RU2502153C2 - Method to modify surfaces of metals or heterogeneous structures of semiconductors - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: in the method of modification of the surface of metals or heterogeneous structures of semiconductors by means of exposing them to energy of ionising radiation; into a structure of a part or design of these materials they introduce a dielectric layer, radiate it with a source of pulse X-ray radiation (XR), and to determine the positive effect they use results of comparison of measurements of microhardness, optical properties or research of surface morphology before and after impact of the ionising radiation and isothermal annealing of semiconductor HPPs.

EFFECT: modification of metal surfaces and semiconductor heteroepitaxial structures, strengthening of metal parts and structures with a complex shape of surface, modification of morphological and electrophysical properties of semiconductor HPPs.

5 cl, 14 dwg

Description

The invention relates to the field of engineering and can be used in space technology, aircraft, automotive, machine tools, technologies for creating building materials and structures, in the field of pipeline transport and in the technology of creating semiconductor devices.

In all these areas of technology, parts and structures with increased strength properties are widely used. To give such properties to solid-state parts, hardening methods are widely used, based on the use of heat treatment (cementing), ultrasonic treatment, exposure to electron beams or laser irradiation / 1 /.

A large number of methods are known for modifying the surface state of parts made of metals, composite materials, dielectric and semiconductor structures, including using laser technologies. From / 1 / the main technologies of laser surface treatment and the results of its modification are known for various operating modes and types of lasers used ((CO ₂ , Nd: YAG, excimer lasers). As a result of surface treatment, the following processes are possible:

(1) transformational hardening;

(2) surface melting;

(3) smoothing surface roughness;

(4) surface welding.

It is known from / 2 / that samples of steel and organometallics were irradiated with laser radiation from a diode laser (Fishba Optic, wavelength 808 nm and a power of 150 W) and a neodymium laser based on a yttrium aluminum garnet - Nd: YAG (2 kW continuous radiation) (cw), wavelength 1064 nm), the evolution of the results of changes in metallography, strength, microhardness was recorded in the hardening zone and in the adjacent region. The recorded result showed an improvement in these characteristics from 8 to 12% when using a diode laser.

The disadvantages of all known methods of modifying the surfaces of parts, materials and structures are as follows:

- the impossibility of processing parts with a complex configuration of the surface and internal cavities of the parts, as well as the requirement of continuous flow of shielding gas or flux additives to the processing zone;

It is known that the processes in which energy is introduced into a solid in a pulsed mode differ from stationary processes. The main difference is that the absorbed energy in the pulsed mode of exposure, released in the local volumes of the irradiated material, acts not on the weakest link in the structure of the material, but on the relationship between the individual elements of the structure / 3 /. This can lead to failure of the strongest link in the structure of the material.

It is known / 4-6 / that the processing of high-energy fluxes of particle or photon radiation can significantly improve the mechanical properties of materials with various types of interatomic bonds, in particular, increase the elastic limit and wear resistance of metals. The type of radiation, its energy and dose characteristics determine both the degree of hardening and the thickness of the modified layer, the physicochemical properties of which depend on the spectrum and distribution profile of the introduced radiation disturbances and the transformed state of the initial material structure due to the so-called “long-range effect” / 7 , 8, 9, 10 /.

With the known technology of ion implantation in microelectronics. (penetration of ions to a given depth in a given volume) the surface of a semiconductor material with a crystalline structure is irradiated with ions with a given energy and then subjected to the procedure of high-temperature isothermal annealing, in which the radiation-induced structural defects are restored. In this case, a change in the impurity-defective composition (PDS) of the material occurs and the principle of long-range action / 7 / is implemented. This method of modifying the surface state of materials is selected for the prototype of the proposed technical solution.

The disadvantage of this method is that to achieve the necessary positive changes in the properties of materials under radiation exposure, high radiation doses and sufficiently stringent processing temperature conditions are required, which ensure effective impurity-defect blocking of mobile dislocations responsible for microhardness, and ultimately for plastic deformation and destruction of products . In addition, traditional radiation methods are also practically unsuitable for hardening products of complex shape, for example, having internal surfaces that are not available for spatially oriented ionic, electronic, or laser beams.

