DE3610293C2 - - Google Patents

Description

The invention relates to a method for applying finer Particles on a substrate at high speed. Such one The method is e.g. B. in the layer formation on a Substrate used, also in the manufacture of a composite material, for doping or for generating a field from fine particles or the like.  

In the present context, the term "fine Particles "atoms, molecules, ultrafine particles and general fine particles. The ultrafine particles are those that are generally smaller than 0.5 microns and z. B. by evaporation in gas or in a plasma chemical reaction in the vapor phase, through colloidal precipitation in a liquid or by pyrolysis of a receives liquid sprays. The generally fine particles are particles that can be obtained by conventional methods such as mechanical Crushed, crystallized or precipitated. The term "beam" here means a stream or one Flow along a substantially constant cross section the direction of the current, regardless of the geometry of the cross-section.  

The term "density of fine particles" means here Density in the current or flow. In other words: density is defined as the number of fine particles per unit volume in the case of generally fine particles or a mass of fine particles per unit volume in the other cases.

Generally fine particles are in a carrier gas dispersed and suspended to keep from the flow of Carrier gas to be transported.

So far, the control of the flow of fine particles only achieved by transporting the entire Flow of the fine flowing together with the carrier gas Particles defined using a pipe or a housing was, the pressure difference between an upstream and a downstream location has been exploited. As a result, the flow of fine particles became inevitable over the entire pipe or housing through which the flow path was dispersed, although it was within the Flow gave a certain distribution.

If fine particles are blown onto a substrate, the Particles generally with the carrier gas from a nozzle pushed out. The nozzle used for such fine particles is either a straight or convergent nozzle, and the cross section of the stream of fine particles immediately  following the ejection of the particles is through the area of the nozzle outlet is limited. But at the same time Current dispersed at the outlet of the nozzle, so that the confinement only takes place temporarily and the flow rate the Speed of sound does not exceed.

However, the fine particles are transported by moving them in a tube or housing through which the flow path is defined, guides, leads the touch of the fine particles with the walls of the pipe or casing into a large one Density distribution of the particles within the stream. That's why varies for example when touching the fine particles with the gas with which they react in the course of the transport route the touch condition due to the non-uniform Density of fine particles. As a result, a stable one and do not achieve a uniform touch condition.

On the other hand, the conventional stretched or converging nozzle a scattered flow in which the fine Particles have an extensive thickness distribution. In the case it is the inflation of fine particles onto a substrate therefore difficult to make this inflation uniform and the area where the inflation is uniform, to dominate.  

In US-PS 42 00 264 is a device for generating metallic Mg or Ca by the carbon reduction process described.

In this device there is a reduction reaction causes a Mg or a Ca oxide in a reaction chamber is heated with carbon, and the resulting Gas mixture is fed into a divergent nozzle to cause adiabatic expansion for cooling purposes and thereby to obtain fine particles of Mg or Ca.

The diverging nozzle described in the document is limited to operation in a sub-expansion condition.

The use of such a nozzle under the condition mentioned certainly allows the generation of a supersonic speed in the gas flowing through, however, the gas flow Scattered at the nozzle opening so that you don't have a stream with it can obtain a substantially constant cross section. Hereby there is only a low capture rate when capturing the resulting fine particles on, for example, a substrate.

The invention is based on the object that shown Avoid problems and create a process by which the density of fine particles is effectively and precisely controlled can be.  

This object is achieved by the specified in claim 1 Invention solved. The invention provides for this Procedure at which in the flow path of the particles has a Laval Nozzle is arranged and the fine particles be passed through the nozzle.

A suitable selection is made of a pressure ratio P / P _{o of} a pressure P prevailing on the downstream side and a pressure prevailing on the upstream side P _o as well as a ratio A / A * of an opening cross-sectional area A of the outlet of the nozzle with respect to the cross-section A * a neck portion of the nozzle.

The term Laval nozzle is used below explained in more detail.

The following are exemplary embodiments of the invention Hand of the drawing explained in more detail. It shows  

Fig. 1 is a schematic view illustrating the basic principle of the invention,

Fig. 2 is a schematic view of a method for producing a layer in ultra fine particles by applying the method according to the invention,

Figs. 3A to 3C show various views of embodiments of a gas excitation device,

FIGS. 4A to 4C are views of various forms of KD nozzles,

Fig. 5 is a schematic view of a baffle.

