CN117015513A - Particle-immobilized substrate, method for producing diamond film-immobilized substrate, and method for producing diamond - Google Patents

Abstract

The present application provides a particle-immobilized substrate that can be easily fabricated, wherein inorganic nanoparticles are present in a region of nanometer scale. Further, the present application provides a method that can easily manufacture a substrate in which nanoparticles are arranged in a region of a nanometer scale on a solid surface. The particle-immobilized substrate (1) is provided with a substrate (2) and a plurality of inorganic nanoparticles (3) disposed on the substrate (2), wherein the plurality of inorganic nanoparticles (3) are disposed in contact with each other in a region having a width (D1) of 1 [ mu ] m or less on the substrate (2).

Description

Particle-immobilized substrate, method for producing diamond film-immobilized substrate, and method for producing diamond

Technical Field

The present disclosure relates to a particle-immobilized substrate, a method for manufacturing a diamond film-immobilized substrate, and a method for manufacturing diamond. More specifically, the present disclosure relates to a particle-immobilized substrate having inorganic nanoparticles immobilized in a nanoscale region on the substrate, a method for manufacturing the particle-immobilized substrate, a method for manufacturing a diamond film-immobilized substrate using the particle-immobilized substrate, and a method for manufacturing diamond using the diamond film-immobilized substrate. The present application claims the priority of japanese patent application No. 2021-38087 of the japanese application on 3 months 10 of 2021 and japanese patent application No. 2021-170513 of the japanese application on 10 months 18 of 2021, the contents of which are incorporated herein by reference.

Background

Inorganic nanoparticles such as nanodiamond and metal nanoparticles may be used by selectively attaching the dispersion to an intended region on the surface of a solid substrate by ink-jet printing or the like. For example, metal nanoparticles such as silver nanoparticles can be fired at low temperatures. By utilizing this property, metal nanoparticles are used for forming electrodes and conductive circuit patterns on a substrate in the manufacture of various electronic devices. In addition, the arrangement of inorganic nanoparticles on a substrate surface for use in nanodevices has also been studied. The substrate having inorganic nanoparticles arranged on the surface thereof is expected to be used in nano devices in semiconductor fields such as thermoelectric conversion elements, solar cells, displays, memories, thin film transistors, and LSIs (large-scale integrated circuits).

Conventionally, as a substrate having inorganic nanoparticles arranged on a surface, a substrate having intended micrometer-sized regions on which inorganic nanoparticles are attached and deposited is known. However, in recent years, there is a tendency that: a technique of attaching inorganic nanoparticles to nano-scale regions on the surface of a solid substrate is required.

Patent document 1 describes a method in which a nanoparticle solution containing nanoparticles having polymer chains bonded thereto is applied to a substrate, the solvent is removed to align the nanoparticles on the substrate, and then the polymer chains are removed from the nanoparticles having polymer chains bonded thereto on the substrate to align the nanoparticles. According to this method, on a substrate in which nanoparticles having polymer chains removed are arranged, gaps derived from the polymer chains before removal exist between the nanoparticles, and the nanoparticles are present in respective dots at equal intervals.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2015-103609

Disclosure of Invention

Problems to be solved by the invention

However, in the method of patent document 1, nanoparticles bonded to polymer chains are arranged. As described above, in order to arrange nanoparticles not having polymer chains bonded thereto, in the method of patent document 1, it is necessary to first produce nanoparticles having polymer chains bonded thereto. Therefore, it is complicated in terms of fabricating a substrate in which nanoparticles are arranged in a region of a nanometer scale on a solid surface.

Accordingly, it is an object of the present disclosure to provide a particle immobilized substrate that can be easily fabricated, wherein inorganic nanoparticles are present in regions of the nanoscale. Further, it is an object of the present disclosure to provide a method that can easily manufacture a substrate in which nanoparticles are arranged in a region of a nanometer scale on a solid surface. Further, it is an object of the present disclosure to provide a method that can easily manufacture a substrate on which a diamond film is fixed on a solid surface, preferably in a region of nano-scale.

Technical proposal

The present disclosure provides a particle-immobilized substrate comprising a substrate and a plurality of inorganic nanoparticles disposed on the substrate, wherein the plurality of inorganic nanoparticles are disposed in contact with each other in a region having a width of 1 [ mu ] m or less on the substrate.

The present disclosure also provides a particle-immobilized substrate comprising a substrate and inorganic nanoparticles disposed on the substrate,

the Zeta potential of the inorganic nanoparticles is at least 30mV from the Zeta potential of the substrate surface at the position where the inorganic nanoparticles are disposed.

Preferably, a plurality of regions having a width of 1 μm or less are arranged on the substrate in a regular manner, and the inorganic nanoparticles are disposed in the plurality of regions having a width of 1 μm or less, respectively.

Preferably, the nanoparticle includes a nano diamond particle.

The present disclosure also provides a method for producing a particle-immobilized substrate, wherein inorganic nanoparticles are arranged by electrostatic interaction in a region having a width of 1 [ mu ] m or less, which is present in a first region and a second region on a substrate having a first region and a second region having a Zeta potential difference of 30mV or more.

Preferably, one of the first region and the second region has a positive Zeta potential, and the other has a negative Zeta potential.

The present disclosure also provides a method for producing a particle-immobilized substrate, wherein inorganic nanoparticles are arranged by electrostatic interaction in a region having a width of 1 [ mu ] m or less, which is present in a first region and a second region on a substrate having a first region in which the Zeta potential of one is positive and a second region in which the Zeta potential of the other is negative.

Preferably, a plurality of the first regions are regularly arranged on the substrate, and the inorganic nanoparticles are disposed in the plurality of the first regions, respectively.

Preferably, the inorganic nanoparticles include nanodiamond particles.

Further, the present disclosure provides a method of manufacturing a diamond film-fixing substrate, including: and a CVD step of growing the nano-diamond particles on the particle-immobilized substrate by chemical vapor deposition using the nano-diamond particles as seed crystals, thereby forming a diamond film on the substrate.

Preferably, in the CVD step, the diamond film is formed in a region having a width of 1 μm or less on the substrate.

Further, the present disclosure provides a method of manufacturing diamond, wherein the substrate is removed from the diamond film-fixing substrate to obtain a separate self-supporting solid of the diamond film or diamond particles constituting the diamond film.

Advantageous effects

According to the particle-immobilized substrate of the present disclosure, it is possible to provide an immobilized substrate that can be easily fabricated, in which inorganic nanoparticles are present in a region of a nanometer scale. Further, according to the method for manufacturing a particle-immobilized substrate of the present disclosure, the above-described particle-immobilized substrate can be easily manufactured. Further, according to the method for manufacturing a diamond film-fixed substrate of the present disclosure, a substrate on which a diamond film is formed on the substrate (particularly, in a nano-scale region on the substrate) can be easily manufactured.

Drawings

Fig. 1 is an enlarged schematic view of a particle immobilization substrate of an embodiment of the present disclosure.

Fig. 2 is an enlarged schematic view of a particle immobilization substrate of another embodiment of the present disclosure.

Fig. 3 is a schematic diagram illustrating an embodiment of a method of manufacturing a substrate having regions having Zeta potentials different from each other.

Fig. 4 is a schematic diagram showing another embodiment of a method of manufacturing a substrate having regions having Zeta potentials different from each other.

Fig. 5 is an enlarged schematic view of a diamond film-fixed substrate of one embodiment of the present disclosure.

Fig. 6 is an enlarged schematic view of a diamond film according to another embodiment of the present disclosure.

Fig. 7 is a photomicrograph of the particle-immobilized substrate produced in example 1.

Fig. 8 is a photomicrograph of the particle-immobilized substrate produced in example 2.

Fig. 9 is a photomicrograph of the diamond film-fixed substrate of No.1 produced in example 3.

Fig. 10 is a photomicrograph of the diamond film-fixed substrate of No.2 produced in example 3.

Fig. 11 is a photomicrograph of the diamond film-fixed substrate of No.3 produced in example 3.

Fig. 12 is a photomicrograph of the diamond film-fixed substrate of No.4 produced in example 3.

FIG. 13 is an Atomic Force Microscope (AFM) photograph showing a portion where the surface roughness of the diamond film surface of No.1 was measured.

FIG. 14 is an Atomic Force Microscope (AFM) photograph showing the highly labeled portion of the diamond film of No.1 and the measurement result.

Detailed Description

[ particle-immobilized substrate ]

The particle-immobilized substrate according to one embodiment of the present disclosure includes at least a substrate and inorganic nanoparticles disposed on the substrate. The inorganic nanoparticles are disposed in a region having a width of 1 μm or less on the substrate. In the particle-immobilized substrate according to one embodiment of the present disclosure, a plurality of inorganic nanoparticles are disposed in contact with each other in a region having a width of 1 μm or less on the substrate. In addition, in the particle-immobilized substrate according to another embodiment of the present disclosure, a potential difference between the Zeta potential of the inorganic nanoparticles and the Zeta potential of the substrate surface at the position where the inorganic nanoparticles are disposed is 30mV or more. In the present specification, the region having a width of 1 μm or less in which the inorganic nanoparticles are disposed may be referred to as a "particle disposition nano region".