To date, it has been experimentally and theoretically proved that elastic (shock) waves (SW) arise in solids when exposed to radiation by radiation of various nature with energies both higher and lower than the threshold energy of elastic displacement of atoms (ions) in the crystal lattice. The sources of hydrocarbons are thermal peaks, cascades of displacements, regions of local reactions between structural defects and relaxation of the initial state of elastically strained interatomic bonds. In semiconductors and dielectrics, shock waves can be generated due to the Coulomb repulsion of ions arising in the field of ionizing radiation. This mechanism is apparently the most effective for heterogeneous and heterophase systems in which the component materials are either heavily doped with acceptor impurities or have a noticeable ionic component of interatomic bonds.

It is accepted that the situation with the Coulomb nature of hydrocarbons is realized in silicon-on-dielectric (KND) structures when photons are irradiated with subthreshold energies, for example, in sapphire, which can be considered as a spatially ordered set of molecules (Al ⁺³ ) ₂ - (O ^{- 2} ) ₃ . When the Auger cascade is excited in oxygen ions (E _k = 0.532 keV), the amplitude of the elastic pulse from one “isolated” Al ₂ O ₃ group can reach ~ 20 GPa. Waves of this amplitude, penetrating the silicon instrument layer, are capable of substantially transforming its PDS and substructure. The latter is confirmed by the results of studies of the micromorphology of the surface of epitaxial silicon layers of silicon-on-sapphire (SSC) structures after irradiation in a pulsed mode by X-rays with an energy of E = 75 keV.

When heterophase structures are irradiated, due to different wave impedances of the mating layers, both amplification and decrease in the shock wave amplitude are possible when passing from one medium to another. This means that the effects of structural rearrangements in such compositions are asymmetrical in quantitative and qualitative respects, since they will be determined by which (elastically hard or soft) side the irradiation is carried out and at what depths the maximum inelastic energy loss of the radiation used is localized.

The hydrocarbon field excited by radiation can lead to a number of negative phenomena, from which it should be highlighted:

1. “Explosive” dissolution of clusters due to the generation of secondary hydrocarbons during annihilation of Frenkel pairs initiated by the field of primary waves / 1 /. With this dissolution, it becomes possible to increase the amplitude of dynamic stresses in the structure and the intensification of degradation processes.

2. HC, propagating along the internal structure boundaries, due to the amplification effect / 2 / can cause lateral transformation of the PDS components at large distances from the irradiation zone. In the case of heterostructures, this will be facilitated by static fields of elastic stresses, which reduce the barriers for reactions between defects.

3. A change in the amplitudes of static and dynamic elastic stresses in a semiconductor material is accompanied by shifts of the minima of the conduction band and the top of the valence band, ie changes in the band gap E _g . In general terms, this can be written: ΔE _g = α · P, where P is the mechanical stress; α is a numerical constant depending on the type of semiconductor and the type of stress state. For example, for silicon in compression and tension along the direction <001>, the constant α, respectively, is equal to -7.39 and -3.57 · 10 ^-11 eV · Pa ^-1 . A decrease in the band gap in the stress field leads to a redistribution of charge carriers and an increase in the concentration of minority charge carriers in the structure:

Where

- n _p (or p _n ) is the concentration of carriers in the deformable material;

- n _lo is the concentration of carriers in its own semiconductor;

- N _A (or N _D ) is the concentration of dopants. Estimates show that for n-type silicon under compression along the direction of the crystallographic axes <001> (the strongest HC phase) with a pressure of P ~ 10 ÷ 15 GPa, the ratio

(n _po is the concentration of carriers in the undeformed structure) is 2 · 10 ¹⁸ . Such an excess concentration of minority carriers, localized near the barrier layers (pn junctions, MOS structures), can significantly impair their functional properties. The dissolution of clusters under the action of hydrocarbons additionally enhances this effect.