Fig. 1 shows a schematic view of the basic principle of the present invention, a process that is for applying fine particles onto a substrate at a high uniformity, a Laval nozzle 1 is placed at the in a flow path of the fine particles and the particles are passed through the nozzle . The invention is based on the basic principle that a stream or flow of fine particles can be made uniform and can take the form of a beam.

The Laval nozzle 1 has an opening cross section, which gradually decreases as shown in FIG. 1 from the inlet 1 a to an intermediate neck section 2 , in order to gradually increase in size in the direction of the outlet 1 b. For ease of illustration 1, the inlet of the Laval nozzle 1 is shown in FIG. Connected to a closed, upstream chamber 3 and the outlet of the nozzle 1 is connected to a closed, downstream chamber 4. In the following, the "upstream" chamber or the "downstream" chamber is also referred to as the "upper" or "lower" chamber. The inlet and outlet of the nozzle 1 according to the invention can be connected to a closed or an open system as long as the fine particles are caused to flow through the nozzle together with a carrier gas due to a pressure difference between the inlet and the outlet.

The term "optimal expansion condition" means here that the pressure P₁ at the nozzle outlet 1 b is as large as the pressure P in the lower chamber 4 , so that the flow from the nozzle has jet properties.

Under the under-expansion condition P₁ <P the expelled Current quickly dispersed towards the outside, starting on Outlet of the nozzle so that a uniform flow is not obtained. On the other hand, the overexpansion condition P₁ <P Flow experienced a detachment in the nozzle, so the flow becomes unstable and shock waves are also generated not suitable for the purposes of the present invention.  

In order to obtain an optimal expansion flow, pressure sensors are arranged at the outlet of the nozzle or around the outlet and in the lower chamber, and the pressure P _o in the upper section and the pressure P in the lower section are controlled so that that of the sensors determined pressure is approximately the same.

According to the invention, a pressure difference is generated between the upper chamber 3 and the lower chamber 4 by feeding a carrier gas into the upper chamber 3 , as shown in Fig. 1, in which the fine particles are dispersed while in suspension while the lower chamber 4 is evacuated with a vacuum pump 5 , so that the carrier gas containing the fine particles flows from the upper chamber 3 through the KD nozzle 1 to the lower chamber 4 .

The nozzle 1 not only has a function of discharging the fine particles together with the carrier gas in accordance with the pressure difference between the upper and lower sides, but also has the function of a diffuser, that is, the function of making a density of the discharged fine particles uniform. Such a uniform density of the fine particles can be used to blow the fine particles uniformly onto a substrate 6 .

The nozzle 1 is capable of accelerating the flow of fine particles ejected with the carrier gas by appropriately selecting a pressure ratio P / P _{o of} the pressure P in the lower chamber 4 with respect to the pressure P _o in the upper chamber, as well by selecting the ratio A / A * of the opening cross-sectional area A of the outlet 1 b with respect to the cross-sectional area A * of the neck section 2 . If the ratio P / P _{o of} the pressures in the upper chamber 3 and the lower chamber 4 is larger than a critical pressure ratio, the flow rate at the outlet of the nozzle 1 becomes lower than the speed of sound, and the fine particles and the carrier gas are decreased with one Ejected speed. If, on the other hand, the pressure ratio P / P _{o is} equal to or less than the critical pressure ratio, a flow rate is obtained at the outlet which corresponds to a supersonic speed, so that the fine particles and the carrier gas are expelled at supersonic speed.

With such an output with a pressure ratio below the critical pressure ratio form the carrier gas and the fine particles an evenly scattered flow, and the fine particles are uniform over a relative large area strewn. In this way, the density can be make the fine particles relatively low.

On the other hand, in the case of ultrasonic ejection, the carrier gas with the fine particles is ejected linearly in the form of a jet, the jet essentially maintaining the cross section immediately after the ejection from the nozzle. In this way, the flow of the fine particles can also be shaped as a jet and as a high-density stream, which is transported with a minimal control in the lower chamber 4 at supersonic speed, the jet or stream being spatially independent of the walls of the lower one Chamber 4 is.

If the flow of fine particles is assumed to be a compressible, one-dimensional flow with adiabatic expansion, the Mach's number M which is achieved by the flow can be calculated by the pressure P _{o of} the upper chamber and the Pressure P in the lower chamber:

where u is the velocity of the flow of fine particles, a is the local velocity of sound and γ is the ratio of the respective specific heat in the fluid. The value M exceeds the value "1" if the ratio P / P _{o is} equal to or less than the critical pressure ratio.

