RU2601745C1 - Method of preserving solid-state surface and coating preserving solid-state surface - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to a technology of making devices of micro- and nanoelectronics. Proposed is a method of preserving a solid-state surface, which involves successively performed stages for preliminary preparation of the surface to preservation and application of a preserving coating. First stage is performed using a non-damaging cleaning of the solid surface resulting in formation on the surface of polar groups. Second one - using carbonyldiimidazole forming the coating containing at least two monolayers formed from the said substance. Also proposed is a preserving the solid-state surface coating containing a monolayer located on the solid surface and at least one monolayer between the environment and the said monolayer. Monolayer located on the surface is rigidly connected to it, is intended for implementation of functionalization of the solid surface. Additionally made monolayer bordering with the environment is intended for protection of the solid-state surface from the environment effects and for the purpose of functionalization it is easily removed.

EFFECT: provided are prevention of damage to structural elements of the solid surface at preservation/depreservation and fast depreservation in case of sensors with simultaneous functionalization.

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Description

Technical solutions relate to semiconductor devices, to the manufacturing technology of micro- and nanoelectronics devices and can be used in the production of a wide class of sensors that are used in biology, chemistry, medicine, and various types of instrument structures, where their electrical characterization requires the creation of identical conditions for surface.

In the process of manufacturing solid-state electronic devices, various types of contamination can be adsorbed on their surfaces, for example, mechanical and organic particles, metal ions, water molecules related to technological pollution. These contaminants lead to an increase in the effective charge, density of surface states, and the formation of intrinsic oxides on the surface (Naumova O.V., Fomin B.I., Malyarenko NF, Popov VP Modification and characterization of the surface of SOI nanowire sensors. - J. NanoRes ., 2012, v. 18-19, pp 139-147). The presence of technological contaminants is often a critical factor for the performance of manufactured devices and often for their further functional purpose, in particular, for semiconductor sensors, since it prevents the immobilization of specific probes upon receipt of the sensor, it contributes to the screening effect of the sensor surface, which reduces the detection efficiency of molecules, of interest for subsequent analysis.

In order to eliminate this effect, various methods of cleaning the surface from technological pollution are developed and applied. Moreover, in some cases, for example, in the manufacture of sensors, it turns out to be important not only to carry out high-quality cleaning of the surface from technological contaminants, but also to avoid possible damage to the manufactured structural elements of the device located on the surface being cleaned when performing this cleaning.

In addition, with respect to sensors, it should be noted that prior to immobilization of specific probes, the sensor is exposed to the environment in which it appears after completion of its structural manufacturing. The environmental condition is critical for the performance of devices, in particular sensors, since it can act as a source of contamination. In this regard, there is a need to develop methods for preserving the surface of the sensor before the stage of putting it in readiness for work. Moreover, the conservation should not determine the presence of damage to the sensors, either directly during its implementation, or subsequently, as a result of re-conservation.

Summarizing the above, the development of means of preservation / de-preservation should be carried out, firstly, taking into account the implementation of the previous preservation, the cleaning procedure that is efficient and gentle on the structural elements of solid-state instrument structures, devices, in particular, the sensor, and secondly, with regard to conservation , it should provide, on the one hand, reliable protection of the working surface from the influence of the environment, and on the other hand, are not a source of pollution with further use The cause and cause of damage to the solid-state surface of instrument structures, devices, in particular sensors, and, thirdly, with regard to the re-conservation procedure, it should not damage structural elements of the solid-state surface of devices based on layers of semiconductor, dielectric, and metals.

A known method of conservation of solid-state surfaces (I.V. Antonova, R.A. Soots, V.A. Seleznev, V.Ya. Prince "Electrical passivation of a silicon surface by 1-octadecene monolayers", FTP, 2007, v. 41, No. 8, p. 1010-1016), which consists in the fact that they carry out the stage of preliminary preparation of the surface for conservation, as the last one by electric passivation of the surface, the stage of intermediate passivation of the surface, providing conditions for the deposition of a passivating monolayer, and the stage of applying the preserving coating ia - a monolayer that provides electrical passivation of a solid-state surface, in particular, a semiconductor. Moreover, at the stage of preliminary preparation of the surface for passivation, a preliminary cleaning of the surface of the semiconductor is carried out. At the stage of intermediate passivation, which provides the conditions for the deposition of a passivating monolayer, the surface of the silicon substrate is hydrogenated (intermediate passivation with hydrogen) or hydrogenated first, and then the surface of the semiconductor is treated with a solution of iodine in benzene (intermediate passivation with iodine). The stage of applying a preservative coating, a monolayer, which provides electrical passivation of the surface of the semiconductor, is carried out by placing the surface of the semiconductor in 1-octadecene and then carrying out stimulated replacement of hydrogen or iodine with a 1-octadecene molecule with the deposition of a monolayer of this substance. The specified stimulation is carried out by photostimulation by exposure to light in the ultraviolet range with a wavelength of 265 nm for 1 + 2 hours or by thermal stimulation using a temperature of 110 ° C for 6 ÷ 18 hours. After applying the 1-octadecene monolayer, the semiconductor substrate is washed in isopropyl alcohol and dried.

There is a method of preserving a solid-state surface (description of the patent of the Russian Federation No. 2341848 for the invention, IPC: H01L 21/312 (2006.01)), adopted as the closest analogue, which consists in the fact that the preliminary preparation of the surface for conservation is carried out sequentially, as the last one by electric surface passivation, the stage of intermediate surface passivation, providing conditions for the deposition of a passivating monolayer, and the stage of applying a preservative coating - a monolayer that provides electrical passivation t erdotelnoy surface, in particular, the semiconductor using the substrate photostimulation or termostimulirovaniya mentioned photostimulation or termostimulirovanie performed in a state stably providing a charge of the monolayer in less than 10 ¹¹ cm ^-2 or completion of the last stage of the heat treatment that reduces the amount of charge, leading to surface bending zones.

In the method, preservation is carried out with respect to silicon, or germanium, or Si / SiGe / Si heterostructures. As a preservative coating, a monolayer of a class 1-alkene is applied (CH ₂ = CH- (CH ₂ ) _n-3 CH ₃ with 10 <n <22) -1-octadecene.

During the preliminary preparation of the solid-state surface of the semiconductor, the surface is first cleaned, then the natural oxide is removed, and then the preserved surface is subjected to chemical oxidation. Intermediate passivation of the surface is carried out using hydrogen passivation or using first hydrogen, and then iodine, or bromine, or fluorine passivation.

At the monolayer deposition step, the surface to be preserved is placed in 1-alkene medium (CH ₂ = CH- (CH ₂ ) _n-3 CH ₃ with 10 <n <22) and the 1-alkene molecules are precipitated as a passivating coating.

Photostimulation in the mode that stably provides a charge in the monolayer of less than 10 ¹¹ cm ^-2 is carried out during the entire deposition period from 1.5 to 2.5 hours using ultraviolet light with a wavelength of 265 nm, a radiation power of 18 W / cm ² , the distance of the ultraviolet source from the substrate from 2 to 4 cm. Thermal stimulation in the mode that stably provides a charge in the monolayer of less than 10 ¹¹ cm ^-2 is carried out during the entire deposition period from 12 to 18 hours using temperatures from 150 to 170 ° C.

