire production apparatus was fabricated according to the procedure described below.

〔material〕
Glass capillary (cylinder) (outer diameter/inner diameter 0.57/0.14 mm, length 32 mm) (EM Meister Mini Cap 0.5 μl, AS ONE) (first member 24)
・Carbon paste (Ultra-high temperature resistant carbon paste G7716) (EM Japan Co., Ltd.)
-Si mesh wafer (hole size 10 μm × 10 μm rectangular (injection port 5)) (Corns Technology Co., Ltd.) (second member 25)

[Production method]
(1) A titanium nitride (TiN) film was deposited to a thickness of 100 nm as a conductive film 6 on the inner wall of a glass capillary using an atomic layer deposition (ALD) apparatus.
(2) On a Si mesh wafer, 300 _nm of SiO2 was deposited as an insulating film by CVD, 300 nm of Ti was deposited as an adhesion improving layer by using a high frequency sputtering device, and 300 nm of TiN was deposited as a conductive film 6 by using a high frequency sputtering device in that order (hereinafter, the surface of the Si mesh wafer on which the insulating film, adhesion improving layer, and conductive film 6 are deposited is referred to as the "deposition surface").
(3) The Si mesh wafer was cut to a diameter of 3 mm using mirror compound GC#320 (particle size 40 μm, AS ONE) and an ultrasonic disk cutter (Model 601, Gatan, Inc.).
(4) The deposition surface of the Si mesh wafer was brought into contact with the tip of the glass capillary, and the glass capillary and the Si mesh wafer were bonded with carbon paste.
(5) The resultant was left in the air for 24 hours, and then heated at 90° C. for 2 hours and at 260° C. for 2 hours to prepare a nanowire production device.

Example 2
[Nanowire Production]
Using the nanowire production apparatus prepared in Example 1, nanowires were produced according to the following procedure.
(1) The nanowire manufacturing apparatus was inserted into a metal needle (outer diameter/inner diameter 1.08/0.72 mm, length 15 mm) (gauge 19, Musashi Engineering Co., Ltd.) serving as a holding jig to hold the nanowire manufacturing apparatus.
(2) A 30 mm long aluminum thin wire (AL-011167, diameter φ0.10 mm, 99.9%) (Nilaco Corporation) was inserted from the opening (supply port 4) of the glass capillary of the nanowire manufacturing device.
(3) The nanowire manufacturing device was connected to a power source. At this time, the deposition surface of the Si mesh wafer was connected to the positive terminal of the power source, and the end of the Al thin wire was connected to the negative terminal of the power source to form a circuit. A multi-output DC stabilized power supply PW8-3AQP (Texio Technology Co., Ltd.) was used as the power source.
(4) A constant current of 1×10 ⁸ A/m ² was applied to the nanowire production device.

Figure 9 shows an image of Al nanowires being ejected from the ejection port 5 of the Si mesh wafer of the nanowire manufacturing device.

The Si mesh wafer of the nanowire manufacturing device has multiple roughly square injection ports 5, and rectangular Al nanowires corresponding to the shape of the injection ports 5 are injected from the multiple injection ports 5. The Al nanowires shown in Figure 9 are smaller than the injection ports 5 (mesh holes) of the Si mesh wafer. This is thought to be because the material gets into the mesh holes during deposition of the insulating film, adhesion improvement layer, and conductive film 6 on the Si mesh wafer, and the size of the mesh holes on the deposition surface becomes smaller than the size of the mesh holes on the surface opposite the deposition surface (the surface shown in Figure 9).

From the above, nanowires can be manufactured using the nanowire manufacturing apparatus disclosed in this application. In addition, since the nanowire manufacturing apparatus has an opening, nanowire material can be supplied at a desired timing, and is not limited by the amount of nanowire material as in the prior art. Furthermore, it is expected that long nanowires can be manufactured by continuing to supply nanowire material.

By using the nanowire manufacturing device disclosed in this application, nanowire material can be supplied at the desired timing. Therefore, it is useful in a wide range of industrial fields such as machinery, materials, electricity, space, and medicine.

Reference Signs List 1, 1a to 1k... nanowire manufacturing apparatus, 2... member, 21... first wall, 22... second wall, 23... third wall, 24... first member, 25... second member, 26... first surface, 27... second surface, 28... third surface, 3... space, 3a... portion where the space gradually becomes larger, 4... supply port, 5... ejection port, 6... conductive film, 7... nanowire, 71... nanowire material, 8... attachment, 81... inlet, 82... outlet

Claims (14)

1. A nanowire manufacturing apparatus for manufacturing nanowires by atomic diffusion through electromigration, comprising:
The nanowire production apparatus includes a member having a space therein,
The components are:
A supply port for supplying a nanowire material to the space;
At least one ejection port for ejecting the nanowire material supplied into the space as nanowires;
Including,
Nanowire manufacturing equipment. When the space is viewed from the injection port of the component toward the opposite end, the cross-sectional area of the space perpendicular to that direction is:
It is the same from the exit side to the end of the space.
or
Including a portion that gradually becomes larger from the injection port side toward the end of the space,
The nanowire manufacturing apparatus according to claim 1 . Further comprising a conductive film,
The conductive film includes a portion that is continuously laminated on the space side and the outside of the component through the injection port.
The nanowire manufacturing apparatus according to claim 1 . The conductive film is laminated continuously from the portion laminated on the space side to the supply port.
The nanowire production apparatus according to claim 3 . The components are:
A first member including a supply port;
A second member including an injection port;
Including,
A space is defined by joining a second member to a first member;
The nanowire manufacturing apparatus according to claim 1 . Further comprising a conductive film,
the second member includes a first surface joined to the first member;
the conductive film includes a portion that is continuously laminated on the space side and the outside through a portion of the first surface where the first member is joined;
The nanowire production apparatus according to claim 5 . Further comprising a conductive film,
The second member is
A first surface joined to the first member;
a second surface opposite the first surface; and
Including,
the conductive film includes a portion continuously laminated from the first surface to the second surface via the injection port;
The nanowire production apparatus according to claim 5 . the first member includes a third surface defining a space;
the conductive film includes a portion that is continuously laminated from a position on the third surface where the second member is joined to the supply port;
The nanowire production apparatus according to claim 6 or 7. the ratio of the electrical conductivity of the nanowire material to the electrical conductivity of the conductive film is between 5 and 20;
9. The nanowire manufacturing apparatus according to claim 3, 4, or 6 to 8. The conductive film is a titanium nitride film.
10. The nanowire manufacturing apparatus according to claim 3, 4, or 6 to 9. Further comprising an attachment,
The attachment is
an inlet into which the nanowire ejected from the ejection port enters;
An exit for the nanowires;
Including,
The outlet is different from the shape of the injection port.
The nanowire manufacturing apparatus according to any one of claims 1 to 10. There are multiple injection ports.
The nanowire manufacturing apparatus according to any one of claims 1 to 11. A nanowire manufacturing method using a nanowire manufacturing apparatus for manufacturing nanowires by atomic diffusion due to electromigration, comprising the steps of:
The nanowire production apparatus includes a member having a space therein,
The components are:
A supply port for supplying a nanowire material to the space;
At least one ejection port for ejecting the nanowire material supplied into the space as nanowires;
Including,
The method for producing nanowires includes:
A supply step of supplying a nanowire material from a supply port into the space;
applying a current to the nanowire material to cause electromigration;
an ejection step of ejecting the nanowire from an ejection port by moving the nanowire material by electromigration;
A method for producing nanowires comprising: During the injection process, the nanowire material is fed into the space from the feed port;
The method for producing nanowires according to claim 13.