TWI434350B - Method of applying the silicon-nitride films under vacuum - Google Patents

Description

Method for coating a tantalum nitride film in a vacuum

The present invention relates to the field of coating a tantalum nitride film and can be used to encapsulate a thin film OLED structure (organic light emitting diode) in a vacuum.

A device for coating a coating in a vacuum is known in which a coating is formed thereon by plasma treatment of a substrate surface in combination with an ion beam source [1] that provides different functions of directional energy flow.

However, since the different types of ion beam sources used in the device operate under different conditions, the structure and phase composition of the usually formed coatings are different from each other, which makes the layers match each other to ensure that the high adhesion is quite complicated, so in practice It is not possible to use a known device to ensure that a multilayer coating is applied to the substrate. In this case, the productivity of the coating coating treatment is drastically lowered because it is necessary to ensure a specific working condition of each individual source and thus takes a large amount of time.

Furthermore, energy sources that use different functions in known devices do not allow deposition of coatings on large sized substrates.

Another known method of applying a coating includes vacuum sputtering a material and its deposit on the surface of the article, wherein the surface of the article is pre-cleaned and activated by a stream of inert gas ions.

In this case, the surface is cleaned, the surface is cleaned, and the material is deposited thereon while maintaining the residual pressure constant in the processing volume of the vacuum chamber, and the sputter material is deposited by the continuous sputtering target to obtain a plurality of coatings, at least one of which The target is made of metal, one made of ceramic, and the ceramic target is sputtered for at least 15 minutes to form a separate layer [2].

The closest to the present invention is a vacuum module, and the method of applying a coating on a substrate is not directly disclosed in the specification using the module.

A method of applying a coating on a substrate is described in explaining the operation of the vacuum module, the substrate is immovably mounted in a vacuum chamber, a working gas mixture is fed thereto, and a target is sputtered using an ion beam formed from the ion source, The sputtering material is deposited layer by layer onto the surface of the substrate by scanning the surface of the substrate with a sputter material while performing relative motion of the ion source and the ruthenium target relative to the substrate [3].

However, the method and apparatus known from the technique [2, 3] have serious general disadvantages: the film obtained by the above method has the following disadvantages: - low density; - high porosity, so that the film does not provide a sufficient seal, especially When the thickness of the film is 0.1-0.3 μm; - the internal stress is high; if a tantalum nitride film is coated on the substrate, all of these disadvantages will appear in a wide range.

The above disadvantages lead to cracking and deformation of the film, and reduce its adhesion (adhesion between layers) and adhesion of the base layer to the metal surface. If a tantalum nitride film is coated on an elastomeric polymer, such as an OLED structure, the polymer breaks and falls off the base layer or substrate.

In addition, the process of coating a tantalum nitride film in many cases is accompanied by a large increase in substrate temperature, i.e., up to 150-200 ° C (423-473 K), which includes the function of a fusible (temperature sensitive) material. In terms of components, it is absolutely not allowed.

The object of the present invention is to eliminate the above disadvantages, namely to ensure the sealing property of the film structure, to increase the film density, to reduce the porosity of the film and the internal stress therein, and to reduce the temperature of the substrate during the deposition of the film coating on the surface of the substrate, And to ensure the high quality of the coating.

The set goal is achieved by a method of coating a tantalum nitride film in a vacuum, wherein the substrate is fixedly placed in a work chamber, and a working gas mixture is fed to the work chamber: nitrogen and argon, forming an ion beam from at least one ion source, The target is sputtered by a directional ion beam and deposited onto the substrate by sputtering the surface of the substrate, and the ion beam source and the target are moved relative to the substrate; according to the first embodiment of the method, At each of the loops of relative movement of the ion beam source relative to the substrate, at least one layer having a thickness in the range of 2-10 nanometers is formed; and helium gas is introduced into the mixture of working gases.

When the method is practiced, the concentration of helium in the working gas mixture is maintained in the range of 2-20%, and the sputter material stream is a given long straight shape; in this case, the sweep amplitude of the sputter material stream and The length of the linear portion exceeds the respective linear dimensions of the substrate, and the working pressure within the chamber during deposition of the film does not exceed 10 ^-1 Pa.