The deposition of a monolayer that provides electrical passivation of a solid-state surface - a semiconductor, using photostimulation or thermal stimulation during deposition is carried out, respectively, during the entire deposition period from 1 to 5 hours using ultraviolet light with a wavelength of 265 nm, a radiation power of 18 W / cm ² , when the distance of the ultraviolet source from the substrate is from 1 to 10 cm, or during the entire deposition period from 6 to 18 hours using temperatures from 110 to 180 ° C, and finally thermal Botko that reduces the amount of charge, resulting in a surface band bending, heat treatment is carried out at conditions of 180 to 260 ° C for 10 ÷ 30 minutes.

The disadvantage of the known methods is:

- the possibility of damage to the solid-state surface of the structural elements of the product during conservation / de-preservation;

- the impossibility of rapid mothballing of the conserved solid-state surface of the structural elements of the product, ensuring readiness for practical use, in particular, of a sensor, while achieving simultaneous functionalization for the subsequent implementation of the formation of selective biolayers on their surface and / or immobilization of specific probes.

The reason that impedes the achievement of the following technical result is as follows.

First, in preparing the surface for conservation, chemicals also act directly on the surface, causing it to change. If on the surface of solid-state devices there are structural elements based on various materials - semiconductor layers, dielectric, metals, they can be damaged due to exposure to chemicals.

Secondly, the presence in the material of a preservative coating of functional groups that have great inertness with respect to the molecules of other substances, which prevents not only speedy, but also further, targeted use of the device, in particular, a sensor made on the basis of solid materials.

Thirdly, in the difficulty of removing the preservative coating without damaging the elements located on the solid surface of the device.

It is known preserving a solid-state surface coating (I.V. Antonova, R.A. Soots, V.A. Seleznev, V.Ya. Prin "Electrical passivation of a silicon surface by 1-octadecene monolayers", FTP, 2007, v. 41, No. 8, pp. 1010-1016), containing a 1-octadecene monolayer having a protective function, located on a solid surface, each molecule of the monolayer being connected to the surface by replacing hydrogen and / or iodine, with which the surface is pretreated to form a monolayer to form their bonds with the surface. As a solid-state surface, the surface of a semiconductor - silicon is chosen.

It is known that the coating preserving the solid-state surface adopted as the closest analogue (description to the patent of the Russian Federation No. 2341848 for the invention, IPC: H01L 21/312 (2006.01)) containing a monolayer of a coating from class 1 alkene (CH ₂ = CH- (CH ₂ ) _{n- 3} CH ₃ with 10 <n <22), which has a protective function located on a solid surface, in particular a semiconductor, with each molecule of a monolayer connected to the surface by substitution of hydrogen, or hydrogen and iodine, or hydrogen and fluorine, or hydrogen and bromine with which, in order to apply a monolayer, The surface is removed with their formation of bonds with the surface. The specified monolayer is used as a preservative coating in relation to the surface of silicon, or germanium, or heterostructures Si / SiGe / Si.

The disadvantage of the known coatings is:

- the possibility of damage to the solid-state surface of the structural elements of the product during conservation / de-preservation;

- the impossibility of rapid mothballing of the conserved solid-state surface of the structural elements of the product, ensuring readiness for practical use, in particular, of a sensor, while achieving simultaneous functionalization for the subsequent implementation of the formation of selective biolayers on their surface and / or immobilization of specific probes.

The reason that impedes the achievement of the following technical result is as follows.

Firstly, the presence in the material of a preservative coating of functional groups that have great inertness with respect to the molecules of other substances, which prevents not only speedy, but also further, targeted use of products, in particular, such a class of devices as solid-state sensors.

Secondly, in the difficulty of removing the preservative coating without damaging the solid-state surface of the structural elements of the products during conservation / de-preservation.

The technical result for the decision group is:

- prevention of damage to the solid-state surface of the structural elements of the product during conservation / de-preservation;

- providing quick de-preservation of the conserved solid-state surface of the structural elements of the product, ensuring readiness for practical use, in particular, of the manufactured sensor with simultaneous functionalization for the subsequent implementation of the formation on their surface of selective biolayers and / or immobilization of specific probes.

The technical result is achieved in the method of conservation of the solid-state surface, which consists in the fact that the preliminary preparation of the surface for conservation, the stage of applying a preservative coating is carried out sequentially, the preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, which leads to the formation of polar groups on the surface, and the application of a preservative coating to the surface is carried out using carbonyldiimidazole in organic solvent, providing its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance - a monolayer of carbonylimidazole residues resulting from the reaction with polar groups, and a monolayer of carbonyldiimidazole.

In the method, non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, is carried out by liquid treatment, first processing in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5 lasting from 30 to 120 seconds. , including the indicated values, at a temperature of about 300 K, and then in the HF: H ₂ O = 1: 100 solution, lasting from 10 to 30 seconds, including the indicated values, the treatment is followed by washing in deionized water and drying with a stream of purified inert gas, or carry out dry processing using using a low-energy plasma of an inert gas of nitrogen or argon lasting from 1 to 2 minutes, the plasma is obtained with a high-frequency induction discharge, with parameters: the frequency of the plasma generators is 13.56 MHz, the power deposited in the plasma is 100 W, the auto bias is 4 ÷ 10 V, duration 1 ÷ 5 min, working pressure - 1 mm Hg, a capacitive type generator with a ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1, is used as a generator, as a result of cleaning, the presence of polar s groups on the solid surface, formed at time of coating.

In the method, the application of a preservative coating to the surface is carried out using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance, so that a solution of carbonyldiimidazole in acetonitrile with a concentration of from 2 up to 30 mg / ml, after which coating is carried out by immersing the preserved solid-state surface in the solution and holding it until completion p surface modification reactions with the deposition of a monolayer of carbonylimidazole residues covalently bonded to the surface and either one monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole.

In the method, exposure to completion of the surface modification reaction with the deposition of a monolayer of carbonylimidazole residues covalently linked to the surface and deposition of either a monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole is carried out for 2 to 24 hours.

In the method, the application of a preservative coating to the surface is carried out using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance, so that a solution of carbonyldiimidazole in acetonitrile with a concentration of from 2 up to 30 mg / ml, after which coating is applied by applying the solution dropwise to the surface to be preserved, with the applied volume preventing the volatilization the formation of acetonitrile until the surface modification reaction is completed with the monolayer of carbonylimidazole residues covalently bonded to the surface being deposited and either one monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole.

In the method, the applied volume, preventing the volatilization of acetonitrile until the surface modification reaction is completed, with the deposition of a monolayer of carbonylimidazole residues and either one monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole, is taken from 1 to 10 ml / cm ² .

The technical result is achieved in preserving a solid-state surface coating containing a monolayer located on the surface, at least one monolayer is made in the coating between the external environment and the monolayer located on the surface, the monolayer of the coating is formed of carbonyldiimidazole, while the monolayer located on the surface , which is a monolayer of carbinylimidazole residues, is tightly bound to it and is designed to implement the functionalization of the solid-state surface, and additionally in The completed monolayer, bordering the external environment, is designed to protect the solid-state surface from environmental influences and is easily removable for functionalization.