Fig. 1 shows an enlarged schematic view of an embodiment of the particle-immobilized substrate. The particle fixing substrate 1 includes a substrate 2 and a plurality of inorganic nanoparticles 3. In the particle-immobilized substrate 1, a plurality of inorganic nanoparticles 3 are arranged in a region (particle-arranged nanoparticle region) having a width D1 of 1 μm or less and extending in a lateral direction (direction orthogonal to the width D1) on the substrate 2, and a single layer composed only of the inorganic nanoparticles 3 is formed in the particle-arranged nanoparticle region. A part of the inorganic nanoparticles 3 are in contact with each other. The Zeta potential of the inorganic nanoparticles 3 is not less than 30mV from the Zeta potential of the surface of the substrate 2 at the position where the inorganic nanoparticles 3 are disposed. Further, the regions extending in the lateral direction in the width D1 are arranged in plurality at intervals of D2 in the longitudinal direction to form a striped pattern.

Fig. 2 shows an enlarged schematic view of another embodiment of the particle-immobilized substrate. The particle fixing substrate 1 includes a substrate 2 and a plurality of inorganic nanoparticles 3. The particle-immobilized substrate 1 shown in fig. 1 is different from the substrate in that the plurality of inorganic nanoparticles 3 are not in contact with each other, but are regularly arranged.

The width of the particle-disposed nano-region may be 1 μm or less, or 600nm or less, 300nm or less, or 150nm or less.

The particle placement nano-region specifically includes: rectangle, other polygon, perfect circle, ellipse, wavy line, oblique line (parallelogram), irregular shape, etc. as shown in fig. 1. It is obvious which dimension of rectangle, ellipse, wavy line, oblique line, etc. corresponds to the above-mentioned "width", whereas with other shapes, the short axis corresponds to the above-mentioned "width" in a shape extending in one direction and having a long axis and a short axis. In a shape in which the major axis and the minor axis are not different from each other, such as a regular polygon or a perfect circle, the longest diameter of the shape corresponds to the "width". In the shape in which the width varies, the shortest width of the shape may be the "width" described above.

The particle-disposed nano-region may be present only in one or a plurality of the same or different shapes on the substrate. The above-mentioned particle-disposed nano-regions may be disposed (arranged) regularly or irregularly, but are preferably disposed regularly. Examples of the pattern expressed by the regular arrangement include: stripe patterns, dot patterns, checkered patterns, grid patterns, bird grids, grid textures, and the like. The shape of the dots in the dot pattern is not particularly limited, and examples thereof include: ++, circles, polygons, etc.

The interval between the plurality of particle placement regions (e.g., D2 in fig. 1) in the shape in which the stripe pattern, the dot pattern, and the like are regularly arranged is not particularly limited, but the dimension relative to the width is preferably 0.1 to 1.5 times, more preferably 0.5 to 1.0 times.

The inorganic nanoparticles are disposed in a region (particle-disposed nano region) having a width of 1 μm or less on the substrate. When a plurality of inorganic nanoparticles are disposed in the particle-disposed nanoparticle region, a part or all of the plurality of inorganic nanoparticles may be in contact with each other in a region having a width of 1 μm or less on the substrate. In addition, in this case, the two inorganic nanoparticles in contact with the above-described substrate may be in contact with each other.

The plurality of inorganic nanoparticles can form a single layer of the particles (a layer composed of only inorganic nanoparticles without other components such as a resin component) on the particle-immobilized substrate. The single layer may be a layer in which inorganic nanoparticles are not accumulated in the height direction (inorganic nanoparticle single layer), or a layer in which inorganic nanoparticles are accumulated in the height direction (inorganic nanoparticle multilayer). In the case of having a plurality of the above-described particle-configured nano-regions, an inorganic nanoparticle monolayer and an inorganic nanoparticle multilayer may exist in the plurality of regions in a mixed manner.

In the particle placement nano-region, the inorganic nano-particles are present in a region having a width of 1 μm or less; and the mutual contact of the plurality of inorganic nanoparticles can be confirmed by observing the particle-immobilized substrate using an Atomic Force Microscope (AFM). The width of the particle placement nano-region and the intervals between the plurality of particle placement nano-regions can also be measured by AFM.

The particle-immobilized substrate includes regions where inorganic nanoparticles are not disposed, in addition to the nanoparticle-disposed nano regions. The particle-immobilized substrate may have a region in which inorganic nanoparticles are immobilized outside the nanoparticle-disposed region (i.e., a region exceeding 1 μm in width).

The potential difference between the Zeta potential of the inorganic nanoparticles and the Zeta potential of the substrate surface at the positions where the inorganic nanoparticles are disposed is preferably 30mV or more, more preferably 40mV or more, and even more preferably 50mV or more. When the potential difference is 30mV or more, the potential difference between the inorganic nanoparticles and the substrate surface at the position where the inorganic nanoparticles are disposed is sufficiently large, and the inorganic nanoparticles can be easily attached to the substrate by electrostatic action, and are not easily detached after attachment. It is preferable that the potential difference at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

Examples of the inorganic nanoparticles include: metal nanoparticles, semiconductor nanoparticles, carbon nanoparticles, and the like. The inorganic nanoparticles may be one kind or two or more kinds.

Examples of the material constituting the metal nanoparticle and the semiconductor nanoparticle include: silver, aluminum, gold, platinum, palladium, copper, cobalt, chromium, indium, nickel, gallium, and the like. Among them, silver is preferable. The above-mentioned materials may be used singly or in combination of two or more. Specific examples of the metal nanoparticle and the semiconductor nanoparticle include: nanoparticles composed of one or a mixture of two or more of the above materials, nanoparticles composed of a compound of the above materials (for example, gaN nanoparticles, gaAs nanoparticles, alN nanoparticles, gaAlN nanoparticles), and the like.

The carbon nanoparticles are not particularly limited, and known or conventional particles of a carbon material (nanocarbon material) of a nanoscale may be used. Examples of the nanocarbon material in the nanocarbon particles include: nanodiamond, fullerene, graphene oxide, nanographite, carbon nanotube, carbon nanowire, onion carbon, diamond-like carbon, amorphous carbon, carbon black, carbon nanohorn, carbon nanocoil, and the like. Among these, diamond nanoparticles are preferable.

In the present specification, the term "inorganic nanoparticle" refers to an inorganic particle having a primary particle size (average primary particle diameter) of less than 1000 nm. The average primary particle diameter of the inorganic nanoparticles is, for example, 100nm or less, preferably 60nm or less, more preferably 50nm or less, and still more preferably 30nm or less. The lower limit of the average primary particle diameter of the inorganic nanoparticles is, for example, 1nm.

As the above-mentioned nanodiamond particles, for example, nanodiamond by the detonation method (i.e., nanodiamond generated by the detonation method), nanodiamond by the high-temperature and high-pressure method (i.e., nanodiamond generated by the high-temperature and high-pressure method) may be used. Among them, detonation nanodiamond is preferable in terms of more excellent dispersibility in a dispersion medium, that is, in terms of the particle diameter of primary particles being one-digit nanometers.

The detonation method nanodiamond described above includes air-cooled detonation method nanodiamond (i.e., nanodiamond generated by the air-cooled detonation method) and water-cooled detonation method nanodiamond (i.e., nanodiamond generated by the water-cooled detonation method). Among them, air-cooled detonation method nanodiamond is preferable in terms of smaller primary particles than water-cooled detonation method nanodiamond.

The nano-diamond particles are not particularly limited, and known or conventional nano-diamond particles can be used. The nano-diamond particles may be surface-modified nano-diamond (surface-modified nano-diamond) particles or non-surface-modified nano-diamond particles. The nano-diamond particles not subjected to surface modification have hydroxyl groups (-OH) and carboxyl groups (-COOH) on the surface. The nano-diamond particles may be used alone or in combination of two or more.

Examples of the compound or functional group that surface-modifies the nanodiamond particle in the surface-modified nanodiamond include: silane compounds, phosphonic acid ions or phosphonic acid residues, surface modification groups having vinyl groups at the ends, amide groups, cations of cationic surfactants, groups containing polyglycerol chains, groups containing polyethylene glycol chains, and the like.

The Zeta potential of the inorganic nanoparticle may be negative or positive. The same sign as the same Zeta potential on the substrate on which the inorganic nanoparticles are not disposed is preferable. When the Zeta potential of the inorganic nanoparticle is positive, the Zeta potential is preferably 5mV or more, more preferably 10mV or more, and even more preferably 20mV or more. When the Zeta potential of the inorganic nanoparticle is negative, the Zeta potential is preferably-5 mV or less, more preferably-10 mV or less, and even more preferably-15 mV or less. The particles having a large number of hydroxyl groups and carboxyl groups on the surface, such as nano-diamond particles having no surface modification, tend to have negative Zeta potential due to oxygen-based functional groups. Examples of the nanodiamond particles having positive Zeta potential include those obtained by surface capping with hydrogen. Further, it is preferable that the Zeta potential at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

The material constituting the substrate is not particularly limited, and examples thereof include: resins, metals, metal oxides, metal carbides, metal nitrides, glass, and the like. Examples of the resin include: polyolefin resins, polyester resins, polyamide resins, polyimide resins, polycarbonate resins, phenolic resins, epoxy resins, silicone resins, fluorine resins, urethane resins, and the like. Examples of the metal include: si, au, cu, pt, zn, fe, ta, bi, te, ga, or an alloy containing at least one metal thereof, and the like. Examples of the metal oxide include oxides of these metals. Among them, from the viewpoint that the particle-immobilized substrate can be used for a semiconductor application, the substrate is preferably a Si substrate or a SiO substrate ₂ Substrate, siC substrate, gaN substrate.

