JPH0230752A - Method and apparatus for forming hyperfine particles film - Google Patents

Abstract

PURPOSE:To increase the adhesive strength of a deposit film formed on a substrate by increasing a differential pressure between pressure in a hyperfine particle feeding chamber and pressure in a film forming chamber and increasing the speed of the hyperfine particles sprayed through a nozzle. CONSTITUTION:Hyperfine particles in a hyperfine particle feeding chamber are introduced into a film forming chamber together with gas. In this film forming chamber, the hyperfine particles are sprayed through a nozzle at high speed, by which a film of the hyperfine particles is formed on a substrate. At this time, the pressure in the above hyperfine particle feeding chamber is set at 1-10atm, and the differential pressure between the pressure in the above film forming chamber and the above pressure is increased, by which the spraying and deposition energy of the particles can be increased and, as a result, the adhesive strength of a deposit film formed on the substrate can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for forming an ultrafine particle film that can be used in the fields of electronic materials, functional materials, structural materials, and the like.

[Prior Art] This type of conventional technology includes the one described in Japanese Patent Application Laid-Open No. 106964/1983, which describes the process of metal vapor generation in a container for metal vapor generation in a non-oxidizing gas atmosphere. The ultrafine particles of the metal material are introduced into a vapor deposition processing container together with a non-oxidizing gas through a transport pipe, and within this vapor deposition processing container, the ultrafine particles are exposed to a jet of non-oxidizing gas from a nozzle attached to the tip of the transport pipe. A method and apparatus for forming an ultrafine particle film are disclosed in which the ultrafine particles are sprayed onto the surface of a treated base to form a film of ultrafine particles on the surface of the treated base. and the differential pressure (100T
orr ~ 1 atm) to the vapor deposition processing container, and is sprayed at high speed from the nozzle to form ultra-fine particles.
It forms a membrane. An example of the velocity of ultrafine particles and gas obtained by this conventional method is shown in FIG. 7 of the attached drawings, where the differential pressure between the metal vapor generation container and the vapor deposition processing container is 100To.
According to calculations, the speed of /l super-particles in the case of rr is about 35
The kinetic energy (1/2 iv
2 = 3/2 kT) is approximately 5X10-2eV/ato
+w is calculated.

In this specification, the term "ultrafine particles" refers to particles with a particle size of 0.1μ.
shall mean less than or equal to m.

[Problems to be Solved by the Invention] By the way, in the conventional ultrafine particle film formation technology described above, the differential pressure between the metal vapor generation container and the vapor deposition processing container is 100 To
Since the pressure is about rr~1 atm, for example, the differential pressure is 100 Torr.
Taking r as an example, the kinetic energy of the ultrafine particles ejected from the nozzle is approximately 5 x 10-2 e as described above.
V/aton, and for vacuum evaporation (approximately 0
．． 1 eV/atoII).

Therefore, the formed ultrafine particle film has weak adhesion to the substrate, that is, the base surface to be processed, and an ultrafine particle film spray deposited at room temperature will peel off during a tape test.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for forming an ultrafine particle film that can solve these problems and significantly improve the adhesion of the film and control the density of the formed film.

[Means for Solving the Problems] In order to achieve the above object, according to the first aspect of the present invention, ultrafine particles in an ultrafine particle supply chamber are introduced into a film forming chamber together with a gas via a transport pipe. In an ultrafine particle film forming method in which ultrafine particles are injected together with gas at high speed from a nozzle attached to the tip of a conveying tube in a film forming chamber to form an ultrafine particle film on a film forming substrate, the pressure in the ultrafine particle supply chamber is The method is characterized in that film formation is performed by increasing the differential pressure with the film forming chamber by increasing the pressure, increasing the injection speed of the ultrafine particles from the nozzle, and increasing the injection deposition energy of the ultrafine particles.

Furthermore, the method for forming an ultrafine particle film according to the second invention of the present invention is characterized in that film formation is performed while heating the film-forming substrate in the method according to the first invention.

In the first or second invention, preferably, the pressure in the ultrafine particle supply chamber can be set to a medium pressure of 1 atm to 10 atm, and the gas introduced into the film forming chamber together with the ultrafine particles has a high sonic velocity value. It can be gas.

Furthermore, a third invention of the present invention resides in an apparatus for carrying out the method according to the first or second invention, which apparatus comprises a pressurizable ultrafine particle generation chamber, a film formation chamber, and the ultrafine particle generation chamber. An ultrafine particle transport pipe extending from the generation chamber into the film formation chamber and having an ultrafine particle injection nozzle at its tip extending into the film formation chamber, and a gas having a high sonic velocity value into the ultrafine particle generation chamber, A gas supply system that sends the ultrafine particles generated in the generation chamber under pressure to the ultrafine particle transport pipe, and a gas supply system that is connected to the film formation chamber and is configured to adjust the pressure in the membrane formation chamber and the pressure in the ultrafine particle generation chamber. It is characterized by having a vacuum exhaust system that maintains a pressure difference.