The speed of sound can be determined by the formula

specify, where T is the local temperature and R is the gas constant. In addition, the following relationship between the opening cross-sections A and A * exists in the outlet 1 b in the neck portion 2 and the Mach number M:

Therefore, it is possible to regulate the velocity of the flow of fine particles discharged from the nozzle 1 by making the opening ratio A / A * according to the pressure ratio P / P _o in the upper one according to the equation (1) Mach number M calculated in the lower chamber or by regulating the pressure P / _Po according to the value M calculated from equation (2) using the opening ratio A / A *. The velocity u of the flow of fine particles can be determined by the following equation (3):

where T _{o determines} the temperature in the upper chamber 3 .

Fig. 2 shows schematically an embodiment of the invention in use in a device for layer formation with ultrafine particles, wherein a nozzle 1 , an upper chamber 3 , a first lower chamber 4 a and a second lower chamber 4 b are present.

The upper chamber 3 and the first lower chamber 4 a are constructed as a one-piece unit, with a baffle plate 7 , a shut-off valve 8 and the second upper chamber 4 b being removable from the first chamber 4 a by means of flanges of the same diameter, hereinafter referred to as common flanges are designated are attached. The upper chamber 3 , the first lower chamber 4 a and the second lower chamber 4 b are kept at a successively higher vacuum with a vacuum system to be explained in more detail below.

To the upper chamber 3 , a gas excitation device 9 is connected with a common flange, which generates ultrafine particles by means of plasma and these particles together with a carrier gas, e.g. B. with hydrogen, helium, argon or nitrogen, to the opposite nozzle 1 . The inner walls of the upper chamber 3 can be provided with a non-stick treatment in order to prevent the ultrafine particles produced from adhering to the inner walls of the chamber. Due to the pressure difference between the upper chamber 3 and the first lower chamber 4 a, caused by the higher vacuum in the lower chamber, the generated ultrafine particles flow together with the carrier gas through the nozzle 1 to the first lower chamber 4 a.

As shown in FIG 3A., Has the gas excitation device 9, a first, rod-shaped electrode 9 a, b which is incorporated in a second, tubular electrode 9, in which the carrier gas and raw material gas is entered. An electrical discharge is caused between the electrodes 9 a and 9 b. The gas excitation means 9 may be, as shown in FIG. 3B, with a first porous electrode 9a is formed, with which the carrier gas is performed the raw material gas to the space between the first and the second electrode. Alternatively, according to FIG. 3C, a tube can consist of two semicircular electrodes 9 a and 9 b, which are spaced apart with the aid of insulators 9 c, so that the carrier gas and the raw material gas are introduced into the tube.

The nozzle 1 is mounted with a common flange on a side facing the upper chamber 3 of the first lower chamber 4 a, so that it projects into the upper chamber 3 , its inlet 1 a opens into the upper chamber and the Outlet 1 b opens into the first lower chamber 4 a. The nozzle 1 can also be mounted so that it protrudes into the first lower chamber 4 a. The direction of protrusion of the nozzle 1 is determined by its size and quantity as well as the nature of the ultrafine particles to be transported.

As already explained above, the cross section of the nozzle 1 is reduced from the inlet 1 a of to the neck 2 out gradually in order then to the outlet 1 b towards gradually widen, and the differential coefficient of the curve of the flow path changes continuously to reach zero on the neck portion 2 , thereby minimizing the growth of flow boundary layers in the nozzle 1 . In the context of the present invention, the curve of the flow path in the nozzle 1 means the curvature of the inner wall, viewed in cross section along the flow direction. In this way it is possible to choose the effective cross section of the flow in the nozzle 1 so that it comes very close to the value provided in the design and fully utilizes the performance of the nozzle 1 . As enlarged in FIG. 4A, the inner circumference in the vicinity of the outlet 1 b is preferably approximately parallel to the central axis or has a differential coefficient equal to zero in order to facilitate the formation of a parallel flow, since the flow direction of the carrier gas and the discharged gas fine particles is influenced to a certain extent by the direction of the inner wall near the outlet 1 b. But if the angle α of the inner wall of the neck 2 to the outlet 1 b with respect to the central axis is less than 7 ° is chosen preferably 5 ° or less, as shown in FIG. 4B, it is possible to prevent the peeling phenomenon, and a to maintain the substantially uniform state of the discharged carrier gas with the ultrafine particles. Accordingly, in such a case, the above-mentioned parallel inner peripheral wall can be omitted, so that the manufacture of the nozzle 1 is simplified by omitting the parallel wall portion. In addition, by using a rectangular nozzle 1 as shown in FIG. 4C, a slit-shaped discharge of the carrier gas and the ultrafine particles can be achieved.