The Zeta potential of the surface of the region of the substrate where the inorganic nanoparticles are disposed may be negative or positive. The same Zeta potential as that of the inorganic nanoparticles is preferably a sign different from that of the inorganic nanoparticles.

The Zeta potential of the surface of the substrate in the region where the inorganic nanoparticles are not arranged may be negative or positive. The same Zeta potential as that of the inorganic nanoparticles is preferably given by the same symbol.

The Zeta potential of the substrate in the region where the inorganic nanoparticles are arranged and the region where the inorganic nanoparticles are not arranged is preferably 5mV or more, more preferably 10mV or more when the Zeta potential of the surface is positive. In the region of the substrate where the inorganic nanoparticles are arranged and the region where the inorganic nanoparticles are not arranged, the Zeta potential is preferably-10 mV or less, more preferably-20 mV or less when the surface Zeta potential is negative. The Zeta potential is a value measured under the same conditions (e.g., pH) as the Zeta potential of the inorganic nanoparticle.

The potential difference between the Zeta potential of the inorganic nanoparticles and the surface of the region of the substrate where the inorganic nanoparticles are disposed is preferably 30mV or more, more preferably 40mV or more, still more preferably 50mV or more, and particularly preferably 60mV or more. If the potential difference is 30mV or more, the potential difference between the inorganic nanoparticles and the region is sufficiently large, and by appropriately setting the Zeta potential of the inorganic nanoparticles, the inorganic nanoparticles can be easily and selectively arranged in a specific region by electrostatic action. In addition, the adhesive is not easy to fall off after being attached. It is preferable that the potential difference at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

The potential difference of Zeta potential between the region of the substrate where the inorganic nanoparticles are arranged and the surface of the region where the inorganic nanoparticles are not arranged is preferably 30mV or more, more preferably 40mV or more, further preferably 50mV or more, and particularly preferably 60mV or more. When the potential difference is 30mV or more, the potential difference between the two regions is sufficiently large, and by appropriately setting the Zeta potential of the inorganic nanoparticles, the inorganic nanoparticles can be easily and selectively arranged in a specific region by electrostatic action. In addition, the adhesive is not easy to fall off after being attached. It is preferable that the potential difference at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

The potential difference between the Zeta potential of the inorganic nanoparticles and the surface of the substrate in the region where the inorganic nanoparticles are not disposed is preferably less than 30mV, more preferably 25mV or less, and even more preferably 20mV or less. If the Zeta potential is less than 30mV, the inorganic nanoparticles repel the regions of the substrate where the inorganic nanoparticles are not disposed, and thus the inorganic nanoparticles in the particle-disposed nano regions are less likely to adhere to the outside of the particle-disposed nano regions. It is preferable that the Zeta potential at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

The substrate preferably has hydroxyl groups and carboxyl groups (more preferably hydroxyl groups) on the surface of the region where the inorganic nanoparticles are not disposed. The metal oxide tends to have hydroxyl groups on the surface of the substrate.

In the particle-immobilized substrate, inorganic nanoparticles are arranged in a very small region having a width of 1 μm. Therefore, the particle-immobilized substrate can be preferably used in, for example, a nano device in a semiconductor field such as a thermoelectric conversion element, a solar cell, a display, a memory, a thin film transistor, and an LSI. Further, it can be preferably used as a semiconductor device (nano device) using a core composed of inorganic nano particles as quantum dots.

[ method for producing particle-immobilized substrate ]

The particle-immobilized substrate can be produced by the following steps (electrostatic adhesion step): the inorganic nanoparticles are arranged in a first region on a substrate having a first region and a second region having different Zeta potentials by electrostatic interaction. Since the electrostatic adhesion step uses electrostatic action on the surface of the inorganic substance constituting the inorganic nanoparticles, the inorganic nanoparticles disposed in the electrostatic adhesion step are particles in which the inorganic substance constituting the inorganic nanoparticles is exposed on the surface, for example, particles in which the surface is not completely covered with a resin layer.

In the substrate, the first region is a region to which inorganic nanoparticles are attached, and has a width of 1 μm or less. The region having a width of 1 μm or less is a region in which the inorganic nanoparticles are disposed to form a nanoparticle region. Accordingly, the shape, pattern, width, etc. of the first region may be appropriately set according to the arrangement of the particles in the nano region. The first region may have a region exceeding the width of 1 μm. The second region is a region other than the first region, and is a region in which the inorganic nanoparticles are not disposed.

The substrate may be a substrate as exemplified and described as the substrate in the particle-fixed substrate.

The Zeta potential difference between the first region and the second region is preferably 30mV or more, more preferably 40mV or more, further preferably 50mV or more, and particularly preferably 60mV or more. If the potential difference is 30mV or more, the potential difference between the first region and the second region is sufficiently large, and by appropriately setting the Zeta potential of the inorganic nanoparticles, the inorganic nanoparticles can be easily and selectively arranged in the first region by electrostatic action. In addition, the adhesive is not easy to fall off after being attached. It is preferable that the potential difference at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range. If the potential difference is within the above range at least one point where the pH is within the above range, the inorganic nanoparticles can be attached to the first region by electrostatic action at the pH.

The first region and the second region may have a Zeta potential of positive or negative, or both of them may have a Zeta potential of positive or negative. Among them, it is preferable that the Zeta potential of one is positive and the Zeta potential of the other is negative. In this case, the inorganic nanoparticles having a Zeta potential having a sign different from that of the Zeta potential of the first region can be easily arranged in the first region by electrostatic action. More preferably, the Zeta potential of the first region is positive, and the Zeta potential of the second region is negative.

The potential difference between the Zeta potential of the first region and the Zeta potential of the inorganic nanoparticle is preferably 30mV or more, more preferably 40mV or more, and still more preferably 50mV or more. If the potential difference is 30mV or more, the potential difference between the inorganic nanoparticles and the first region is sufficiently large, so that the inorganic nanoparticles can be easily attached to the first region by electrostatic action, and the inorganic nanoparticles are not easily detached after the attachment. It is preferable that the potential difference at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range. If the potential difference is within the above range at least one point where the pH is within the above range, the inorganic nanoparticles can be attached to the first region by electrostatic action at the pH.

The difference between the Zeta potential of the second region and the Zeta potential of the inorganic nanoparticle is preferably less than 30mV, more preferably 25mV or less, and even more preferably 20mV or less. If the Zeta potential is less than 30mV, the inorganic nanoparticles are less likely to adhere to the second region because the inorganic nanoparticles repel the second region. It is preferable that the Zeta potential at least one point of pH2 to pH 12 (preferably pH4 to pH 10, more preferably pH5 to pH 8) is within the above range.

In the first region and the second region, the Zeta potential of the region having a positive Zeta potential is preferably 5mV or more, more preferably 10mV or more. The Zeta potential is a value measured under the same conditions (e.g., pH) as the Zeta potential of the inorganic nanoparticle.

The region having a positive Zeta potential preferably has a cationic group, more preferably an amino group, on the surface. The cationic group is preferably present at 1 or more, more preferably 2 to 4, and still more preferably 2, at one bonding position (within one cationic group-containing group) in a region where Zeta potential is positive. The amino group may be any of a primary amino group, a secondary amino group, and a tertiary amino group, and preferably has a primary amino group (particularly a primary amino group and a secondary amino group). The amino group forms ammonium ions in the electrostatic adhesion step, and the Zeta potential of the region becomes positive.

In the first region and the second region, the Zeta potential of the region having a negative Zeta potential is preferably-10 mV or less, more preferably-20 mV or less. The region having negative Zeta potential preferably has a hydroxyl group or a carboxyl group (more preferably a hydroxyl group). The Zeta potential is a value measured under the same conditions (e.g., pH) as the Zeta potential of the inorganic nanoparticle.

(electrostatic adhesion Process)

In the electrostatic adhesion step, the inorganic nanoparticles are arranged by electrostatic action in a first region on the substrate having a first region and a second region having different Zeta potentials. Specifically, for example, the substrate is immersed in an aqueous dispersion of inorganic nanoparticles. At this time, when the Zeta potential of the surface of the inorganic nanoparticle is large in potential difference from the Zeta potential of the first region and the Zeta potentials are different in sign from each other (that is, when one Zeta potential is negative and the other Zeta potential is positive), the inorganic nanoparticle is attached to the first region by electrostatic action.

The Zeta potential of the surface of the inorganic nanoparticle can be adjusted by a known or conventional method. In the case where the inorganic nanoparticle is a nanodiamond particle, for example, the Zeta potential of the surface of the nanodiamond particle can be adjusted by appropriately selecting a compound or a functional group that modifies the surface of the nanodiamond particle. The preferred range of Zeta potential of the inorganic nanoparticles used in the electrostatic adhesion step is as described above.

The impregnation temperature is, for example, 0 to 100 ℃ (preferably 10 to 40 ℃), and the impregnation time is, for example, 10 seconds to 1 hour (preferably 20 seconds to 10 minutes). The surface of the substrate may be sufficiently cleaned with pure water after the immersing, and then the water remaining on the surface may be blown off by a blower or the like.

