JP2008274318A - Aerosol discharge nozzle and film-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aerosol discharge nozzle which inhibits fine particles from depositing on the periphery of the aerosol discharge nozzle, and can stably form a dense uniform film on a substrate for a long period of time, and to provide a film-forming apparatus using the nozzle. <P>SOLUTION: The aerosol discharge nozzle 2 which is connected to an aerosol pipeline 1 for transporting an aerosol containing the fine particles dispersed in a gas, and discharges the aerosol toward a part to be film-formed of a substrate comprises: a nozzle body having a space for passing the aerosol; an introduction opening 2c for introducing the aerosol, which is connected to a feeding opening 1a of the aerosol pipeline 1; and a rectangular discharge opening 2b for discharging the aerosol. The introduction opening 2c has the same shape as or the similar shape to that of the feeding opening 1a of the aerosol pipeline 1. The inner wall surface of the introduction opening 2c is seamlessly connected to the inner wall surface of the feeding opening 1a without forming a step. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an aerosol discharge nozzle used in an aerosol deposition (hereinafter referred to as AD) method in which an aerosol containing fine particles is sprayed on a substrate or the like to form a coating or a structure on the substrate, and a coating using the nozzle The present invention relates to a forming apparatus.

  As a method for forming a film on a substrate, there is a method for forming a film or structure of a brittle material called a fine particle beam deposition method or an AD method. In the AD method, an aerosol containing fine particles of a brittle material is discharged from a nozzle toward a substrate, the fine particles collide with the substrate, and a polycrystalline structure of the brittle material is directly applied to the substrate by using the mechanical impact force. (See, for example, Patent Document 1).

  In addition, various nozzle shapes are known for improving film formation efficiency in the AD method. For example, a structure with a uniform film thickness can be produced in a short time by devising the internal shape of the nozzle body having an aerosol passage space through which the aerosol passes so that the aerosol concentration derived from the discharge opening becomes uniform. A nozzle for forming a composite structure that makes it possible is known (see Patent Document 2).

However, when a composite structure is formed for a long time using the nozzle of Patent Document 2, ceramic powder accumulates on the wall surface inside the nozzle or the connection portion between the nozzle and the piping, and the discharge amount may not be stable, resulting in film formation failure. is there. Further, when clogging or deposits are ejected at once, aerosol pulsation is observed, and stable operation cannot be ensured. When such a phenomenon occurs, conventionally, it has been necessary to periodically stop the apparatus, inject only the carrier gas, clean the wall surface, and remove the deposits. Also, if cleaning with carrier gas is insufficient, cleaning of nozzles and piping, and the connection between nozzles and piping, etc., will necessitate removal and cleaning of ceramic powder deposits, increasing cleaning costs and increasing productivity. There was a problem of causing a drop in
Japanese Patent Laid-Open No. 11-21677 JP 2003-247080 A

  The present invention has been made in order to cope with such problems. Even when the film forming apparatus is operated for a long time, the generation of fine particles around the aerosol discharge nozzle is suppressed, and the fine particles can be stably and densely formed for a long time. It is an object of the present invention to provide an aerosol discharge nozzle capable of forming a uniform film and a film forming apparatus using the nozzle.

An aerosol discharge nozzle according to the present invention is an aerosol discharge nozzle that is connected to an aerosol pipe that transports an aerosol in which fine particles are dispersed in a gas and discharges the aerosol toward a film forming portion of a base material. The nozzle comprises a nozzle body having an aerosol passage space through which the aerosol passes, an introduction opening connected to the outlet opening of the aerosol pipe to introduce the aerosol, and a rectangular discharge opening for discharging the aerosol, The introduction opening has the same shape or a similar shape as the outlet opening of the aerosol pipe.
In the present invention, the term “similar shape” means that there is less change in fluid resistance such that fine particles are stalled and accumulated from the passing aerosol at the connecting portion between the introduction opening of the aerosol discharge nozzle and the outlet opening of the aerosol pipe. It means that it is a shape to be.

The inner wall surface of the introduction opening and the inner wall surface of the outlet opening of the aerosol pipe are continuously connected without a step.
The fine particles have an average particle size of 0.01 to 2 μm.
The fine particles are ceramic fine particles.

  The film forming apparatus of the present invention is a film forming apparatus for forming a film by discharging and colliding an aerosol in which fine particles are dispersed in a gas from an aerosol discharge nozzle onto a substrate in a vacuum chamber. Is the aerosol discharge nozzle of the present invention.