The above-mentioned peeling phenomenon means the formation of an enlarged boundary layer between the inner wall of the nozzle 1 and the fluid flowing through the nozzle, caused, for example, by a protrusion of the inner wall, thereby promoting an uneven flow. This phenomenon is more common with higher speed currents. In order to avoid the detachment phenomenon, the above-mentioned angle α is preferably chosen to be smaller if the inner wall of the nozzle 1 is not finished so precisely. The inner wall of the nozzle 1 should be finished with a fineness which corresponds to three, preferably four triangular marks standing on the tip in accordance with Japanese Industrial Standard (JIS) B 0601. Since the peeling phenomenon in the diverging section of the nozzle 1 subsequently significantly influences the flow of the carrier gas and the ultrafine particles, special attention should be paid to the surface treatment of the diverging section so that the manufacture of the nozzle 1 is simplified as a whole. In addition, in order to prevent the peeling phenomenon, it is necessary to provide the neck portion 2 with a smooth curvature and to avoid the existence of an infinitely large differential coefficient when changing the cross-sectional area.

Examples of the material to be selected for the KD nozzle 1 are metals such as iron and stainless steel, plastics such as acrylic resin, polyvinyl chloride, polyethylene, polystyrene and polypropylene, ceramic materials, quartz, glass and the like. The material can be selected considering the lack of reaction with the ultrafine particles to be produced, in view of the ease of processing and gas emission in the vacuum system. In addition, the inner wall of the nozzle 1 may be coated or coated with a material which prevents sticking or reaction with the ultrafine particles. An example of such a material is a coating made of polyfluoroethylene.

The length of the nozzle 1 can be chosen freely taking into account the total length of the device. The thermal energy inherent in the carrier gas is converted into kinetic energy when the carrier gas flows through the nozzle. As a result, the thermal energy of the ultrafine particles also decreases noticeably, and the flow rate of these particles follows that of the carrier gas. Furthermore, if a condensable gas is contained in the carrier gas, this condensable gas can condense in the stream due to the cooling effect caused by the aforementioned decrease in thermal energy. Due to the homogeneous nucleation, the process enables the production of homogeneous ultrafine particles. In this case, too, the nozzle 1 should preferably be extended for sufficient condensation. On the other hand, condensing increases thermal energy and reduces kinetic energy. In order to maintain a high ejection speed, the nozzle 1 should be shortened. By passing the carrier gas stream containing the ultrafine particles through the above-explained nozzle 1 with a suitable selection of the pressure ratio P / P _{o of} the upper chamber 3 and the lower chamber 4 and with a suitable selection of the opening cross-section ratio A / A * of the neck 2 and the outlet 1 b, the current takes the form of a beam, which passes at high speed from the first lower chamber 4 a into the second lower chamber 4 b.

The baffle 7 is a variable opening that is adjustable from the outside in order to gradually change the opening cross section between the first lower chamber 4 a and the second lower chamber 4 b and thereby a greater vacuum in the second lower chamber 4 b maintain than in the first chamber 4 a. Specifically, there is the impingement cover shown in FIG. 5 consists of two adjusting plates 11 and 11 'provided with notches 10 and 10' are equipped. The plates can be moved so that the notches 10 and 10 ' overlap each other. The adjustment plates 11 and 12 can be moved from the outside in order to define an opening with the notches 10 and 10 ' which allow the beam to pass through and still maintain a sufficient vacuum in the second lower chamber. The shape of the notches 10 and 10 'of the baffle plate 7 and the shape of the adjusting plates 11 and 11' is not limited to the shape shown in Fig. 5, but it can also be a semi-circular or similar shape.

The shut-off valve 8 has a very similar valve part 13 , which can be opened or closed with the aid of a handle 12 . If the jet is available, it is opened completely. By closing the valve 8 there is the possibility of exchanging the unit of the second lower chamber 4 b, while a vacuum is maintained in the upper chamber 3 and in the first lower chamber 4 a. If the ultrafine particles are easily oxidizing metal particles, the unit can be replaced without risk of rapid oxidation by using a ball valve or a similar arrangement as a shut-off valve 8 and exchanging the second chamber 4 b together with the ball valve.