In the coating, a rigidly bonded monolayer located on the surface, which is a monolayer of carbinylimidazole residues, is covalently bonded to it as a result of the interaction of carbonyldiimidazole with polar groups on a solid surface.

In the coating, an additionally made monolayer bordering the external environment is intended to protect the solid-state surface from environmental influences and, for functionalization purposes, is readily removable in the organic solvent used in the re-preservation of the solid-state surface, acetonitrile.

The essence of the technical solution is illustrated by the following description and the accompanying figures.

In FIG. Figure 1 shows the dependences of the source-drain current on the gate voltage (I _DS -V _G ) for sensors based on silicon-on-insulator structures obtained before preliminary preparation of the solid-state surface of structural elements based on a semiconductor, dielectric, and metal for conservation, and after preliminary preparing a solid-state surface of structural elements based on a semiconductor, dielectric, and metal for conservation, where 1 and 2 are the dependences (I _DS -V _G ) obtained before preliminary preparation of the sensor surface for conservation; 3 - dependence (I _DS -V _G ) obtained after preliminary preparation of the sensor surface for conservation using liquid treatments, first ammonium peroxide, then using hydrofluoric acid; 4 - dependence (I _DS -V _G ) obtained after preliminary preparation of the sensor surface for conservation using nitrogen plasma; 5 - dependence (I _DS -V _G ) obtained after preliminary preparation of the sensor surface for conservation using argon plasma and applying a preservative coating.

In FIG. Figure 2 shows the dependences of the source-drain current on the gate voltage (I _DS -V _G ) for sensors based on silicon-on-insulator structures with different initial state of the solid-state surface of structural elements, obtained before its preliminary preparation for conservation (light symbols) and after preliminary preparing it for preservation using argon plasma and applying a preservative coating (dark symbols).

In FIG. Figure 3 shows the dependences of the source-drain current on the gate voltage (I _DS -V _G ) for sensors based on silicon-on-insulator structures obtained after preliminary preparation of the solid-state surface of structural elements for conservation using nitrogen plasma and applying a preservative coating, the inset shows dependence of the flat-band voltage (V _fb) from the sensor storage time in air in the absence of the preservative on the surface of the coating (open symbols) in the presence on their surface preservative pokr ment (filled symbols), where 6 - dependence (I _DS -V _G), obtained from the measurements carried out immediately after applying the coating preservative; 7 - dependence (I _DS -V _G ), obtained as a result of measurements taken after 1 hour after applying a preservative coating; 8 - dependence (I _DS -V _G ), obtained as a result of measurements taken after one day after applying a preservative coating; 9 - dependence (I _DS -V _G ), obtained as a result of measurements taken after a week after applying a preservative coating; 10 - dependence (I _DS -V _G ), obtained as a result of measurements taken after two months after applying a preservative coating.

In FIG. Figure 4 shows the dependences of the source-drain current on the gate voltage (I _DS -V _G ) for sensors based on silicon-on-insulator structures obtained after preliminary preparation of the solid-state surface of structural elements for conservation using argon plasma, with / without a preservative coating preservative coatings, the presence / absence of immobilized molecules on the surface of the test protein BSA (bovine serum albumin), wherein 11 - dependent (I _DS -V _G), obtained after pre constructs surface by the elements to the preservation using argon plasma, with the application of a preservative coating, in the absence of adsorbed molecules on the surface of the test protein BSA; 12 - dependence (I _DS -V _G ), obtained after preliminary preparation of the surface of structural elements for conservation using argon plasma, without applying a preservative coating, in the presence of immobilized molecules of the BSA test protein on the surface; 13 - dependence (I _DS -V _G ) obtained after preliminary preparation of the surface of structural elements for conservation using argon plasma, with the application of a preservative coating, in the presence of adsorbed BSA test protein molecules on the surface.

The proposed group of technical solutions provides solutions for micro- and nanoelectronics products, firstly, the problems of non-damaging conservation / de-preservation of solid-state device structures with structural elements based on a semiconductor, dielectric and metal, in particular, when they are electrically characterized and, secondly, the solution to one of the key problems of nanobiosensor technology is the creation of a highly effective means of protecting (preserving) a solid-state surface for the period between two basic stages - const uktivnym manufacturer of sensors and solid state elements forming on their surface biosloev selective and / or specific probe molecule immobilization. The method and coating obtained by the method allows maintaining the required surface condition of solid-state sensors when they are stored in air without using an inert medium at room temperature (about 300 K) and eliminates the need for any additional processing procedures to immobilize any kind of biological and chemical molecules containing a primary amino group.

The technical result in a method for preserving a solid-state surface, including the sequential stage of preliminary preparation of a solid-state surface of structural elements from a semiconductor, dielectric and metal, in particular a sensor, for preservation and the stage of applying a preservative coating, as well as for the coating obtained by the specified method of preservation, is based on the following.

Firstly, at the stage of preliminary preparation of a solid-state surface for conservation and the formation of a preservative coating ultimately by cleaning the surface, ensuring that only mechanical particles and organic substances are removed from the surface, leading to gyrophilization of the surface of the semiconductor and / or dielectric, without destroying the structural elements, - non-damaging solid-state surface cleaning with the accompanying receipt on the surface of the polar groups.

The indicated cleaning of the solid-state surface can be carried out using liquid treatments or using dry treatments by exposing the surface to a low-energy inert gas plasma. For example, a sensor with structural elements based on silicon and silicon dioxide with obtaining on the surface of the polar groups either by liquid treatments first with peroxide-ammonia, then using hydrofluoric acid, or in a plasma of nitrogen or argon.

In particular, surface cleaning is carried out by liquid treatment, first processing in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5 lasting from 30 to 120 seconds. at a temperature of about 300 K, and then in a HF: H ₂ O = 1: 100 solution lasting from 10 to 30 seconds. at the same temperature. After completing the treatment, first rinsing in deionized water and then drying using a purged stream of inert gas, in particular nitrogen, are carried out. The last operation completes the cleaning cycle.

Alternatively, the surface is cleaned by dry treatment using a plasma of nitrogen or argon lasting from 1 to 2 minutes. The specified plasma is obtained, for example, with a high-frequency (HF) induction discharge, with parameters: the frequency of the plasma generators is 13.56 MHz, the power deposited in the plasma is 100 W, the autodisplacement is 4 ÷ 10 V, the duration is 1-5 min, the working pressure - 1 mmHg A capacitive type generator with a ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1, was used as a generator.

Performing any of the above treatments, on the solid-state surface of the semiconductor and / or dielectric, in particular, on the surface of the sensor, the presence of polar groups, in particular OH, on the oxidized surface of silicon containing a natural, chemical or thermal oxide existing at the time of applying the preservative coating is provided. In the future, carbonyldiimidazole (CDI), the substance used to obtain the coating, will interact with polar groups in the coating formation stage.

Procedures for liquid cleaning the surface of semiconductor substrates, on which any elements of the device structure can be performed, using solutions and mixtures of acids and alkalis, as well as dry cleaning based on ion or plasma chemical etching are well known.