In the aerosol discharge nozzle of the present invention, the introduction opening for introducing the aerosol has the same shape as or similar to the outlet opening of the aerosol pipe for carrying the aerosol, for example, a step between the inner wall surface of the inlet opening and the inner wall surface of the outlet opening. Since the connection is continuous, there is no space for depositing fine particles at the connection portion, and the fluid resistance to the aerosol flow does not change. For this reason, the aerosol can flow between the outlet opening and the inlet opening and flow to the discharge opening while maintaining a predetermined particle concentration without depositing fine particles.
As a result, even if the film forming apparatus is operated for a long time, it is not necessary to stop the apparatus and disassemble and clean the nozzles, pipes, and connecting portions, and a stable and dense and uniform film can be formed over a long period of time.

  Since the coating film forming apparatus of the present invention uses the above-mentioned aerosol discharge nozzle, fine particles are not deposited at the connection portion between the outlet opening of the aerosol pipe and the introduction opening of the aerosol discharge nozzle, and it is stable and dense for a long time. A uniform film can be formed.

  In the present invention, the AD method is a coating made of a constituent material of fine particles, in which an aerosol in which fine particles of ceramics or the like are dispersed in a gas is directed toward a base material, and is ejected from an aerosol discharge nozzle, and the aerosol collides with the base material surface at high speed. Is formed on a substrate.

  Conventionally, as shown in FIG. 4 (a), the connecting portion between the outlet opening of the aerosol pipe and the inlet opening of the aerosol discharge nozzle has a circular outlet section 1a of the aerosol pipe having a circular sectional shape and a square sectional shape. The introduction opening 2a of the aerosol discharge nozzle was simply connected. For this reason, since the shape of the connecting portion is different, for example, when the outlet opening 1a of the aerosol pipe having an inner diameter of 5 mm is connected to the inlet opening 2a of the 5 mm × 5 mm square aerosol discharge nozzle, the sectional area suddenly increases and the nozzle wall surface It was confirmed that the fine particles that had stalled due to separation from the aerosol adhered to the inner wall surface of the nozzle 2. FIG. 4B is a diagram illustrating the internal space of the nozzle 2 from the introduction opening 2a to the discharge opening 2b. In FIG. 4B, it has been found that the most particulate deposit 12 is generated in the vicinity of the introduction opening 2a where the cross-sectional area suddenly increases.

Further, the adhesion state of the fine particles differs depending on the connection method between the outlet opening of the aerosol pipe and the inlet opening of the aerosol discharge nozzle. FIG. 5 is a diagram showing an example of a connection method in a vertical section. As shown in FIG. 5, when the outlet opening surface of the aerosol pipe and the introduction opening surface of the aerosol discharge nozzle are connected on the same plane, the largest amount of deposit is observed at both ends of the introduction opening having a wide cross-sectional area. In addition, deposits were observed on the inner wall of the outlet opening of the aerosol pipe. Moreover, it was recognized that the deposit gradually decreased toward the discharge opening of the aerosol discharge nozzle.
On the other hand, as shown in FIG. 6, in the case where connection is made in such a manner that the outlet opening surface of the aerosol pipe is pushed below the introduction opening face of the aerosol discharge nozzle, deposits are generated on the inner wall surface of the outlet opening of the aerosol pipe. Although not recognized, it was confirmed that the aerosol exiting the outlet opening was deposited with fine particles rolled up to both ends of the inlet opening where the cross-sectional area widened.

  In view of the above observation results, the present invention has completed an aerosol discharge nozzle capable of suppressing the generation of deposits. That is, in the present invention, in this connection portion, the shape of the outlet opening of the aerosol pipe and the shape of the inlet opening of the aerosol discharge nozzle are the same or similar as shown in FIGS. Space is eliminated and the fluid resistance to aerosol flow is kept constant. For this reason, the aerosol can flow between the outlet opening and the inlet opening and flow to the discharge opening while maintaining a predetermined particle concentration without depositing the particles.

  An aerosol discharge nozzle according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of the aerosol discharge nozzle of the present invention. As shown in FIG. 1, the aerosol discharge nozzle 2 of the present invention is continuously displaced from a circular introduction opening 2c having the same cross-sectional shape as that of the outlet opening 1a of the aerosol pipe 1 and the introduction opening 2c. The nozzle 2 has a discharge opening 2b which is an open end of the internal space of the main body. Although FIG. 1 is an exploded perspective view, in use, the outlet opening 1a of the aerosol pipe and the introduction opening 2c of the aerosol discharge nozzle 2 are connected. Further, the inner wall surface of the introduction opening 2c and the inner wall surface of the outlet opening 1a are continuously connected without any step.

  When the aerosol exits the outlet opening 1a passes through the inlet opening 2c, the aerosol can pass in a stable flow without changing the fluid resistance at the connection portion between the outlet opening 1a and the inlet opening 2c. The aerosol that has passed through the connecting portion passes through the nozzle body 2 having an internal space shape that is continuously displaced from the introduction opening 2c toward the rectangular tip discharge opening 2b, so that a stable flow can be maintained. It discharges toward the base material from the discharge opening 2b without generating.