Therefore, the development of hardening technologies is very urgent, which, on the one hand, as well as radiation methods, would allow for the controlled modification of the mechanical properties of materials and the morphological and electrophysical properties of semiconductor heteroepitaxial structures (HES), and on the other, would have universal capabilities for processing products of various forms.

The technical result of the proposed method is the ability to implement the modification of the surfaces of metals or semiconductor hydroelectric power stations by pulsed x-ray radiation, hardening of metal parts and structures with complex surface shapes, in particular, having internal cavities, modification of the morphological and electrophysical properties of semiconductor hydroelectric power stations.

The technical result is achieved by the fact that in the method of modifying the surface of metals or heterogeneous structures of semiconductors by exposing them to ionizing radiation energy, in order to harden the surface layer in metals or to change the impurity-defective composition (PDS) of the instrument layer in semiconductor heterostructures, into the structure of a part or structure of these materials, a dielectric layer is introduced, irradiated with a source of pulsed x-ray radiation (RI), and to determine the positive effect using comfort results of comparing microhardness measurements, optical properties, or studying surface morphology before and after exposure to pulsed radiation and isothermal annealing of semiconductor hydroelectric power stations.

In order to transform the energy of pulsed RI into the energy of a volumetric shock wave (OVW), the surface of an object made of metal external to the incident RI is pre-coated with a layer of liquid silicate glass with a thickness of 480-600 μm, solidified, and then the surface of the object is pulsed by RI with with pre-threshold energy for the formation of structural defects, E _X-Ray ≈100-300 keV, pulse duration at half maximum τ _P ≈50-150 ns, and the remaining silicate glass is removed after radiation treatment in an accessible way.

, где t - толщина стенки образца для случая, если длина свободного пробега рентгеновских квантов в материале детали δ_X-Ray сравнима или меньше толщины стенки детали t.In order to impart uniform strength properties to the machined metal part, its surface is treated using repeated exposure to pulsed _X-ray radiation with an energy of E _X-Ray ≈100-300 keV, a pulse width at half maximum τ _P ≈50-150 ns, and an X-ray beam diameter D _hkl equal to the distance d _i between nearest the Bragg planes in the material to maximize the energy spectrum of photons incident RI and positioning pulses acting on the surface in the multiple exposure mode variou x surface points is determined from the relation

, where t is the wall thickness of the sample for the case where the mean free path of x-ray quanta in the material of the part δ _X-Ray is comparable to or less than the wall thickness of the part t.

In order to strengthen metal parts with an internal cavity, the treated internal surface after curing of silicate glass is irradiated along the longitudinal axis of the cavity with a pulsed radiation source with an energy of E _X-Ray ≈100-300 keV, pulse duration at half maximum τ _P ≈50-150 ns.

In semiconductor heterostructures of silicon-on-dielectric (KND) systems, in order to modify the morphological and electrophysical properties of such structures, the process of the formation of SWCs at the instrument-dielectric interfaces by the Coulomb interaction of silicon and oxygen ions in oxide layers at the layer interface semiconductor-insulator ", which SOI structure is irradiated with an energy pulse RI E _X-Ray ≈100-300 keV FWHM pulse duration τ _P ≈50-150 ns, and then produce annealing at a temperature of 250 ° C Techa s 1 hour to SOI structures and at a temperature of at least 100 ° C for 1.5 hour for SPS structures.

Figure 1 shows the dependence of the strength properties of metals (microhardness N) on the dislocation density (N _d ).

Figure 2 shows the scheme of hardening of metals under the influence of pulsed ionizing radiation with an energy less than the threshold, where E _k is the energy of the Coulomb interaction of photoelectrons with the Coulomb field of oxygen ions, hν is the energy of the incident RI, P (z) is the distribution over the depth z of the pressure pulse from interface "dielectric - metal".