According to a second embodiment of the method of applying a tantalum nitride film in a vacuum, the substrate is fixedly placed in a work chamber, and the working chamber is fed with a mixture of working gases: nitrogen and argon, forming ions from at least two ion sources The beam is sputtered by a directional ion beam, and the sputter material is deposited layer by layer onto the surface of the substrate. The ion beam source and the target are fixedly mounted with respect to the surface of the substrate, and the target is sprayed in a pulse mode. The interval between the preceding and succeeding pulses is at least 0.1 second; in this case, at least one layer having a thickness in the range of 2-10 nm is formed in one pulse, and helium gas is introduced into the working gas mixture.

As with the first embodiment, the concentration of helium in the working gas mixture is maintained in the range of 2-20%, and the working pressure in the tank during the deposition of the film does not exceed 10 ^-1 Pa.

However, the ion beam source can be fixedly mounted about its axis.

A first embodiment of a method of coating a tantalum nitride film in a vacuum is carried out as follows.

The substrate for coating the film and the target and one or more ion beam sources are fixed in a vacuum chamber, wherein the pressure should not exceed 10 ^-1 Pa during the implementation process. The substrate should be stationary and capable of holding the target and one or more ion beam sources in relative motion relative to the surface of the substrate to be processed.

The vacuum chamber is then fed a mixture of working gases (nitrogen, argon, and helium), and the ion beam is formed using one or more ion beam sources. The vacuum box can accommodate several ion sources, and the working gas content ratio in the mixture is, for example, nitrogen: argon: helium = 70%: 20%: 10%.

The target is sputtered by an ion beam obtained from at least one or more ion beam sources. By scanning the surface of the substrate during relative movement of the ion beam source and the target relative to the surface of the substrate, the material from the sputtering target is deposited layerwise on the surface of the substrate to be processed, in this manner at the ion beam source and target. During each loop with respect to the relative motion of the substrate, a film having a thickness of 2-10 nm will be formed.

During the implementation of the method, the concentration of helium in the working gas mixture is maintained in the range of 2-20%, and the sputter material stream is a given long straight shape; in this case, the sputter material flow The scan amplitude and the length of the linear portion exceed the respective linear dimensions of the substrate.

During the relative movement of the ion beam source and the ruthenium target relative to the substrate surface, the desired thickness can be formed by layering the sputter material on the surface of the stationary substrate by scanning the surface of the substrate with a sputter material. The film has a low porosity.

One of the causes of the voids is micro-defects (holes, protrusions, and particles) that appear on the surface of the substrate before and during coating of the film.

Under constant deposition conditions, when the ion source (eg, one) and the target are stationary and the sputtered material stream is deposited onto the surface of the substrate at a constant (unchanged) angle, the pores created at the microdefect are penetrated. And growing to the outer surface of the film, thus reducing the density of the film and impairing the sealing properties of the film.

If the ion beam source and the target move relative to the surface of the substrate, the sputter material is deposited onto the surface of the substrate in such a manner that each of the ion beam source and the relative movement of the target relative to the surface of the substrate is in a loop. The thickness of each subsequent layer from the first layer is in the range of 2-10 nm.

In this way, each layer is formed discontinuously in time.

During the time interval, absorption, diffusion, and relaxation treatments are performed on the deposited film layer when no material is deposited onto the substrate. These treatments improve the stoichiometry of the film components, consolidate the layer structure, and reduce the internal stress levels of the film.

At the atomic level, the layer thickness of 2-10 nm corresponds to several tens of single atom layers, because the particle energy during ion beam sputtering is very large, so the atoms deposited on the surface of the substrate have high mobility, thereby promoting effective sealing. Pores and microcracks that appear in a single discontinuous layer.

During the relative movement of the ion beam source and the target relative to the substrate, the angle at which the coating is deposited on the substrate varies depending on the extent of the pores and micro-defects (holes, protrusions, and particles) on the surface of the closed substrate.

In addition, even if only one layer is applied at the atomic level, the degree of closed pores and micro-defects is improved due to the deposition of the sputter material.

The film deposited on the substrate in this way has high amorphousness and low crystallinity, thereby increasing the density of the film and reducing the porosity of the film.

The absorption process of the working gas atoms is performed on the surface of the film during the time interval in which each film is deposited. These atoms not only fill the holes between the atoms formed in the film layer, but also prevent further growth of the crystal structure.

Therefore, the absorption treatment performed on the surface of each of the film layers contributes to the suppression of crystal growth by suppressing the formation of the inter-microcrystalline channels, and the inter-microcrystalline channels are potential through pores.