[Function] In the first or third aspect of the present invention configured as described above, the pressure difference between the ultrafine particle generation chamber or the ultrafine particle supply chamber and the film formation chamber is large, for example, as large as 1 atm to 10 atm. As a result, the injection speed of ultrafine particles from the nozzle attached to the tip of the ultrafine particle transport tube increases, and as a result, the ejection deposition energy increases. By the way, when the same amount of gas is to be flowed with the same pump capacity, the diameter of the nozzle is made smaller to increase the flow rate.

Furthermore, if a substrate heat treatment is added as in the second aspect of the present invention, the increase in the ejection deposition energy will be further promoted.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows an example of an apparatus implementing the method for forming an ultrafine particle film of the present invention, and 1 is an ultrafine particle generation chamber forming an ultrafine particle supply chamber that can withstand pressures of up to about 10 atmospheres. , in which an evaporation source 2 of metallic material is provided, which evaporation source 2 may be of conventional construction, and an external power source 3
heated by. Further, a gas supply system 4 is connected to the ultrafine particle generation chamber 1, and a non-oxidizing gas having a high sonic velocity value, such as He, 2, etc., is introduced into the ultrafine particle generation chamber.

Reference numeral 5 denotes a film formation chamber, which communicates with the ultrafine particle generation chamber 1 via a transport pipe 6. A spray nozzle 7 is attached to the tip of the transport pipe 6 located inside the film forming chamber 5 . Further, a substrate 8 on which a film of ultrafine particles is to be formed is disposed within the film forming chamber 5, and this substrate 8 is movable relative to the injection nozzle 7. The inside of the film forming chamber 5 is normally maintained at a vacuum level of 0.1 Torr by a vacuum exhaust system 9. Although not shown in the drawings, a safety valve is attached to the ultrafine particle generation chamber 1 for safety. Further, a substrate heating means (not shown) may also be provided for the substrate 8 disposed in the film forming chamber 5.

An example in which an Ag film is formed using the illustrated apparatus configured as described above will be described.

The pressure inside the ultrafine particle generation chamber 1 is approximately 100 TOrr to 10 atmospheres, and the power input to the W basket of the alumina coat in the evaporation source 2 within the ultrafine particle generation chamber 1 is approximately 180V.
A, and alumina was used as the substrate 8.

When the pressure difference between the ultrafine particle generation chamber 1 and the film formation chamber 5 is 3 atm, the average particle diameter of the ultrafine particles of A(l) is 300, and the gas is 1-y e gas (2.3 x 104 Torr).
-cc/5ec), and set the dimensions of the nozzle 7 to 0
．． 31n and a length of 130 mm, the flow velocities of Ag ultrafine particles and He gas are shown in FIG. 2. In this case, the influence of shock waves at speeds higher than the speed of sound is ignored. )re gas has a sound velocity of about 97 (ln/s), and ultrafine Ag particles have a sound velocity of about 1000 ln/s.
It is calculated to be more than II/s, but considering that it is accelerated to at least the speed of sound, the kinetic energy is approximately 0.35
It is estimated that eV/atoll. This is on the same order as in the case of vacuum evaporation (0.1 eV/atoli). As can be seen from Figure 3, which shows the measurement results of the adhesion force of the formed A(l film), as the pressure in the ultrafine particle generation chamber 1 increases, the adhesion force of the /l film increases. When the pressure in chamber 1 is 2 atm and 3 atm, l+WA
The adhesion force is 180 kof/C112 and 43 respectively.
It showed a value of 0 kOf/cm2.

Further, the particle size of ultrafine Ag particles was 100 Torr, and there was no significant difference between 2 and 3 atmospheres, and the average size was 600.

Figures 4 and 5 show transmission electron micrographs of ultrafine Ag particles produced in He gas at 100 Torr and 3 atm, respectively. The magnification of these photographs is X 1350.
00, and 13.51111 corresponds to 1000 people. In addition, when the pressure in the ultrafine particle generation chamber 1 is 100 Torr, the surface color of the A There is a tendency towards

Next, an example in which heating means for the substrate 8 is also used will be described.

Ultrafine particles of Ag are generated in He gas at 2 atmospheres in the ultrafine particle generation chamber 1, with a diameter of 0.3 nn and a length of 130 nm.
Using a nozzle 7 of approximately 0. AgWA was deposited on an alumina ceramic substrate in the film formation chamber 5 of ITOrr. The temperature of the substrate during deposition was between room temperature and 400°C. The adhesion force of the Ag film in this case with respect to the substrate heating temperature is shown in FIG. 6. It is recognized that the adhesion force of AQH increases as the substrate heating temperature increases.