The manufacturing method may further include a step other than the electrostatic adhesion step. The other steps include the following steps (step of forming region AB): the electrostatic adhesion step is preceded by forming two regions a and B having different Zeta potentials on the substrate surface. Here, one of the region a and the region B may be a first region, and the other may be a second region.

(Process (i))

The region AB forming step includes: step (i) of: a step of reacting a reactive functional group present on a substrate with a compound reactive with the reactive functional group to form a region a having a Zeta potential different from the Zeta potential of the substrate surface before the reaction (region a forming step); and a step of forming a region B having a Zeta potential different from the Zeta potential of the region a by irradiating with an electron beam to cleave at least a part of the group formed by the reaction in a part of the region a (region B forming step).

The above step (i) will be described in detail with reference to fig. 3. In the region a formation step, a compound reactive with the reactive functional groups present on the substrate 2 is applied to the substrate 2, and reacts with the reactive functional groups to form a region a (4). The coating may be performed by using a known or conventional coater, or by immersing the substrate 2 in the above-mentioned compound. The compound may be applied using a solution or dispersion using a solvent such as an organic solvent that can dissolve or disperse the compound. In the region a forming step, the region a (4) may be formed on the entire surface of the substrate 2 or may be formed on a part of the substrate 2.

In the region a formation stage, for example, a Si substrate may be used as the substrate 2, and an amino group-containing silane coupling agent may be used as the above-described compound. In general, siO is present on the Si substrate surface ₂ A layer. In this case, siO can be used as ₂ The hydroxyl group (silanol group) on the surface of the layer reacts with an amino group-containing silane coupling agent to form a siloxane bond by condensation reaction, and a group having an amino group is formed on the surface of the Si substrate to form a region a. Examples of the amino group-containing silane coupling agent include: 3-aminopropyl triethoxysilane, 3- (2-aminoethylamino) propyl trimethoxysilane, and the like.

The condensation reaction is carried out by immersing the substrate in a solvent such as an organic solvent, which can dissolve and disperse the silane coupling agent, and further adding the silane coupling agent and stirring the mixture under an inert gas atmosphere. The temperature in the condensation reaction is, for example, 10 to 90℃and the time is, for example, 3 to 30 hours. The condensation reaction is preferably carried out at a pH of 2 to 12, more preferably at a pH of 4 to 10, and still more preferably at a pH of 5 to 8. After the condensation reaction, the substrate surface may be cleaned as needed. In the case of washing, it is preferable to perform washing with ethanol and washing with pure water after washing with a solvent used in the reaction. After that, if necessary, the water remaining on the surface of the substrate may be blown off by a blower or the like, and further dried by a dryer. As described above, the region a having the amino group on the surface can be formed.

In the region B formation step, for example, as shown in fig. 3, electron beam irradiation 5 is performed on a part of the region a (4) formed in the region a formation step, and the groups (for example, groups having amino groups) formed by the reaction are decomposed and restored to the state of the surface of the substrate 2 before the formation of the region a (4), thereby forming a region B (6). That is, the Zeta potential of the region B (6) is the same as the Zeta potential of the surface of the substrate 2 before the formation of the region a (4).

As shown in fig. 3, the substrate surface before the formation of the region a may be restored by electron beam irradiation, or the region B having a Zeta potential different from the Zeta potential of the region a may be formed by cutting at least some of the bonds in the groups formed by the reaction or decomposing the groups.

The electron beam irradiation of a part of the region a may be performed in accordance with a pre-designed pattern using an EB lithography apparatus. That is, the shapes of the first region and the second region can be formed according to the designed pattern shape using an EB lithography apparatus.

As described above, the substrate having the two regions a and B having the different Zeta potentials on the substrate surface can be manufactured by the step (i).

The region B may be the first region when the region B formed in the region B forming step has a region having a width of 1 μm or less, and the region a may be the first region when the region a remaining in the region B forming step has a region having a width of 1 μm or less.

For example, when a Si substrate is used as the substrate 2 and an amino group-containing silane coupling agent is used as the compound, the Zeta potential tends to be positive in the region a having an amino group on the surface at pH7 or lower. The region B formed by electron beam irradiation has a Zeta potential derived from an oxygen-based functional group, and tends to have a negative Zeta potential, similarly to the Si substrate surface before the formation of the region a. Therefore, when the region a is the first region, the inorganic nanoparticles are fixed to the region a in the electrostatic adhesion step by using the inorganic nanoparticles having a negative Zeta potential. On the other hand, when the region B is the first region, the inorganic nanoparticles are fixed to the region B in the electrostatic adhesion step by using inorganic nanoparticles having a positive Zeta potential.

(step (ii))

The step (ii) of forming the region AB may include: a step of forming a resist film on a substrate surface, and then dissolving a part of the resist film by electron beam irradiation and development to open a hole in the resist film, thereby exposing the substrate (resist mask forming step); a step of reacting a reactive functional group present on the exposed substrate with a compound reactive with the reactive functional group to form a region a having a Zeta potential different from the Zeta potential of the substrate surface before the reaction (region a forming step); and a step (resist removal step) of removing the resist film on the substrate surface to expose the substrate surface and form a region B.

The above step (ii) will be described in detail with reference to fig. 4. In the resist mask formation stage, a resist film 7 is formed on the substrate 2 by a known or conventional method. Next, the resist film 7 is partially irradiated with an electron beam 5, and then the resist film of the electron beam irradiation portion 7' is dissolved by etching or the like by a development process, so that the substrate surface 8 is exposed, thereby forming a resist mask. In fig. 4, the resist film in the portion not irradiated with the electron beam may be dissolved by etching or the like to expose the substrate surface 8 instead of the electron beam irradiation portion 7'.

Then, in the region a formation stage, the above compound is applied to the exposed substrate surface 8. The application of the above-mentioned compound is preferably performed in a gas phase (deposition) from the viewpoint of preventing dissolution of the resist film 7 at the time of application. Specifically, the substrate 2 having the resist film 7 and the container in the open state in which the compound is put are put into a closed container, and the closed container is closed and left to stand. During the standing, the compound volatilizes in the sealing device, and the volatilized compound adheres to the substrate surface 8. The compound may be applied using a solution or dispersion using a solvent such as an organic solvent that can dissolve or disperse the compound.

When a Si substrate is used as the substrate 2 and an amino group-containing silane coupling agent is used as the compound, the condensation reaction is performed in the same manner as the step of forming the region a in the step (i), and a group having an amino group is formed on the substrate surface 8 to form the region a (4). In addition, the region a (4) may be formed only on the substrate surface 8 in the region a forming stage, but may be formed on the resist film 7.

Next, in the resist removal step, the remaining resist film (resist mask) 7 is removed to expose the substrate surface, and the exposed region is formed as a region B (6). The removal of the resist mask can be performed by a known or conventional method, and for example, the resist mask can be immersed in an organic solvent (developer) for dissolving the resist film.

As described above, the substrate having the two regions a and B having the different Zeta potentials on the substrate surface can be produced by the step (ii).

When the region of the substrate surface exposed in the resist mask forming step has a region having a width of 1 μm or less, the region a to be formed later may be the first region, and when the region of the resist film remaining in the resist mask forming step has a region having a width of 1 μm or less, the substrate surface (region B) exposed in the resist removing step may be the first region.

For example, when a Si substrate is used as the substrate 2 and an amino group-containing silane coupling agent is used as the compound, the Zeta potential tends to be positive in the region a having an amino group on the surface at pH7 or lower. The region B formed by removing the resist mask has a Zeta potential derived from the oxygen-based functional group, and tends to have a negative Zeta potential, similarly to the Si substrate surface before the formation of the region a. Therefore, when the region a is the first region, the inorganic nanoparticles are fixed to the region a in the electrostatic adhesion step by using the inorganic nanoparticles having a negative Zeta potential. On the other hand, when the region B is the first region, the inorganic nanoparticles are fixed to the region B in the electrostatic adhesion step by using inorganic nanoparticles having a positive Zeta potential.

In the case of describing the above-described production method, an example was described in which a Si substrate was used as the substrate and an amino group-containing silane coupling agent was used as the compound having reactivity with the reactive functional group on the substrate surface, but the above-described production method is not limited to this example. That is, when a substrate having a reactive functional group on the surface and a compound having a functional group which is reactive with the reactive functional group and has a Zeta potential different from that of the substrate surface are used in combination, the particle-immobilized substrate can be produced by the same method as the above example using a known or conventional technique.

[ method for producing diamond film-fixed substrate ]

The substrate (diamond film-fixing substrate) to which the diamond film is fixed can be manufactured by performing a process (CVD process) of growing the nano-diamond particles by a chemical vapor deposition method (CVD method) using the nano-diamond particles as seed crystals on the particle-fixing substrate using the nano-diamond particles as the inorganic nano-particles, and forming a diamond film on the substrate.

The CVD method can be performed by a known method or a conventional method. For example, the particle-fixed substrate is put into a gas phase containing a carbon source such as methane and hydrogen, and a plasma of a mixed gas of hydrogen and methane is generated in the gas phase. Thereby, atomic hydrogen and carbon radicals are generated, and nano diamond particles on the particle-immobilized substrate are grown as seed crystals, and they are bonded to each other (Coalescence) to thereby form a diamond film.