The standard surface treatment SC-1 is close to the liquid surface cleaning used in the proposed solution during the preliminary preparation of the solid surface for conservation. However, through this treatment, a slightly different effect is achieved. Processing SC-1 (the so-called peroxide-ammonia), was developed as one of the main stages of the general liquid purification of RCA [W. Kerns and DA Puotinen, RCA Rev. 31, 187, 1970] silicon wafers and crystals in the manufacture of integrated circuits (ICs). SC-1 treatment involves the use of hydrogen peroxide (H ₂ O ₂ ), ammonium hydroxide (NH ₄ OH) and deionized water (H ₂ O) as part of NH ₄ OH: H ₂ O ₂ : H ₂ O = 1: 1: 6 . The treatment with this composition is carried out at a temperature of 80 ° C for 10-15 minutes and is used to remove mechanical particles and organic substances from a solid surface, in particular silicon and silicon dioxide due to oxidation-dissolution reactions. Residual oxide from the surface of the semiconductor is removed by subsequent processing in an aqueous solution of 0.5% HF (as a result of this treatment, the formation of non-polar bonds occurs - dangling bonds are passivated by hydrogen, the surface is hydrophobic). Currently, SC-1 is used with some changes in solution concentrations, temperature and duration in order to reduce the oxidation rate and the development of roughness (microrelief) of the silicon surface. For example, the composition NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5, temperatures from 80 to 90 ° C, processing time from 10 to 15 minutes are used [Ohmi T. “Total Room Temperature Wet Cleaning for Si Substrate Surfaces - J. Electrochem. Soc, 1996, v. 143, N 9, pp 2957-2964].

However, with respect to the proposed group of technical solutions, the following factors of known purification are unacceptable. Firstly, fever. Secondly, in addition to removing contaminants, the material of the solid-state surface is oxidized and etched in a more rigid form, which is critical for nanoscale layers of structural elements, in particular, of Si. Thirdly, the possibility of violation of the solid-state sensor of the working layers, in particular, of SiO ₂ . To eliminate these factors, the modes of operations used were adjusted in the above manner.

In the dry cleaning procedure of materials of micro- and nanoelectronics by plasma-chemical etching, contaminants from the surface are removed as a result of physical atomization and / or chemical reactions with radicals generated in the plasma with conversion to volatile compounds. The achieved cleaning effect is determined by a number of parameters: composition of the working gas, pressure, power, RF bias potential, and others. As a rule, the parameters are selected depending on the specific materials and products in order to obtain a surface of high structural perfection.

The dry cleaning of the surface used in the proposed solution, accompanied by the formation of polar groups, in particular OH, on the surface during the preliminary preparation of the solid-state surface for conservation is close, for example, cleaning by plasma-chemical etching (see the description of the RF patent for invention No. 2456702) consisting in the following. Material with a surface to be cleaned is placed on a substrate holder in a vacuum chamber. The working gas, C ₄ F ₈ , is supplied to the vacuum chamber, the plasma is ignited by an RF induction discharge, the RF power is supplied to the substrate holder and etched. Etching is carried out in the mode of repeating cycles, including the operation of etching and passivation. During etching, the RF power is applied directly to the substrate holder in the range from 280 to 300 W for a time from 0.1 to 100 s.

Unacceptable features of this known cleaning are the etching of surface layers of a solid-state material and the introduction of radiation defects, since they are critical for the electrical properties of solid-state sensors with nanometer layers of a semiconductor. In this regard, in the proposed solution, the conditions for cleaning were adjusted in the above manner.

The effectiveness of the cleaning in the proposed conservation method allows us to judge the measured dependence of the source-drain current on the gate voltage (I _DS -V _G ) for solid-state sensors, in particular, based on silicon-on-insulator structures, before processing (see Fig. 1 , positions 1 and 2) and after treatment (see Fig. 1): after liquid treatment, position 3, after treatment in nitrogen plasma, position 4, after treatment in argon plasma, position 5. As in the case of liquid treatment, in cases of dry processing, a shift of the gate characteristics with sensors (voltages of flat zones) towards lower voltages. The stresses of the flat zones are close in value. There is no significant variation in the curves. The experimental data presented show the coincidence of the obtained quality of the treated solid surface during preliminary preparation for conservation with the use of different treatments.

In addition, to evaluate the cleaning efficiency, the effect of the initial (before processing) state of the solid-state surface was tested using the argon plasma as an example (see Fig. 2). The dependences of the source-drain current on the gate voltage (I _DS -V _G ) were measured for solid-state sensors based on silicon-on-insulator structures with different initial surface conditions. Obtained before preliminary preparation of the surface for conservation (light symbols) and after preliminary preparation of the surface for conservation through the use of argon plasma, with the same characteristics, with the application of a preservative coating (dark symbols), show that the treatment causes a shift of the gate characteristics (flat voltage zones) towards lower stresses, and the stresses of the flat zones are close in their values, and the scatter of the curves is insignificant.

Thus, as was shown by the example of using argon for plasma processing, the resulting quality of the treated solid-state surface during preliminary preparation for conservation does not depend on the initial state of the surface.

Carrying out the stage of preliminary preparation of the solid-state surface for conservation by means of non-damaging cleaning structural elements, leading to the formation of polar groups by the above cleaning options, prepares the surface for conservation. In this case, due to the presence of polar groups, a prerequisite is provided for the implementation of obtaining the first monolayer of the coating rigidly bonded to the solid-state surface and, subsequently, due to it, functionalization of the solid-state sensor on which the monolayer is laminated, which performs a protective function. After the cleaning operation with the formation of polar groups on a solid surface, the latter can be in the air for one minute or less in a "clean room" (class not higher than 100). The specified time interval does not lead to the appearance of contaminants that will require repeated cleaning. In this regard, the method does not require the use of special means to prevent the exposure of the air of the "clean room" to the solid surface before applying a preservative coating. The use of these tools is possible, but not necessary.

Secondly, the achievement of the indicated technical result is based on the formation of a preservative coating using an environmentally protective organic material with weakly interconnected molecules, in which the molecules are able to interact with polar groups on a cleaned solid surface, modifying the latter, being rigidly bound to her, and ensuring the functionalization of the sensors when removing part of the preservative coating for subsequent implementation of the formation on overhnosti biosloev selective and / or immobilization specific probes.

Known protocols for the functionalization of the surface of sensors with the formation of a reactive surface with respect to the primary amino groups of probe molecules [Dmitrienko EV, Tronin AV, Popov VP, Pyshnaya IA, Pyshny D.V. . Immobilization of biomolecular probes on the surface of Si / SiO ₂ // Vestnik NSU. Series: Biology, Clinical Medicine. - 2013 .-- T. 11 (4). - SS. 35-43]. Functionalization is the final step in the process of obtaining a workable sensor. At the stage of functionalization, the circumstance is clearly manifested that when developing semiconductor sensors, it is necessary to take into account factors caused by the surface features and the specific method for detecting biomolecules, the implementation of which is based on the use of this sensor. In the general case, the semiconductor material of the sensor can impose a number of restrictions, among which the effective charge of the surface is of great importance, since the presence of a large amount of charge can lead to a decrease in the response of the system to the formation of an immobilized probe-analyte marker complex. An additional condition regarding the fixation of biomolecular probes is minimization of the distance between the surface and the detected molecule, since the nearest environment of the conductor has a maximum effect on the conductivity. In this case, the use of, for example, modified silanes (a common method of surface functionalization) may be undesirable, since the stage of silanizing the surface of silicon dioxide is accompanied by the formation of a rather significant layer on the surface, with a thickness of 5 to 20 nm. In this regard, the best option for surface functionalization should take into account a short uncharged linker, while the functionalization procedure should be as simple as possible. One possible functionalization option is to treat the surface of the sensor with carbonyldiimidazole molecules dissolved in an organic solvent [Srikant Pathak, Anup K. Singh, James R. McElhanon, and Paul M. Dentinger // Dendrimer-Activated Surfaces for High Density and High Activity Protein Chip Applications // Langmuir, V. 20, No. 15, PP. 6075-6079 (2004)]. Note that the authors of the work considered only the possibility of functionalization, but not preservation, using carbonyldiimidazole (CDI) and only the flat surfaces of the slides. In this case, as a immobilized molecule, a low molecular weight compound is used, acting as a linker for the further attachment of macromolecular probes.