FIG. 2 is an exploded perspective view showing another example of the aerosol discharge nozzle of the present invention. As shown in FIG. 2, the aerosol discharge nozzle 2 of the present invention is continuously displaced from a square inlet opening 2a having the same cross-sectional shape as the outlet opening 1b of the aerosol pipe 1 and the inlet opening 2a. The nozzle 2 has a discharge opening 2b which is an open end of the internal space of the main body. In this case, the aerosol piping 1 is used in which the internal space shape is continuously displaced from the circular cross-sectional shape in advance in the carry-out adjusting portion 1c and the cross-sectional shape of the outlet opening 1b is made square.
FIG. 2 is an exploded perspective view. In use, the outlet opening 1a of the aerosol pipe and the introduction opening 2c of the aerosol discharge nozzle 2 are connected. Further, the inner wall surface of the introduction opening 2a and the inner wall surface of the outlet opening 1b are continuously connected without any step.

The aerosol passing through the carry-out adjusting portion 1c passes through the internal space continuously displaced from the circular pipe cross-sectional shape toward the lead-out opening 1b having a square cross-sectional shape, so that a stable flow can be maintained. It flows toward the lead-out opening 1b without generating.
When the aerosol exits the outlet opening 1b passes through the inlet opening 2a, the aerosol can pass through the connecting portion between the outlet opening 1b and the inlet opening 2a with a stable flow without changing the fluid resistance. The aerosol that has passed through the connecting portion passes through the nozzle body 2 having an internal space shape that is continuously displaced from the introduction opening 2a toward the rectangular tip discharge opening 2b. Without being discharged from the discharge opening 2b toward the base material.

A film forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 3 is a view showing a film forming apparatus in the case of forming a ceramic film on a flat substrate.
As shown in FIG. 3, the film forming apparatus 3 based on the AD method includes an aerosol generator 4 and a vacuum chamber 5. In the vacuum chamber 5, a base material 6 on which a ceramic film is to be formed and an aerosol discharge nozzle 2 of the present invention connected to the aerosol pipe 1 are disposed. The inside of the vacuum chamber 5 is depressurized by a vacuum pump 7 and a particulate filter 8 is provided immediately before the vacuum pump 7 in order to prevent ceramic particulates from being mixed. The substrate 6 is fixed on the XY table 9 and moved in the horizontal direction in the vacuum chamber 5 (A in the figure).

The aerosol generation device 4 having ceramic fine particles inside includes a gas supply facility 10 outside, and an aerosol composed of ceramic fine particles and a carrier gas is formed by the carrier gas supplied from the gas supply facility 10, and the flow of the carrier gas The aerosol is supplied to the aerosol discharge nozzle 2 in the vacuum chamber 5 by the suction of the vacuum pump 7. An inert gas is used as the aerosol carrier gas. Usable inert gases include argon, nitrogen, helium and the like.
In the above-described configuration, any device or component normally used in the AD method can be used for the aerosol generating device other than the aerosol discharge nozzle.

  In the film forming apparatus of the present invention, while discharging the aerosol from the aerosol discharge nozzle 2, the substrate 6 is moved in the horizontal direction by the XY table 9, or the aerosol discharge nozzle 2 is moved to form a desired material on the substrate 6. A film having the shape and thickness is formed.

The fine particles that can be used in the aerosol discharge nozzle and the film forming apparatus of the present invention may be fine particles capable of forming a film, and mainly include ceramic fine particles. Examples of the ceramic fine particles include oxides such as alumina, zirconia, and titania, and fine particles such as silicon carbide and silicon nitride. Among these, alumina fine particles are preferable because each ceramic has a smaller true specific gravity and is more easily aerosolized.
In addition to ceramic fine particles, fine particles of brittle materials with strong cleavage, such as silicon and germanium, can also be used.

The average particle size of the fine particles used in the aerosol discharge nozzle and the film forming apparatus of the present invention is preferably 0.01 to 2 μm. If it is less than 0.01 μm, it is easy to agglomerate and it is difficult to form an aerosol. In the present invention, the average particle diameter is a value measured by Nikkiso Co., Ltd .: Laser type particle size analyzer Microtrac MT3000.
Further, in order to satisfactorily form a film, it is preferable to previously form cracks in the fine particles using a pulverizer such as a ball mill or a jet mill so that the fine particles are easily pulverized upon collision with the substrate.