. Здесь:Figure 3 presents the structure of liquid glass Na ₂ SiO ₃ + 9H ₂ O and a single silicate anion

. Here:

- the amplitude of the pressure pulse at a depth of z;

q1 and q2 are the charges of interacting ions;

e is the elementary charge;

τ _i is the interaction time

z - coordinate along the depth of the sample;

r≈ <a> ≈2.10 ^-8 cm is the average distance between interacting ions;

J _R is the ion interaction potential;

Figure 4 presents the processes of enhancing the effects of ionization and increasing the area of hardening due to diffraction effects. Here:

- the condition of the Bragg scattering of x-ray quanta in a solid;

d _l - the distance between the planes of the Bragg reflection RI;

h is Planck's constant;

c is the speed of light;

E is the energy of x-ray quanta;

n is the number of the replica (reflection);

θ _i is the angle of reflection (θ> 45 °);

D _hkl is the diameter of the spot RI;

S is the transverse size of the hardening zone;

S ₀ - the cone of reflection (solid segment) RI from the Bragg planes.

Figure 5 presents a method of hardening metal products with internal surfaces.

Figure 6 presents the results of measuring the microhardness H, in GPa, from the magnitude of the radiation load P (integral dose of pulsed irradiation D, in P), for samples of steel grade 08PS with a thickness of 0.4 mm:

1 - before irradiation; 2 - after pulsed irradiation without a dielectric coating; 3 - after irradiation with a silicate coating with a thickness of 480-600 microns. The dose of RI per pulse ~ 12 R.

Figure 7 shows the cross sections of semiconductor hydroelectric power plants: a) silicon-on-insulator (SOI or SOI); b) "silicon-on-sapphire" (KNS or SOS).

On Fig presents: a) a micrograph of the surface of sample No. 1 of the SOI structure after irradiation with 10 pulses of the radiation source and subsequent isothermal annealing from the side of the instrument layer; b) spatial distribution of peaks on the surface (Peak Spacing Distribution).

Figure 9 presents: a) a micrograph of the surface of sample No. 2 of the SOI structure after irradiation with 20 pulses of the radiation source and subsequent isothermal annealing from the side of the instrument layer; b) spatial distribution of peaks on the surface (Peak Spacing Distribution).

Figure 10 presents: a) a micrograph of the surface of sample No. 3 of the SOI structure after irradiation with 30 pulses of a radiation source and subsequent isothermal annealing from the side of the instrument layer; b) spatial distribution of peaks on the surface (Peak Spacing Distribution).

Figure 11 presents: a) a micrograph of the surface of sample No. 3 of the SOI structure after irradiation with 50 pulses of a radiation source and subsequent isothermal annealing from the side of the instrument layer; b) spatial distribution of peaks on the surface (Peak Spacing Distribution).

On Fig presents the dependence of the optical thickness of the instrument layer of the HPS HPS from the integrated dose of radiation (radiation from the Si side): 1 - initial value; 2 - after exposure to RI; 3 - after exposure to RI and subsequent annealing.

On Fig - presents the dependence of the reflection coefficient N of optical radiation in Al ₂ O ₃ from the dose of radiation (radiation from the side of Si): 1 - initial value; 2 - after exposure to RI; 3 - after exposure to RI and subsequent annealing.

On Fig presents the dependence of the reflection coefficient N of optical radiation in Si from the dose of radiation (radiation from the side of Si): 1 - initial value; 2 - after exposure to RI; 3 - after exposure to RI and subsequent annealing.

The proposed method is implemented as follows.

To harden the surface layer in metals or change the PDS of the instrument layer in semiconductor hydroelectric power plants, a dielectric layer is introduced into the structure of a part or structure of these materials, irradiated with a pulsed x-ray source, and to determine the positive effect. use the results of comparing microhardness measurements, optical properties, or studying surface morphology before and after exposure to ionizing radiation and isothermal annealing of semiconductor heterostructures.

1. Metal processing.

The method is implemented as follows for metal objects (material, parts, structures). A dielectric layer (a composite material or a dielectric in the liquid phase) is applied to the surface of a metal object and is held for a certain time until it is completely cured (Figure 2).

