RU2533330C1 - Method of forming nanowires from colloidal natural material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: in a method of forming nanowires from a colloidal natural material, based on a self-organised formation of linearly ordered nanosized current-conducting structures with a strictly specified orientation for the connection of separate micro- and nanoelectronic elements and/or formation of nanocomponents of an electronic element base, formation of structures and/or elements is carried out in one process for not more than 3 minutes under an impact of an electric constant field only with an intensity not higher than 5×103 V/m, configuration of which directly specifies both the dimensions and forms and the orientation of the nanosized current-conducting carbon structures, which are stably preserved without the application of any protective layers on a substrate from any material, including the one, containing separate micro- and nanoelectronic elements for their connection and/or for the formation of nanocomponents of the electronic element base.

EFFECT: invention makes it possible to simplify the process of control of the form and location of the synthesised particles.

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Description

The invention relates to electronics and connection methods in micro- and nano-integrated circuits.

One of the analogues of the invention is the method of forming a nanometer-sized conductive element / 1 /, which consists in the fact that the nanometer-sized conductive element is formed by scanning an anode located at a distance of 2 to 100 nm from the surface of the cathode coated with a carbon conductive medium. Negative feedback is used in the anode-cathode circuit, with which, when scanning the anode, the first random point on the cathode surface is detected, characterized by a jump in conductivity (maximum U ₀ ), along which a voltage is established and maintained (in the range from 2 to 0 V), which ensures the formation of an element of nanometer size.

The disadvantages of this method are that the length of the created nanowire is limited by the scanning range, its location and size are determined randomly, and the formation takes place over a sufficiently long time and is nonlinear, ambiguous, caused by the dynamic self-organization that underlies the shaping process.

In accordance with another method / 2 /, a single-crystal substrate having cleavage steps and / or other linear defects is used to form ordered one-dimensional conductive nanostructures without a bending radius. The method includes vacuum condensation carried out in a predetermined range of substrate temperatures, condensation rates and during the formation time at which at least one nanowire is formed on the linear defects of the substrate, and the fill factor of the substrate on the rest of the substrate must be exclusive of island coalescence.

The disadvantages of this method are that the optimal distance between the steps, excluding the formation of islands on defect-free areas of the substrate, must be established experimentally. Using this method, it is difficult to create a nanowire with a given regular structure, since the surface of the substrate is not specially processed: chips are random in nature, various linear defects may be present.

The closest in technical essence and the problems to be solved is a way to control the shape of the synthesized particles and obtain materials and devices containing oriented anisotropic particles and nanostructures / 3 /. In this method, the synthesis of nanoparticles in the reaction mixture from metal-containing or ligand compounds is multistage using both electric and magnetic fields, Langmuir monolayers are formed, which are then transferred to the magnetically soft substrate in a controlled and predetermined orientation and coated with a protective layer.

The disadvantages of this method are the multi-stage and complexity of the process of controlling the shape and location of the particles synthesized from the reaction mixture in the form of Langmuir polymerized monolayers from metal-containing or ligand compounds, and the synthesis of materials and the creation of devices constructed by transferring oriented anisotropic particles and nanostructures onto a magnetically soft substrate to stabilize necessarily covered with a protective layer, using at all stages both electric and magnetic fields.

The solution to the technical problem of eliminating the identified disadvantages of the prototype is achieved by placing a colloidal natural carbon-containing material in the form of an ensemble of nanoparticles from 30 nm to 70 nm, which ensures the formation of linearly ordered nanoscale conductive structures with a strictly specified orientation for only 3 minutes under the influence of only DC electric field with a strength of not more than 5 × 10 ³ V / m, which allows for the connection of individual micro and nanoelectronics elements r and to generate nanokomponentnuyu element base for the creation of electronic devices of new generation.

As a result of the tests of the method of forming nanowires from colloidal natural material in electric constant fields with an intensity of not more than 5 × 10 ³ V / m, a set of significant differences from the prototype / 3 / is established, namely, that linearly ordered nanoscale conductive structures with strictly specified orientation, for connecting individual micro- and nanoelectronic elements and / or the formation of nanocomponents of the electronic element base, characterized in that the formation of structures and / or elements occurs in one process for no more than 3 minutes under the action of only an electric constant field with an intensity of no more than 5 × 10 ³ V / m, the configuration of which directly determines both the sizes and shapes, and the orientation of nanoscale conductive carbon structures that are stable saved without applying any protective layers on a substrate of any material, including those containing separate micro- and nanoelectronic elements for their connection and / or for the formation of nanocomponents of electronic elemental th base.