In the proposed solution, carbonyldiimidazole (CDI) is used as an active material providing conservation of the solid surface, as well as with respect to the sensor and the possibility of functionalization with the simplest procedure possible. In this case, the main requirement for the surface to be preserved is the presence of polar groups on it, which are obtained by completing the surface pre-treatment cycle, and, of course, the absence of contamination. Under these conditions, the carbonyldiimidazole molecules interact with polar groups on the surface to form covalent bonds, the surface is modified to form a monolayer of carbonylimidazole (CI), which is rigidly bonded to the surface as a result of the chemical reaction. The monolayer thus formed plays a key role in the functionalization process. We emphasize that the condition for the absence of contaminants on the surface is important, since it determines the binding by means of polar bonds of carbonyldiimidazole molecules precisely to the surface of structural elements, and not to pollution particles. This is important for a full functionalization process and, in general, for sensor efficiency.

Note that a monolayer formed from CDI covalently bonded to the sensor’s solid surface can be used both directly to immobilize analyte test particles and as an intermediate layer for further immobilization of marker probes that increase the selectivity of the sensor’s interaction with analyte particles (to form selective biolayers).

Thus, the monolayer is sufficient for functionalization of the surface. However, carbonylimidazole (CI) residues, if only a single layer of carbonyldiimidazole is precipitated, are highly reactive, and without additional coating they will be inactivated upon contact with environmental components. A covalently bonded monolayer, i.e., a carbonylimidazole (CI) residue, can react with the environment and dehydrate, thereby losing the ability to participate in a subsequent reaction with specific probes. In this regard, the presence of a single monolayer of carbonyldiimidazole cannot provide both functionalization and conservation, since when stored in air, the molecules will interact with various atmospheric organic pollution. As a result of the latter, the probability of interaction of molecules with analyte particles or with immobilized marker probes is reduced, which helps to reduce the response of the system of the formed complex of an immobilized probe - an analyzed marker.

In order to preserve the solid state surface of the sensor and, thus, protect it from negative environmental influences, a second monolayer is required before interaction with analyte particles. The second monolayer of carbonyldiimidazole directly performs a protective function. For preservation, it is necessary and sufficient to apply, in addition to the first monolayer, a second monolayer in contact with the external environment. It pulls on itself the consequences of the negative impact of the environment. Molecules of carbonyldiimidazole of the second monolayer neutralize the effect of environmental pollution, reacting with them. The second monolayer blocks the negative environmental impact in relation to the first monolayer, which ensures functionalization.

Note that in addition to the first monolayer of carbonylimidazole residues, not only one, the second monolayer of carbonyldiimidazole, but also a larger number of monolayers can be deposited. Although in order to achieve a technical result, this will be redundant. In the case of applying monolayers of carbonyldiimidazole in an amount of more than two (a monolayer of carbonylimidazole residues and a monolayer of carbonyldiimidazole), the protective function is performed by the carbonyldiimidazole monolayer located externally and in contact with the external environment. In this case, the second and subsequent monolayers of carbonyldiimidazole located between the first monolayer of the residue of carbinylimidazole and the last monolayer of carbinylldiimidazole are excess monolayers. Their application is justified by the fact that in case of damage to the monolayer of carbonyldiimidazole in contact with the external environment and the impossibility of fulfilling its protective function in full, they begin to play an active role, filling the lack of the protective function of the outer layer. Thus, a more complete conservation is guaranteed.

The functionalization procedure during de-preservation is quite simple, since all additional layers of carbonyldiimidazole, except the first one, covalently bonded to the surface, are not rigidly bonded to the surface being preserved and weakly interact with each other. For its implementation, the second surface layer, which is in contact with the external environment, is removed (in the case of excess layers, the surface layer and all excess layers), which is made easily due to loosely coupled molecules, leaving the first monolayer of residues associated with it carbonylimidazole (CI), whose molecules are covalently bonded to the solid state surface of the sensor. Then selective biolayers are formed on the surface and / or specific probes are directly immobilized.

Thus, in order to achieve a technical result, at least two monolayers formed from carbonyldiimidazole are required. However, the number of monolayers formed from carbonyldiimidazole may be more than two. A key role is played by a monolayer bonded by covalent bonds to a solid surface and a monolayer in contact with the environment. The monolayers located between them are redundant; they do not play in the normal situation during the conservation and functionalization of the active role, while remaining passive. They are also easily removed during reconservation, as is the monolayer in contact with the environment.

The application of a preservative coating requires the possibility of contacting carbonyldiimidazole with a solid surface. This condition is fulfilled using carbonyldiimidazole in an organic solvent. The preserved surface is brought into contact with the indicated carbonyldiimidazole solution, due to which the carbonyldiimidazole molecules react with the polar groups that are pre-formed on the surface, resulting in surface modification, the formation of covalent bonds - precipitation of a monolayer of carbonylimidazole residues. Next, the contact is prolonged and at least one monolayer of carbonyldiimidazole is precipitated. When applying at least two monolayers of carbonyldiimidazole - a monolayer of carbonylimidazole residues and a monolayer of carbonyldiimidazole - the contact is interrupted.

To apply a preservative coating, a CDI solution is prepared using an organic solvent, in particular acetonitrile. The lower limit of CDI concentration is determined by the need to deposit at least two monolayers. There are no fundamental restrictions regarding the upper concentration limit.

In specific cases of the method, the concentration of carbonyldiimidazole is different, a range of 2 to 30 mg / ml was used. Moreover, in each case, with the amount taken in excess. A small excess is taken in case of partial hydrolysis of the carbonyldiimidazole molecules in solution before joining the solid surface.

The step of applying a preservative coating of at least two monolayers formed from carbonyldiimidazole is performed after the stage of preliminary preparation of the solid surface for conservation. Application is carried out by immersion of a preserved solid-state surface in a solution and holding in it until the surface modification reaction is completed with the precipitation of two or more monolayers formed from carbonyldiimidazole. In a solution of carbonyldiimidazole in acetonitrile of the indicated concentration, the surface to be preserved is immersed and incubated for 2 to 24 hours. During this time, when using a solution of the indicated concentration, the surface is completely modified to obtain the first monolayer of the carbonyldiimidazole residue associated with the surface being preserved due to the presence of pre-obtained polar groups on it and the second monolayer of carbonyldiimidazole located on top of it. At a different concentration, exposure to the solution is possible for less time.