Since a large number of crystals are formed at a thickness of 2 to 10 nm, if the thickness of each layer deposited is within these ranges, absorption treatment and crystal growth inhibition on the surface of the deposited film are most effective.

In addition, since the material is deposited layer by layer on the surface of the substrate, wherein each of the loops of the relative movement of the ion beam source and the target relative to the substrate forms a thin film layer having a thickness of 2-10 nm, which is more advantageous for heat dissipation. Does not reduce the deposition strength.

When the desired film thickness is reached, i.e., during multiple scans of the substrate surface, the process becomes a low temperature process due to discontinuities, and the process prevents the substrate due to the high density of the film deposited on the surface of the substrate. The surface is too hot.

Since the linear size of germanium atoms is much smaller than that of germanium atoms and nitrogen atoms, and the introduction of germanium atoms in the tantalum nitride structure reduces the internal stress level in the film, the introduction of helium gas into the composition of the working gas can be reduced. The internal stress in the tantalum nitride film is 2.5-3 times.

The sputter material flow during film deposition is a given long straight shape which ensures that the thickness of the film is uniform across the surface of the substrate.

This is also achieved because the scanning amplitude of the sputter material stream and the length of the linear portion exceed the respective linear dimensions of the substrate, which eliminates the uniformity of the sputter material flow within the dimensions of the surface of the substrate to be treated, which is dependent on exceeding the sputter material. The boundary condition of the flow profile.

Due to the advancement of the technology of the present invention, it is confirmed by experiments that if the concentration of helium in the working gas mixture is less than 2%, the internal stress in the film will be considerably large.

If the concentration of helium in the working gas mixture exceeds 20%, the stress is not further lowered, and the deposition rate of the film on the surface of the substrate is lowered.

Therefore, it has been experimentally determined that the optimum percentage range of helium in the working gas mixture is 2-20%.

This range ensures that the internal stresses in the film deposited on the surface of the substrate are minimal, which undoubtedly improves the quality of the applied coating.

The optimum pressure in the vacuum box ensures the necessary quality of the film deposited on the substrate, which is also experimentally determined.

According to the experiment, the pressure in the vacuum box should not exceed 10 ^-1 Pa.

When the pressure exceeds 10 ^-1 Pa, the phenomenon called thermal energy of the deposition stream becomes very intense. This is because the possibility of collision of sputtering atoms with working gas atoms in the drift space between the target and the substrate increases, and the energy of the condensed flow drops sharply, thereby greatly affecting the density of the coating.

In addition, the saturation of the tantalum nitride film having working gas (nitrogen and argon) atoms is also improved. Each of the above results in an increase in the porosity of the film, a decrease in density, and an increase in internal stress in the film, thereby lowering the quality of the coating deposited on the substrate.

According to a second embodiment of the implementation method, unlike the first embodiment, the target and the ion beam source (eg, a single ion beam source) are fixedly placed in the vacuum box relative to the fixedly placed substrate, in this case The pulse mode sputtering target ensures a layered coating.

In this case, for example, a single layer formed by a single pulse has a thickness in the range of 2-10 nm, and the time interval between the previous and subsequent pulses is at least 0.1 second.

Therefore, a layer having a thickness corresponding to several tens of atomic layers at the atomic level is formed in each pulse.

Since the energy of the particles is sufficiently high during ion beam sputtering, the atoms of the sputter material deposited on the surface of the substrate have a high mobility, thereby effectively sealing the emerging pores and micro-defects in a single discontinuous layer.

In the material-free time interval, absorption, diffusion, and relaxation treatment are performed on the deposited film layer, thereby increasing the stoichiometry of the film components, consolidating the layer structure, and reducing the internal stress level of the film.

As in the first case, the deposited film obtained in this manner has high amorphousness and low crystallinity, thereby increasing the density of the film and reducing the porosity.

The time interval between pulses is selected according to actual research. It has been experimentally determined that a period of 0.1 second between pulses ensures a high quality dense film. Increasing this time does not significantly improve the quality of the film, but it will affect the production efficiency of the process and the productivity will decrease.

As in the first embodiment, since the linear size of the germanium atom is much smaller than the linear size of the germanium and the nitrogen atom, and the internal stress is reduced in the thin film when the germanium atom is introduced into the tantalum nitride structure, in the composition of the working gas Injecting helium gas can reduce the internal stress in the tantalum nitride film by 2.5-3 times.