To form linearly ordered nanoscale conductive structures from colloidal natural carbon-containing material, the design shown in Fig. 1 was used with the distance between the electrodes: 0.1, 0.25, 0.5, and 1.0 mm. The ongoing sequencing processes are illustrated in the diagrams shown in FIG. 2 to illustrate the first step and FIG. 3 to illustrate the second step. In Fig.1-3 and Fig.6: 1 - colloidal natural carbon-containing material, 2 - electrodes, 3 - substrate; figure 3: 4 - dipole-polarized particles, 5 - charged chains of nanoparticles. The creation of individual electronic nanocomponents is carried out according to the scheme shown in Fig.6: 9 is a system of pointed cathodes, 10 is a substrate-anode, 11 is a formed nanocomponent, the image of which is shown in Fig.7. A colloidal, naturally-occurring carbon-containing material is applied by a drop method onto a surface of a substrate containing and / or without separate micro- and nanoelectronic elements in order to form nanocomponents of the electronic element base. Further, in accordance with the task to be solved for the formation of nanocomponents and / or compounds between individual micro- and nanoelectronic elements, an electric constant field with a voltage of not more than 5 × 10 ³ W / is applied to the circuit shown in FIG. 2 and / or FIG. 6 m The duration of the formation process is no more than 3 minutes.

The basis of a qualitative physical model of the method of forming nanowires from colloidal natural materials, structures and / or elements connecting individual micro- and nanoelectronic elements takes into account the conclusions that nanosystems with organic inclusions are the ideal material / 5 / for studying processes as self-organization - in diffusion-limited conditions, when the flow of particles entering the system exceeds their diffusion, and self-assembly - when the condition: E _b > E _inter ≥ E _kin > E _d is the binding energy particles with a substrate exceeds the energy of intermolecular interaction and kinetic, as well as the energy of their diffusion. In this case, nanosystems with a dominant organic composition are prone to self-assembly processes, while inorganic nanoparticles are characterized by self-organization processes with the formation of dendritic nanostructures. Linearly ordered nanoscale conductive structures oriented mainly along the direction specified by the electric constant field are formed under the action of an electrophoretic force, the value of which, according to / 6 /, is proportional to the square of the gradient of the electric field amplitude - ∇E ² and the cube of the particle radius - R ³ (volume particles):

Where

Re | K (ω) | = [(ε ₂ -ε ₁ ) / (ε ₂ + 2ε ₁ )] + {3 (ε ₁ σ ₂ -ε ₂ σ ₁ / [τ _MW (σ ₂ + 2σ ₁ ) ² (1 + ω ² τ _MW ² )]} is the real part of the Clausis-Massoti function; ε ₁ and σ ₁ , as well as ε ₂ and σ ₂ are the dielectric constant and conductivity of the medium and particles, respectively, ω is the frequency of the alternating electric field. is the recharge time in alternating electric fields: τ _MW = (ε ₂ + 2ε ₁ ) / (σ ₂ + 2σ ₁ ) is the relaxation time of Maxwell-Wagner charges. In accordance with (1), at the first stage / 6 /, the action FEFS causes redistribution of colloidal particles in an electric field (1), since F ~ _EFS ∇E ^2. As have carried out studies / 4 / on a colloidal natural carbon-containing material, the formation of linearly ordered nanoscale conductive nanostructures begins after about 15 s, which, by analogy with / 6 /, corresponds to the second stage (Figure 3), when nanoparticles 4 in an electric field are dipole polarized under the influence of the interaction forces of Coulomb nature:

$$F_{\mathrm{AT}H}=C\pi {\epsilon }_{\mathrm{one}}{\left(KRE\right)}^2,\left(\text{2}\right)$$

line up in self-organized conductive structures 5. Here C is a numerical coefficient depending on the distances between particles 4 and the length of chains of them 5. From (2) it follows that dipole-polarized particles of the same size are oriented along the lines of electric field 6, which are visible on Photos of Fig. 4. Along with this, insufficiently polarized particles 7, in particular having large sizes or a different phase composition, can line up perpendicular to the lines of electric field 6, as shown in Figure 4, but, while dipole-polarized particles of the same small size are oriented along the lines of tension electric field, forming dendritic structures 7 (Figure 4, b), which is consistent with the conclusions / 6 /.

Thus, charged chains 5 are formed, schematically depicted in FIG. 3, which is experimentally confirmed by their confocal microscopic images 8, presented in FIG. 5.

Example 1

Determination of the characteristics of the method of forming nanowires from a colloidal natural material of linearly ordered nanoscale conductive structures was performed in 4 designs, the view of which is schematically depicted in Fig. 1 without the proposed material and with it Figs. 2 and 3. The distance between the electrodes ("+/- "And" - / + ") - l, indicated in Figure 1-3 by the number 2, is: 0.1, 0.25, 0.5 and 1.0 mm. The resulting micro- and nanoscale structures of colloidal natural carbonaceous material are presented in the photographs of FIG. 4, a-b and FIG. 5.