Incidentally, in the illustrated embodiment, the ultrafine particles are generated in the ultrafine particle generation chamber and are then supplied to the film formation chamber to form a film. It is also possible to form a film by mixing fine particles with a non-oxidizing gas and supplying the mixture to a film forming chamber. Furthermore, in the above example, the formation of an ultrafine particle film of Ag has been exemplified, but
The present invention can be similarly applied to the formation of ultrafine particle films of other materials such as metal materials other than Ag and ceramics.

[Effects of the Invention] As explained above, according to each invention of the present invention, the pressure difference between the pressure inside the ultrafine particle supply chamber and the pressure inside the film formation chamber is increased (up to about 10 atmospheres), so that the nozzle The speed of the ultrafine particles that are injected together with the gas increases, and the deposition energy can be increased, and as a result, the adhesion of the deposited film of the ultrafine particles to the substrate can be greatly increased.

Furthermore, according to the second aspect of the present invention, since the film is formed while heating the substrate placed in the film forming chamber, an increase in deposition energy is facilitated and a strong adhesion force can be obtained.

Furthermore, in each aspect of the present invention, it is possible to control the deposition energy, and as a result, it is possible to freely form a film ranging from a porous film to a dense film.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an apparatus implementing the method of the present invention, FIG. 2 is a graph illustrating the velocity of the gas and AIJ ultrafine particles obtained by the method of the present invention, and FIG. Graphs illustrating the relationship between the adhesion force of the A(l ultrafine particle film formed according to the method of the invention and the pressure of the ultrafine particle generation chamber), FIGS. 4 and 5 respectively show the differences when the method according to the invention is implemented. 6 is a graph illustrating the relationship between the adhesion force of the A(l ultrafine particle film and the substrate temperature) formed according to the method of the present invention. , FIG. 7 is a graph illustrating the velocity of gas and Ag ultrafine particles obtained by the conventional method. In the figure: 1: Ultrafine particle generation chamber 2: Evaporation source 3: External power source 4: Gas supply system 5: Film formation Chamber 6: Transfer pipe 7: Injection nozzle 8: Substrate 9: Vacuum exhaust system Figure 3/'': 3!;

Claims (1)

[Claims] 1. The ultrafine particles in the ultrafine particle supply chamber are introduced into the film forming chamber along with gas through a conveyance tube, and the ultrafine particles are transported together with gas at high speed from a nozzle attached to the tip of the conveyance tube inside the film formation chamber. In the method of forming an ultrafine particle film in which an ultrafine particle film is formed on a film forming substrate, the pressure in the ultrafine particle supply chamber is increased to increase the pressure difference between the ultrafine particle supply chamber and the film forming chamber. 1. A method for forming an ultrafine particle film, which comprises forming a film by increasing the injection speed of the ultrafine particles and increasing the energy for ejecting and depositing the ultrafine particles. 2. The method for forming an ultrafine particle film according to claim 1, wherein the pressure in the ultrafine particle supply chamber is set to a medium pressure of 1 atm to 10 atm. 3. The method for forming an ultrafine particle film according to claim 1, wherein the gas introduced into the film forming chamber together with the ultrafine particles is a non-oxidizing gas with a high sonic velocity value. 4. The ultrafine particles in the ultrafine particle supply chamber are introduced into the film forming chamber along with gas via the transport pipe, and the ultrafine particles are injected together with gas at high speed from the nozzle attached to the tip of the transport pipe within the film forming chamber to form a film. In an ultrafine particle film forming method for forming an ultrafine particle film on a substrate, the pressure in the ultrafine particle supply chamber is increased to increase the differential pressure with the film forming chamber, and the injection speed of the ultrafine particles from the nozzle is increased. A method for forming an ultrafine particle film, characterized in that the film is formed while increasing the energy for ejecting and depositing the ultrafine particles and heating the film forming substrate. 5. The method for forming an ultrafine particle film according to claim 3, wherein the pressure in the ultrafine particle supply chamber is set to a medium pressure of 1 atm to 10 atm. 6. The method for forming an ultrafine particle film according to claim 3, wherein the gas introduced into the film forming chamber together with the ultrafine particles is a non-oxidizing gas with a high sonic velocity value. 7. An ultrafine particle generation chamber that can be pressurized, a film formation chamber containing a film forming substrate, an ultrafine particle injection nozzle extending from the ultrafine particle generation chamber into the film formation chamber, and an ultrafine particle injection nozzle at the tip extending into the film formation chamber. a gas supply system that supplies a gas with a high sonic velocity value into the ultrafine particle generation chamber and sends out the ultrafine particles generated in the ultrafine particle generation chamber under pressure to the ultrafine particle transfer tube; An apparatus for forming an ultrafine particle film, comprising: a vacuum evacuation system connected to the film forming chamber to maintain a predetermined pressure difference between the pressure in the film forming chamber and the pressure in the ultrafine particle generation chamber.