Therefore, the optimum percentage range of helium in the working gas mixture is experimentally determined to be 2-20%.

As in the first embodiment, it is experimentally determined that the pressure in the vacuum chamber in the second embodiment should not exceed 10 ^-1 Pa.

In addition, the ion beam source rotating about its axis can: first, ensure more complete utilization of the target material; second, change the pattern of material deposition during the coating process; and third, coat a film that is more uniform in thickness and porosity. Fourth, increase the productivity of processing.

Specific implementation of the first embodiment

A substrate 2 having a size of 200 × 200 mm fixed on the substrate holder 3 is fixedly placed in the vacuum box 1, as shown in Fig. 1. An ion beam source (one in this example) 4 and a target 5 are placed in the same vacuum box relative to the surface of the substrate to be treated. Air was evacuated from the vacuum box 1 by means of a vacuum pump, and the residual pressure was lowered to 5 × 10 ^-4 Pa.

The vacuum tank 1 is then fed with a mixture of working gases (argon and nitrogen) and helium is injected such that the percentage of helium in the working gas mixture is in the range of 2-20%, ie not less than 2% and not greater than 20%. In a specific embodiment of the method, the percentage of working gas in the mixture is 90% (nitrogen 70%, argon 20%) and the percentage of helium is 10%.

At this time, the total pressure in the tank was adjusted to 8 × 10 ^-2 Pa.

A positive potential of 4.0 kV was applied to the anode of the ion beam source 4; followed by an ignition discharge in which an ion beam directed at the target 5 with a total current of 450 mA was formed. Due to the sputtering target 5, a flow of tantalum nitride (Si ₃ N ₄ ) is formed. The scanning system is then turned on to perform the relative movement of the ion source 4 with the target 5 relative to the substrate 2, which is placed in the vacuum box 1 together with the substrate holder 3.

The value of the scanning speed is set such that a 3 nm thick layer can be applied to the substrate during a single loop of relative movement of the ion beam source 4 and the target 5 relative to the substrate 2. In order to coat a 180 nm thick film, 60 scanning loops need to be performed with respect to the substrate 2 processing apparatus. When the thin film deposition process on the substrate 2 is completed, the ion beam source 4 is turned off and the feeding of the working gas into the vacuum chamber is stopped. The process of applying a coating to the surface of the substrate 2 is completed.

Therefore, the stress level of the tantalum nitride film deposited on the substrate according to the first embodiment is as low as 383 MPa, which is achieved by optimizing the composition of the gas mixture with respect to the percentage of helium.

Even at thicknesses greater than 0.3 microns, the film resists cracking and peeling.

Meanwhile, the internal stress of the tantalum nitride film obtained using standard techniques without introducing helium into the mixed gas component was 934 MPa, and the thickness was easily broken and peeled off from the substrate at a thickness exceeding 0.07 μm.

According to the first embodiment of the implementation method, a layout of the substrate, the target, and the ion beam source positioned to each other is as shown in FIG.

A substrate 2 having a size of 620 × 375 mm fixed to the substrate holder 3 is fixedly placed in the vacuum box 1. The ion beam source 4 (in this case one) and the target 5 are relatively movable relative to the surface of the substrate to be treated and placed in a vacuum box at an angle of 45-60 degrees. Air was evacuated from the vacuum box 1 by means of a vacuum pump, and the residual pressure was lowered to 5 × 10 ^-4 Pa.

The vacuum tank 1 is then fed with a mixture of working gases (argon and nitrogen) and helium is injected such that the percentage of helium in the working gas mixture is in the range of 2-20%, ie not less than 2% and not greater than 20%.

In a specific embodiment of the process, the percentage of working gas in the mixture is 85% (nitrogen 75%, argon 10%) and the percentage of helium is 15%.

At this time, the total pressure in the tank 1 was adjusted to 7.5 × 10 ^-2 Pa.

A positive potential of 4.5 kV was applied to the anode of the ion beam source 4; followed by an ignition discharge in which an ion beam directed at the target 5 with a total current of 550 mA was formed. Due to the sputtering target 5, a flow of tantalum nitride (Si ₃ N ₄ ) is formed. The scanning system is then turned on to perform the relative motion of the ion source 4 and the target 5 with respect to the substrate 2.