The conditions such as the temperature, pressure, gas supply amount, and gas concentration in the CVD process are not particularly limited, and can be appropriately adjusted. The time for performing the CVD process may be appropriately adjusted according to the thickness of the obtained diamond film, the growth of the diamond film, the width of the pattern (the width of the nano-region to be formed, described later), and the interval of the pattern. The concentration of methane in the gas phase (the concentration relative to the total of methane and hydrogen) in the CVD step is, for example, 0.1 to 10% by volume, and preferably 1 to 5% by volume. The concentration of hydrogen in the gas phase (the concentration relative to the total of methane and hydrogen) in the CVD process is, for example, 90 to 99.9% by volume, and preferably 95 to 99% by volume. The temperature is preferably 200℃to 1500℃and more preferably 500℃to 1200 ℃. The diamond growth time in the CVD step is, for example, 1 to 30 minutes, preferably 5 to 25 minutes, and more preferably 10 to 20 minutes.

The diamond film-fixing substrate obtained by the above-described production method is provided with the above-described substrate and a diamond film formed on the above-described substrate. The diamond film is formed by growing (growing diamond particles) nano-diamond particles immobilized as inorganic nano-particles on the particle-immobilized substrate, or by growing and bonding. The diamond film may be: a film formed of a plurality of grown diamond particles in which each diamond particle grows and is not bonded to adjacent particles; and a film in which each diamond particle grows and bonds with adjacent diamond particles. The diamond film may have voids or pores derived from gaps between nano-diamond particles on the particle-immobilized substrate.

The diamond film-fixing substrate preferably has a region (film-forming nano region) having a width of 1 μm or less in which the diamond film is formed on the substrate. Such a diamond film can be produced by growing nanodiamond particles disposed in the particle-disposed nanoregion. The diamond film may be formed in a region other than the region having a width of 1 μm or less on the substrate.

An enlarged schematic view of an embodiment of the diamond film-fixing substrate having the film-forming nano-region is shown in fig. 5. The diamond film-fixing substrate 10 is produced by growing the nanodiamond particles 3 in the particle-fixing substrate 1 shown in fig. 1 by CVD. The diamond film fixing substrate 10 shown in fig. 5 includes a substrate 2 and a plurality of diamond films 3'. In the diamond film-fixing substrate 10, one diamond film 3' is arranged in a region (film-forming nano-region) on the substrate 2, which has a width D1 of 1 μm or less and extends in the lateral direction (direction orthogonal to the width D1). The regions extending in the lateral direction in the width D1 are arranged in plurality at intervals D2 in the longitudinal direction to form a striped pattern.

An enlarged schematic view of another embodiment of the above-described diamond film-fixing substrate having the above-described film-forming nano-region is shown in fig. 6. The diamond film-fixing substrate 10 is produced by growing the nanodiamond particles 3 in the particle-fixing substrate 1 shown in fig. 2 by CVD. The diamond film fixing substrate 10 shown in fig. 6 includes a substrate 2 and a diamond film 3'. The diamond film 3' is a film formed of a plurality of grown diamond particles in which the nano diamond particles 3 on the particle-immobilized substrate shown in fig. 2 are grown to such an extent that the nano diamond particles 3 are not bonded to each other. In the diamond film-fixing substrate 10, the diamond film 3' is arranged in a region (film-forming nano-region) on the substrate 2, the region having a width D1 of 1 μm or less and extending in the lateral direction (direction orthogonal to the width D1). The regions extending in the lateral direction in the width D1 are arranged in plurality at intervals D2 in the longitudinal direction to form a striped pattern.

The diamond film-fixing substrate may have a region (substrate-exposed nano region) of 1 μm or less in width, on which the diamond film is not formed, as shown in fig. 6 and 14, for example. The substrate exposed nano region may be present in the film-forming nano region. Such a diamond film-fixing substrate can be manufactured by: the nanodiamond particles disposed in the particle-disposed nanoregions are grown so that gaps between the nanodiamond particles are not completely filled, and the nanodiamond particles remain in the substrate exposed nanoregions. Such a diamond film-fixing substrate is produced by growing the nanodiamond particles 3 in the particle-fixing substrate 1 shown in fig. 2 by CVD.

The film-forming nano-regions may be of the shape illustrated and described as the particle-disposing nano-regions. The knowledge of the "width" of the film-forming nano-region is the same as the knowledge of the "width" of the particle-disposing nano-region. The film-forming nano-region may be present only in one or a plurality of regions having the same or different shapes on the substrate. The film-forming nano-regions may be regularly arranged (aligned) or irregularly arranged, but are preferably regularly arranged. Examples of the pattern expressed by the regular arrangement include: stripe patterns, dot patterns, checkered patterns, grid patterns, bird grids, grid textures, and the like. The shape of the dots in the dot pattern is not particularly limited, and examples thereof include: ++, circles, polygons, etc.

The interval between the plurality of particle placement regions (e.g., D2 in fig. 5 to 6) in the shape in which the stripe pattern, the dot pattern, and the like are regularly arranged is not particularly limited, but the size with respect to the width is preferably 0.1 to 1.5 times, more preferably 0.5 to 1.0 times.

The diamond film is formed by growing nano diamond particles, and therefore the arithmetic average roughness Ra of the film surface (for example, 3' a of fig. 5 to 6) is preferably 6nm or more (for example, 6nm to 20 nm), more preferably 7nm or more (for example, 7nm to 15 nm). The root mean square height Rq of the diamond film surface (e.g., 3' a of fig. 5 to 6) is preferably 8nm or more (e.g., 8nm to 30 nm), and more preferably 10nm or more (e.g., 10nm to 20 nm). In the conventional method, a fixed substrate is formed using a diamond film in which a flat diamond film is formed on a substrate, the surface of the diamond film is polished and smoothed, and then a part of the diamond film and the substrate is removed by etching, whereby the diamond film remains in a region of 1 μm or less in width on the substrate. However, in such conventional methods, in order to perform resist mask pattern formation and uniform etching, it is necessary to smooth the diamond film surface, and therefore the roughness of the etched diamond film surface is generally low.

The thickness of the diamond film (the distance between the substrate surface and the highest point of the diamond film surface) is preferably 10nm to 200nm, more preferably 30nm to 100nm.

The diamond film-fixing substrate is obtained by growing nano-diamond particles on the particle-fixing substrate, and thus the diamond film on the diamond film-fixing substrate is formed in a state where the shape of the nano-diamond particles is maintained. Therefore, the diamond film-attached substrate can be used for mechanical conversion elements such as MEMS (Micro-Electro-Mechanical System: micro Electro-mechanical system), NEMS (Nano-Electromechanical System: nano Electro-mechanical system), and vibrators. In addition, when the diamond film is produced by a CVD method under high-temperature heating conditions, the substrate and at least a part of the diamond film react to form bonds, and thus the adhesion is excellent.

[ method for producing diamond ]

By removing the base material from the diamond film-fixing substrate on which the diamond film is fixed on the substrate, diamond derived from the nanodiamond film can be produced.

The diamond derived from the nano-diamond film is diamond obtained by peeling the diamond film from the substrate, and is a self-supporting solid of the diamond film or diamond particles constituting the diamond film. Specifically, in the case where the diamond film is formed of each grown diamond particle, the obtained diamond is the grown diamond particle. In the case where the diamond film is formed by bonding a plurality of diamond particles by growth of each other, the diamond obtained is the film-shaped diamond. The film-shaped diamond may have voids or pores originating from gaps between the nano-diamond particles on the particle-immobilized substrate.

The substrate removal method may be a known or conventional method, and examples thereof include: a method of physically separating the substrate from the diamond film-fixing substrate, a method of chemically removing the substrate, and the like.

According to the method for producing diamond, a diamond film having a geometric shape formed on the diamond film-fixing substrate can be obtained as a single self-supporting solid diamond such as a film-like diamond (rod-like diamond). Further, as the grown diamond particles, a self-supporting solid of diamond particles in a particle form slightly larger than the nano diamond particles as seed crystals can be obtained alone. In addition, when the self-supporting solid diamond is nano-sized, the self-supporting solid diamond is dispersed in a solvent, and a nanodiamond dispersion composition in which diamond is dispersed in a solvent can be produced. The nanodiamond dispersion composition can be expected to be used for biosensing, bioimaging and other biological applications.

The various aspects disclosed herein may be combined with any of the other features disclosed herein. Each configuration and the combination of each configuration in each embodiment are examples, and addition, omission, substitution, and other modifications of the appropriate configuration may be made without departing from the scope of the present disclosure. Furthermore, the inventions of the present disclosure are not limited by the embodiments, examples below, but only by the patent claims.

Examples

Hereinafter, an embodiment of the present disclosure will be described in more detail based on examples.