For example, liquid glass (liquid silicon (silicon silicide of the composition Na ₂ SiO ₃ + 9H ₂ O) (FIG. 3) and a thickness of 480 ... 600 μm is used as a liquid dielectric, and the object is dried at a temperature of + 20 ... + 70 ° С until liquid is completely cured glass, then irradiated with a source of pulsed x-ray radiation with an average quantum energy of ~ 100 keV, a pulse duration of 150 ns.

Under the influence of pulsed X-ray radiation, one of the main mechanisms of absorption of quantum energy is photoelectric absorption (photoelectric effect), in which a sufficiently large number of primary photoelectrons and secondary photoelectrons are formed.

), при однократной ионизации атомов для кулоновского отталкивания имеем энергию Е_к≈0,4 эВ, а амплитуда давления будет равна

Since the energy of the used X-ray diffraction is less than the threshold value at which the formation of point and spatial defects in the crystallographic disordered silicate network of SiO ₄ (Na) becomes possible, it is natural to assume that the changes in the microhardness of metal samples under the dielectric are mainly caused by the rearrangement of the dislocation structure under the influence of the SHW. As was shown in / 3 /, the mechanism of the formation of OWS is associated with the Coulomb repulsion of ionized silicon and oxygen atoms that make up the silicone network. Under the assumption that the source of the elastic momentum is the elementary SiO ₄ tetrahedron (silicate anion

), with a single ionization of atoms for Coulomb repulsion, we have the energy E _k ≈0.4 eV, and the pressure amplitude will be equal to

(Ω - the volume of the tetrahedron is ~ 2.48 · 10 ^-23 cm ³ ). Waves with such an amplitude are quite capable of activating both conservative and non-conservative rearrangement of the dislocation in the surface metal layer to depths of tens of micrometers / 1, 4 /.

The expansion of the surface treatment area is ensured by Bragg diffraction of the X-ray beam, for which the diameter of the X-ray beam is selected commensurate with the distance between the crystalline planes (D _hkl ~ d _l ). In this case, the surface treatment zone extends from the normal to the point of interaction of the quantum with diffraction planes at an angle θ _i on both sides of the normal (up to 2θ> 90 °). Given the fact that the spectral distribution of X-ray quanta of X-rays is almost continuous, and the number of replicas is large enough, with sufficient energy values, the near-surface region with a solid segment S ₀ undergoes hardening (Figure 5). A preliminary assessment of the dimensions of the solid angle allows us to determine the procedure of radiation exposure: the number and positioning of the radiation zones on the surface S ₀ .

After processing, the silicate coating is removed in one way or another.

The results of measuring the microhardness N, in GPa, on the value of the radiation load P (integral exposure dose of pulsed irradiation D), in X-rays, for 0.4PS steel samples with a thickness of 0.4 mm are shown in FIG. 6.

When processing internal surfaces containing internal cavities, a layer of silicate glass is applied to the internal surface of the part, a pulsed x-ray tube is placed along the longitudinal axis of the cavity, and radiation treatment of the surface is performed (Figure 5).

The main measurement results demonstrate the following:

- on the initial samples, the profile of changes in microhardness at a depth is quite uniform, however, it is characterized by high dispersion over the surface at a given load on the indenter (coefficient of variation reaches 12 ... 13%);

- after x-ray irradiation on samples without a silicone layer, a decrease in microhardness is observed, most pronounced at low loads, corresponding to depths of 1.3 ... 2.0 microns;

- irradiation of samples with a dielectric coating transforms the microhardness distribution profile over their thickness, which becomes sharply inhomogeneous with a maximum at depths of 4 ... 7 μm;

- after irradiation, the dispersion of microhardness values on the surface of the samples decreases and in some areas the coefficient of variation does not exceed 3%.

- at depths exceeding 7.5 ... 9.0 μm, the microhardness values of the irradiated and control samples coincide.

The heterogeneity of the depth distribution of microhardness values after irradiation is associated with an increase in the dispersion of the metal substructure, as occurs with impact methods of hardening by surface plastic deformation.