The value of the scanning speed is set such that a 4.5 nm thick layer can be applied to the substrate during a single loop of the relative movement of the ion beam source 4 and the target 5 relative to the substrate 2. In order to coat a 225 nm thick film, 50 scanning loops need to be performed with respect to the substrate 2 processing apparatus. When the thin film deposition process on the substrate 2 is completed, the ion beam source 4 is turned off and the feeding of the working gas into the vacuum chamber 1 is stopped. The treatment of applying a coating to the surface of the substrate is completed.

The tantalum nitride film deposited on the substrate according to this embodiment has a stress level as low as 315 MPa, which is achieved by optimizing the composition of the gas mixture and the low pressure of the working gas relative to the percentage of helium.

Specific implementation of the second embodiment

A substrate 2 having a size of 200 × 200 mm fixed to the substrate holder 3 is fixedly placed in the vacuum box 1. The target 5 and the two ion beam sources 4 and 4' which are rotatable about their axes are placed in the same tank. The ion beam sources 4 and 4' are operated in a synchronous pulse mode in such a manner that the interval between the previous and subsequent pulses is at least 0.1 second. The film of the desired thickness is obtained by layering, similar to the method according to the first embodiment, as shown in FIG.

Air was evacuated from the vacuum box 1 by means of a vacuum pump, and the residual pressure was lowered to 4.5 × 10 ^-4 Pa.

A mixture of working gases (argon and nitrogen) is fed into the vacuum tank 1, in which helium gas is also injected. The percentage of helium in the working gas mixture should be in the range of 2-20%, i.e., not less than 2% and not more than 20%. In a specific embodiment of the process, the percentage of working gas in the mixture is 92% (nitrogen 75%, argon 17%) and the percentage of helium is 8%.

At this time, the total pressure in the tank 1 was adjusted to 6.5 × 10 ^-2 Pa.

A positive potential of 5.0 kV was applied to the anodes of the ion beam sources 4 and 4'; followed by an ignition discharge in which an ion beam directed at the target 5 was formed at a total current of 950 mA.

Due to the sputtering target 5, a flow of tantalum nitride (Si ₃ N ₄ ) is formed.

The time value at which the pulses of the ion beam sources 4 and 4' are continuously operated is set, during which the target 5 is sputtered and a tantalum nitride film is deposited on the surface of the substrate to coat a 5 nm thick layer during a single pulse.

In order to coat a 200 nm thick film on the surface of the substrate 2, 40 pulses were generated at a pulse interval of 0.2 seconds. During this interval, the film was subjected to relaxation and desorption treatment. These treatments enable the acquisition of dense, non-porous tantalum nitride films with low internal stress levels.

When the thin film deposition process is completed, the ion beam sources 4 and 4' are turned off and the supply of the working gas to the vacuum chamber 1 is stopped. The process of applying a coating to the substrate 2 is completed.

The tantalum nitride film obtained on the surface of the substrate according to the second embodiment has a stress level as low as 395 MPa, which is achieved by optimizing the composition of the gas mixture with respect to the percentage of helium and having a thickness of more than 0.3 μm. Resistant to cracking and peeling.

4 is a layout view of a substrate, a target, and an ion beam source positioned to each other according to a second embodiment of the embodiment.

A substrate 2 having a size of 620 × 375 mm fixed to the substrate holder 3 is fixedly placed in the vacuum box 1. The target 5 and four ion beam sources 4, 4', 4" and 4"' which are rotatable about their axes are mounted in the same tank. The ion beam sources 4, 4', 4" and 4' are operated in a synchronized pulse mode. '', in this way, a layered film of a desired thickness can be obtained discontinuously, similar to the method according to the first embodiment.

Air was evacuated from the vacuum box 1 by means of a vacuum pump, and the residual pressure was lowered to 4.0 × 10 ^-4 Pa.

A mixture of working gases (argon and nitrogen) is fed into the vacuum tank 1 and helium gas is injected. The percentage of helium in the working gas mixture should be in the range of 2-20%, i.e., not less than 2% and not more than 20%. In a specific embodiment of the process, the percentage of working gas in the mixture is 85% (nitrogen 70%, argon 15%) and the percentage of helium is 15%.

At this time, the total pressure in the vacuum chamber was adjusted to 8.5 × 10 ^-5 Pa.