In the second lower chamber 4 b there is a substrate 6 for collecting the transported ultrafine particles in the form of a layer. The substrate is mounted on a substrate holder 16 located at the end of a push rod 15 . The push rod is mounted in the second lower chamber 4 b by means of a common flange and is moved by the cylinder 14 . In front of the substrate 6 there is a shutter 17 to intercept the beam if necessary. In addition, the substrate holder 16 can heat or cool the substrate 6 in order to create optimal conditions for the collection process of the ultrafine particles.

In the upper and lower wall of the upper chamber 3 and the second lower chamber 4 b are glass windows 18 which are mounted with common flanges in the manner shown in the drawing Darge, and which allow observation of the interior. Similar glass windows (not shown here) are available with the help of common flanges in the front and rear walls of the upper chamber 3 , the first lower chamber 4 a and the second lower chamber 4 b. The glass windows can be removed so that different measuring instruments or a load locking chamber can be installed using the common flanges. In the following a vacuum system according to the invention is explained.

The upper chamber 3 is connected via a pressure control valve 19 to a main valve 20 a. The first lower chamber 4 a is connected directly to the main valve 20 a, which in turn is coupled to the vacuum pump 5 a. The second lower chamber 4 b is connected to a main valve 20 b, which is connected to a vacuum pump 5 b. Backing pumps 21 a and 21 b are connected to the upstream (upper) side of the main valves 20 a and 20 b via backing valves 22 a, 22 b and also via auxiliary valves 23 a and 23 b to the vacuum pumps 5 and 5 b, respectively. The backing pumps 21 a and 21 b are used for the pre-evacuation of the upper chamber 3 , the first lower chamber 4 a and the second lower chamber 4 b. For the chambers 3 , 4 a and 4 b and the pumps 5 a, 5 b, 21 a and 21 b, leakage drain valves 24 a- 24 h are provided.

First, the roughing valves 22 a and 22 b and opens the pressure regulating valve 19 to a pre-evacuation of the upper chamber 3 and the first and second lower chamber 4 a and 4 b with the help of the backing pumps 21 a and 21 b to perform. Then the backing valves 22 a and 22 b are closed and the auxiliary valves 23 a and 23 b and the main valves 20 a and 20 b are opened to the upper chamber 3 and the first and second lower chambers 4 a, 4 b with the aid of Vacuum pumps 5 a and 5 b to be evacuated sufficiently. In this state, the opening dimension of the pressure control valve 19 is controlled so that a higher vacuum is achieved in the first lower chamber 4 a than in the upper chamber 3 . Then, the carrier gas and the raw material gas are fed, and the baffle plate 7 is inserted so assumed that in the second lower chamber 4 b a higher vacuum is generated than in the first lower chamber 4a. The setting can also be made via the main valve 20 b. In addition, the control is carried out so that a constant vacuum is present in each of the chambers 3, 4 a, 4 b during the generation of the ultrafine particles and the layer formation by the ejected jet. This control can be achieved either manually or automatically by determining the pressures in the chamber 3, 4 a and 4 b and accordingly adjusting the pressure control valve, the main valves 20 a and 20 b and the baffle 7 .

The upper chamber 3 and the first lower chamber 4 a can be equipped with separate vacuum pumps in order to achieve the aforementioned setting of the vacuum. However, if only a single vacuum pump 5 a is used, as was explained above, the pressure difference between the chambers can be kept constant for evacuation in the direction of the jet flow in order to control the vacuum values in the upper chamber 3 and the first lower chamber 4 a, and even if the vacuum pump 5 a is pulsating to a certain extent. It is therefore easier to maintain a constant flow state which is easily influenced by a change in the pressure difference.

The suction through the vacuum pumps 5 a and 5 b is preferably from the top, especially in the first and the second lower chamber 4 a, 4 b, since such a suction from the top to a certain extent decrease from of the beam prevented due to gravity.

The system according to the invention explained above can be modified in the following way:
First, the nozzle can be tilted vertically or horizontally. It can also be constructed in such a way that it scans over a certain area in order to build up a layer over a larger area. Such an inclination or scanning movement is advantageous if the nozzle shown in FIG. 4C with a rectangular cross section is used.

It is also possible to make the nozzle 1 from an insulating material such. B. to produce quartz to generate energy active ultrafine particles in the nozzle by supplying microwaves. The nozzle can also be made of translucent material so that the current in the nozzle can be irradiated with light of different wavelengths, e.g. B. with UV light, with IR light or with laser light. In addition, several nozzles 1 can be provided for the simultaneous generation of several jets. In particular, the connection of several nozzles 1 with independent upper chambers 3 enables the simultaneous generation of rays of different fine particles, so that one can achieve lamination or a mixed collection of different particles and moreover there is also the possibility of generating new fine particles by collision of intersecting rays.