2. Processing of semiconductor heterostructures "silicon-on-insulator" (SOI) and "silicon-on-sapphire" (SOI).

In samples of silicon-on-insulator semiconductor heterostructures (KND is the general designation of SOI and SSC structures), the dielectric layer (SiO ₂ for SHO) is either built-in or “hidden”, and Al ₂ O ₃ — sapphire (SSS) is made of a substrate for the instrument layer in which the electronic circuit is formed (Fig. 7). Therefore, the procedure for applying a liquid dielectric was excluded. The objects of study were SOI structures with a thickness of 0.48 μm of the Si instrument layer, a hidden dielectric thickness of 0.5-0.52 μm, and a total thickness of ~ 0.25 mm.

Samples of the SOI structures were exposed to pulsed X-ray radiation with an average effective energy of a maximum of E≤75 keV of 10, 20, and 30 pulses of 10 ns duration and an interval of 5 minutes. The average exposure dose in one pulse was ~ 30 R. Annealing was carried out in the air of a heat and cold chamber at a temperature of 300 ° C for 1 hour. Images of surfaces were obtained with an Accurex TMX-2100 atomic force scanning probe microscope in the Non-Contact mode. The measurement results are given in table 1. The change in surface morphology is shown in Fig.8-11. Since morphological changes are associated with the dislocation density in the structure of the instrument layer, it can be argued that pulsed radiation leads to a hardening of the material structure.

For SPS structure samples, the same radiation-thermal treatment was performed as for SPS structures. The change in surface morphology was recorded on a Smena-A atomic force microscope manufactured by NT-MDT, Russia.

Some of the samples were annealed at two temperatures of 50 ° С and 100 ° С and various times, for example, samples No. 1, 3, 5 were annealed at a temperature of 50 ° С for 30, 60, 90 minutes, respectively, and the same time at 100 ° FROM. After each annealing, ellipsometric measurements were performed, and after the last annealing procedure, surface microrelief images were taken for this group of samples.

Some of the samples (samples Nos. 2, 4, 6, 8, 10, 12, 14, 16) were irradiated on a pulsed X-ray unit with a pulse duration of 5 nsec and a duty cycle of 300 s. These samples were irradiated with a dose of 10, 20, 30, 40 pulses, respectively, from the side of both Si and Al ₂ O ₃ . After that, this group was annealed at the same temperature conditions as the previous one, and after each annealing procedure, ellipsometric measurements were carried out, based on which the values of refractive index N, extinction coefficient K, and optical thickness of the instrument layer D, in Å, were calculated.

The measurements were carried out on an automated laser ellipsometer LEF-753. The wavelength of the helium-neon laser of the ellipsometer is 0.6328 μm, the permissible error in the measurement of polarization angles did not exceed ± 0.09 °, the instrumental threshold sensitivity was 0.01 °, the instrumental error in determining the refractive indices and absorption was ± 0.005, and the thickness was ± 3Å.

According to the results of the experiments, the following dependences were built: the dependence of the optical thickness on the integral dose (radiation from the Si side) in Figure 12; the dependence of the reflection coefficient N in Al ₂ O ₃ from the dose (irradiation, from the side of Si) in Fig.13; dose dependence of the reflection coefficient N in Si (radiation from the Si side) in Figure 14.

12-14 that both annealing and irradiation lead to a smoothing of the surface, i.e. the maximum surface height decreases and the peak at the maximum grain distribution is smoothed. It has been established that irradiation from the side of silicon leads to more significant effects compared to irradiation from the side of sapphire.

It follows from the above dependences: 1) after irradiation, the optical thickness of the Si layer increases, subsequent annealing leads to its relaxation almost to its initial state; 2) the values of the refractive indices for silicon and for sapphire are reduced in comparison with the initial value after irradiation and subsequent annealing.