Example 1

(pretreatment of Si substrate)

A 500mL beaker was prepared, 200mL deionized water (pure water) was injected, 100mL of 12 mass% aqueous ammonia was added thereto, and the beaker was immersed in an oil bath and heated to about 96 ℃. Thereafter, the temperature of the oil bath was set to 80 ℃, and 40mL of a 30 mass% aqueous hydrogen peroxide solution was poured into the beaker. Thus, RCA (SC-1) cleaning liquid at 75℃to 80℃was obtained. On the other hand, a commercially available semiconductor Si wafer (diameter: 4 inches, si (100), p-type, single-sided polishing) was cut (cracked) into 1.5cm×1.5cm squares by a wafer cutter (diamond scriber), and a Si substrate was fabricated. Before the decomposition of the aqueous hydrogen peroxide solution proceeds, the Si substrate is rapidly put into the cleaning liquid, the surface dish is covered on the opening of the beaker, and then the temperature of the oil bath is raised to 75 to 80 ℃ and maintained in this state for 30 minutes. This cleaning process is called SC-1 cleaning in RCA cleaning, which is a general cleaning method for Si substrates, and has the effects of dissolving and removing organic matters on the surface of the Si substrate and removing insoluble particles by peeling. After 30 minutes, the power supply of the oil bath is turned off, and the cleaning liquid is waited to be cooled to below 30 ℃. After cooling, the Si substrate was sufficiently cleaned by washing with running water using pure water without taking out the Si substrate and without bringing the substrate into contact with air. The cleaned substrate is stored in a sealed container with the polished surface dried by a blower so that dust in the air does not adhere.

(amino modification of Si substrate with aminosilane coupling agent in liquid-phase reaction System)

Into a three-necked flask, 20mL of toluene was charged, and the Si substrate subjected to the pretreatment was placed in a toluene solvent. Then, about 0.1mL of an aminosilane coupling agent (N- (2-aminoethyl) -3-aminopropyl trimethoxysilane) was added to the flask by syringe. The flask was heated in an oil bath at 70℃for 12 hours while flowing nitrogen gas therethrough to effect a reaction. About 10mL of toluene was added to the flask after the reaction, and the Si substrate was washed. Repeatedly washing with toluene for 2-3 times, then adding 10mL of ethanol, and repeatedly washing for 2-3 times. After the cleaning, the Si substrate was taken out and repeatedly rinsed 3 times with pure water. The cleaned substrate was blown to remove water, and immediately after being placed in a dish, it was dried at 110℃with a dryer. Thus, the entire surface of the Si substrate was subjected to silane coupling treatment, and a region having an N- (2-aminoethyl) -3-aminopropylsilyl group incorporated (amino-modified) therein was formed over the entire surface. The processed substrate is used for the next patterning process.

(patterning of an amino-modified Si substrate depicted by an Electron Beam)

An Electron Beam (EB) was irradiated to the amino-modified Si substrate surface along a pre-designed pattern using an EB lithography apparatus. Specifically, EB irradiation was performed for 9 design patterns shown in table 1. The amino groups in the regions irradiated with EB were decomposed to expose the original Si substrate surface, while the amino groups remained in the regions not irradiated with EB. Thus, a region having a negative Zeta potential (about-40 mV) derived from an oxygen-based functional group on the surface of an unmodified Si substrate and a region having a positive Zeta potential (about 30 mV) derived from an amino group can be patterned at pH 6. The Zeta potential measurement method is described below.

TABLE 1

In the table, "L & S" (Line and space: line width) represents a stripe shape, L represents a dimension of a width of an electron beam irradiation region, and S represents a dimension of a width of an electron beam non-irradiation region. Further, "hole (SQ)" indicates a shape of a hole having a square shape, Λ indicates a size of a width of an electron beam irradiation region, and Φ indicates a size of a width of an electron beam non-irradiation region.

(Selective coating (Electrostatic adsorption) of nanodiamond)

Nanodiamond was coated on the surface of the Si substrate using an aqueous dispersion of Zeta-nanodiamond (trade name "DINNOVARE", manufactured by Daicel, inc., zeta potential at pH 6: about-27 mV). Specifically, 10mL of the nanodiamond aqueous dispersion was taken into a plastic container, and the Si substrate subjected to the patterning treatment was immersed in the nanodiamond aqueous dispersion. After about 1 minute, the Si substrate was taken out, and the surface of the substrate was sufficiently rinsed with pure water. The surface of the cleaned Si substrate was blown to remove the residual water, and stored in a sealed container. The surface of the obtained Si substrate (nanodiamond particle-immobilized substrate) was analyzed for surface morphology by Atomic Force Microscopy (AFM) as follows.

(evaluation of the attached State of nanodiamond on Si substrate by AFM)

The surface morphology of the nanodiamond particle-immobilized substrate was analyzed using an AFM apparatus (device name "Dimension Icon", manufactured by Bruker corporation). The analysis conditions are as follows.

Probe: scanAsyst-Air.

Mode: QNM in air (standard).

Scanning rate: 0.5Hz.

Analysis of L & S (X: 1, Y: 1), (X: 1, Y: 2), (X: 1, Y: 3) and (X: 2, Y: 1) shown in Table 1 above was performed by an AFM device, and as a result, it was confirmed that the regions where nano-diamond particles were adsorbed and the regions where nano-diamond particles were not adsorbed were obtained. In the patterning of (X: 1, Y: 3), it was confirmed that nanodiamond was adsorbed in the region of 500nm width and that nanodiamond was not adsorbed in the region of 200nm width. As a representative example, AFM images obtained during patterning of (X: 1, Y: 3) are shown in FIG. 7.

Example 2

(formation of resist Pattern by Electron Beam writing)

A resist resin (trade name "ZEP520A", manufactured by Zeon corporation) was uniformly coated on the surface of the Si substrate pretreated in the same manner as in example 1 by a spin coater. Using an EB lithography apparatus, EB irradiation was performed on the resist resin formed on the Si substrate in accordance with a pre-designed pattern. Specifically, EB irradiation was performed for 9 design patterns shown in table 2. Thereafter, the substrate was immersed in 100mL of a developer (anisole solvent) for ZEP520A resist placed in a 200mL beaker, thereby forming a pattern of a resist mask based on the design pattern.

TABLE 2

(amino modification of Si substrate with aminosilane coupling agent in gas-phase reaction System)

A 400mL sealed glass container was prepared, and the Si substrate on which the resist mask pattern was formed was set so that the surface faced outward. A screw tube containing about 10mL of 3-aminopropyl triethoxysilane (APTES) was provided in a state of not covering the Si substrate in the sealed glass container. After that, the lid of the closed glass container was closed and left to stand for 20 hours. During the leaving, the volatilized APTES reacts with silanol groups in the regions of the Si substrate where the resist mask is not formed, and selectively modifies amino groups in the regions. After leaving for 20 hours, the Si substrate was taken out and immersed in toluene for 10 minutes, whereby the resist mask pattern was completely peeled off. Thus, a region having a negative Zeta potential (about-40 mV) derived from an oxygen-based functional group on the surface of an unmodified Si substrate and a region having a positive Zeta potential (about 30 mV) derived from an amino group can be patterned at pH 6. The Zeta potential measurement method is described below.

(Selective coating (Electrostatic adsorption) of nanodiamond)

As for the Si substrate subjected to the patterning treatment as described above, nanodiamond was coated on the surface of the Si substrate in the same manner as in example 1. The surface of the obtained Si substrate (nanodiamond particle-immobilized substrate) was analyzed for surface morphology by Atomic Force Microscopy (AFM) as follows. The conditions for AFM analysis were the same as in example 1.

Of all the 9 design patterns shown in table 2, analysis by AFM apparatus revealed that the regions where nano-diamond particles were adsorbed and the regions where nano-diamond particles were not adsorbed. As a representative example, an AFM image obtained in patterning (X: 3, Y: 3) as the finest pattern is shown in FIG. 8.

< method for measuring Zeta potential >

Trade name "Zetasizer Nano ZS" (manufactured by Malvern Panalytical corporation) was used for the measurement of Zeta potential. The Zeta potential cannot be measured as a plate-like substance, but can be measured only as particles dispersed in a solvent. Therefore, the Zeta potential of the nanodiamond particles was measured by setting the aqueous dispersion of the nanodiamond particles to be used in the apparatus as it is. On the other hand, the Zeta potential of the pretreated Si substrate surface was measured by performing Zeta potential measurement on a dispersion obtained by dispersing silicon nanoparticles in pure water. The Zeta potential of the amino-modified Si substrate was measured by replacing the Zeta potential measurement with a dispersion obtained by dispersing the silicon nanoparticles subjected to the amino-modification treatment similar to that of the substrate in pure water. As a measurement principle, the velocity of electrophoresis of nanoparticles dispersed in a solvent in a certain electric field intensity was measured based on the laser doppler effect using a laser of 633nm, and the velocity was converted to Zeta potential using Henry's formula. As measurement conditions, an average of results of scanning 300 times with a backscattering arrangement of 173 ° was calculated. When the particle concentration in the liquid is about 0.01 to 1 mass%, the Zeta potential independent of the concentration can be calculated. In this example, the measurement was performed with the concentration of the nano diamond particles being 1 mass% and the concentration of the silicon nano particles being 0.1 mass%.

Example 3

(production of nanodiamond particle-immobilized substrate)

A nanodiamond particle-immobilized substrate was produced in the same manner as in example 2. The patterns were formed of 4 types, i.e., "L & S" (200/200 (L/S)) "," L & S "(150/150 (L/S))", "L & S" (100/100 (L/S)) "," hole (SQ) "(200/200 (+/φ)").