Example 1
Using the coating film forming apparatus 3 shown in FIG. 3 provided with an aerosol discharge nozzle 2 having a circular introduction opening 2c having an inner diameter of 5 mm shown in FIG. 1 and a rectangular discharge opening 2b of 10 mm × 1 mm. A coating made of alumina fine particles was formed on the surface of the substrate 6 (manufactured by SUJ2, 30 mm × 30 mm × 2 mm (mirror finish)) by the AD method.
In the AD method, an aerosol containing fine alumina particles is discharged from the discharge opening 2b at the tip of the fixed aerosol discharge nozzle 2 toward the substrate 6 under a reduced pressure of 100 Pa or less in the vacuum chamber 5 to form a coating film. Formation was performed. The base material 6 was reciprocated at a stroke of 15 mm at a speed of 10 mm / min to form a film for 60 minutes.
Alumina fine particles were manufactured by Daimei Chemical Industry Co., Ltd .: Tymicron TM-DAR, and used after heat-drying under reduced pressure of 10 Pa or less with an average particle size of 0.16 μm. Helium was used as the carrier gas, and the particle velocity was controlled by the carrier gas flow rate.

Example 2
The introduction opening 2c of the nozzle 2 used in Example 1 was changed to the shape of the introduction opening 2a shown in FIG. At this time, the aerosol pipe 1 used was one in which the internal space shape was continuously displaced from the circular cross-sectional shape in advance in the carry-out adjusting portion 1c and the cross-sectional shape of the outlet opening 1b was made square.

Comparative Example 1
The introduction opening 2c of the nozzle 2 used in Example 1 was changed to the shape of the introduction opening 2a shown in FIG. At this time, the aerosol pipe 1 used was connected to the nozzle so that the discharge opening 1a having a circular cross-sectional shape was flush with the nozzle introduction opening 2a.

When the formed substrate was ultrasonically cleaned with an ethanol solution and observed in cross section, in Example 1 and Example 2, an α-alumina coating having a dense, transparent and smooth surface was formed to a thickness of 24 μm. On the other hand, in Comparative Example 1, the α-alumina coating was formed with a thickness of 5 μm or less.
Further, when these nozzles were used continuously for 60 minutes, no decrease in film formation efficiency was observed in Examples 1 and 2, and no fine particles were deposited on the nozzles decomposed after use. On the other hand, in Comparative Example 1, when the film was used continuously for 60 minutes, the film formation efficiency was reduced, and fine particles were also deposited on the nozzle decomposed after use.

  The coating film forming apparatus equipped with the aerosol discharge nozzle of the present invention is capable of forming a fine and uniform film stably over a long period of time by suppressing the generation of fine particles around the aerosol discharge nozzle. For example, it can be suitably used for forming a ceramic film on the surface.

It is a disassembled perspective view which shows an example of the aerosol discharge nozzle of this invention. It is a perspective view which decomposes | disassembles and shows the other example of the aerosol discharge nozzle of this invention. It is drawing which shows the film formation apparatus which concerns on one Example of this invention. It is drawing which shows an example of the conventional aerosol discharge nozzle. It is a figure which shows an example of the connection method in a vertical cross section. It is a figure which shows the other example of the connection method in a vertical cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aerosol piping 2 Aerosol discharge nozzle 3 Film formation apparatus 4 Aerosol generator 5 Vacuum chamber 6 Base material 7 Vacuum pump 8 Fine particle filter 9 XY table 10 Gas supply equipment 11 Derivation adjustment part 12 Deposit

Claims (5)

An aerosol discharge nozzle that is connected to an aerosol pipe that conveys an aerosol in which fine particles are dispersed in a gas and discharges the aerosol toward a film forming portion of a substrate,
The aerosol discharge nozzle includes a nozzle body having an aerosol passage space through which the aerosol passes, an introduction opening that is connected to a discharge opening of the aerosol pipe and introduces the aerosol, and a rectangular discharge opening that discharges the aerosol. Equipped,
The aerosol discharge nozzle, wherein the introduction opening has the same shape or a similar shape as the outlet opening of the aerosol pipe.   The aerosol discharge nozzle according to claim 1, wherein the inner wall surface of the introduction opening and the inner wall surface of the outlet opening of the aerosol pipe are continuously connected without a step.   The aerosol discharge nozzle according to claim 1, wherein the fine particles have an average particle diameter of 0.01 to 2 μm.   The aerosol discharge nozzle according to claim 1, wherein the fine particles are ceramic fine particles. A film forming apparatus for forming a film by discharging and colliding an aerosol in which fine particles are dispersed in a gas from an aerosol discharge nozzle onto a substrate in a vacuum chamber,
The said aerosol discharge nozzle is an aerosol discharge nozzle as described in any one of Claim 1 thru | or 4. The film formation apparatus characterized by the above-mentioned.

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