The extinction coefficients of silicon and sapphire also decrease under the influence of irradiation and annealing, but the extinction coefficient of sapphire varies somewhat more than for silicon. For example, for a sample irradiated with 10 pulses for silicon: 0.06 (initial) - 0.028 (irradiation) - 0.022 (annealing); and for sapphire: 0.695 (initial) - 0.129 (irradiation) - 0.23 (annealing). But sapphire is an order of magnitude higher than that of silicon. This is due to the difference in materials in density and the presence of oxygen in the structure of sapphire. The most probable cause of these changes is the redistribution of metallic impurities and structural defects between the epitaxial layer and the substrate under the action of SWCs arising in sapphire in the field of ionizing radiation.

The nonequivalence of the reactions of the components of the SSC structures to irradiation from different sides can be caused by the asymmetry, the density function of the distribution of the absorbed energy of radiation over the thickness of the compositions. In the case of irradiation from the silicon side, the minimum value of the absorbed energy, and, consequently, the smaller total amplitude of the SWC, falls on the epitaxial layer and the substrate region conjugated to it. When exposed to sapphire, this zone is affected by a wave field with a larger amplitude, since it is formed by a superposition of elastic impulses arising in the entire volume of the sapphire substrate. In this case, alternating mechanical stresses can activate not only the channel of non-conservative rearrangement of dislocation-type defects in the epitaxial layer, but also microplastic deformation of silicon due to sliding. The latter process leads to differences in the nature of measurements of the microrelief of natural layers during x-ray irradiation of structures from the side of silicon and sapphire.

There is an oscillating character of the dependences of K and N on the integrated dose of x-ray radiation, regardless of the annealing temperature. An increase in the duration of isothermal annealing and temperature leads to a smoothing of the oscillations of the coefficients K and N, and it can be expected that, with an increase in the duration of the annealing process, the dependence transitions to saturation mode.

From the analysis of the data presented, it follows that: 1) irradiation of the structures of the SSS by pulses of radiation causes a decrease in the maximum size of micro roughness, to a decrease in lateral spread. Subsequent annealing after irradiation leads to more noticeable changes in lateral dispersion compared with the irradiation process; and an increase in dose leads to a less intense change in the controlled parameters.

The surfaces of irradiated structures are less sensitive to thermal effects than non-irradiated ones. This is explained by the fact that pulsed X-ray radiation, generating non-equilibrium intrinsic point defects by the “subthreshold” mechanism, transfers the PDS of the component layers of structures to a thermodynamically more equilibrium state compared to the initial one, and this is accompanied by a change in the micromorphology of the surface of the instrument layers and an increase in their thermal stability.

Experiments demonstrating the feasibility of the proposed method were carried out on steel samples St.08 composition: Fe; 0.05 ÷ 0.1% C; 0.17 ÷ 0.37% Si, on the surface of which layers of liquid glass were applied with a thickness of 480 ... 600 microns. Glass composition: Na ₂ SiO ₃ + 9H ₂ O. After drying the coating, the samples were irradiated with X-ray radiation with an average quantum energy of 100 keV

Table 1 The effect of X-ray radiation and annealing on the size of the microroughnesses of the silicon surface of SOI structures No. Type of processing R _a , nm R _z , nm D1 nm ΔR _a / R _a ΔR _z / R _z Δdl / dl one 10 pulses irradiation 51.09 24.45 193.75 0.74 1.89 -0.55 10 pulses irradiation and annealing 88.85 70.74 87.9 2 20 pulses irradiation 50,5 26.72 158.80 0.66 0.88 -0.37 Irradiation with 20 pulses and annealing 83.65 50.24 100.70 3 30 pulse irradiation 46.47 25.01 166.07 0.72 0.86 -0.27 Irradiation with 30 pulses and annealing 80.07 46.60 121.35 four Control without processing 51.19 24.79 204.68 1.32 0.80 -0.41 Control without irradiation after annealing 119.06 44.50 121.34 R _a - the maximum size of microroughnesses, nm R _z - the average size of the microroughness, nm dl — lateral size distribution, nm.

pulse mode with a pulse duration of about 150 ns. The total exposure dose was 12 ± 3.6 R. Before, and after irradiation, the microhardness was measured on the samples on a PMT-3 device in the load range of 20 ... 200 g. The microhardness measurement error did not exceed ± 7%.