In addition to immersion in the solution and holding it, it is possible to precipitate the indicated amount of monolayers formed from carbonyldiimidazole by applying the solution dropwise to the surface to be preserved. In this case, the solution is applied so that the applied volume is from 1 to 10 ml / cm ² . In view of the rather rapid drying of the solution, since it is easy to volatilize with acetonitrile to prepare it, the applied volume should be sufficient to modify the surface (the formation of a monolayer of the carbonylimidazole residue associated with the surface being preserved due to the presence of previously obtained polar groups) and the formation of an additional at least one carbonyldiimidazole monolayer was completed before the solvent evaporated. The indicated applied volume of the solution at the indicated concentration of carbonyldiimidazole satisfies this condition. Accordingly, at other concentrations, the applied volume should be taken by others.

Drying of the treated solid surface is carried out in air.

Reconservation of the solid surface is also carried out using an acetonitrile solvent. During the re-preservation procedure, the removal of the upper protective, bordering the environment, monolayer, excess passive monolayers, if any, has been removed. A monolayer of carbonyldiimidazole molecules covalently bonded to the surface - the monolayer of the carbonylimidazole residue remains on the surface due to a stronger bond, it is rigidly bonded to the surface. By means of it, the solid-state sensor is functionalized.

The effectiveness of a preservative coating based on carbonyldiimidazole for solid-state sensors based on silicon-on-insulator structures was evaluated. To this end, measurements were made (see Fig. 3) of the dependence of the source-drain current on the gate voltage (I _DS -V _G ) after preliminary preparation of the solid-state surface for conservation using nitrogen plasma and applying a preservative coating. The dependence of the voltage of flat zones (V _fb ) on the storage time of the sensors in air in the absence of a preservative coating on their surface (light symbols), if there is a preservative coating on their surface (dark symbols) (see Fig. 3, inset) is obtained. Dependence (I _DS -V _G ) obtained as a result of measurements carried out immediately after applying a preservative coating, - 6, dependence (I _DS -V _G ) obtained as a result of measurements taken after 1 hour after applying a preservative coating, - 7 the dependence (I _DS -V _G ) obtained as a result of measurements taken one day after applying a preservative coating, - 8, the dependence (I _DS -V _G ) obtained as a result of measurements taken one week after applying a preservative coating, - 9, the relationship (I _DS -V _G), the floor ennaya resulting measurements made after two months after application of the preservative coating - 10 show little variation with respect to each other, demonstrate the stability characteristics of the shutter time for two months. Comparison of the dependences of flat zones shows the stability over time in the case of the presence of a protective coating of carbonyldiimidazole.

In addition, on the example of solid-state sensors based on silicon-on-insulator structures and BSA protein immobilization, experimentally, by measuring the source-drain current versus gate voltage (I _DS -V _G ) (dependence (I _DS -V _G ) obtained after preliminary preparation of the solid-state surface of structural elements for conservation using argon plasma, with the application of a preservative coating, in the absence of BSA-11 test protein molecules on the surface, the dependence (I _DS -V _G ) obtained after the preliminary thorough preparation of the surface of structural elements for conservation using argon plasma, without applying a preservative coating, if BSA-12 test protein is present on the surface of adsorbed molecules, the dependence (I _DS -V _G ) obtained after preliminary preparation of the surface of structural elements for conservation using argon plasma, with the application of a preservative coating, in the presence of adsorbed molecules of the BSA-13 test protein on the surface) (see FIG. 4), it is shown that it is possible in principle to use the sensors for the intended purpose after removing the protective layer of CDI (a monolayer in contact with the external environment, possibly excessive monolayers of carbonyldiimidazole) of the preservative coating and the simultaneous formation of reactive groups (carbonylimidazole residues) on the surface of the solid-state sensor, as illustrated by the location curves on the graph.

As information confirming the possibility of implementing the method with the achievement of a technical result, we give the following examples.

Example 1

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, is carried out by liquid treatment. Processed first in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5 lasting 30 seconds. at a temperature of about 300 K, and then in a solution of HF: H ₂ O = 1: 100 for 10 seconds. After treatment, washing is carried out in deionized water, then drying in an inert gas, in particular in nitrogen, withstanding until complete drying and more (purging with a stream of purified compressed nitrogen until complete drying). The temperature throughout the cleaning cycle, room temperature, is about 300 K. Performing the cleaning process, the presence of polar groups on the solid surface formed at the time of coating is provided.

At the end of exposure in a nitrogen atmosphere, the solid-state surface is removed into the air and begin to apply a preservative coating. A solution of carbonyldiimidazole in acetonitrile at a concentration of 30 mg / ml is preliminarily prepared. Coating is carried out by immersing the surface to be preserved in the solution and holding it until the surface modification reaction is completed with the monolayer of carbonylimidazole residues covalently bonded to the surface being precipitated and the carbonyl diimidazole monolayer is in contact with the external environment - the protective monolayer, as well as excess monolayers of carbonyldiimidazole located between these monolayers. Exposure to the completion of the surface modification reaction with the deposition of these monolayers from carbonyldiimidazole is carried out for 2 hours. The temperature during the implementation of the conservation stage is room temperature, about 300 K.

After the conservation of the solid-state surface, it is removed from the solution. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 2

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, is carried out by liquid treatment. Processed first in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5 lasting 120 seconds. at a temperature of about 300 K, and then in a HF: H ₂ O = 1: 100 solution for 30 seconds. After treatment, washing is carried out in deionized water, then drying in an inert gas, in particular in nitrogen, withstanding until complete drying and more (purging with a stream of purified compressed nitrogen until complete drying). The temperature throughout the cleaning cycle, room temperature, is about 300 K. Performing the cleaning process, the presence of polar groups on the solid surface formed at the time of coating is provided.

At the end of exposure in a nitrogen atmosphere, the solid-state surface is removed into the air and begin to apply a preservative coating. A solution of carbonyldiimidazole in acetonitrile at a concentration of 2 mg / ml is preliminarily prepared. Coating is carried out by immersing the surface to be preserved in the solution and holding it until the surface modification reaction is completed with the monolayer of carbonyldiimidazole covalently bonding to the surface and the monolayer of carbonyldiimidazole in contact with the external environment, a protective monolayer, as well as excess monolayers of carbonyldiimidazole located between these monolayers . Exposure to the completion of the surface modification reaction with the deposition of these monolayers from carbonyldiimidazole is carried out for 24 hours. The temperature during the implementation of the conservation stage is room temperature, about 300 K.

After the conservation of the solid-state surface, it is removed from the solution. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 3

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, is carried out by liquid treatment. Processed first in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05: 1: 5 lasting 60 seconds. at a temperature of about 300 K, and then in a HF: H ₂ O = 1: 100 solution lasting 20 seconds. After treatment, washing is carried out in deionized water, then drying in an inert gas, in particular nitrogen, keeping in a nitrogen atmosphere until complete drying and more (blowing a stream of purified compressed nitrogen to complete drying). The temperature throughout the cleaning cycle, room temperature, is about 300 K. Performing the cleaning process, the presence of polar groups on the solid surface formed at the time of coating is provided.