(production of Diamond film fixed substrate)

The nano-diamond particle-fixed substrate produced in the above was subjected to a CVD process to form a diamond film. In the CVD step, a microwave plasma CVD apparatus (trade name: SDS5200S "manufactured by CORNES Technologies Co., ltd.) was used. Specifically, the nanodiamond particle-fixing substrate was placed in the center of a disk made of Mo in the CVD apparatus, a boron nitride ring was placed around the nanodiamond particles, and then the inside of the vacuum vessel was evacuated to 3×10 ^-6 And Torr or below. Will H ₂ And CH (CH) ₄ The pressure was set to 10Torr at a ratio of 97:3, and the microwave oscillation was started to generate plasma. By one side with gas flow rate H ₂ ：291sccm、CH ₄ : the pressure in the apparatus was kept constant by introducing the gas in a form of 300sccm in total of 9sccm while continuously exhausting the gas by a rotary pump. At the beginning The microwave was emitted to rapidly bring the pressure to 60Torr, and changed to CVD conditions suitable for diamond growth. Regarding the substrate temperature, the Si substrate surface was measured using an optical power meter. The diamond growth time was set to 10min. The diamond growth conditions are shown below. After the growth, the gas was discharged by a rotary pump and a turbo molecular pump, and after naturally cooling for about 30 minutes, the sample was taken out by opening the atmosphere.

< conditions for diamond growth by microwave plasma CVD >

Pre-exhaust pressure: 1.0X10 ^-6 And Torr or below.

·CH ₄ Concentration { CH } ₄ /(CH ₄ +H ₂ ) }: 3% by volume.

Discharge gas pressure: 60Torr.

Gas flow rate: 300sccm.

Microwave power: 1.2kW.

Substrate temperature: about 1030 ℃.

Growth time: and 10min.

The surface of the obtained Si substrate (diamond film-fixed substrate) was analyzed for surface morphology by a Scanning Electron Microscope (SEM) (model "SU5000", manufactured by HITACHI Hightech, inc.). The acceleration voltage was set to 3.0kV.

The types of patterns and the numbers of the SEM images of the substrates subjected to SEM analysis are shown in table 3. The patterns shown in table 3 are design patterns on the nanodiamond particle-immobilized substrate before the CVD process. In all of the 4 design patterns shown in table 3, analysis was performed by SEM apparatus, and as a result, it was confirmed that there were areas where diamond films formed by growth of nano diamond particles and areas where diamond films formed by growth of nano diamond particles were not present. Further, regarding No.1, the surface roughness of the diamond film was measured by Atomic Force Microscope (AFM) at each of two locations, and as a result, the arithmetic average roughness Ra was 8.70nm and 11.2nm, and the root mean square height Rq was 11.1nm and 14.4nm (the measurement locations are shown in FIG. 13). Further, regarding No.1, a cross-sectional indication of the height of the diamond film was measured. The measurement sites and measurement results are shown in fig. 14.

TABLE 3

The following describes modifications of the disclosed invention.

[ additional note 1] A particle-immobilized substrate comprising a substrate and a plurality of inorganic nanoparticles disposed on the substrate, wherein the plurality of inorganic nanoparticles are disposed in contact with each other in a region having a width of 1 [ mu ] m or less on the substrate.

The particle-immobilized substrate according to appendix 2, wherein a potential difference between the Zeta potential of the inorganic nanoparticles and the Zeta potential of the substrate surface at the positions where the inorganic nanoparticles are disposed is 30mV or more (or 40mV or more, 50mV or more).

The particle-immobilized substrate according to any one of the supplementary notes 3 to 1 or 2, wherein one of the inorganic nanoparticles and the substrate surface at the position where the inorganic nanoparticles are disposed has a positive Zeta potential and the other has a negative Zeta potential.

[ additionally provided is a particle-immobilized substrate comprising a substrate and inorganic nanoparticles disposed on the substrate, wherein the potential difference between the Zeta potential of the inorganic nanoparticles and the Zeta potential of the substrate surface at the positions where the inorganic nanoparticles are disposed is 30mV or more (or 40mV or more, 50mV or more).

The particle-immobilized substrate according to any one of the appended note 5, wherein the Zeta potential of one of the inorganic nanoparticles and the substrate surface at the position where the inorganic nanoparticles are disposed is positive and the Zeta potential of the other is negative.

[ additionally described 6] is a particle-immobilized substrate comprising a substrate and inorganic nanoparticles disposed on the substrate, wherein one of the inorganic nanoparticles and the substrate surface at the position where the inorganic nanoparticles are disposed has a positive Zeta potential and the other has a negative Zeta potential.

The particle-immobilized substrate according to any one of supplementary notes 7, wherein a plurality of regions having a width of 1 μm or less (or 600nm or less, 300nm or less, 150nm or less) are regularly arranged on the substrate, and the inorganic nanoparticles are disposed in the plurality of regions having a width of 1 μm or less (or 600nm or less, 300nm or less, 150nm or less) respectively.

The particle-immobilized substrate according to any one of supplementary notes 8 to 1 to 7, wherein the nanoparticle comprises one or more (preferably, a nano carbon particle, more preferably, a nano diamond particle) selected from the group consisting of a metal nanoparticle, a semiconductor nanoparticle, and a nano carbon particle.

The particle-immobilized substrate according to any one of supplementary notes 9, wherein the Zeta potential of the inorganic nanoparticles and the Zeta potential of the surface of the region of the substrate where the inorganic nanoparticles are disposed are different signs.

The particle-immobilized substrate according to any one of supplementary notes 10, wherein the Zeta potential of the inorganic nanoparticles is the same as that of the surface of the region of the substrate where the inorganic nanoparticles are not disposed.

[ additional note 11] the particle-immobilized substrate according to any one of additional notes 1 to 10, wherein the Zeta potential of the inorganic nanoparticles is negative (preferably Zeta potential is-5 mV or less, -10mV or less, or-15 mV or less).

The particle-immobilized substrate according to any one of the appended 12 to 11, wherein the Zeta potential in the region of the substrate where the inorganic nanoparticles are disposed is positive (preferably 5mV or more, more preferably 10mV or more).

The particle-immobilized substrate according to any one of supplementary notes 11 or 12, wherein the Zeta potential in the region of the substrate where the inorganic nanoparticles are not disposed is negative (preferably-10 mV or less, more preferably-20 mV or less).

The particle-immobilized substrate according to any one of supplementary notes 14, wherein the inorganic nanoparticle has a Zeta potential of positive value (preferably a Zeta potential of 5mV or more, 10mV or more, or 20mV or more).

The particle-immobilized substrate according to appendix 15, wherein the Zeta potential of the substrate in the region where the inorganic nanoparticles are disposed is negative (preferably-10 mV or less, more preferably-20 mV or less).

The particle-immobilized substrate according to any one of supplementary notes 14 to 15, wherein the Zeta potential of the substrate in the region where the inorganic nanoparticles are not disposed is positive (preferably 5mV or more, more preferably 10mV or more).

The particle-immobilized substrate according to any one of supplementary notes 17 to 1 to 16, wherein a Zeta potential difference between the inorganic nanoparticles and a surface of a region of the substrate where the inorganic nanoparticles are disposed is 30mV or more (or 40mV or more, 50mV or more, 60mV or more).

The particle-immobilized substrate according to any one of supplementary notes 18 to 1 to 17, wherein a difference in Zeta potential between a region of the substrate where the inorganic nanoparticles are arranged and a region where the inorganic nanoparticles are not arranged is 30mV or more (or 40mV or more, 50mV or more, or 60mV or more).

The particle-immobilized substrate according to any one of supplementary notes 19 to 18, wherein a difference in Zeta potential between the inorganic nanoparticles and a surface of a region of the substrate where the inorganic nanoparticles are not disposed is less than 30mV (or 25mV or less, 20mV or less).

The particle-immobilized substrate according to any one of supplementary notes 20 to 1 to 19, wherein the substrate has a hydroxyl group or a carboxyl group (preferably a hydroxyl group) on a surface of a region where the inorganic nanoparticle is not disposed.

The particle-immobilized substrate according to any one of supplementary notes 21 to 20, wherein the inorganic nanoparticles are particles in which an inorganic substance constituting the inorganic nanoparticles is exposed on the surface.

[ additionally provided with reference 22] a method for producing a particle-immobilized substrate, wherein inorganic nanoparticles are arranged by electrostatic interaction in a region having a width of 1 [ mu ] m or less (or 600nm or less, 300nm or less, 150nm or less) in a first region and a second region on a substrate having a difference in Zeta potential between them of 30mV or more (or 40mV or more, 50mV or more).

The method for manufacturing a particle-immobilized substrate according to the item 22, wherein one of the first region and the second region has a positive Zeta potential and the other has a negative Zeta potential.

The additional note 24 is a method for producing a particle-immobilized substrate, wherein inorganic nanoparticles are arranged by electrostatic interaction in a region having a width of 1 μm or less in a first region and a second region on a substrate having a first region in which the Zeta potential is positive and the Zeta potential is negative.

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 24, wherein a plurality of the first regions are regularly arranged on the substrate, and the inorganic nanoparticles are disposed in the plurality of first regions, respectively.

The method for producing a particle-immobilized substrate according to any one of supplementary notes 26 to 22 to 25, wherein the nanoparticle comprises one or more (preferably, a nanocarbon particle, more preferably, a nanodiamond particle) selected from the group consisting of a metal nanoparticle, a semiconductor nanoparticle, and a nanocarbon particle.

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 26, wherein the inorganic nanoparticles and the surface of the second region have the same Zeta potential.