The substrate can be vertically or horizontally movable or rotatably mounted to intercept the beam in a large area. In addition, a substrate for receiving the beam can be pulled off a roll and transported further, so that a strip or cloth-shaped substrate can be treated with fine particles. In addition, the treatment with fine particles can also be applied to a rotating, drum-shaped substrate 6 .

The embodiments described above include the upper chamber 3 , the first lower chamber 4 a and the second lower chamber 4 b. But you can also do without the second lower chamber 4 b or add additional lower chambers to the second lower chamber. The first lower chamber can also be operated in an open system when the upper chamber 3 is under pressure or the upper chamber 3 can be operated in an open system when the first lower chamber 4 a is under reduced pressure. It is also possible to pressurize the upper chamber like an autoclave and to keep the first and subsequent lower chambers under negative pressure.

As described above, the active ultrafine particles are generated in the upper chamber 3 . However, they can also be generated at another location in order to be fed into the chamber together with the carrier gas. It is also possible to provide a valve for opening and closing the nozzle 1 and for opening and closing the valve intermittently, thereby temporarily storing the fine particles in the upper chamber 3 . The energy supply to the lower side, including the neck portion 2 of the nozzle 1 , can be synchronized with the opening and closing of the valve, thereby reducing the load on the vacuum system and maintaining a pulsating flow of fine particles while effectively utilizing the raw material gas becomes. For a given vacuum condition, a given degree of vacuum can be reached more easily on the lower, downstream ge side if such intermittent opening and closing is provided. In this case, a chamber can be provided to temporarily store the fine particles, this chamber then being arranged between the upper chamber 3 and the nozzle 1 .

It is also possible to use several nozzles in series and the pressure ratio between upstream and downstream side of each nozzle to regulate one to maintain a constant jet speed. Also lets a spherical chamber to avoid dead spaces use.

According to the invention, fine particles can be considered uniform dispersed and relatively scattered stream or as a beam are transported with high density, the density is controlled. In particular, a supersonic trans port of the fine particles in a spatially independent state achieve so that the density can be controlled safely. It is also possible to keep the active fine particles safe  to be transported to the collecting point at the desired density and the collection cross section by controlling the collection area to control exactly. It is also expected that one receives new reaction field, realized by the presence a beam in the form of an ultrafast, beam-shaped Flow and through the implementation of thermal energy in kinetic energy during beam formation so that the fine particles in an energetically frozen state will hold. In addition, by taking advantage of the above energetically frozen state the invention Method of controlling the density of a microscope to define the copy state of the molecules in the fluid to make a transition from one state to another. The possibility of a new chemical gas opens up reaction in which the molecules by their energy level are defined and they correspond to the energy level Get energy. A new area of energy is emerging transmission, which can be used in a simple manner lets molecular connections with relatively weak intermediate to maintain molecular forces, such as with water weave or the Van der Waals force.

Claims (6)

1. A method for applying fine particles to a substrate with high uniformity, in particular uniform thickness, for which purpose a gas stream leading the particles or their precursors is formed, characterized in that the gas stream is converted by expansion into a free and stable jet by means of a Laval nozzle is, the conditions are set such that the difference between the pressure P₁ at the nozzle outlet and the pressure P in the environment ( 4 ) downstream of the nozzle is selected to form a stable beam, while the ratio of the pressure P to the pressure P _o in the environment ( 3 ) upstream of the nozzle is selected so that the point ( 2 ) of the smallest cross section of the nozzle ( 2 ) assumes the speed of sound and the particle density within the stream is uniform. 2. The method of claim 1, wherein the gas stream thereby is set that a ratio A / A * of an opening cross Sectional area A of the nozzle outlet with respect to a cross section area A * of a neck portion of the nozzle is selected. 3. The method of claim 1, wherein the fine particles ultra are fine particles. 4. The method according to claim 1, characterized in that the fine particles on the substrate in the form of a layer be applied. 5. The method according to claim 3, characterized in that the ultrafine particles are active ultrafine particles that generated by a gas plasma. 6. The method according to claim 1, characterized in that for the nozzle, the angle of the inner wall from the neck portion to the nozzle outlet with respect to the central axis of the nozzle Has a value of 7 ° or less.