Moreover, this process proceeds most intensively directly near the surface under the dielectric layer and is accompanied by a decrease in the size of grains (blocks) to a level where the occurrence of the “superplasticity effect” is not excluded. In the case of irradiation without a dielectric, the decrease in microhardness at low loads on the indenter is most likely associated with the dissolution of the Kottrelov ableospheres due to the ionization of their impurities and the unlocking of dislocations, which become mobile during local loading and reduce hardness.

The presented results testify to the realization of the goal - hardening the surface of parts, including complex shapes, and the results show the promise of using special dielectric coatings (which are easily removed after processing) for hardening the surface layers of products of any shape, since such coatings are applied by any of the traditional methods, including the usual exposure in a solution (melt), and the field of ionizing radiation generated by x-ray sources has much less the spatial anisotropy of the spatial distribution compared to laser or particle radiation.

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Claims (5)

1. A method of modifying the surface of metals or heterogeneous structures of semiconductors by exposing them to ionizing radiation energy, characterized in that, in order to harden the surface layer in metals or to change the impurity-defective composition of the instrument layer in semiconductor heterostructures, into the structure of a part or structure of these materials a dielectric layer is introduced, irradiated with a source of pulsed x-ray radiation, and to determine the positive effect, use the results of comparison before and after exposure to ionizing radiation and isothermal annealing of semiconductor heterostructures of any of their physical properties: microhardness, optical properties, surface morphology. 2. The method according to claim 1, characterized in that, in order to transform the energy of the pulsed X-ray radiation into the energy of a volumetric shock wave, the surface of an object made of metal external to the incident X-ray radiation is pre-coated with a layer of liquid silicate glass with a thickness of 480-600 μm, cured it, and then the surface of the object is treated with pulsed x-ray radiation with a threshold energy for the formation of structural defects, E _X-Ray ≈100-300 keV, pulse duration at half maximum τ _P ≈50-150 ns, and the lacquered glass is removed after radiation treatment in an affordable manner. 3. The method according to claim 1, characterized in that, in order to impart uniform strength properties to the metal part being treated or to modify the morphological and electrophysical properties of semiconductor heterostructures, their surface is treated using repeated exposure to pulsed x-ray radiation with subthreshold structure defect formation energy, E _{X -Ray} ≈100-300 keV, pulse width at half maximum τ _P ≈50-150 ns and X-ray beam diameter D _hkl equal to the distance d between the nearest Bragg methods in this material for maximum energy in the spectrum of quanta of incident x-ray radiation, and the positioning of pulses acting on the surface in the regime of repeated irradiation of various points on the surface is determined from the relation

, where t is the wall thickness of the part for the case where the mean free path of x-ray quanta in the material of the object δ _X-Ray is comparable to or less than the wall thickness of the object t. 4. The method according to claim 2, characterized in that, in order to harden the metal parts with the inner cavity, the treated inner surface after curing silicate glass is irradiated along the longitudinal axis of the cavity with a source of pulsed x-ray radiation with subthreshold energy for the formation of structural defects, E _X-Ray ≈ 100-300 keV, pulse duration at half maximum τ _P ≈50-150 ns. 5. The method according to claim 1, characterized in that in semiconductor heterostructures of silicon-on-dielectric (KND) systems, in order to modify the morphological and electrophysical properties of such structures, the process of formation of bulk shock waves at the interface between the instrument layer and dielectric is used "By the Coulomb interaction of silicon ions and oxygen in oxide layers at the interface of the semiconductor-insulator layers, for which the CPV structures are irradiated with pulsed X-ray radiation with subthreshold defect formation energy st structures, E _X-Ray ≈100-300 keV, pulse duration at half maximum τ _P ≈50-150 ns, and then anneal at 250 ° С for 1 h for SOI structures and at a temperature of at least 100 ° С for 1.5 hours for the structures of the SSC.

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