[ additional note 28] the method for producing a particle-immobilized substrate according to any one of additional notes 22 to 27, wherein the Zeta potential of the inorganic nanoparticles is negative (preferably Zeta potential is-5 mV or less, -10mV or less, or-15 mV or less).

The method for producing a particle-immobilized substrate according to the additional note 29, wherein the Zeta potential of the surface of the first region of the substrate is positive (preferably 5mV or more, more preferably 10mV or more).

The method for producing a particle-immobilized substrate according to any one of the supplementary notes 28 to 29, wherein the Zeta potential of the surface of the second region of the substrate is negative (preferably-10 mV or less, more preferably-20 mV or less).

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 27, wherein the Zeta potential of the inorganic nanoparticle is positive (preferably Zeta potential is 5mV or more, 10mV or more, or 20mV or more).

[ additional note 32] the method for producing a particle-immobilized substrate according to additional note 31, wherein the Zeta potential of the surface of the first region of the substrate is negative (preferably-10 mV or less, more preferably-20 mV or less).

[ additional note 33] the method for producing a particle-immobilized substrate according to additional note 31 or 32, wherein the Zeta potential of the surface of the second region of the substrate is positive (preferably 5mV or more, more preferably 10mV or more).

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 33, wherein a potential difference between the inorganic nanoparticle and the Zeta potential of the surface of the first region is 30mV or more (or 40mV or more, 50mV or more).

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 34, wherein a potential difference between the inorganic nanoparticle and the Zeta potential of the surface of the second region is less than 30mV (or 25mV or less, 20mV or less).

The method for producing a particle-immobilized substrate according to any one of supplementary notes 36, wherein the region having a negative data potential on the surface of the first region and the second region has a hydroxyl group or a carboxyl group (preferably a hydroxyl group) on the surface.

The method for producing a particle-immobilized substrate according to any one of supplementary notes 37 to 36, wherein the positive data potential region of the surface has a cationic group (preferably an amino group) on the surface of the first region and the second region.

The method for producing a particle-immobilized substrate according to the additional note 38, wherein the cationic group is present at 1 or more (preferably 2 to 4, more preferably 2) bonding positions in a region where Zeta potential is positive.

Appendix 39 the method for producing a particle-immobilized substrate according to appendix 37 or 38, wherein the cationic group has a primary amino group (preferably a primary amino group and a secondary amino group).

The method for producing a particle-immobilized substrate according to any one of supplementary notes 40 to 39, wherein the inorganic nanoparticles are particles in which an inorganic substance constituting the inorganic nanoparticles is exposed on the surface.

The method for producing a particle-immobilized substrate according to any one of supplementary notes 22 to 40, further comprising: and a region AB forming step of forming, on the surface of the substrate, a region A and a region B having different Zeta potentials, one of the region A and the region B being the first region and the other being the second region, before the electrostatic adhesion step.

The method for manufacturing a particle-immobilized substrate according to any one of the preceding paragraphs 41, wherein the step of forming the region AB comprises: a region A forming step of reacting a reactive functional group present on a substrate with a compound reactive with the reactive functional group to form a region A having a Zeta potential different from the Zeta potential of the substrate surface before the reaction; and a region B formation step of forming a region B having a Zeta potential different from the Zeta potential of the region A by cutting at least a part of the radicals formed by the reaction in a part of the region A by electron beam irradiation.

The method for producing a particle-immobilized substrate according to appendix 43, wherein a Si substrate is used as the substrate and an amino group-containing silane coupling agent is used as the compound.

The method for manufacturing a particle-immobilized substrate according to any one of the preceding clauses 41, wherein the step of forming the region AB includes: a resist mask forming step of forming a resist film on the surface of the substrate, and then dissolving a part of the resist film by electron beam irradiation and development to open a hole in the resist film to expose the substrate; a region A forming step of reacting a reactive functional group present on the exposed substrate with a compound reactive with the reactive functional group to form a region A having a Zeta potential different from the Zeta potential of the substrate surface before the reaction; and a resist removing step of removing the resist film on the substrate surface to expose the substrate surface and form a region B.

[ additional note 45] A method for producing a diamond film-fixed substrate, comprising: a CVD step of growing the nano-diamond particles by a chemical vapor deposition method using the nano-diamond particles as seed crystals on the particle-immobilized substrate according to any one of supplementary notes 1 to 21, wherein the nano-diamond particles contain nano-diamond particles, and forming a diamond film on the substrate.

The method for manufacturing a diamond film-attached substrate according to the additional note 46, wherein the diamond film is formed in a region having a width of 1 μm or less on the substrate in the CVD step.

The method for manufacturing a diamond film-fixed substrate according to any one of the supplementary notes 47, wherein a region having a width of 1 μm or less, in which the diamond film is not formed, is formed on the substrate by the CVD step.

[ additionally provided with 48] a diamond film-fixing substrate comprising a substrate and a diamond film formed on the substrate, wherein the diamond film is formed on the substrate in a region having a width of 1 [ mu ] m or less, and the diamond film has an arithmetic average roughness Ra of 6nm or more (7 nm or more, 6nm to 20nm, or 7nm to 15 nm).

The diamond film-fixing substrate according to appendix 49, wherein the root mean square height Rq of the diamond film surface is 8nm or more (10 nm or more, 8nm to 30nm, or 10nm to 20 nm).

[ additionally provided is a diamond film-fixing substrate comprising a substrate and a diamond film formed on the substrate, wherein the diamond film is formed on the substrate in a region having a width of 1 [ mu ] m or less, and the root mean square height Rq of the diamond film surface is 8nm or more (10 nm or more, 8nm to 30nm, or 10nm to 20 nm).

The diamond film-fixing substrate according to any one of supplementary notes 51 to 48 to 50, wherein the substrate has a region having a width of 1 μm or less where the diamond film is not formed.

The diamond film-fixing substrate according to appendix 52, wherein the region having a width of 1 μm or less in which the diamond film is formed on the substrate has a region having a width of 1 μm or less in which the diamond film is not formed on the substrate.

[ additional note 53] a method for producing diamond, wherein the substrate is removed from the diamond film-fixing substrate according to any one of additional notes 45 to 52, to obtain diamond derived from the diamond film.

The method for producing diamond according to the additional note 54, wherein the diamond derived from the diamond film is the diamond film or diamond particles constituting the diamond film.

Description of the reference numerals

1: a resin fixing substrate;

2: a substrate;

3: an inorganic nanoparticle;

4: region A;

5: irradiating with electron beam;

6: an area B;

7: a resist film;

7': an electron beam irradiation section;

8: a substrate surface;

10: a diamond film fixing substrate;

3': a diamond film;

3' a: a diamond film surface;

d1: the width of the particle placement region;

d2: spacing of particle placement regions.

Claims (12)

1. A particle-immobilized substrate comprising a substrate and a plurality of inorganic nanoparticles disposed on the substrate,

the plurality of inorganic nanoparticles are disposed in contact with each other in a region having a width of 1 μm or less on the substrate.

2. A particle-immobilized substrate comprising a substrate and inorganic nanoparticles disposed on the substrate,

the Zeta potential of the inorganic nanoparticles is at least 30mV from the Zeta potential of the substrate surface at the position where the inorganic nanoparticles are disposed.

3. The particle-immobilized substrate according to claim 1 or 2, wherein,

the plurality of regions having a width of 1 μm or less are arranged on the substrate in a regular manner, and the inorganic nanoparticles are disposed in the plurality of regions having a width of 1 μm or less, respectively.

4. The particle-immobilized substrate according to any one of claim 1 to 3, wherein,

the nanoparticles comprise nanodiamond particles.

5. A method for manufacturing a particle-immobilized substrate, wherein,

the inorganic nanoparticles are arranged by electrostatic interaction in a region having a width of 1 [ mu ] m or less and existing in a first region on a substrate having a first region and a second region having a Zeta potential difference of 30mV or more.

6. The method for producing a particle-immobilized substrate according to claim 5, wherein,

one of the first region and the second region has a positive Zeta potential, and the other has a negative Zeta potential.

7. A method for manufacturing a particle-immobilized substrate, wherein,

the inorganic nanoparticles are arranged by electrostatic action in a region having a width of 1 [ mu ] m or less and existing in a first region on a substrate having a first region and a second region having a negative Zeta potential.

8. The method for producing a particle-immobilized substrate according to any one of claims 5 to 7, wherein,

the plurality of first regions are regularly arranged on the substrate, and the inorganic nanoparticles are disposed in the plurality of first regions, respectively.

9. The method for producing a particle-immobilized substrate according to any one of claims 5 to 8, wherein,

the inorganic nanoparticles comprise nanodiamond particles.

10. A method of manufacturing a diamond film-fixing substrate, the method comprising:

a CVD step of growing the nano-diamond particles by a chemical vapor deposition method using the nano-diamond particles as seed crystals on the particle-fixed substrate according to claim 4, thereby forming a diamond film on the substrate.

11. The method for manufacturing a diamond film fixed substrate according to claim 10, wherein,

in the CVD process, the diamond film is formed in a region having a width of 1 μm or less on the substrate.

12. A method for manufacturing diamond, wherein,

removing the substrate from the diamond film-fixing substrate according to claim 10 or 11, to obtain a separate self-supporting solid of the diamond film or diamond particles constituting the diamond film.