At the end of aging in a nitrogen atmosphere, the solid surface is removed into the air and the application of a preservative coating is started. A solution of carbonyldiimidazole in acetonitrile with a concentration of 10 mg / ml is preliminarily prepared. Coating is carried out by immersing the surface to be preserved in the solution and holding it until the surface modification reaction is completed with the monolayer of carbonylimidazole residues covalently bonded to the surface being precipitated and the carbonyl diimidazole monolayer is in contact with the external environment - the protective monolayer, as well as excess monolayers of carbonyldiimidazole located between these monolayers. Exposure to the completion of the surface modification reaction with the deposition of these monolayers formed from carbonyldiimidazole is carried out for 8 hours. The temperature during the implementation of the conservation stage is room temperature, about 300 K.

After the conservation of the solid-state surface, it is removed from the solution. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 4

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar bonds on the surface, is carried out by dry treatment using a low-energy inert gas plasma, in particular nitrogen, lasting 2 minutes. Plasma is obtained at a high-frequency induction discharge, with the following parameters: the frequency of the plasma generators is 13.56 MHz, the power deposited in the plasma is 100 W, the auto-bias is 10 V, the duration is 2 minutes, and the working pressure is 1 mm Hg. As the generator, a capacitive type generator is used with the ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1. Performing cleaning, ensure the presence of polar groups on the solid surface formed at the time of coating.

At the end of the cleaning, the solid-state surface is removed into the air and the application of a preservative coating is started. A solution of carbonyldiimidazole in acetonitrile at a concentration of 2 mg / ml is preliminarily prepared. Coating is carried out by applying the solution dropwise to the surface to be preserved. Take damage volume, preventing volatilization acetonitrile to surface modification completion of the reaction the precipitation is covalently bound to the surface of the monolayer residues carbonylimidazole, and in contact with the exterior monolayer carbonyldiimidazole - protective monolayer and excess monolayers carbonyldiimidazole disposed between said monolayers of 10 ml / cm ² . The procedure is carried out in air at room temperature, about 300 K.

After the conservation of the solid-state surface, it dries. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 5

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar bonds on the surface, is carried out by dry treatment using a low-energy plasma of an inert gas, in particular argon, lasting 1 minute. Plasma is obtained at a high-frequency induction discharge, with the following parameters: frequency of plasma generators - 13.56 MHz, power deposited in the plasma - 100 W, auto-bias - 4 V, duration 1 min, working pressure - 1 mm Hg As the generator, a capacitive type generator is used with the ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1. Performing cleaning, ensure the presence of polar groups on the solid surface formed at the time of coating.

At the end of the cleaning, the solid-state surface is removed into the air and the application of a preservative coating is started. A solution of carbonyldiimidazole in acetonitrile at a concentration of 2 mg / ml is preliminarily prepared. Coating is carried out by applying the solution dropwise to the surface to be preserved. Take damage volume, preventing volatilization acetonitrile to surface modification completion of the reaction the precipitation is covalently bound to the surface of the monolayer residues carbonylimidazole, and in contact with the exterior monolayer carbonyldiimidazole - protective monolayer and excess monolayers carbonyldiimidazole disposed between said monolayers of 1 ml / cm ² . The procedure is carried out in air at room temperature, about 300 K.

After the conservation of the solid-state surface, it dries. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 6

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric, in particular, a sensor based on a silicon-on-insulator structure, includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar bonds on the surface, is carried out by dry treatment using a low-energy inert gas plasma, in particular, argon lasting 5 minutes. Plasma is obtained at a high-frequency induction discharge, with the following parameters: the frequency of plasma generators is 13.56 MHz, the power deposited in the plasma is 100 W, the self-bias is 5 V, the duration is 5 minutes, and the working pressure is 1 mm Hg. As the generator, a capacitive type generator is used with the ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1. Performing cleaning, ensure the presence of polar groups on the solid surface formed at the time of coating.

At the end of the cleaning, the solid-state surface is removed into the air and the application of a preservative coating is started. A solution of carbonyldiimidazole in acetonitrile at a concentration of 5 mg / ml is preliminarily prepared. Coating is carried out by applying the solution dropwise to the surface to be preserved. An applied volume is taken to prevent acetonitrile from escaping until the surface modification reaction is completed by precipitation of a monolayer of carbonylimidazole residues covalently bonded to the surface and a carbonyl diimidazole monolayer in contact with the external environment - a protective monolayer, as well as excess monolayers located between these layers of 8 ml / cm ² . The procedure is carried out in air at room temperature, about 300 K.

After the conservation of the solid-state surface, it dries. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, the sensor until it is claimed in work.

Example 7

The conservation of the solid-state surface of structural elements from a semiconductor and a dielectric of the instrument structure of a transistor type or with a different type of nanostructured surface includes the following steps.

When carrying out surface conservation, the stage of preliminary preparation of the surface for conservation is first carried out. Then carry out the stage of applying a preservative coating. In this case, the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface. The preservative coating is applied to the surface using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance — a monolayer of carbiniimidazole residues resulting from the reaction with polar groups and a monolayer carbonyldiimidazole.

Non-damaging cleaning of the solid-state surface, leading to the formation of polar bonds on the surface, is carried out by dry treatment using a low-energy inert gas plasma, in particular nitrogen, lasting 2 minutes. Plasma is obtained at a high-frequency induction discharge, with the following parameters: the frequency of the plasma generators is 13.56 MHz, the power deposited in the plasma is 100 W, the auto-bias is 10 V, the duration is 2 minutes, and the working pressure is 1 mm Hg. As the generator, a capacitive type generator is used with the ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1. Performing cleaning, ensure the presence of polar groups on the solid surface formed at the time of coating.

At the end of the cleaning, the solid-state surface is removed into the air and the application of a preservative coating is started. A solution of carbonyldiimidazole in acetonitrile at a concentration of 2 mg / ml is preliminarily prepared. Coating is carried out by applying the solution dropwise to the surface to be preserved. Take damage volume, preventing volatilization acetonitrile to surface modification completion of the reaction the precipitation is covalently bound to the surface of the monolayer residues carbonylimidazole, and in contact with the exterior monolayer carbonyldiimidazole - protective monolayer and excess monolayers carbonyldiimidazole disposed between said monolayers of 10 ml / cm ² . The procedure is carried out in air at room temperature, about 300 K.

After the conservation of the solid-state surface, it dries. Preservation provides reliable storage in a normal environment, in the air, without the use of any special means, of the instrument structure until it is needed for operation.

The surface-preserving solid-state coating comprises a monolayer located on the surface and at least an additional single monolayer between the external environment and the monolayer located on the surface. Monolayers of the coating are formed from carbonyldiimidazole. In the coating, a monolayer located on the surface, which is a monolayer of carbinylimidazole residues, is rigidly bonded to the surface. The specified monolayer is intended for the implementation of the functionalization of the solid surface. An additional monolayer bordering the external environment, a monolayer of carbonyldiimidazole, is intended to protect the solid-state surface from environmental influences and is made to be easily removable for functionalization.

The implementation of the tight bond of the monolayer located on the surface, which is a monolayer of carbinylimidazole residues, is ensured by the fact that the monolayer is covalently bonded to it as a result of the interaction of carbonyldiimidazole with polar groups present on the solid surface.