A positive potential of 5.2 kV was applied to the anodes of the ion beam sources 4, 4', 4" and 4"'; followed by an ignition discharge in which an ion beam directed at the target 5 was formed at a total current of 1,850 mA.

Due to the sputtering target 5, a flow of tantalum nitride (Si ₃ N ₄ ) is formed.

The values of the pulse durations of the ion beam sources 4, 4', 4" and 4"' are set, during which the target 5 is sputtered and a tantalum nitride film is deposited on the surface of the substrate 2 to coat 15 during a single pulse. Nano thick layer.

In order to coat a film of 0.30 μm thick on the surface of the substrate 2, 20 pulses were generated at intervals of 0.3 seconds. During this interval, the film was subjected to relaxation and desorption treatment. These treatments enable the acquisition of dense, non-porous tantalum nitride films with low internal stress levels.

When the thin film deposition process is completed, the ion beam sources 4, 4', 4" and 4"' close and stop feeding the working gas into the vacuum chamber 1. The process of applying a coating to the substrate is completed.

The tantalum nitride film obtained on the surface of the substrate 2 according to the second embodiment has a stress level as low as 285 MPa, which is achieved by optimizing the composition of the gas mixture with respect to the percentage of helium, and optimizing pulse sputtering. Mode and thickness of the deposited layer.

The proposed method of coating a tantalum nitride film in a vacuum and its embodiment can be applied to industrial production, ensuring high quality of the coating applied on the substrate, as well as high productivity of processing.

Open source

1. Russian Patent No. 2095467; C23C 14/34, published on November 10, 1997; 2. Russian Patent No. 2017563; C23C 14/46, published on June 19, 1995; 3. Eurasian Patent No. 003148 C23C 14/54; 14/56; 14/34; published in EAB20301.

1. . . Vacuum box

2. . . Substrate

3. . . Substrate holder

4, 4', 4", 4'''... ion beam source

5. . . target

1 is a schematic view of a method of coating a tantalum nitride film in a vacuum according to a first embodiment of the present invention.

2 is a layout view of a substrate, a target, and an ion beam source positioned to each other in accordance with a first embodiment of the present invention.

3 is a schematic view of a method of coating a tantalum nitride film in a vacuum in accordance with a second embodiment of the present invention.

4 is a layout view of a substrate, a target, and an ion beam source positioned to each other in accordance with a second embodiment of the present invention.

1. . . Vacuum box

2. . . Substrate

3. . . Substrate holder

4. . . Ion beam source

5. . . target

Claims (8)

A method of coating a nitrided film onto a fixedly placed substrate in a vacuum, wherein a mixture of working gases is fed into the vacuum chamber: nitrogen and argon, an ion beam is formed from at least one ion source, and is directed by a directional ion beam. The target is deposited and deposited on the substrate by a surface sputter material of the scanned substrate; further, the ion source and the target are collectively moved relative to the substrate, characterized by a relative movement of the ion source relative to the substrate Each loop forms at least one layer having a thickness in the range of 2-10 nanometers and introducing helium gas into the mixture of working gases. The method of claim 1, characterized in that the concentration of helium in the mixture of working gases is maintained in the range of 2-20%. The method of any one of claims 1 to 2, wherein the sputter material stream is a given long straight shape; in this case the scanning amplitude of the sputter material stream and the length of the linear portion exceed The individual linear dimensions of the substrate. The method of claim 3, wherein the working pressure in the tank during the deposition of the film does not exceed 10 ^-1 Pa. A method of depositing a tantalum nitride film on a fixedly placed substrate in a vacuum, wherein a mixture of working gases is fed into a vacuum chamber: nitrogen and argon, an ion beam is formed from at least two ion sources, and a directed ion beam is sputtered The target is shot and the sputter material is deposited layer by layer onto the surface of the substrate, wherein the ion source and the target are fixedly mounted with respect to the surface of the substrate, and the target is sputtered in a pulse mode, in the manner of the previous and the latter The spacing between the pulses is at least 0.1 seconds; in this case at least one layer having a thickness in the range of 2-10 nm is formed in one pulse, and helium gas is introduced into the mixture of working gases. The method of claim 5, characterized in that the concentration of helium in the mixture of working gases is maintained in the range of 2-20%. The method of claim 5, wherein the ion source is rotatably mounted about its axis. The method of claim 7, wherein the working pressure in the tank during the deposition of the film does not exceed 10 ^-1 Pa.