The start time of the formation of linearly ordered nanoscale conductive structures from the moment the electric field is turned on and before the start of the formation of structures τ is almost proportional to the distance between the electrodes, as is confirmed by the obtained dependence τ (l) shown in Fig. 8. So for a distance of 0.5 mm, this time is 15 s.

Figure 9 shows the time dependence of the formation of dendritic structures S (t) under the influence of a constant electric field with a strength of more than 4 × 10 ⁴ V / m, based on the analysis of photographs of dendritic structures from the colloidal natural carbon-containing material shown in Figure 4 , a-b. The analysis shows that S (t) consists of two sections: on the first, with a slight change in the size of dendrites at a constant speed of 10 ^-5 m / s, when they are polarized, and on the second, a rapid growth of dendritic structures with acceleration of 6 × 10 ^-5 m / s ² . On this basis, a constant electric field strength of 5 × 10 ³ V / m was established at which linearly ordered nanoscale conductive structures are formed from colloidal naturally-occurring carbon-containing material.

Example 2

In the method of forming nanowires from a colloidal natural material, it is applied by a drop method onto the surface of a substrate containing individual micro- and nanoelectronic elements. Figure 1-3 shows: 1 - colloidal natural carbon-containing material, 2 - electrodes, 3 - substrate; figure 3: 4 - dipole-polarized particles, 5 - charged chains of nanoparticles. In Fig.1, the distance between the electrodes ("+/-" and "- / +") - 2, denoted by l, is 0.1, 0.25, 0.5 or 1.0 mm, respectively. This allows after the inclusion of a constant electric field with an intensity of not more than 5 × 10 ³ V / m after 15 s to structure the colloidal natural carbon-containing material, as shown in Figure 2, which corresponds to the first stage. After that, the formation of linearly ordered nanoscale conductive structures in the form of charged chains of different sizes from nanoparticles 5 begins, the microphotographic confocal images of which are shown in FIG. 5, which corresponds to the second stage. Thus, linearly ordered nanoscale conductive structures are shaped in the form of charged chains of different sizes with a constant electric field with an intensity of not more than 5 × 10 ³ V / m, which lasts about 3 minutes.

Example 3

In the method of forming nanowires from a colloidal natural material, it is applied by a drop method to the surface of a substrate in order to form nanocomponents of an electronic element base. The creation of individual electronic nanocomponents is carried out according to the scheme shown in Fig.6. For this, a constant electric field with a voltage of not more than 5 × 10 ³ V / m is applied to a system of pointed cathodes, one of which is shown in FIG. 6. On it, 9 is a system of pointed cathodes, 10 is a substrate-anode, 11 is a formed nanocomponent. Its microphotographic confocal image is presented in Fig.7. Figure 6-7 shows: 1 - colloidal natural carbon-containing material, 2 - electrodes, 3 - substrate; figure 3: 4 - dipole-polarized particles, 5 - charged chains of nanoparticles. Thus, the formation of a system of point micro- and nanocomponents under the influence of a constant electric field with a strength of not more than 5 × 10 ³ V / m occurs.

INFORMATION SOURCES

1. Mordvintsev V.M., Kudryavtsev S.E., Levin V.L. / The method of forming a conductive element of nanometer sizes // RF Patent No. 2194334, publ. 12/10/2002.

2. Omorokov DB, Kozlenko NI, Shvedov EV / The method of forming a conductive element of nanometer size // RF Patent No. 2401246, publ. 10/10/2010.

3. Gubin SP, Obydenov A.Yu., Soldatov ES, Trifonov AS, Khanin VV, Khomutov GB / The way to control the shape of synthesized particles and obtain materials and devices containing oriented anisotropic particles and nanostructures (options) // RF Patent No. 2160697, publ. 12/20/2000.

4. Kuzmenko A.P., Dobritsa V.P., Chan Nyen Aung, Abakumov P.V., Timakov D.I. / The processes of fractal formation in diffusion-limited conditions on the example of peat // Bulletin of the South-West State University. 2011. No6 (39). Part 2. S.17-24.

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6. Angelika Kiihnie / Self-assembly of organic molecules at metal surfaces // Current Opinion in Colloid and Interface Science 2009. No. 14. P.157-168.

Claims (1)

A method of forming nanowires from a colloidal natural material based on the self-organized formation of linearly ordered nanoscale conductive structures with a strictly defined orientation for connecting individual micro- and nanoelectronic elements and / or the formation of nanocomponents of an electronic element base, characterized in that the formation of structures and / or of elements occurs in one process for no more than 3 minutes under the action of only an electric constant field with an intensity not greater its 5 × 10 ³ V / m, a configuration which directly specifies both the dimensions and the shape and orientation of conductive nanosize carbon structures are stably preserved without causing any protective layers on a substrate of any material, including some containing micro and nanoelectronic elements for their connection and / or for the formation of nanocomponents of the electronic element base.

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