An additionally made monolayer, bordering the external environment, designed to protect the solid-state surface from environmental influences, for functionalization, is made easily removable in the organic solvent used in the re-preservation of the solid-state surface - acetonitrile. It is not rigidly bound to the surface being preserved and weakly interacts with a monolayer located on a solid surface.

In addition to these monolayers, which are active and perform their intended functions, passive monolayers that are located between these active monolayers may be present in the preservation coating. They are easily removable layers. All additional layers of carbonyldiimidazole, except for the first monolayer covalently bonded to the surface — the monolayer of carbinylimidazole residues — are not rigidly bonded to the conserved surface (solid surface) and weakly interact with each other. During de-preservation, the passive layers are removed along with the layer that performs the protective function.

Conserving a solid surface coating is used as follows.

The method of conservation of the solid-state surface of the structural elements of the instrument structure (in particular, the transistor type or nanostructured surfaces) with structural elements based on a semiconductor, dielectric and metal provides the application of a preservative coating for the period between the completion of the structural manufacturing of the instrument structure and the beginning of the electrical characterization procedure. Through the coating obtained by implementing the method, containing at least two monolayers formed from carbonyldiimidazole, the required state of the solid-state surface of the instrument structure is maintained for a specified period of time when stored in air without using an inert medium at room (about 300 K) temperature .

This makes it possible to ensure identical conditions on the surface during the electrical characterization of structures at different times and / or during the comparative characterization of various instrument structures. Electrical characterization can be carried out with re-preservation or with a preservative coating. In particular, as follows from the voltage values of the flat zones (see Fig. 3), the preservative coating provides an effective charge not exceeding 2.5 × 10 ¹¹ cm ^-2 .

The above-described method of preserving the solid-state surface of structural elements, in particular, the sensor provides the application of a preservative coating for the period between the completion of the structural manufacturing of the sensor and its preparation directly for work, including the formation of a selective biolayer on the surface of the solid-state sensor and / or immobilization of molecules of specific probes. Through the coating obtained by implementing the method, containing at least two monolayers formed from carbonyldiimidazole, the required state of the solid surface, in particular the sensor, is maintained for a specified period of time when stored in air without using an inert atmosphere at room temperature (about 300 K) temperature and eliminate the need for any additional processing procedures to immobilize any kind of biological and chemical molecules containing a primary amino group. When the sensor is in demand for operation, it is re-mothballed with simultaneous functionalization. A monolayer of carbonyldiimidazole, bordering the external environment, designed to protect the solid-state surface from environmental influences, is removed in an organic solvent, acetonitrile (passive monolayers are removed with it). Since carbonyldiimidazole molecules are loosely coupled, this operation is easy to do. A monolayer in the coating, located on the surface, rigidly bonded to it, remains on the surface and is capable of forming covalent bonds with amino-containing biomolecules acting as specific probes.

Claims (9)

1. The method of preservation of the solid-state surface, which consists in the fact that carry out sequentially the stage of preliminary preparation of the surface for conservation and the stage of applying a preservative coating, characterized in that the stage of preliminary preparation of the surface for conservation is carried out by non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, and applying a preservative coating to the surface is carried out using carbonyldiimidazole in an organic solution body, ensuring its contact with the surface and forming a coating comprising at least two monolayers formed from said material - monolayer carbonylimidazole residues obtained in the reaction with polar groups and a monolayer carbonyldiimidazole. 2. The method according to p. 1, characterized in that the non-damaging cleaning of the solid-state surface, leading to the formation of polar groups on the surface, is carried out by liquid treatment, treating the surface first in a solution of NH ₄ OH: H ₂ O ₂ : H ₂ O = 0.05 : 1: 5 lasting from 30 to 120 s, including the indicated values, at a temperature of about 300 K, and then in a HF: H ₂ O solution = 1: 100 lasting from 10 to 30 s, including the indicated values, the treatment is followed by washing in deionized water and drying with a stream of purified inert gas or by dry by using a low-energy plasma of an inert gas of nitrogen or argon lasting from 1 to 2 minutes, the plasma is obtained with a high-frequency induction discharge, with the following parameters: frequency of plasma generators 13.56 MHz, power deposited in the plasma, 100 W, autodisplacement 4 ÷ 10 B, duration 1 ÷ 5 min, operating pressure 1 mm Hg, a capacitive type generator with a ratio of the areas of the RF electrode and the grounded electrode, which determines the power on the substrate holder, equal to 1: 1, as a result of ki ensure the presence of polar groups on the solid surface, formed at time of coating. 3. The method according to p. 1, characterized in that the application of the preservative coating on the surface is carried out using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance, so that previously prepare a solution of carbonyldiimidazole in acetonitrile with a concentration of 2 to 30 mg / ml, and then apply the coating by immersing the preserved solid surface in the solution and rzhki therein to complete the surface modification reaction with precipitating covalently bound to the surface of the monolayer residues carbonylimidazole and either one monolayer carbonyldiimidazole or more monolayers carbonyldiimidazole. 4. The method according to p. 3, characterized in that the exposure until the completion of the surface modification reaction with the deposition of a covalently linked surface monolayer of carbonylimidazole residues and either one monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole is carried out for a period of time from 2 to 24 hours. 5. The method according to p. 1, characterized in that the application of the preservative coating on the surface is carried out using carbonyldiimidazole in an organic solvent, ensuring its contact with the surface and forming a coating containing at least two monolayers formed from the specified substance, so that previously prepare a solution of carbonyldiimidazole in acetonitrile with a concentration of from 2 to 30 mg / ml, and then carry out the coating, applying the solution to the surface to be preserved dropwise, with the applied volume ohm preventing volatilization acetonitrile to complete the surface modification reaction with precipitating covalently bound to the surface of the monolayer residues carbonylimidazole and either one monolayer carbonyldiimidazole or more monolayers carbonyldiimidazole. 6. The method according to p. 5, characterized in that the applied volume, preventing the volatilization of acetonitrile until the completion of the surface modification reaction with the precipitation of a monolayer of carbonylimidazole residues and either one monolayer of carbonyldiimidazole or more monolayers of carbonyldiimidazole, is taken from 1 to 10 ml / cm ² . 7. A surface-preserving solid-state coating containing a monolayer located on the surface, characterized in that at least one monolayer is made in the coating between the external environment and the monolayer located on the surface, the monolayers of the coating are formed of carbonyldiimidazole, and the monolayer located on the surface , which is a monolayer of carbinylimidazole residues, is rigidly bonded to it and is designed to implement the functionalization of the solid-state surface, and additionally made mon The donkey, bordering the external environment, is designed to protect the solid-state surface from environmental influences and is easily removable for functionalization. 8. The coating according to claim 7, characterized in that the rigidly bonded monolayer located on the surface, which is a monolayer of carbinylimidazole residues, is covalently bonded to it as a result of the interaction of carbonyldiimidazole with polar groups on a solid surface. 9. The coating according to claim 7, characterized in that the additionally made monolayer bordering the external environment is intended to protect the solid-state surface from the effects of the environment and, for functionalization, is readily removable in the organic solvent used in the conservation of the solid-state surface, acetonitrile.

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